WorldWideScience

Sample records for fiber optic laser

  1. Optical coatings for fiber lasers

    Institute of Scientific and Technical Information of China (English)

    HONG Dong-mei; ZHU Zhen; YUE Wei

    2005-01-01

    Fiber laser is the future development direction for the high energy lasers. This paper describs two kinds of optical coatings for fiber laser, including long and short wave pass filters. The one characteristic of fiber laser coatings lies in that coatings should separate two closely wavelength light including laser pump wavelength (980 nm) and laser irradiation wavelength(1 050~1 100 nm). At the same time, the coatings should have high laser damage threshold.

  2. Fiber laser coupled optical spark delivery system

    Science.gov (United States)

    Yalin, Azer [Fort Collins, CO; Willson, Bryan [Fort Collins, CO; Defoort, Morgan [Fort Collins, CO; Joshi, Sachin [Fort Collins, CO; Reynolds, Adam [Fort Collins, CO

    2008-03-04

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  3. Mobile fiber-optic laser Doppler anemometer.

    Science.gov (United States)

    Stieglmeier, M; Tropea, C

    1992-07-20

    A laser Doppler anemometer (LDA) has been developed that combines the compactness and low power consumption of laser diodes and avalanche photodiodes with the flexibility and possibility of miniaturization by using fiber-optic probes. The system has been named DFLDA for laser diode fiber LDA and is especially suited for mobile applications, for example, in trains, airplanes, or automobiles. Optimization considerations of fiber-optic probes are put forward and several probe examples are described in detail. Measurement results from three typical applications are given to illustrate the use of the DFLDA. Finally, a number of future configurations of the DFLDA concept are discussed.

  4. Nanosecond laser damage of optical multimode fibers

    Science.gov (United States)

    Mann, Guido; Krüger, Jörg

    2016-07-01

    For pulse laser materials processing often optical step index and gradient index multimode fibers with core diameters ranging from 100 to 600 μm are used. The design of a high power fiber transmission system must take into account limitations resulting from both surface and volume damage effects. Especially, breakdown at the fiber end faces and selffocusing in the fiber volume critically influence the fiber performance. At least operation charts are desirable to select the appropriate fiber type for given laser parameters. In industry-relevant studies the influence of fiber core diameter and end face preparation on laser-induced (surface) damage thresholds (LIDT) was investigated for frequently used all-silica fiber types (manufacturer LEONI). Experiments on preform material (initial fiber material) and compact specimens (models of the cladding and coating material) accompanied the tests performed in accordance with the relevant LIDT standards ISO 21254-1 and ISO 21254-2 for 1-on-1 and S-on-1 irradiation conditions, respectively. The relation beam diameter vs. LIDT was investigated for fused silica fibers. Additionally, laser-induced (bulk) damage thresholds of fused silica preform material F300 (manufacturer Heraeus) in dependence on external mechanical stress simulating fiber bending were measured. All experiments were performed with 10-ns laser pulses at 1064 and 532 nm wavelength with a Gaussian beam profile.

  5. Lasers and optical fibers in medicine

    CERN Document Server

    Katzir, Abraham

    1993-01-01

    The increasing use of fiber optics in the field of medicine has created a need for an interdisciplinary perspective of the technology and methods for physicians as well as engineers and biophysicists. This book presents a comprehensive examination of lasers and optical fibers in an hierarchical, three-tier system. Each chapter is divided into three basic sections: the Fundamentals section provides an overview of basic concepts and background; the Principles section offers an in-depth engineering approach; and the Advances section features specific information on systems an

  6. Advanced Optical Fiber Development for kW Fiber Lasers with Sub-GHz Linewidth

    Science.gov (United States)

    2016-01-12

    Advanced Optical Fiber Development for kW Fiber Lasers with Sub-GHz Linewidth The project is for acquiring an optical spectrum analyzer (OSA) covering...27709-2211 Specialty optical fibers , optical fiber lasers REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S...Number of Papers published in non peer-reviewed journals: Final Report: Advanced Optical Fiber Development for kW Fiber Lasers with Sub-GHz Linewidth

  7. Packaging considerations of fiber-optic laser sources

    Science.gov (United States)

    Heikkinen, Veli; Tukkiniemi, Kari; Vaehaekangas, Jouko; Hannula, Tapio

    1991-12-01

    The continuous progress in material and component technology has generated new laser-based applications that require special packaging techniques. Hybrid integration offers a flexible method to accomplish custom design needs. This paper discusses several aspects in fiber optic packaging including optical, thermal, and mechanical issues. Special emphasis is on optical coupling between a laser diode and a single-mode fiber.

  8. All-optical, Three-axis Fiber Laser Magnetometer

    Science.gov (United States)

    2012-04-16

    E-1 1.  INTRODUCTION ...achieved with other magnetic field sensing technologies such as those based on flux gates and fiber optic magnetostrictive sensors. The deployed...ALL-OPTICAL, THREE-AXIS FIBER LASER MAGNETOMETER 1. INTRODUCTION This report describes the development of an undersea fiber optic magnetometer

  9. Optical Cutting Interruption Sensor for Fiber Lasers

    Directory of Open Access Journals (Sweden)

    Benedikt Adelmann

    2015-09-01

    Full Text Available We report on an optical sensor system attached to a 4 kW fiber laser cutting machine to detect cutting interruptions. The sensor records the thermal radiation from the process zone with a modified ring mirror and optical filter arrangement, which is placed between the cutting head and the collimator. The process radiation is sensed by a Si and InGaAs diode combination with the detected signals being digitalized with 20 kHz. To demonstrate the function of the sensor, signals arising during fusion cutting of 1 mm stainless steel and mild steel with and without cutting interruptions are evaluated and typical signatures derived. In the recorded signals the piercing process, the laser switch on and switch off point and waiting period are clearly resolved. To identify the cutting interruption, the signals of both Si and InGaAs diodes are high pass filtered and the signal fluctuation ranges being subsequently calculated. Introducing a correction factor, we identify that only in case of a cutting interruption the fluctuation range of the Si diode exceeds the InGaAs diode. This characteristic signature was successfully used to detect 80 cutting interruptions of 83 incomplete cuts (alpha error 3.6% and system recorded no cutting interruption from 110 faultless cuts (beta error of 0. This particularly high detection rate in combination with the easy integration of the sensor, highlight its potential for cutting interruption detection in industrial applications.

  10. Novel fiber optic tip designs and devices for laser surgery

    Science.gov (United States)

    Hutchens, Thomas Clifton

    Fiber optic delivery of laser energy has been used for years in various types of surgical procedures in the human body. Optical energy provides several benefits over electrical or mechanical surgery, including the ability to selectively target specific tissue types while preserving others. Specialty fiber optic tips have also been introduced to further customize delivery of laser energy to the tissue. Recent evolution in lasers and miniaturization has opened up opportunities for many novel surgical techniques. Currently, ophthalmic surgeons use relatively invasive mechanical tools to dissect retinal deposits which occur in proliferative diabetic retinopathy. By using the tight focusing properties of microspheres combined with the short optical penetration depth of the Erbium:YAG laser and mid-IR fiber delivery, a precise laser scalpel can be constructed as an alternative, less invasive and more precise approach to this surgery. Chains of microspheres may allow for a self limiting ablation depth of approximately 10 microm based on the defocusing of paraxial rays. The microsphere laser scalpel may also be integrated with other surgical instruments to reduce the total number of handpieces for the surgeon. In current clinical laser lithotripsy procedures, poor input coupling of the Holmium:YAG laser energy frequently damages and requires discarding of the optical fiber. However, recent stone ablation studies with the Thulium fiber laser have provided comparable results to the Ho:YAG laser. The improved spatial beam profile of the Thulium fiber laser can also be efficiently coupled into a fiber approximately one third the diameter and reduces the risk of damaging the fiber input. For this reason, the trunk optical fiber minus the distal fiber tip can be preserved between procedures. The distal fiber tip, which degrades during stone ablation, could be made detachable and disposable. A novel, low-profile, twist-locking, detachable distal fiber tip interface was designed

  11. Optical fiber transmission of high power excimer laser radiation.

    Science.gov (United States)

    Pini, R; Salimbeni, R; Vannini, M

    1987-10-01

    An experimental investigation of optical fiber transmission of high power excimer laser radiation is presented. Different types of commercially available UV fiber have been tested, measuring energy handling capabilities and transmission losses of short samples at the XeCl (308-nm) and KrF (249-nm) wavelengths by using a standard excimer laser. A power density dependent damage process has been observed over 1 GW/cm(2). Fiber losses due to different radii of curvature are also reported. Experimental results have been examined to evaluate the effectiveness of excimer laser transmission through optical fibers for such medical uses as laser angioplasty, including also a comparison between the use of KrF or XeCl emission lines for this purpose. Finally, optimum excimer laser characteristics to increase the energy coupling in fibers are discussed.

  12. Fiber Optic Laser Delivery For Endarterectomy Of Experimental Atheromas

    Science.gov (United States)

    Eugene, John; Pollock, Marc E.; McColgan, Stephen J.; Hammer-Wilson, Marie; Berns, Michael W.

    1986-08-01

    Fiber optic delivery of argon ion laser energy and Nd-YAG laser energy were compared by the performance of open laser endarterectomy in the rabbit arteriosclerosis model. In Group I, 6 open laser endarterectomies were performed with an argon ion laser (488 nm and 514.5 nm) with the laser beam directed through a 400 pm quartz fiber optic. In Group II, 6 open laser endarterectomies were performed with a Nd-YAG laser (1.06 pm) with the laser beam directed through a 600 pm quartz fiber optic. Gross and light microscopic examination revealed smooth endarterectomy surfaces with tapered end points in Group I. In Group II, the endarterectomy surfaces were uneven and perforation occurred at 5/6 end points. Although energy could be precisely delivered with each laser by fiber optics, satisfactory results could only be achieved with the argon ion laser because argon ion energy was well absorbed by atheromas. Successful intravascular laser use requires a strong interaction between wavelength and atheroma as well as a precise delivery system.

  13. Mode profiling of optical fibers at high laser powers

    DEFF Research Database (Denmark)

    Nielsen, Peter Carøe; Pedersen, David Bue; Simonsen, R.B.

    2008-01-01

    This paper describes the development of a measuring equipment capable of analysing the beam profile at high optical powers emitted by delivery fibers used in manufacturing processes. Together with the optical delivery system, the output beam quality from the delivery fiber and the shape...... of the focused spot can be determined. The analyser is based on the principle of a rotating wire being swept though the laser beam, while the reflected signal is recorded [1]. By changing the incident angle of the rotating rod from 0° to 360° in relation to the fiber, the full profile of the laser beam...... is obtained. Choosing a highly reflective rod material and a sufficiently high rotation speed, these measurements can be done with high laser powers, without any additional optical elements between the fiber and analyzer. The performance of the analyzer was evaluated by coupling laser light into different...

  14. Optical fiber sensing based on reflection laser spectroscopy.

    Science.gov (United States)

    Gagliardi, Gianluca; Salza, Mario; Ferraro, Pietro; Chehura, Edmond; Tatam, Ralph P; Gangopadhyay, Tarun K; Ballard, Nicholas; Paz-Soldan, Daniel; Barnes, Jack A; Loock, Hans-Peter; Lam, Timothy T-Y; Chow, Jong H; De Natale, Paolo

    2010-01-01

    An overview on high-resolution and fast interrogation of optical-fiber sensors relying on laser reflection spectroscopy is given. Fiber Bragg-gratings (FBGs) and FBG resonators built in fibers of different types are used for strain, temperature and acceleration measurements using heterodyne-detection and optical frequency-locking techniques. Silica fiber-ring cavities are used for chemical sensing based on evanescent-wave spectroscopy. Various arrangements for signal recovery and noise reduction, as an extension of most typical spectroscopic techniques, are illustrated and results on detection performances are presented.

  15. Optical Fiber Sensing Based on Reflection Laser Spectroscopy

    Directory of Open Access Journals (Sweden)

    Gianluca Gagliardi

    2010-03-01

    Full Text Available An overview on high-resolution and fast interrogation of optical-fiber sensors relying on laser reflection spectroscopy is given. Fiber Bragg-gratings (FBGs and FBG resonators built in fibers of different types are used for strain, temperature and acceleration measurements using heterodyne-detection and optical frequency-locking techniques. Silica fiber-ring cavities are used for chemical sensing based on evanescent-wave spectroscopy. Various arrangements for signal recovery and noise reduction, as an extension of most typical spectroscopic techniques, are illustrated and results on detection performances are presented.

  16. Ultrafast Optics: Vector Cavity Fiber Lasers - Physics and Technology

    Science.gov (United States)

    2016-06-14

    fiber lasers the effective cavity gain bandwidth could be far broader than the laser emission bandwidth, if the optical field is in resonance with the...periodic modulation on the CW laser field , where fc is the modulation frequency. Fig. 2.1 shows the evolution of the laser emission under existence of...real saturable absorber (SA) mode locking techniques, such as the carbon nanotube mode locking, 2D-nano-materials mode locking, formation of bound

  17. High precision optical fiber alignment using tube laser bending

    NARCIS (Netherlands)

    Folkersma, Ger; Römer, Gerardus Richardus, Bernardus, Engelina; Brouwer, Dannis Michel; Herder, Justus Laurens

    2016-01-01

    In this paper, we present a method to align optical fibers within 0.2 μm of the optimal position, using tube laser bending and in situ measuring of the coupling efficiency. For near-UV wavelengths, passive alignment of the fibers with respect to the waveguides on photonic integrated circuit chips

  18. Fiber laser master oscillators for optical synchronization systems

    Energy Technology Data Exchange (ETDEWEB)

    Winter, A.

    2008-04-15

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  19. Precision laser processing for micro electronics and fiber optic manufacturing

    Science.gov (United States)

    Webb, Andrew; Osborne, Mike; Foster-Turner, Gideon; Dinkel, Duane W.

    2008-02-01

    The application of laser based materials processing for precision micro scale manufacturing in the electronics and fiber optic industry is becoming increasingly widespread and accepted. This presentation will review latest laser technologies available and discuss the issues to be considered in choosing the most appropriate laser and processing parameters. High repetition rate, short duration pulsed lasers have improved rapidly in recent years in terms of both performance and reliability enabling flexible, cost effective processing of many material types including metal, silicon, plastic, ceramic and glass. Demonstrating the relevance of laser micromachining, application examples where laser processing is in use for production will be presented, including miniaturization of surface mount capacitors by applying a laser technique for demetalization of tracks in the capacitor manufacturing process and high quality laser machining of fiber optics including stripping, cleaving and lensing, resulting in optical quality finishes without the need for traditional polishing. Applications include telecoms, biomedical and sensing. OpTek Systems was formed in 2000 and provide fully integrated systems and sub contract services for laser processes. They are headquartered in the UK and are establishing a presence in North America through a laser processing facility in South Carolina and sales office in the North East.

  20. Fiber-optic Doppler velocimeter based on a dual-polarization fiber grating laser

    Science.gov (United States)

    Kuang, Zeyuang; Cheng, Linghao; Liang, Yizhi; Liang, Hao; Guan, Bai-Ou

    2015-07-01

    A fiber-optic Doppler velocimeter based on a dual-polarization fiber grating laser is demonstrated. The fiber grating laser produces two orthogonally polarized laser outputs with their frequency difference proportional to the intra-cavity birefringence. When the laser outputs are reflected from a moving targets, the laser frequencies will be shifted due to the Doppler effect. It shows that the frequency difference between the beat note of the laser outputs and the beat note of the reflected lasers is proportional to the velocity. The proposed fiber-optic Doppler velocimeter shows a high sensitivity of 0.64 MHz/m/s and is capable of measurement of wide range of velocity.

  1. Application and the key technology on high power fiber-optic laser in laser weapon

    Science.gov (United States)

    Qu, Zhou; Li, Qiushi; Meng, Haihong; Sui, Xin; Zhang, Hongtao; Zhai, Xuhua

    2014-12-01

    The soft-killing laser weapon plays an important role in photoelectric defense technology. It can be used for photoelectric detection, search, blinding of photoelectric sensor and other devices on fire control and guidance devices, therefore it draws more and more attentions by many scholars. High power fiber-optic laser has many virtues such as small volume, simple structure, nimble handling, high efficiency, qualified light beam, easy thermal management, leading to blinding. Consequently, it may be used as the key device of soft-killing laser weapon. The present study introduced the development of high power fiber-optic laser and its main features. Meanwhile the key technology of large mode area (LMA) optical fiber design, the beam combination technology, double-clad fiber technology and pumping optical coupling technology was stated. The present study is aimed to design high doping LMA fiber, ensure single mode output by increasing core diameter and decrease NA. By means of reducing the spontaneous emission particle absorbed by fiber core and Increasing the power density in the optical fiber, the threshold power of nonlinear effect can increase, and the power of single fiber will be improved. Meantime, high power will be obtained by the beam combination technology. Application prospect of high power fiber laser in photoelectric defense technology was also set forth. Lastly, the present study explored the advantages of high power fiber laser in photoelectric defense technology.

  2. Fiber Optic Coupling of CW Linear Laser Diode Array

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaowei; XIAO Jianwei; MA Xiaoyu; WANG Zhongming; FANG Gaozhan

    2002-01-01

    Based on a set of microoptics the output radiation from a continuous wave (CW) linear laser diode array is coupled into a multi-mode optical fiber of 400 μm diameter.The CW linear laser diode array is a 1 cm laser diode bar with 19 stripes with 100 μm aperture spaced on 500 μm centers.The coupling system contains packaged laser diode bar,fast axis collimator,slow axis collimation array,beam transformation system and focusing system.The high brightness,high power density and single fiber output of a laser diode bar is achieved.The coupling efficiency is 65% and the power density is up to 1.03×104 W/cm2.

  3. Controllable optical delay line using a Brillouin optical fiber ring laser

    Institute of Scientific and Technical Information of China (English)

    Yongkang Dong; Zhiwei Lü; Qiang Li; Wei Gao

    2006-01-01

    A controllable optical delay line using a Brillouin optical fiber ring laser is demonstrated and a large timedelay is obtained by cascading two optical fiber segments. In experiment, a single-mode Brillouin opticalfiber ring laser is used to provide Stokes wave as probe wave. We achieve a maximum tunable time delayof 61 ns using two cascading optical fiber segments, about 1.5 times of the input probe pulse width of 40ns. In the meantime, a considerable pulse broadening is observed, which agrees well with the theoreticalprediction based on linear theory.

  4. Spectral selectivity in optical fiber capillary dye lasers.

    Science.gov (United States)

    Mobini, Esmaeil; Abaie, Behnam; Peysokhan, Mostafa; Mafi, Arash

    2017-05-01

    We explore the spectral properties of a capillary dye laser in the highly multimode regime. Our experiments indicate that the spectral behavior of the laser does not conform to a simple Fabry-Perot (FP) analysis; rather, it is strongly dictated by a Vernier resonant mechanism involving multiple modes, which propagate with different group velocities. The laser operates over a very broad spectral range and the Vernier effect gives rise to a free spectral range, which is orders of magnitude larger than that expected from a simple FP mechanism. The theoretical calculations presented confirm the experimental results. Propagating modes of the capillary fiber are calculated using the finite-element method and it is shown that the optical path lengths resulting from simultaneous beatings of these modes are in close agreement with the optical path lengths directly extracted from the Fourier transform of the experimentally measured laser emission spectra.

  5. Studies of beam expansion and distributed Bragg reflector lasers for fiber optics and optical signal processing

    Science.gov (United States)

    Garmire, E. M.

    1981-03-01

    Separate studies were performed on beam expansion and on distributed Bragg Reflector (DBR) lasers preliminary to monolithic integration on GaAs substrates. These components are proposed for use in optical signal processing, for fiber optic sources and for high brightness lasers.

  6. High power fiber lasers

    Institute of Scientific and Technical Information of China (English)

    LOU Qi-hong; ZHOU Jun

    2007-01-01

    In this review article, the development of the double cladding optical fiber for high power fiber lasers is reviewed. The main technology for high power fiber lasers, including laser diode beam shaping, fiber laser pumping techniques, and amplification systems, are discussed in de-tail. 1050 W CW output and 133 W pulsed output are ob-tained in Shanghai Institute of Optics and Fine Mechanics, China. Finally, the applications of fiber lasers in industry are also reviewed.

  7. Test Port for Fiber-Optic-Coupled Laser Altimeter

    Science.gov (United States)

    Ramos Izquierdo, Luis; Scott, V. Stanley; Rinis, Haris; Cavanaugh, John

    2011-01-01

    A test port designed as part of a fiber optic coupled laser altimeter receiver optical system allows for the back-illumination of the optical system for alignment verification, as well as illumination of the detector(s) for testing the receiver electronics and signal-processing algorithms. Measuring the optical alignment of a laser altimeter instrument is difficult after the instrument is fully assembled. The addition of a test port in the receiver aft-optics allows for the back-illumination of the receiver system such that its focal setting and boresight alignment can be easily verified. For a multiple-detector receiver system, the addition of the aft-optics test port offers the added advantage of being able to simultaneously test all the detectors with different signals that simulate the expected operational conditions. On a laser altimeter instrument (see figure), the aft-optics couple the light from the receiver telescope to the receiver detector(s). Incorporating a beam splitter in the aft-optics design allows for the addition of a test port to back-illuminate the receiver telescope and/or detectors. The aft-optics layout resembles a T with the detector on one leg, the receiver telescope input port on the second leg, and the test port on the third leg. The use of a custom beam splitter with 99-percent reflection, 1-percent transmission, and a mirrored roof can send the test port light to the receiver telescope leg as well as the detector leg, without unduly sacrificing the signal from the receiver telescope to the detector. The ability to test the receiver system alignment, as well as multiple detectors with different signals without the need to disassemble the instrument or connect and reconnect components, is a great advantage to the aft-optics test port. Another benefit is that the receiver telescope aperture is fully back-illuminated by the test port so the receiver telescope focal setting vs. pressure and or temperature can be accurately measured (as

  8. Characterization of the Los Alamos IPG YLR-6000 fiber laser using multiple optical paths and laser focusing optics

    Energy Technology Data Exchange (ETDEWEB)

    Milewski, John O [Los Alamos National Laboratory; Bernal, John E [Los Alamos National Laboratory

    2009-01-01

    Fiber laser technology has been identified as the replacement power source for the existing Los Alamos TA-55 production laser welding system. An IPG YLR-6000 fiber laser was purchased, installed at SM-66 R3, and accepted in February 2008. No characterization of the laser and no welding was performed in the Feb 2008 to May 2009 interval. T. Lienert and J. Bernal (Ref. 1, July 2009) determined the existing 200 mm Rofin collimator and focus heads used with the Rofin diode pumped lasers were inadequate for use with the IPG laser due to clipping of the IPG laser beam. Further efforts in testing of the IPG laser with Optoskand fiber delivery optics and a Rofin 120 mm collimator proved problematic due to optical fiber damage. As a result, IPG design optical fibers were purchased as replacements for subsequent testing. Within the same interval, an IPG fiber-to-fiber (F2F) connector, custom built for LANL, (J. Milewski, S. Gravener, Ref.2) was demonstrated and accepted at IPG Oxford, MA in August 2009. An IPG service person was contracted to come to LANL to assist in the installation, training, troubleshooting and characterization of the multiple beam paths and help perform laser head optics characterization. The statement of work is provided below: In summary the laser system, optical fibers, F2F connector, Precitec head, and a modified Rofin type (w/120mm Optoskand collimator) IWindowIBoot system focus head (Figure 1) were shown to perform well at powers up to 6 kW CW. Power measurements, laser spot size measurements, and other characterization data and lessons learned are contained within this report. In addition, a number of issues were identified that will require future resolution.

  9. Optical-fiber laser amplifier for ultrahigh-speed communications

    Energy Technology Data Exchange (ETDEWEB)

    Gosnell, T.; Xie, Ping; Cockroft, N.

    1996-04-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to develop a praseodymium-based 1.31-{mu}m fiber amplifier that can be optically pumped with off-the-shelf semiconductor diode lasers. Development of optical amplifiers for the 1.31-{mu}m communications window is motivated by the push towards ``all-optical`` networks that will support multigigabits per second communication rates. Our approach exploited radiationless energy transfer from optically pumped Yb{sup 3+} ions co-doped with Pr{sup 3+} into a fluorozirconate glass (ZBLAN). We obtained a gain of approximately 10 on a 1.31-{mu}m amplifier, a value too low for practical applications. In two spin- off applications, all-solid-state operation at all four output wavelengths was achieved in the development of a four-color visible laser, and laser cooling of a solid material was demonstrated for the first time in the development of a fluorescent cryogenic refrigerator.

  10. All-optical fiber anemometer based on laser heated fiber Bragg gratings.

    Science.gov (United States)

    Gao, Shaorui; Zhang, A Ping; Tam, Hwa-Yaw; Cho, L H; Lu, Chao

    2011-05-23

    A fiber-optic anemometer based on fiber Bragg gratings (FBGs) is presented. A short section of cobalt-doped fiber was utilized to make a fiber-based "hot wire" for wind speed measurement. Fiber Bragg gratings (FBGs) were fabricated in the cobalt-doped fiber using 193 nm laser pulses to serve as localized temperature sensors. A miniature all-optical fiber anemometer is constructed by using two FBGs to determine the dynamic thermal equilibrium between the laser heating and air flow cooling through monitoring the FBGs' central wavelengths. It was demonstrated that the sensitivity of the sensor can be adjusted through the power of pump laser or the coating on the FBG. Experimental results reveal that the proposed FBG-based anemometer exhibits very good performance for wind speed measurement. The resolution of the FBG-based anemometer is about 0.012 m/s for wind speed range between 2.0 m/s and 8.0 m/s.

  11. Fiber optic and laser sensors V; Proceedings of the Meeting, San Diego, CA, Aug. 17-19, 1987

    Science.gov (United States)

    De Paula, Ramon P. (Editor); Udd, Eric (Editor)

    1988-01-01

    The papers contained in this volume focus on recent developments in fiber optic and laser sensors. Topics discussed include electric and magnetic field sensors, fiber optic pressure sensors, fiber optic gyros, fiber optic sensors for aerospace applications, fiber sensor multiplexing, temperature sensors, and specialized fiber optic sensors. Papers are presented on remote fiber optic sensors for angular orientation; fiber optic rotation sensor for space missions; adaptation of an electro-optic monitoring system to aerospace structures; optical fiber sensor for dust concentration measurements; and communication-sensing system using a single optical fiber.

  12. Compact Ultra-Wideband Optical Frequency Comb Fiber Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on our success in developing the world first commercial 10 W femtosecond fiber laser system and our leading technology development in ultrashort pulsed fiber...

  13. Fiber optic and laser sensors VII; Proceedings of the Meeting, Boston, MA, Sept. 5-7, 1989

    Science.gov (United States)

    Udd, Eric (Editor); Depaula, Ramon P. (Editor)

    1990-01-01

    Various papers on fiber optic and laser sensors are presented. Individual topics addressed include: fiber optic photoelastic pressure sensor for high-temperature gases, fiber optic gyroscope using an eight-component LiNbO3 integrated optic circuit, design and performance of a fiber optic gyroscope using integrated optics, digital angular position sensor using wavelength division multiplexing, simple repeatable fiber optic intensity sensor for temperature measurement, compensation for effects of ambient temperature on rare-earth-doped fiber optic thermometer.

  14. Optical fiber configurations for transmission of laser energy over great distances

    Science.gov (United States)

    Rinzler, Charles C; Zediker, Mark S

    2013-10-29

    There are provided optical fiber configurations that provide for the delivery of laser energy, and in particular, the transmission and delivery of high power laser energy over great distances. These configurations further are hardened to protect the optical fibers from the stresses and conditions of an intended application. The configurations provide means for determining the additional fiber length (AFL) need to obtain the benefits of such additional fiber, while avoiding bending losses.

  15. Optical fiber configurations for transmission of laser energy over great distances

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C; Zediker, Mark S

    2014-11-04

    There are provided optical fiber configurations that provide for the delivery of laser energy, and in particular, the transmission and delivery of high power laser energy over great distances. These configurations further are hardened to protect the optical fibers from the stresses and conditions of an intended application. The configurations provide means for determining the additional fiber length (AFL) need to obtain the benefits of such additional fiber, while avoiding bending losses.

  16. Fiber-optic laser Doppler turbine tip clearance probe.

    Science.gov (United States)

    Büttner, Lars; Pfister, Thorsten; Czarske, Jürgen

    2006-05-01

    A laser Doppler based method for in situ single blade tip clearance measurements of turbomachines with high precision is presented for what we believe is the first time. The sensor is based on two superposed fanlike interference fringe systems generated by two laser wavelengths from a fiber-coupled, passive, and therefore compact measurement head employing diffractive optics. Tip clearance measurements at a transonic centrifugal compressor performed during operation at 50,000 rpm (833 Hz, 586 m/s tip speed) are reported. At these speeds the measured uncertainty of the tip position was less than 20 microm, a factor of 2 more accurate than that of capacitive probes. The sensor offers great potential for in situ and online high-precision tip clearance measurements of metallic and nonmetallic turbine blades.

  17. Advanced Optical Fibers for High power Fiber lasers

    Science.gov (United States)

    2015-08-24

    cores, which are formed by spinning the preform during fiber drawing. Another notable example is based on the © 2015 The Author(s). Licensee InTech ...years later, single-mode operation in a record core diameter of ~180μm was demonstrated in a LCF [8]. Many other approaches based on conventional...however, be computationally very demanding. If only circular boundaries are involved, a Multipole mode solver is a good option [17, 18]. It is based on the

  18. Laser Communications and Fiber Optics Lab Manual. High-Technology Training Module.

    Science.gov (United States)

    Biddick, Robert

    This laboratory training manual on laser communications and fiber optics may be used in a general technology-communications course for ninth graders. Upon completion of this exercise, students achieve the following goals: match concepts with laser communication system parts; explain advantages of fiber optic cable over conventional copper wire;…

  19. QUANTITATIVE DETECTION OF ENVIRONMENTALLY IMPORTANT DYES USING DIODE LASER/FIBER-OPTIC RAMAN

    Science.gov (United States)

    A compact diode laser/fiber-optic Raman spectrometer is used for quantitative detection of environmentally important dyes. This system is based on diode laser excitation at 782 mm, fiber optic probe technology, an imaging spectrometer, and state-of-the-art scientific CCD camera. ...

  20. Laser & Fiber Optics: Instructional Manual. The North Dakota High Technology Mobile Laboratory Project.

    Science.gov (United States)

    Eickhoff, Luvern R.

    This instructional manual contains 20 learning activity packets for use in a workshop on lasers and fiber optics. The lessons cover the following topics: what a laser; coherent light; setting up the laser; characteristics of the laser beam; scattering of light; laser beam divergence, intensity, color, ophthalmology, and reflections; directivity of…

  1. Laser & Fiber Optics: Instructional Manual. The North Dakota High Technology Mobile Laboratory Project.

    Science.gov (United States)

    Eickhoff, Luvern R.

    This instructional manual contains 20 learning activity packets for use in a workshop on lasers and fiber optics. The lessons cover the following topics: what a laser; coherent light; setting up the laser; characteristics of the laser beam; scattering of light; laser beam divergence, intensity, color, ophthalmology, and reflections; directivity of…

  2. DFB fiber laser as source for optical communication systems

    DEFF Research Database (Denmark)

    Varming, Poul; Hübner, Jörg; Kristensen, Martin

    1997-01-01

    The results demonstrate that DFB fiber lasers are an attractive alternative as sources in telecommunication systems. The lasers show excellent long-term stability with very high signal to noise ratio and a reasonable output power, combined with exceptional temperature stability and inherent fiber...

  3. Femtosecond laser inscription of asymmetric directional couplers for in-fiber optical taps and fiber cladding photonics.

    Science.gov (United States)

    Grenier, Jason R; Fernandes, Luís A; Herman, Peter R

    2015-06-29

    Precise alignment of femtosecond laser tracks in standard single mode optical fiber is shown to enable controllable optical tapping of the fiber core waveguide light with fiber cladding photonic circuits. Asymmetric directional couplers are presented with tunable coupling ratios up to 62% and bandwidths up to 300 nm at telecommunication wavelengths. Real-time fiber monitoring during laser writing permitted a means of controlling the coupler length to compensate for micron-scale alignment errors and to facilitate tailored design of coupling ratio, spectral bandwidth and polarization properties. Laser induced waveguide birefringence was harnessed for polarization dependent coupling that led to the formation of in-fiber polarization-selective taps with 32 dB extinction ratio. This technology enables the interconnection of light propagating in pre-existing waveguides with laser-formed devices, thereby opening a new practical direction for the three-dimensional integration of optical devices in the cladding of optical fibers and planar lightwave circuits.

  4. Ground Water Monitoring Using Laser Fluorescence And Fiber Optics

    Science.gov (United States)

    Chudyk, Wayne; Pohlig, Kenneth; Rico, Nicola; Johnson, Gregory

    1989-01-01

    In-situ measurement of aromatic ground water contaminants, including the benzene, ethylbenzene, toluene, and xylenes (BTEX) fraction of gasoline, has been demonstrated using fiber optic systems. A prototype field instrument has shown that this method has advantages over traditional sampling and analysis. Problems encountered and solved include coupling of the laser energy into to fiber, sensor design, and detector configuration to optimize instrument sensitivity. The effects of sensor length, corresponding to well depth, on limits of detection are presented. Effects of potential interferences, including external fluorescence quenchers, are discuss-ed. The resolution of complex mixtures is addressed, with modifications to the detector shown to be effective in separation of groups of contaminants. Instrument design considerations include the need for portability, ruggedness at field sites, and ease of operation. The modular instrument design used is shown to help solve these potential problems, while maintaining analytical sensitivity and reproducibility. Modular optical system design has also shown to be useful when modifications are made. Changes in the detector as well as provisions for multiple laser sources have allowed a flexible system to be configured to meet analytical demands as they arise. Sensor design considerations included high ultraviolet transmission, physical flexibility, resistance to breakage, and resistance to chemical and/or biological fouling. The approach to these problem areas is presented, as well as discussion of the methods used to minimize effects of fiber solarization. Results of testing the field portable prototype are presented for a variety of typical ground water analysis sites, illustrating the usefulness of this new technology in environmental monitoring.

  5. Novel Optical Fiber Materials With Engineered Brillouin Gain Coefficients SSL 1: Novel Fiber Lasers

    Science.gov (United States)

    2015-12-29

    NAME(S) AND ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 High energy lasers, optical fiber, glass...Technologies workshop, Le Centre National de la Recherche Scientifique , Institute for Engineering and Systems Sciences (INSIS), Paris, France, October...Sub Contractors (DD882) Names of Personnel receiving masters degrees Names of personnel receiving PHDs Names of other research staff Number of

  6. Towards high-quality optical ceramic YAG fibers for high-energy laser (HEL) applications

    Science.gov (United States)

    Lee, HeeDong; Keller, Kristin; Sirn, Brian

    2012-06-01

    There is a critical demand for high quality, transparent ceramic YAG fibers for high powered fiber lasers. The production of laser quality ceramic fibers hinges on advanced ceramic processing technology, along with the availability of highly sinterable powder with high phase and chemical purity. These two fundamental technologies have been successfully developed at UES. Nd (1.1 a/o) and Yb (1.0 a/o)-doped yttrium aluminum garnet (YAG) fibers with high optical quality were produced by combining UES's tailored powders with advanced consolidation processes including fiber extrusion and vacuum sintering. The as-sintered and as-annealed fibers, approximately 30 microns in diameter, appeared transparent and successfully transmitted laser beams; further development will allow for the production of doped ceramic YAG fiber lasers for advanced high power and high energy fiber laser systems.

  7. Tunable multi-wavelength fiber lasers based on an Opto-VLSI processor and optical amplifiers.

    Science.gov (United States)

    Xiao, Feng; Alameh, Kamal; Lee, Yong Tak

    2009-12-07

    A multi-wavelength tunable fiber laser based on the use of an Opto-VLSI processor in conjunction with different optical amplifiers is proposed and experimentally demonstrated. The Opto-VLSI processor can simultaneously select any part of the gain spectrum from each optical amplifier into its associated fiber ring, leading to a multiport tunable fiber laser source. We experimentally demonstrate a 3-port tunable fiber laser source, where each output wavelength of each port can independently be tuned within the C-band with a wavelength step of about 0.05 nm. Experimental results demonstrate a laser linewidth as narrow as 0.05 nm and an optical side-mode-suppression-ratio (SMSR) of about 35 dB. The demonstrated three fiber lasers have excellent stability at room temperature and output power uniformity less than 0.5 dB over the whole C-band.

  8. Chaotic generation based on figure-of-eight erbium-doped fiber laser with an optical fiber ring

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; YANG Rong; YANG Ling-zhen

    2012-01-01

    We experimentally demonstrate the chaotic generation in a figure-of-eight erbium-doped fiber laser (F8L) with an optical fiber ring (OFR).With an appropriate combination of polarization controllers,we find that the fiber laser exhibits perioddoubling route to chaos,and the chaotic self-synchronous dynamics has a tendcncy to be reduced significantly.The experimental results show the tendency is related to the interference and the nonlinear phase shift of light in the optical fiber ring.Meanwhile,the chaotic dynamics is related to the polarization state and pump power.

  9. Tunable Laser Development for In-flight Fiber Optic Based Structural Health Monitoring Systems

    Science.gov (United States)

    Richards, Lance; Parker, Allen; Chan, Patrick

    2014-01-01

    The objective of this task is to investigate, develop, and demonstrate a low-cost swept lasing light source for NASA DFRC's fiber optics sensing system (FOSS) to perform structural health monitoring on current and future aerospace vehicles. This is the regular update of the Tunable Laser Development for In-flight Fiber Optic Based Structural Health Monitoring Systems website.

  10. Using Brillouin fiber-optic ring laser to provide base station with uplink optical carrier in a 10 GHz radio over fiber system

    Institute of Scientific and Technical Information of China (English)

    CHEN Hao-shuo; LIN Ru-jian; YE Jia-jun

    2009-01-01

    In this paper, a 10 GHz radio over fiber system is analyzed. The Brillouin fiber-optic ring laser is used in the center station (CS) to suppress the optical carrier for the modulation depth enhancement. Simultaneously, the Stockes waveinduced by the Brillouin amplification injects and locks the Fabry-Perot (FP) laser to output a signal-mode optical source,which works as the uplink optical carrier.

  11. Thermo-optical properties of air-clad photonic crystal fiber lasers in high power operation

    Science.gov (United States)

    Limpert, J.; Schreiber, T.; Liem, A.; Nolte, S.; Zellmer, H.; Peschel, T.; Guyenot, V.; Tünnermann, A.

    2003-11-01

    We report on the investigation of the thermo-optical behavior of air-clad ytterbium-doped large-mode-area photonic crystal fiber lasers. Analytical and numerical models are applied to calculate the heat distribution and induced stresses in a microstructured fiber. The results are compared to conventional double-clad fiber lasers and design guidelines are provided to ensure maximum heat dissipation and scalability to power levels of several kWs.

  12. Optical fiber cable for transmission of high power laser energy over great distances

    Science.gov (United States)

    Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Moxley, Joel F.; Koblick, Yeshaya

    2016-05-24

    There is provided a system and apparatus for the transmission of high power laser energy over great distances without substantial power loss and without the presence of stimulated Raman scattering. There is further provided systems and optical fiber cable configurations and optical fiber structures for the delivering high power laser energy over great distances to a tool or surface to perform an operation or work with the tool or upon the surface.

  13. Optical fiber cable for transmission of high power laser energy over great distances

    Energy Technology Data Exchange (ETDEWEB)

    Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Moxley, Joel F.; Koblick, Yeshaya

    2016-05-24

    There is provided a system and apparatus for the transmission of high power laser energy over great distances without substantial power loss and without the presence of stimulated Raman scattering. There is further provided systems and optical fiber cable configurations and optical fiber structures for the delivering high power laser energy over great distances to a tool or surface to perform an operation or work with the tool or upon the surface.

  14. Optical fiber link for transmission of 1-nJ femtosecond laser pulses at 1550 nm

    DEFF Research Database (Denmark)

    Eichhorn, Finn; Olsson, Rasmus Kjelsmark; Buron, Jonas Christian Due

    2010-01-01

    We report on numerical and experimental characterization of the performance of a fiber link optimized for the delivery of sub-100-fs laser pulses at 1550 nm over several meters of fiber. We investigate the power handling capacity of the link, and demonstrate all-fiber delivery of 1-nJ pulses over...... a distance of 5.3 m. The fiber link consists of dispersion-compensating fiber (DCF) and standard single-mode fiber. The optical pulses at different positions in the fiber link are measured using frequency-resolved optical gating (FROG). The results are compared with numerical simulations of the pulse...... propagation based on the generalized nonlinear Schrödinger equation. The high input power capacity of the fiber link allows the splitting and distribution of femtosecond pulses to an array of fibers with applications in multi-channel fiber-coupled terahertz time-domain spectroscopy and imaging systems. We...

  15. Transmission of solar radiation through optical fiber and application to solar beam excited laser

    Energy Technology Data Exchange (ETDEWEB)

    Arashi, Haruo; Kaimai, Atsushi; Ishigame, Mareo

    1987-12-01

    This paper describes the transmission of high density solar radiation through optical fiber and application to a solar beam excited laser. Input solar beam, rendered a high density through a solar collector, is transmitted through optical fiber, and is separated into several fluxes. The fluxes of light are introduced into the side of a cylindrical laser mirror, where the optical fibres are made up into a rectangular form. The transmitted beam, passing through a side slit, excites a rod positioned at the centre of the laser. The separation of a solar collecting and an oscillating portion serves to increase the degree of freedom. The core of the optical fiber is composed of quartz, and a polymer cladding type having a large number of apertures. The input end of the fiber is a heat resistant air-cladding type. The fibre has a transmission of 93%, which is satisfactory for use. The optical excitation system is composed of, in combination, an elliptically cylindrical laser mirror and a cylindrical laser mirror, both of which have an internal surface gold-plated throughout. The output beam from the fiber is multiple-refracted to excite the laser efficiently. When laser beam with low intensity excited by a lamp is made to pass through a crystal of the above excitation system, the intensity is amplified. It is planned that direct laser oscillation is realized by increase of solar radiation intensity. (9 figs, 5 refs)

  16. Free-standing membrane polymer laser on the end of an optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Tianrui, E-mail: trzhai@bjut.edu.cn, E-mail: zhangxinping@bjut.edu.cn; Li, Songtao; Hu, Yujie; Wang, Yimeng; Wang, Li; Zhang, Xinping, E-mail: trzhai@bjut.edu.cn, E-mail: zhangxinping@bjut.edu.cn [Institute of Information Photonics Technology and College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Chen, Li [Department of Mathematics and Physics, North China Electric Power University, Hebei 071000 (China)

    2016-01-25

    One- and two-dimensional distributed feedback cavities were constructed on free-standing polymer membranes using spin-coating and lift-off techniques. Low threshold lasing was generated through feedback amplification when the 290-nm membrane device was optically pumped, which was attributed to the strong confinement mechanism provided by the active waveguide layer without a substrate. The free-standing membrane polymer laser is flexible and can be transplanted. Single- and dual-wavelength fiber lasers were achieved by directly attaching the membrane polymer laser on the optical fiber end face. This technique provides potential to fabricate polymer lasers on surfaces with arbitrary shapes.

  17. Studies of beam expansion and distributed Bragg reflector lasers for fiber optics and optical signal processing. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Garmire, E.M.

    1981-03-03

    Separate studies were performed on beam expansion and on Distributed Bragg Reflector (DBR) lasers preliminary to monolithic integration on GaAs substrates. These components are proposed for use in optical signal processing, for fiber optic sources and for high-brightness lasers.

  18. Tunable multiwavelength erbium-doped fiber laser based on nonlinear optical loop mirror and birefringence fiber filter

    Science.gov (United States)

    Li, Yuan; Quan, Mingran; Tian, Jiajun; Yao, Yong

    2015-05-01

    A tunable multiwavelength erbium-doped fiber laser (MWEDFL) based on nonlinear optical loop mirror (NOLM) and tunable birefringence fiber filter (BFF) is proposed and demonstrated. By combination of intensity-dependent loss modulation induced by NOLM and pump power adjustment, the proposed laser can achieve independent control over the number of lasing lines, without affecting other important characteristics such as channel spacing and peak location. In addition, the laser allows wavelength tuning with both the peak location and the spectral range of lasing lines controllable. Specifically, the peak location of lasing lines can be controlled to scan the whole spectral range between adjacent channels of comb filter by adjusting the BFF. Moreover, the spectral range of lasing lines can be controlled by adjusting NOLM. This tunable MWEDFL may be useful for fiber-optic communication and fiber-optic sensing.

  19. Capturing a reflective cross-sectional image of an optical fiber with partially coherent laser light to measure the refractive index profile of a multimode optical fiber.

    Science.gov (United States)

    Sheu, Fang-Wen; Jhang, Heng-Jian

    2013-01-28

    We focused partially coherent laser light onto an optical fiber end-face and captured a high-quality reflective cross-sectional image of the fiber. By analyzing the reflected light intensity distribution of the captured fiber image, we can achieve refractive-index profiling of a step-index multimode optical fiber. The measurement error caused by the reflected light from the other fiber end-face positioned in air can be greatly improved by inserting that end of the fiber into water. This simple and easy technique for fiber index profiling by employing reduced-coherence laser light is very useful in determining the refractive index profiles of various multimode optical fibers.

  20. High repetition rate passively Q-switched fiber and microchip lasers for optical resolution photoacoustic imaging

    Science.gov (United States)

    Shi, Wei; Utkin, Ilya; Ranasinghesagara, Janaka; Pan, Lei; Godwal, Yogesh; Kerr, Shaun; Zemp, Roger J.; Fedosejevs, Robert

    2010-02-01

    Optical-resolution photoacoustic microscopy is a novel imaging technology for visualizing optically-absorbing superficial structures in vivo with lateral spatial resolution determined by optical focusing rather than acoustic detection. Since scanning of the illumination spot is required, the imaging speed is limited by the scanning speed and the laser pulse repetition rate. Unfortunately, lasers with high-repetition rate and suitable pulse durations and energies are difficult to find. We are developing compact laser sources for this application. Passively Q-switched fiber and microchip lasers with pulse repetition rates up to 300 kHz are demonstrated. Using a diode-pumped microchip laser fiber-coupled to a large mode-area Yb-doped fiber amplifier we obtained 60μJ 1-ns pulses at the frequency-doubled 532-nm wavelength. The pulse-repetition rate was determined by the power of the microchip laser pump source at 808nm and may exceed 10 kHz. Additionally, a passively Q-switched fiber laser utilizing a Yb-doped double-cladding fiber and an external saturable absorber has shown to produce 250ns pulses at repetition rates of 100-300 KHz. A photoacoustic probe enabling flexible scanning of the focused output of these lasers consisted of a 45-degree glass prism in an optical index-matching fluid. Photoacoustic signals exiting the sample are deflected by the prism to an ultrasound transducer. Phantom studies with a 7.5-micron carbon fiber demonstrate the ability to image with optical rather than acoustic resolution. We believe that the high pulse-repetition rates and the potentially compact and fiber-coupled nature of these lasers will prove important for clinical imaging applications where realtime imaging performance is essential.

  1. Optical feedback-induced light modulation for fiber-based laser ablation.

    Science.gov (United States)

    Kang, Hyun Wook

    2014-11-01

    Optical fibers have been used as a minimally invasive tool in various medical fields. However, due to excessive heat accumulation, the distal end of a fiber often suffers from severe melting or devitrification, leading to the eventual fiber failure during laser treatment. In order to minimize thermal damage at the fiber tip, an optical feedback sensor was developed and tested ex vivo. Porcine kidney tissue was used to evaluate the feasibility of optical feedback in terms of signal activation, ablation performance, and light transmission. Testing various signal thresholds demonstrated that 3 V was relatively appropriate to trigger the feedback sensor and to prevent the fiber deterioration during kidney tissue ablation. Based upon the development of temporal signal signatures, full contact mode rapidly activated the optical feedback sensor possibly due to heat accumulation. Modulated light delivery induced by optical feedback diminished ablation efficiency by 30% in comparison with no feedback case. However, long-term transmission results validated that laser ablation assisted with optical feedback was able to almost consistently sustain light delivery to the tissue as well as ablation efficiency. Therefore, an optical feedback sensor can be a feasible tool to protect optical fiber tips by minimizing debris contamination and delaying thermal damage process and to ensure more efficient and safer laser-induced tissue ablation.

  2. Polymer optical fiber Bragg grating inscription with a single UV laser pulse

    DEFF Research Database (Denmark)

    Pospori, Andreas; Marques, A.T.; Bang, Ole

    2017-01-01

    We experimentally demonstrate the first polymer optical fiber Bragg grating inscribed with only one krypton fluoride laser pulse. The device has been recorded in a single-mode poly(methyl methacrylate) optical fiber, with a core doped with benzyl dimethyl ketal for photosensitivity enhancement. One...... laser pulse with a duration of 15 ns, which provide energy density of 974 mJ/cm2, is adequate to introduce a refractive index change of 0.74×10-4 in the fiber core. After the exposure, the reflectivity of the grating increases for a few minutes following a second order exponential saturation...

  3. DFB laser based electrical dynamic interrogation for optical fiber sensors

    Science.gov (United States)

    Carvalho, J. P.; Frazão, O.; Baptista, J. M.; Santos, J. L.; Barbero, A. P.

    2012-04-01

    An electrical dynamic interrogation technique previously reported by the authors for long-period grating sensors is now progressed by relying its operation exclusively on the modulation of a DFB Laser. The analysis of the detected first and second harmonic generated by the electrical modulation of the DFB Laser allows generating an optical signal proportional to the LPG spectral shift and resilient to optical power fluctuations along the system. This concept permits attenuating the effect of the 1/f noise of the photodetection, amplification and processing electronics on the sensing head resolution. This technique is employed in a multiplexing sensing scheme that measures refractive index variations.

  4. Chaotic laser synchronization and its application in optical fiber secure communication

    Institute of Scientific and Technical Information of China (English)

    YAN Senlin; CHI Zeying; CHEN Wenjian

    2004-01-01

    In this paper, optical fiber chaotic secure communication is proposed by coupling chaotic laser synchronous system with optical fiber propagation channel.Feedback synchronous system of chaotic semiconductor lasers is presented and synchronous error and decoding formulae are demonstrated. Synchronization between two chaotic laser systems with distributed feedback semiconductor lasers at wavelength of 1.31 μm is simulatively achieved with almost zero synchronous error. Parameter mismatch, synchronous transient response and noise effect on the system are studied.Robustness of synchronization and anti-perturbation can increase by increasing the feedback coefficient of the system. Influence of group-velocity-dispersion and self-phase modulation of optical fiber on chaotic laser signal and synchronization are analyzed, and it is found that group-velocity-dispersion affects pulse shape, synchronization and decoding,and limits optical fiber propagation distances, and self-phase modulation does not affect pulse shape, while its product of nonlinear phase shift can affect synchronization and decoding, and restrict propagation distances of optical fiber chaotic communication system and hence the maximum optical power formula is educed. Injecting parameter secure communication systems.

  5. Raman fiber lasers

    Science.gov (United States)

    Supradeepa, V. R.; Feng, Yan; Nicholson, Jeffrey W.

    2017-02-01

    High-power fiber lasers have seen tremendous development in the last decade, with output powers exceeding multiple kilowatts from a single fiber. Ytterbium has been at the forefront as the primary rare-earth-doped gain medium owing to its inherent material advantages. However, for this reason, the lasers are largely confined to the narrow emission wavelength region of ytterbium. Power scaling at other wavelength regions has lagged significantly, and a large number of applications rely upon the diversity of emission wavelengths. Currently, Raman fiber lasers are the only known wavelength agile, scalable, high-power fiber laser technology that can span the wavelength spectrum. In this review, we address the technology of Raman fiber lasers, specifically focused on the most recent developments. We will also discuss several applications of Raman fiber lasers in laser pumping, frequency conversion, optical communications and biology.

  6. A 980 nm pseudomorphic single quantum well laser for pumping erbium-doped optical fiber amplifiers

    Science.gov (United States)

    Larsson, A.; Forouhar, S.; Cody, J.; Lang, R. J.; Andrekson, P. A.

    1990-01-01

    The authors have fabricated ridge waveguide pseudomorphic InGaAs/GaAs/AlGaAs GRIN-SCH SQW (graded-index separate-confinement-heterostructure single-quantum-well) lasers, emitting at 980 nm, with a maximum output power of 240 mW from one facet and a 22 percent coupling efficiency into a 1.55-micron single-mode optical fiber. These lasers satisfy the requirements on efficient and compact pump sources for Er3+-doped fiber amplifiers.

  7. Novel laser machining of optical fibers for long cavities with low birefringence

    CERN Document Server

    Takahashi, Hiroki; Orucevic, Fedja; Noguchi, Atsushi; Kassa, Ezra; Keller, Matthias

    2015-01-01

    We present a novel method of machining optical fiber surfaces with a CO${}_2$ laser for use in Fiber-based Fabry-Perot Cavities (FFPCs). Previously FFPCs were prone to large birefringence and limited to relatively short cavity lengths ($\\le$ 200 $\\mu$m). These characteristics hinder their use in some applications such as cavity quantum electrodynamics with trapped ions. We optimized the laser machining process to produce large, uniform surface structures. This enables the cavities to achieve high finesse even for long cavity lengths. By rotating the fibers around their axis during the laser machining process the asymmetry resulting from the laser's transverse mode profile is eliminated. Consequently we are able to fabricate fiber mirrors with a high degree of rotational symmetry, leading to remarkably low birefringence. Through measurements of the cavity finesse over a range of cavity lengths and the polarization dependence of the cavity linewidth, we confirmed the quality of the produced fiber mirrors for us...

  8. Laser forming for sub-micron adjustment: with application to optical fiber assembly

    NARCIS (Netherlands)

    Folkersma, Klaas Gerrit Pieter

    2015-01-01

    Laser forming is a method to deform a material by controlled local laser heating. In combination with a dedicated actuator topology, those deformations can be used for high precision alignment of components. This thesis applies this method to the alignment of optical fibers with respect to the waveg

  9. Laser forming for sub-micron adjustment: with application to optical fiber assembly

    NARCIS (Netherlands)

    Folkersma, Ger

    2015-01-01

    Laser forming is a method to deform a material by controlled local laser heating. In combination with a dedicated actuator topology, those deformations can be used for high precision alignment of components. This thesis applies this method to the alignment of optical fibers with respect to the

  10. Fiber Optic Versus Direct Laser Delivery For Endarterectomy Of Experimental Atheromas

    Science.gov (United States)

    Eugene, John; Pollock, Marc E.; McColgan, Stephen J.; Hammer-Wilson, Marie; Berns, Michael W.

    1986-01-01

    Direct laser energy delivery was compared to fiber optic laser energy delivery by the performance of open laser endarterectomy in the rabbit arteriosclerosis model. In Group I, 6 open laser endarterectomies were performed with a hand-held CO2 laser (10.6 pm). In Group II, 6 open laser endarterectomies were performed with an argon ion laser (488 nm and 514.5 nm) with the laser beam directed through a 400 μm quartz fiber optic. Gross and light microscopic examination revealed uneven endarterectomy surfaces and frequent perforations at the end points in Group I. In Group II, the endarterectomy surfaces were even and the end points were fused with a tapered transition. Energy density for Group I was 38 ±5 J/cm2. Energy density for Group II was 110±12 J/cm2. CO2 laser energy was better absorbed by arteriosclerotic rabbit aortas than argon ion laser energy, but it could not be as easily controlled. We conclude that a more precise endarterectomy can be performed with fiber optic delivery of laser energy.

  11. Fiber optic and laser sensors IX; Proceedings of the Meeting, Boston, MA, Sept. 3-5, 1991

    Science.gov (United States)

    Depaula, Ramon P. (Editor); Udd, Eric (Editor)

    1991-01-01

    The present volume on fiber-optic and laser sensors discusses industrial applications of fiber-optic sensors, fiber-optic temperature sensors, fiber-optic current sensors, fiber-optic pressure/displacement/vibration sensors, and generic fiber-optic systems. Attention is given to a fiber-sensor design for turbine engines, fiber-optic remote Fourier transform IR spectroscopy, near-IR fiber-optic temperature sensors, and an intensity-type fiber-optic electric current sensor. Topics addressed include fiber-optic magnetic field sensors based on the Faraday effect in new materials, diaphragm size and sensitivity for fiber-optic pressure sensors, a microbend pressure sensor for high-temperature environments, and linear position sensing by light exchange between two lossy waveguides. Also discussed are two-mode elliptical-core fiber sensors for measurement of strain and temperature, a fiber-optic interferometric X-ray dosimeter, fiber-optic interferometric sensors using multimode fibers, and optical fiber sensing of corona discharges.

  12. Fiber optic and laser sensors IX; Proceedings of the Meeting, Boston, MA, Sept. 3-5, 1991

    Science.gov (United States)

    Depaula, Ramon P. (Editor); Udd, Eric (Editor)

    1991-01-01

    The present volume on fiber-optic and laser sensors discusses industrial applications of fiber-optic sensors, fiber-optic temperature sensors, fiber-optic current sensors, fiber-optic pressure/displacement/vibration sensors, and generic fiber-optic systems. Attention is given to a fiber-sensor design for turbine engines, fiber-optic remote Fourier transform IR spectroscopy, near-IR fiber-optic temperature sensors, and an intensity-type fiber-optic electric current sensor. Topics addressed include fiber-optic magnetic field sensors based on the Faraday effect in new materials, diaphragm size and sensitivity for fiber-optic pressure sensors, a microbend pressure sensor for high-temperature environments, and linear position sensing by light exchange between two lossy waveguides. Also discussed are two-mode elliptical-core fiber sensors for measurement of strain and temperature, a fiber-optic interferometric X-ray dosimeter, fiber-optic interferometric sensors using multimode fibers, and optical fiber sensing of corona discharges.

  13. Diffractive-optics-based beam combination of a phase-locked fiber laser array.

    Science.gov (United States)

    Cheung, Eric C; Ho, James G; Goodno, Gregory D; Rice, Robert R; Rothenberg, Josh; Thielen, Peter; Weber, Mark; Wickham, Michael

    2008-02-15

    A diffractive optical element (DOE) is used as a beam combiner for an actively phase-locked array of fiber lasers. Use of a DOE eliminates the far-field sidelobes and the accompanying loss of beam quality typically observed in tiled coherent laser arrays. Using this technique, we demonstrated coherent combination of five fiber lasers with 91% efficiency and M2=1.04. Combination efficiency and phase locking is robust even with large amplitude and phase fluctuations on the input laser array elements. Calculations and power handling measurements suggest that this approach can scale to both high channel counts and high powers.

  14. Femtosecond laser direct-write of optofluidics in polymer-coated optical fiber

    Science.gov (United States)

    Joseph, Kevin A. J.; Haque, Moez; Ho, Stephen; Aitchison, J. Stewart; Herman, Peter R.

    2017-03-01

    Multifunctional lab in fiber technology seeks to translate the accomplishments of optofluidic, lab on chip devices into silica fibers. a robust, flexible, and ubiquitous optical communication platform that can underpin the `Internet of Things' with distributed sensors, or enable lab on chip functions deep inside our bodies. Femtosecond lasers have driven significant advances in three-dimensional processing, enabling optical circuits, microfluidics, and micro-mechanical structures to be formed around the core of the fiber. However, such processing typically requires the stripping and recoating of the polymer buffer or jacket, increasing processing time and mechanically weakening the device. This paper reports on a comprehensive assessment of laser damage in urethane-acrylate-coated fiber. The results show a sufficient processing window is available for femtosecond laser processing of the fiber without damaging the polymer jacket. The fiber core, cladding, and buffer could be simultaneously processed without removal of the buffer jacket. Three-dimensional lab in fiber devices were successfully fabricated by distortion-free immersionlens focusing, presenting fiber-cladding optical circuits and progress towards chemically-etched channels, microfluidic cavities, and MEMS structure inside buffer-coated fiber.

  15. Review of self-focusing of high power lasers in large-mode-area optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Chujun; Li Ying; Lei Dajun; Yang Hua; Wen Shuangchun; Fan Dianyuan; Wen Jianguo, E-mail: scwen@vip.sina.com [Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education, School of Computer and Communication, Hunan University, Changsha 410082 (China)

    2011-02-01

    The main progress about the self-focusing of high power lasers in large-mode-area optical fiber has been reviewed. The theoretical models including the self-focusing effects have been discussed. Some different views on the whole beam self focusing and small scale self-focusing effects in optical fiber have been introduced. Moreover, the possible methods exceeding the bulk-media self-focusing threshold have been discussed and explored.

  16. An acousto-optic Q-switched fiber laser using China-made double-cladding fiber

    Institute of Scientific and Technical Information of China (English)

    Hongming Zhao; Qihong Lou; Jun Zhou; Fangpei Zhang; Jingxing Dong; Yunrong Wei; Libo Li; Zhijiang Wang

    2007-01-01

    @@ A simple laser-diode pumped acoustic-optic Q-switched fiber laser is reported by using China-made largemode-area ytterbium-doped fiber. Q-switched pulses with a beam quality factor of M2 ≈ 2 and several hundred nanoseconds pulse duration are achieved at the repetition rate of 1 - 50 kHz. When the repetition rate is 1 kHz, the pulse energy is 0.93 mJ with the pulse duration of 132 ns. Meanwhile, the profile of laser pulses shows some mode-locking phenomena, the mechanism of the phenomena is discussed.

  17. Optical Fiber Lasers and All Solid-State Passively Modulated Microchip Lasers

    Institute of Scientific and Technical Information of China (English)

    Junewen; Chen; Pie-Yau; Chien; Yu-Ting; Lee

    2003-01-01

    Erbium fiber lasers of continuous mode outputs and of pulsed picosecond and sub-picosecond pulses train are reported. Compact all solid state passively modulated microchip lasers are also developed to the same degree.

  18. A NUMERICAL MODEL OF THE LASER LIGHT INTENSITY TRANSVERSAL DISTRIBUTION INTO UNDEFORMED/DEFORMED OPTICAL FIBERS

    Directory of Open Access Journals (Sweden)

    Paula COPĂESCU

    2009-12-01

    Full Text Available Preliminary results obtained in developing a numerical model of laser light intensity transversedistribution into undeformed/deformed step index optical fiber are presented. The main purpose ofthe presented preliminary numerical modelling results consists in developing a simple method offiber optical sensors interrogation, especially concerning strain and pressure measurements. It is apotential important matter for aeronautical research and industry because of the more extendeduse of fibre optic sensors in aircraft manufacturing. The developed numerical model relies onsolving the equations of electromagnetic waves propagation into optical fibers by using the finiteelement method technique (FEM. The results of numerical simulation obtained by consideringsingle mode or multimode and various laser wavelengtsh are presented. One importantachievement reported in this paper consists in preliminary experimental results concerning themodification of laser intensity transverse distribution observed for multimode optical fiber with andwithout perpendicular mechanical load. The reported preliminary experimental results confirm tosome extent the predictions of numerical simulations regarding laser intensity distribution underlow and medium transverse mechanical load. One important conclusion of this paper consists inthe future development of fiber optic sensor interrogation techniques based on the reportedpreliminary experimental and numerical simulation results.

  19. On the Theory of the Modulation Instability in Optical Fiber and Laser Amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Rubenchik, A M; Turitsyn, S K; Fedoruk, M P

    2010-11-03

    The modulation instability (MI) in optical fiber amplifiers and lasers with anomalous dispersion leads to CW beam breakup and the growth of multiple pulses. This can be both a detrimental effect, limiting the performance of amplifiers, and also an underlying physical mechanism in the operation of MI-based devices. Here we revisit the analytical theory of MI in fiber optical amplifiers. The results of the exact theory are compared with the previously used adiabatic approximation model, and the range of applicability of the latter is determined. The same technique is applicable to the study of spatial MI in solid state laser amplifiers and MI in non-uniform media.

  20. Fundamentals of fiber lasers and fiber amplifiers

    CERN Document Server

    Ter-Mikirtychev, Valerii (Vartan)

    2014-01-01

    This book covers the fundamental aspects of fiber lasers and fiber amplifiers, and includes a wide range of material from laser physics fundamentals to state-of-the-art topics in this rapidly growing field of quantum electronics. Emphasis is placed on the nonlinear processes taking place in fiber lasers and amplifiers, their similarities, differences to, and their advantages over other solid-state lasers. The reader will learn basic principles of solid-state physics and optical spectroscopy of laser active centers in fibers, main operational laser regimes, and practical recommendations and suggestions on fiber laser research, laser applications, and laser product development. The book will be useful for students, researchers, and professionals who work with lasers, in the optical communications, chemical and biological industries, etc.

  1. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2011-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last 5 years. Many of the traditional manufacturers of gas and solid-state lasers are now pursuing the fiber-based systems, which are displacing the conventional technology in many areas. High-power fiber laser systems...... laser system. We present the latest advancements within airclad fiber technology including a new 100 m single-mode polarization-maintaining rod-type fiber capable of amplifying to megawatt power levels. Furthermore, we describe the novel airclad-based pump combiners and their use in a completely...... monolithic 350 W cw fiber laser system with an M2 of less than 1.1. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE)....

  2. Medical Application of Free Electron Laser Trasmittance using Hollow Optical Fiber

    CERN Document Server

    Suzuki, Sachiko; Ishii, Katsonuri

    2004-01-01

    Mid-infrared Free Electron Laser (FEL) is expected as new application for biomedical surgery. However, delivery of MIR-FEL into the body is difficult because the common glass optical fibers have strong absorption at MIR region. A good operational and flexible line for FEL is required at medical field. A Hollow optical fiber is developed for IR laser and high-power laser delivery. We evaluated the fiber for FEL transmission line. This fiber is coated with cyclic olefin polymer (COP) and silver thin film on the inside of glass capillary tube. It is 700 μm-bore and 1m in lengths. The fiber transmission loss of the measured wavelength region of 5.5 μm to 12 μm is less than 1dB/m when the fiber is straight and 1.2 dB/m when bent to radius of 20 cm. Additionally, the output beam profile and the pulse structure is not so different form incidence beam. In conclusion, the fiber is suitable for delivery of the FEL energy for applications in medical and laser surgery.

  3. Fabrication quality analysis of a fiber optic refractive index sensor created by CO2 laser machining.

    Science.gov (United States)

    Chen, Chien-Hsing; Yeh, Bo-Kuan; Tang, Jaw-Luen; Wu, Wei-Te

    2013-03-26

    This study investigates the CO2 laser-stripped partial cladding of silica-based optic fibers with a core diameter of 400 μm, which enables them to sense the refractive index of the surrounding environment. However, inappropriate treatments during the machining process can generate a number of defects in the optic fiber sensors. Therefore, the quality of optic fiber sensors fabricated using CO2 laser machining must be analyzed. The results show that analysis of the fiber core size after machining can provide preliminary defect detection, and qualitative analysis of the optical transmission defects can be used to identify imperfections that are difficult to observe through size analysis. To more precisely and quantitatively detect fabrication defects, we included a tensile test and numerical aperture measurements in this study. After a series of quality inspections, we proposed improvements to the existing CO2 laser machining parameters, namely, a vertical scanning pathway, 4 W of power, and a feed rate of 9.45 cm/s. Using these improved parameters, we created optical fiber sensors with a core diameter of approximately 400 μm, no obvious optical transmission defects, a numerical aperture of 0.52 ± 0.019, a 0.886 Weibull modulus, and a 1.186 Weibull-shaped parameter. Finally, we used the optical fiber sensor fabricated using the improved parameters to measure the refractive indices of various solutions. The results show that a refractive-index resolution of 1.8 × 10(-4) RIU (linear fitting R2 = 0.954) was achieved for sucrose solutions with refractive indices ranging between 1.333 and 1.383. We also adopted the particle plasmon resonance sensing scheme using the fabricated optical fibers. The results provided additional information, specifically, a superior sensor resolution of 5.73 × 10(-5) RIU, and greater linearity at R2 = 0.999.

  4. Effect of optical fiber type and absorption medium on the endovenous laser ablation mechanism

    Science.gov (United States)

    Ignatieva, N. Yu; Zakharkina, O. L.; Mazayshvili, C. V.; Bagratashvili, V. N.; Lunin, V. V.

    2017-10-01

    Our experimental investigation was aimed at revealing the mechanism behind the action of laser radiation on venous wall under endovenous laser ablation conditions. We determined the critical laser power P cr at which the objective effect of complete denaturation of the vascular tissue collagen was attained for two types of optical fiber in the presence and absence of blood cells. We demonstrated that for the radial optical fiber the presence of blood cells had no effect on the magnitude of P cr, which came to 4.3  ±  0.1 and 5.6  ±  01 W for 1.56 and 1.47 µm lasers, respectively. For the bare fiber and 1.56 µm laser, P cr increased up to 5.2  ±  0.2 W in a blood-filled vessel and up to 7.1  ±  0.2 W when the blood was replaced by a sodium chloride solution. Our data show that the heating and degradation of insufficient veins go on more effectively when the tissue is heated by laser radiation directly absorbed therein, rather than the red-hot carbonized optical fiber tip.

  5. Non-invasive image-guided laser microsurgery by a dual-wavelength fiber laser and an integrated fiber-optic multi-modal system.

    Science.gov (United States)

    Tsai, Meng-Tsan; Li, Dean-Ru; Chan, Ming-Che

    2016-10-15

    A new approach to non-invasive image-guided laser micro-treatment is demonstrated by a dual-wavelength fiber laser source and an integrated fiber-based multi-modal system. The fiber-based source, operated in 1.55 and 1.2 μm simultaneously, was directly connected to an integrated fiber-based multi-modal system for imaging and laser micro-treatment at the same time. The 1.2 μm radiations, within the 1.2-1.35 μm bio-penetration window of skin, were utilized for spectral domain optical coherence tomography imaging. The 1.55 μm radiations, highly absorptive to waters, were utilized for laser microsurgery. The new approach, which is simple in configuration and accurately controls the positions and exposure time of the laser microsurgery, shows great promises for future clinical applications.

  6. Theoretical model of optical fiber secure communication system with chaotic multiple-quantum-well lasers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chaotic synchronization of injected multiple-quantum-well lasers of optical fiber system and a theoretical model of optical fiber chaotic secure communication system are presented by coupling a chaotic multiple-quantum-well laser synchronization system and a fiber channel. A new chaotic encoding method of chaos phase shift keying On/Off is proposed for optical fiber secure communications. Chaotic synchronization is achieved numerically in long-haul fiber system at wavelength 1.55μm. The effect of the nonlinear-phase of fiber is analyzed on chaotic signal and synchronization. A sinusoidal signal of 0.2 GHz frequency is simulated numerically with chaos masking in long-haul fiber analog communication at wavelength 1.55μm while a digital signal of 0.5 Gbit/s bit rate is simulated numerically with c1 haos masking and a rate of 0.05 Gbit/s are also simulated numerically with chaos shift keying and chaos phase shift keying On/Off in long-haul fiber digital communications at wavelength 1.55μm

  7. Laser Trimming for Adjustment of Grating Offset in Phase-Shifted Fiber Grating Coupler for All-Optical Switching Application

    Institute of Scientific and Technical Information of China (English)

    Hirohisa; Yokota; Yutaka; Sasaki

    2003-01-01

    We theoretically investigated laser trimming to adjust grating offset in phase-shifted fiber grating coupler (FGC) for all-optical switching application. It was clarified that the trimming made the extinction ratio higher in all-optical FGC switch.

  8. Nanosecond laser damage resistance of differently prepared semi-finished parts of optical multimode fibers

    Science.gov (United States)

    Mann, Guido; Vogel, Jens; Preuß, Rüdiger; Vaziri, Pouya; Zoheidi, Mohammadali; Eberstein, Markus; Krüger, Jörg

    2007-12-01

    Optical multimode fibers are applied in materials processing (e.g. automotive industry), defense, aviation technology, medicine and biotechnology. One challenging task concerning the production of multimode fibers is the enhancement of laser-induced damage thresholds. A higher damage threshold enables a higher transmitted average power at a given fiber diameter or the same power inside a thinner fiber to obtain smaller focus spots. In principle, different material parameters affect the damage threshold. Besides the quality of the preform bulk material itself, the drawing process during the production of the fiber and the preparation of the fiber end surfaces influence the resistance. Therefore, the change of the laser-induced damage threshold of preform materials was investigated in dependence on a varying thermal treatment and preparation procedure. Single and multi-pulse laser-induced damage thresholds of preforms (F300, Heraeus) were measured using a Q-switched Nd:YAG laser at 1064 nm wavelength emitting pulses with a duration of 15 ns, a pulse energy of 12 mJ and a repetition rate of 10 Hz. The temporal and spatial shape of the laser pulses were controlled accurately. Laser-induced damage thresholds in a range from 150 J cm -2 to 350 J cm -2 were determined depending on the number of pulses applied to the same spot, the thermal history and the polishing quality of the samples, respectively.

  9. Optical Connecting of Fibers by Laser Beams Propagating from the Fibers Edges

    Directory of Open Access Journals (Sweden)

    Sergey Nikolayevich Mensov

    2008-01-01

    Full Text Available A possibility to connect nonprecise positioned fibers in photopolymerizable compositions is under discussion in this paper. The processes of optical synthesis of connective waveguiding structures forming in such mediums directly by the radiation leaving the edges of connecting fibers are investigated numerically and experimentally as well. It was shown that nonlinear interaction of the light beams allows to connect misaligned and transversally shifted fibers with high efficiency.

  10. Influence of nuclear radiation and laser beams on optical fibers and components

    Directory of Open Access Journals (Sweden)

    Pantelić Slađana N.

    2011-01-01

    Full Text Available The influence of nuclear radiation and particles has been the object of investigation for a long time. For new materials and systems the research should be continued. Human activities in various environments, including space, call for more detailed research. The role of fibers in contemporary communications, medicine, and industry increases. Fibers, their connections and fused optics components have one type of tasks - the transmission of information and power. The other type of tasks is reserved for fiber lasers: quantum generators and amplifiers. The third type of tasks is for fiber sensors, including high energy nuclear physics. In this paper we present some chosen topics in the mentioned areas as well as our experiments with nuclear radiation and laser beams to fiber and bulk materials of various nature (glass, polymer, metallic, etc..

  11. Optical fiber link for transmission of 1-nJ femtosecond laser pulses at 1550 nm.

    Science.gov (United States)

    Eichhorn, Finn; Olsson, Rasmus Kjelsmark; Buron, Jonas C D; Grüner-Nielsen, Lars; Pedersen, Jens Engholm; Jepsen, Peter Uhd

    2010-03-29

    We report on numerical and experimental characterization of the performance of a fiber link optimized for the delivery of sub-100-fs laser pulses at 1550 nm over several meters of fiber. We investigate the power handling capacity of the link, and demonstrate all-fiber delivery of 1-nJ pulses over a distance of 5.3 m. The fiber link consists of dispersion-compensating fiber (DCF) and standard single-mode fiber. The optical pulses at different positions in the fiber link are measured using frequency-resolved optical gating (FROG). The results are compared with numerical simulations of the pulse propagation based on the generalized nonlinear Schrödinger equation. The high input power capacity of the fiber link allows the splitting and distribution of femtosecond pulses to an array of fibers with applications in multi-channel fiber-coupled terahertz time-domain spectroscopy and imaging systems. We demonstrate THz pulse generation and detection using a distributed fiber link with 32 channels and 2.6 nJ input pulse energy.

  12. Multiwavelength laser light transmission of hollow optical fiber from the visible to the mid-infrared

    Science.gov (United States)

    Shi, Yi Wei; Ito, Kentaro; Matsuura, Yuji; Miyagi, Mitsunobu

    2005-11-01

    We report on low-loss multiwavelength laser delivery of hollow optical fiber in a wide wavelength region, from the visible to the infrared. Improved methods of liquid-phase coating were used to fabricate the hollow fiber with inner films of a silver and a cyclic olefin polymer (COP) layer. The surface roughness of the silver layer was reduced dramatically by pretreatment on the inner glass surface with an SnCl2 solution. The COP layer roughness was also decreased by using an ambient atmosphere of tetrahydrofuran (THF) solvent during the COP layer formation. Owing to the smooth surfaces, hollow fiber with optimum COP film thickness for CO2 laser light simultaneously yields low losses for a Er:YAG laser and a red pilot beam. The power durability of CO2 and Er:YAG lasers, as well as the loss properties for the pilot beam, is demonstrated.

  13. Multiwavelength laser light transmission of hollow optical fiber from the visible to the mid-infrared.

    Science.gov (United States)

    Shi, Yi Wei; Ito, Kentaro; Matsuura, Yuji; Miyagi, Mitsunobu

    2005-11-01

    We report on low-loss multiwavelength laser delivery of hollow optical fiber in a wide wavelength region, from the visible to the infrared. Improved methods of liquid-phase coating were used to fabricate the hollow fiber with inner films of a silver and a cyclic olefin polymer (COP) layer. The surface roughness of the silver layer was reduced dramatically by pretreatment on the inner glass surface with an SnCl2 solution. The COP layer roughness was also decreased by using an ambient atmosphere of tetrahydrofuran (THF) solvent during the COP layer formation. Owing to the smooth surfaces, hollow fiber with optimum COP film thickness for CO2 laser light simultaneously yields low losses for a Er:YAG laser and a red pilot beam. The power durability of CO2 and Er:YAG lasers, as well as the loss properties for the pilot beam, is demonstrated.

  14. Diode Pumped Fiber Laser.

    Science.gov (United States)

    1984-12-01

    FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION .............. 5 A. FIBER GROWTH .......................... 5 B. FIBER PROCESSING 7...1.32 pm FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION A. FIBER GROWTH The single crystal fibers used in this work were grown at Stanford University

  15. Generation of femtosecond optical vortex beams in all-fiber mode-locked fiber laser using mode selective coupler

    CERN Document Server

    Wang, Teng; Shi, Fan; Pang, Fufei; Huang, Sujuan; Wang, Tingyun; Zeng, Xianglong

    2016-01-01

    We experimentally demonstrated a high-order optical vortex pulsed laser based on a mode selective all-fiber fused coupler composed of a single-mode fiber (SMF) and a few-mode fiber (FMF). The fused SMF-FMF coupler inserted in the cavity not only acts as mode converter from LP01 mode to LP11 or LP21 modes with a broadband width over 100 nm, but also directly delivers femtosecond vortex pulses out of the mode locked cavity. To the best of our knowledge, this is the first report on the generation of high-order pulse vortex beams in mode-locked fiber laser. The generated 140 femtosecond vortex beam has a spectral width of 67 nm centered at 1544 nm.

  16. Vector soliton fiber laser passively mode locked by few layer black phosphorus-based optical saturable absorber.

    Science.gov (United States)

    Song, Yufeng; Chen, Si; Zhang, Qian; Li, Lei; Zhao, Luming; Zhang, Han; Tang, Dingyuan

    2016-11-14

    We report on the optical saturable absorption of few-layer black phosphorus nanoflakes and demonstrate its application for the generation of vector solitons in an erbium-doped fiber laser. By incorporating the black phosphorus nanoflakes-based saturable absorber (SA) into an all-fiber erbium-doped fiber laser cavity, we are able to obtain passive mode-locking operation with soliton pulses down to ~670 fs. The properties and dynamics of the as-generated vector solitons are experimentally investigated. Our results show that BP nanoflakes could be developed as an effective SA for ultrashort pulse fiber lasers, particularly for the generation of vector soliton pulses in fiber lasers.

  17. Femtosecond laser aided processing of optical sensor fibers for 3D medical navigation and tracking (FiberNavi)

    Science.gov (United States)

    Waltermann, Christian; Koch, Jan; Angelmahr, Martin; Schade, Wolfgang; Witte, Michael; Kohn, Nils; Wilhelm, Dirk; Schneider, Armin; Reiser, Silvano; Feußner, Hubertus

    2014-05-01

    A new concept for fiber-optical 3D shape sensing applying femtosecond laser technology for highprecision direct writing of Bragg gratings within the core and the cladding of single core standard telecom fibers is presented. This new technology enables a cost-efficient and real-time 3D shape sensing and navigation of medical catheters or endoscopes only by means of passive optical sensor elements. First prototypes showed the possibility to achieve absolute navigation accuracy of four mm per meter and have successfully been tested in clinical environment.

  18. Optical-fiber-based laser-induced breakdown spectroscopy for detection of early caries

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-06-01

    A laser-induced breakdown spectroscopy (LIBS) system targeting for the in vivo analysis of tooth enamel is described. The system is planned to enable real-time analysis of teeth during laser dental treatment by utilizing a hollow optical fiber that transmits both Q-switched Nd:YAG laser light for LIBS and infrared Er:YAG laser light for tooth ablation. The sensitivity of caries detection was substantially improved by expanding the spectral region under analysis to ultraviolet (UV) light and by focusing on emission peaks of Zn in the UV region. Subsequently, early caries were distinguished from healthy teeth with accuracy rates above 80% in vitro.

  19. Optical-fiber-based laser-induced breakdown spectroscopy for detection of early caries.

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-06-01

    A laser-induced breakdown spectroscopy (LIBS) system targeting for the in vivo analysis of tooth enamel is described. The system is planned to enable real-time analysis of teeth during laser dental treatment by utilizing a hollow optical fiber that transmits both Q-switched Nd:YAG laser light for LIBS and infrared Er:YAG laser light for tooth ablation. The sensitivity of caries detection was substantially improved by expanding the spectral region under analysis to ultraviolet (UV) light and by focusing on emission peaks of Zn in the UV region. Subsequently, early caries were distinguished from healthy teeth with accuracy rates above 80% in vitro.

  20. Multi-wavelength fiber ring laser based on a chirped moiré fiber grating and a semiconductor optical amplifier

    Institute of Scientific and Technical Information of China (English)

    Shaohua Lu; Ou Xu; Suchun Feng; Shuisheng Jian

    2009-01-01

    A simple and cost-effective multi-wavelength fiber ring laser based on a chirped Moire fiber grating (CMFG)arid a semiconductor optical amplifier (SOA) is proposed.Stable triple-wavelength lasing oscillations at room temperature are experimentally demonstrated.The measured optical signal-to-noise ratio (SNR) reaches the highest value of 50 dB and the power fluctuation of each wavelength is less than 0.2 dB within a 1-h period.To serve as a wavelength selective element,the CMFG possesses excellent comb-like filtering chaxacteristics including stable wavelength interval arid ultra-narrow passband,and its fabrication method is easy and flexible.The lasing oscillation shows a narrower bandwidth than SOA-based multi-wavelength fibcr lasers utilizing some other kinds of wavelength selective components.Methods to optimize the laser performance are also discussed.

  1. Characterization of novel microsphere chain fiber optic tips for potential use in ophthalmic laser surgery

    OpenAIRE

    Hutchens, Thomas C.; Darafsheh, Arash; Fardad, Amir; Antoszyk, Andrew N.; Ying, Howard S.; Astratov, Vasily N.; Fried, Nathaniel M.

    2012-01-01

    Ophthalmic surgery may benefit from use of more precise fiber delivery systems during laser surgery. Some current ophthalmic surgical techniques rely on tedious mechanical dissection of tissue layers. In this study, chains of sapphire microspheres integrated into a hollow waveguide distal tip are used for erbium:YAG laser ablation studies in contact mode with ophthalmic tissues, ex vivo. The laser’s short optical penetration depth combined with the small spot diameters achieved with this fibe...

  2. Nd:YAG laser bloodless tonsillectomy by fiber optic doppler coupled handpiece beam delivery

    Science.gov (United States)

    Palmieri, Beniamino; Rottigni, Valentina

    2012-09-01

    Laser ablation of palatine tonsils is a relatively new technique recently performed in head and neck surgery departments, in order to treat recurrent tonsillar infections or obstructions from enlarged tonsils. In our study, we have investigated a new procedure using the fiber optic laser beam Nd:YAG to remove up to the 89% of tonsillar tissue, and leaving in place the capsule avoiding any hemorrhagic complication and limiting the pain.

  3. Torsion sensing characteristics of long period fiber gratings fabricated by femtosecond laser in optical fiber

    Science.gov (United States)

    Duan, Ji'an; Xie, Zheng; Wang, Cong; Zhou, Jianying; Li, Haitao; Luo, Zhi; Chu, Dongkai; Sun, Xiaoyan

    2016-09-01

    With the alignment of the fiber core systems containing dual-CCDs and high-precision electric displacement platform, twisted long period fiber gratings (T-LPFGs) were fabricated in two different twisted SMF-28 fibers by femtosecond laser. The torsion characteristics of the T-LPFGs were experimentally and theoretical investigated and demonstrated in this study. The achieved torsion sensitivity is 117.4 pm/(rad/m) in the torsion range -105-0 rad/m with a linearity of 0.9995. Experimental results show that compared with the ordinary long period fiber gratings, the resonance wavelength of the gratings presents an opposite symmetrical shift depending on the twisting direction after the applied torsion is removed. In addition, high sensitivity could be obtained, which is very suitable for the applications in the torsion sensor. These results are important for the design of new torsion sensors based on T-LPFGs fabricated by femtosecond laser.

  4. Graphene thickness-dependent Er-doped Q-switched optical fiber laser

    Science.gov (United States)

    Wang, Xiaolong; Sang, Mei; Zhu, Pan; Liu, Ke; Yang, Tianxin

    2013-02-01

    A stable Q-switched laser is useful in the area of remote sensing, range finding, optical imaging, material processing, and fiber communications. With its excellent linear and nonlinear optical characteristics, graphene has been proven to be an attractive material to generate nanosecond, picosecond and femtosecond laser pulses. It has a lot of advantages, such as lower saturation intensity, larger saturable-absorption modulation depth, higher damage threshold, sub-picosecond recovery time and an ultrabroad wavelength-independent saturable-absorption range. In this paper, we demonstrate a graphene based Q-switched fiber laser. Graphene was deposited on the fiber interface by the optically driven deposition method. The thickness of the graphene can be controlled by changing depositing time. The compact Q-switched erbium-doped fiber laser based on graphene operated stably, and got Q-switched pulse sequences output with the repetition rate of 19KHz and the average power of 1.4mW when pump power is 40mW. Higher peak power, shorter pulse duration, and higher repetition rate could be achieved by adjusting the thickness of the graphene layer appropriately. Besides, the pulse duration and output power is proved to be a function of the pump power. The repetition rate of this fiber laser had a characteristic of monotonically increasing, near-linear with the changing of pump power. The stable Q-switching pulse output can be observed on the oscilloscope with differently specific repetition rate and pump power. Theory analysis of this fiber laser and further improvement methods is also studied combined with the experimental results.

  5. Spatial-Resolution Improvement in Optical Frequency Domain Reflectometry System Based on Tunable Linear Fiber Laser

    Energy Technology Data Exchange (ETDEWEB)

    Li Guoyu; Li Yan [Institute of Information Engineering, Handan College, Handan, 056005 (China); Zhao Peng, E-mail: guoyu_li@yahoo.cn [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China)

    2011-02-01

    In optical frequency domain reflectometry (OFDR) system, the spatial resolution is obtained by using the total frequency-sweep span of the tunable laser. However, in practice, the spatial resolution is severely limited by nonlinearity in the lightwave-frequency sweep of the tunable laser. A closed-loop PZT modulated DBR linear fiber laser is proposed to improve the spatial resolution of the OFDR system. Experimental results show that the spatial resolution of OFDR system has improved greatly. When the frequency sweep excursion is 66GHz and the fiber under test (FUT) is 7 m, the OFDR system has a spatial resolution of 1.5 m with open-loop PZT modulated laser. But the spatial resolution increases to 35 cm with closed-loop PZT modulated laser.

  6. Field Determination Of Ground Water Contamination Using Laser Fluorescence And Fiber Optics

    Science.gov (United States)

    Chudyk, Wayne; Pohlig, Kenneth; Wolf, Lisa; Fordiani, Rita

    1990-02-01

    Experience at over sixteen sites containing over one hundred wells has shown the feasibility of using fiber optic systems for in situ measurement of aromatic ground water contaminants. Aromatic solvents, as well as the benzene, ethylbenzene, toluene, and xylenes (BTEX) fraction of gasoline, have been detected using a prototype field instrument. Well depths have varied from 5 m to 30 m, and limits of detection at 10 m have been in the ppb range. We are routinely using two separate clear tefzel-coated optical fibers bound in a black teflon tubing for in situ sensing of aromatic organic ground water contaminants via laser-induced fluorescence. One fiber, the excitation fiber, carries the 266 nm, 15 nanosecond, laser pulse down to the sensor. The other fiber, used for detection, carries collected fluorescence plus scattered laser light back up to the surface to the detector. Optical crosstalk has been observed to occur along the entire length of the sensor tubing. This may be due to fiber fluorescence. The fiber crosstalk is eliminated by use of a 320 nm cutoff filter in the detector optics. Black tefzel-coated fibers are also commercially available which could eliminate this potential problem. Evaluation of fluorescence emission versus concentration using serial dilution of standards shows that fluorescence lifetimes are important when evaluating different concentrations as well as in evaluation of mixtures. Minimization of signal-to-noise ratios in the detector electronics involves tuning the gate width used in measuring the fluorescent pulse, in order to include the full fluorescent signal returning from the contaminants. Field tests of the modular prototype instrument have been successful in their demonstration of the feasibility of this new technology. Results at a variety of types of sites are presented, showing the flexibility of the modular approach used in the design and operation of this new instrument.

  7. Development of a Fiber Laser with Independently Adjustable Properties for Optical Resolution Photoacoustic Microscopy.

    Science.gov (United States)

    Aytac-Kipergil, Esra; Demirkiran, Aytac; Uluc, Nasire; Yavas, Seydi; Kayikcioglu, Tunc; Salman, Sarper; Karamuk, Sohret Gorkem; Ilday, Fatih Omer; Unlu, Mehmet Burcin

    2016-12-08

    Photoacoustic imaging is based on the detection of generated acoustic waves through thermal expansion of tissue illuminated by short laser pulses. Fiber lasers as an excitation source for photoacoustic imaging have recently been preferred for their high repetition frequencies. Here, we report a unique fiber laser developed specifically for multiwavelength photoacoustic microscopy system. The laser is custom-made for maximum flexibility in adjustment of its parameters; pulse duration (5-10 ns), pulse energy (up to 10 μJ) and repetition frequency (up to 1 MHz) independently from each other and covers a broad spectral region from 450 to 1100 nm and also can emit wavelengths of 532, 355, and 266 nm. The laser system consists of a master oscillator power amplifier, seeding two stages; supercontinuum and harmonic generation units. The laser is outstanding since the oscillator, amplifier and supercontinuum generation parts are all-fiber integrated with custom-developed electronics and software. To demonstrate the feasibility of the system, the images of several elements of standardized resolution test chart are acquired at multiple wavelengths. The lateral resolution of optical resolution photoacoustic microscopy system is determined as 2.68 μm. The developed system may pave the way for spectroscopic photoacoustic microscopy applications via widely tunable fiber laser technologies.

  8. Development of a Fiber Laser with Independently Adjustable Properties for Optical Resolution Photoacoustic Microscopy

    Science.gov (United States)

    Aytac-Kipergil, Esra; Demirkiran, Aytac; Uluc, Nasire; Yavas, Seydi; Kayikcioglu, Tunc; Salman, Sarper; Karamuk, Sohret Gorkem; Ilday, Fatih Omer; Unlu, Mehmet Burcin

    2016-12-01

    Photoacoustic imaging is based on the detection of generated acoustic waves through thermal expansion of tissue illuminated by short laser pulses. Fiber lasers as an excitation source for photoacoustic imaging have recently been preferred for their high repetition frequencies. Here, we report a unique fiber laser developed specifically for multiwavelength photoacoustic microscopy system. The laser is custom-made for maximum flexibility in adjustment of its parameters; pulse duration (5-10 ns), pulse energy (up to 10 μJ) and repetition frequency (up to 1 MHz) independently from each other and covers a broad spectral region from 450 to 1100 nm and also can emit wavelengths of 532, 355, and 266 nm. The laser system consists of a master oscillator power amplifier, seeding two stages; supercontinuum and harmonic generation units. The laser is outstanding since the oscillator, amplifier and supercontinuum generation parts are all-fiber integrated with custom-developed electronics and software. To demonstrate the feasibility of the system, the images of several elements of standardized resolution test chart are acquired at multiple wavelengths. The lateral resolution of optical resolution photoacoustic microscopy system is determined as 2.68 μm. The developed system may pave the way for spectroscopic photoacoustic microscopy applications via widely tunable fiber laser technologies.

  9. An optical fiber spool for laser stabilization with reduced acceleration sensitivity to 10-12/g

    Institute of Scientific and Technical Information of China (English)

    胡永奇; 董靖; 黄军超; 李唐; 刘亮

    2015-01-01

    Environmental vibration causes mechanical deformation in optical fibers, which induces excess frequency noise in fiber-stabilized lasers. In order to solve such a problem, we propose an ultralow acceleration sensitivity fiber spool with symmetrically mounted structure. By numerical analysis with the finite element method, we obtain the optimal geometry parameters of the spool with which the horizontal and vertical acceleration sensitivity can be reduced to 3.25 × 10−12/g and 5.38 × 10−12/g respectively. Moreover, the structure features the insensitivity to the variation of geometry parameters, which will minimize the infl uence from numerical simulation error and manufacture tolerance.

  10. Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler.

    Science.gov (United States)

    Beaudette, Kathy; Baac, Hyoung Won; Madore, Wendy-Julie; Villiger, Martin; Godbout, Nicolas; Bouma, Brett E; Boudoux, Caroline

    2015-04-01

    Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to induce coagulation of an ex vivo swine esophagus allowing a real-time assessment of thermal dynamic processes. We therefore demonstrate a DCFC-based system combining OCT imaging with laser coagulation through a single fiber, thus enabling both modalities to be performed simultaneously and in a co-registered manner. Such a system enables endoscopic image-guided laser marking of superficial epithelial tissues or laser thermal therapy of epithelial lesions in pathologies such as Barrett's esophagus.

  11. Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

    Science.gov (United States)

    Egorova, O N; Semjonov, S L; Velmiskin, V V; Yatsenko, Yu P; Sverchkov, S E; Galagan, B I; Denker, B I; Dianov, E M

    2014-04-07

    We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

  12. Measuring a Fiber-Optic Delay Line Using a Mode-Locked Laser

    Science.gov (United States)

    Tu, Meirong; McKee, Michael R.; Pak, Kyung S.; Yu, Nan

    2010-01-01

    The figure schematically depicts a laboratory setup for determining the optical length of a fiber-optic delay line at a precision greater than that obtainable by use of optical time-domain reflectometry or of mechanical measurement of length during the delay-line-winding process. In this setup, the delay line becomes part of the resonant optical cavity that governs the frequency of oscillation of a mode-locked laser. The length can then be determined from frequency-domain measurements, as described below. The laboratory setup is basically an all-fiber ring laser in which the delay line constitutes part of the ring. Another part of the ring - the laser gain medium - is an erbium-doped fiber amplifier pumped by a diode laser at a wavelength of 980 nm. The loop also includes an optical isolator, two polarization controllers, and a polarizing beam splitter. The optical isolator enforces unidirectional lasing. The polarization beam splitter allows light in only one polarization mode to pass through the ring; light in the orthogonal polarization mode is rejected from the ring and utilized as a diagnostic output, which is fed to an optical spectrum analyzer and a photodetector. The photodetector output is fed to a radio-frequency spectrum analyzer and an oscilloscope. The fiber ring laser can generate continuous-wave radiation in non-mode-locked operation or ultrashort optical pulses in mode-locked operation. The mode-locked operation exhibited by this ring is said to be passive in the sense that no electro-optical modulator or other active optical component is used to achieve it. Passive mode locking is achieved by exploiting optical nonlinearity of passive components in such a manner as to obtain ultra-short optical pulses. In this setup, the particular nonlinear optical property exploited to achieve passive mode locking is nonlinear polarization rotation. This or any ring laser can support oscillation in multiple modes as long as sufficient gain is present to overcome

  13. Semiconductor Lasers and Their Application in Optical Fiber Communication.

    Science.gov (United States)

    Agrawal, Govind P.

    1985-01-01

    Working principles and operating characteristics of the extremely compact and highly efficient semiconductor lasers are explained. Topics include: the p-n junction; Fabry-Perot cavity; heterostructure semiconductor lasers; materials; emission characteristics; and single-frequency semiconductor lasers. Applications for semiconductor lasers include…

  14. Q-switching of an all-fiber laser by acousto-optic modulation of a fiber Bragg grating

    Science.gov (United States)

    Delgado-Pinar, M.; Zalvidea, D.; Diez, A.; Perez-Millan, P.; Andres, M.

    2006-02-01

    We report active Q-switching of an all-fiber laser using a Bragg grating based acousto-optic modulator. Q-switching is performed by modulating a fiber Bragg grating with an extensional acoustic wave. The acoustic wave modulates periodically the effective index profile of the FBG and changes its reflection features. This allows controlling the Q-factor of the cavity. Using 1 m of 300 ppm erbium-doped fiber and a maximum pump power of 180 mW, Q-switch pulses of 10 W of peak power and 82 ns wide were generated. The pulse repetition rate of the laser can be continuously varied from few Hz up to 62.5 kHz.

  15. Magneto-optic Crystal Polarization Controller Assisted Mode-Locked Fiber Laser

    Institute of Scientific and Technical Information of China (English)

    ZHAO Guang-Zhen; GUI Li-Li; XIAO Xiao-Sheng; YANG Chang-Xi

    2011-01-01

    We report a passively mode-locked erbium-doped fiber laser based on a compact magneto-optic crystal polarization controller. The length of the polarization controller consisting of four magneto-optic crystal rotators and two quarter wave-plates is only 10cm.Adjusting the polarization controller, central wavelength around 1559nm and repetition rate 21.10 MHz mode-locked pulse are obtained. Pulse duration and 3 dB spectrum width are 598.4fs and 6.24nm respectively. Single pulse energy is about 151.7pJ. Because of its small size, low insertion loss,good controllability and negligible dispersion, the magneto-optic crystal polarization controller could be an ideal polarization controller in fiber lasers.

  16. Preparation of Fiber Optics for the Delivery of High-Energy High-Beam-Quality Nd:YAG Laser Pulses.

    Science.gov (United States)

    Kuhn, A; French, P; Hand, D P; Blewett, I J; Richmond, M; Jones, J D

    2000-11-20

    Recent improvements in design have made it possible to build Nd:YAG lasers with both high pulse energy and high beam quality. These lasers are particularly suited for percussion drilling of holes of as much as 1-mm diameter thick (a few millimeters) metal parts. An example application is the production of cooling holes in aeroengine components for which 1-ms duration, 30-J energy laser pulses produce holes of sufficient quality much more efficiently than with a laser trepanning process. Fiber optic delivery of the laser beam would be advantageous, particularly when one is processing complex three-dimensional structures. However, lasers for percussion drilling are available only with conventional bulk-optic beam delivery because of laser-induced damage problems with the small-diameter (approximately 200-400-mum) fibers that would be required for preserving necessary beam quality. We report measurements of beam degradation in step-index optical fibers with an input beam quality corresponding to an M(2) of 22. We then show that the laser-induced damage threshold of 400-mum core-diameter optical fibers can be increased significantly by a CO(2) laser treatment step following the mechanical polishing routine. This increase in laser-induced damage threshold is sufficient to propagate 25-J, 1-ms laser pulses with a 400-mum core-diameter optical fiber and an output M(2) of 31.

  17. Fiber optic geophysical sensors

    Science.gov (United States)

    Homuth, Emil F.

    1991-01-01

    A fiber optic geophysical sensor in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects.

  18. Fiber optic and laser sensors X; Proceedings of the Meeting, Boston, MA, Sept. 8-11, 1992

    Science.gov (United States)

    Udd, Eric (Editor); Depaula, Ramon P. (Editor)

    1993-01-01

    Topics addressed include acoustic and pressure sensors; fiber optic gyros; electric and magnetic field sensors; bend, strain, and temperature sensors; industrial applications of sensors; and processing techniques. Particular attention is given to fiber optic interferometric acoustic sensors for wind tunnel applications, polished coupler and resonator fabrication, second-harmonic detection for rotation sensing in fiber optic gyros, simplified control theory in closed-loop fiber optic gyroscopes, and a Fabry-Perot sensor with digital signal processing for the measurement of magnetostriction. Also discussed are a Bragg fiber laser sensor, commercialization of fiber optic strain gauge systems, thermal ignition in hazardous environments due to stray light from optical fibers, a system for absolute measurements by interferometric sensors, and high-performance interferometric demodulation techniques.

  19. Fiber optic and laser sensors X; Proceedings of the Meeting, Boston, MA, Sept. 8-11, 1992

    Science.gov (United States)

    Udd, Eric (Editor); Depaula, Ramon P. (Editor)

    1993-01-01

    Topics addressed include acoustic and pressure sensors; fiber optic gyros; electric and magnetic field sensors; bend, strain, and temperature sensors; industrial applications of sensors; and processing techniques. Particular attention is given to fiber optic interferometric acoustic sensors for wind tunnel applications, polished coupler and resonator fabrication, second-harmonic detection for rotation sensing in fiber optic gyros, simplified control theory in closed-loop fiber optic gyroscopes, and a Fabry-Perot sensor with digital signal processing for the measurement of magnetostriction. Also discussed are a Bragg fiber laser sensor, commercialization of fiber optic strain gauge systems, thermal ignition in hazardous environments due to stray light from optical fibers, a system for absolute measurements by interferometric sensors, and high-performance interferometric demodulation techniques.

  20. A fiber optic PD sensor using a balanced Sagnac interferometer and an EDFA-based DOP tunable fiber ring laser.

    Science.gov (United States)

    Wang, Lutang; Fang, Nian; Wu, Chunxu; Qin, Haijuan; Huang, Zhaoming

    2014-05-12

    A novel fiber-optic acoustic sensor using an erbium-doped fiber amplifier (EDFA)-based fiber ring laser and a balanced Sagnac interferometer for acoustic sensing of the partial discharge (PD) in power transformers is proposed and demonstrated. As a technical background, an experimental investigation on how the variations of the fiber birefringence affect the sensor performances was carried out, and the results are discussed. The operation principles are described, and the relevant formulas are derived. The analytical results show that an EDFA-based fiber ring laser operating in chaotic mode can provide a degree of polarization (DOP) tunable light beam for effectively suppressing polarization fading noises. The balanced Sagnac interferometer can eliminate command intensity noises and enhance the signal-to-noise ratio (SNR). Furthermore, it inherently operates at the quadrature point of the response curve without any active stabilizations. Several experiments are conducted for evaluating the performances of the sensor system, as well as for investigating the ability of the detection of high-frequency acoustic emission signals. The experimental results demonstrate that the DOP of the laser beam can be continuously tuned from 0.2% to 100%, and the power fluctuation in the whole DOP tuning range is less than 0.05 dBm. A high-frequency response up to 300 kHz is reached, and the high sensing sensitivity for detections of weak corona discharges, as well as partial discharges also is verified.

  1. A Fiber Optic PD Sensor Using a Balanced Sagnac Interferometer and an EDFA-Based DOP Tunable Fiber Ring Laser

    Directory of Open Access Journals (Sweden)

    Lutang Wang

    2014-05-01

    Full Text Available A novel fiber-optic acoustic sensor using an erbium-doped fiber amplifier (EDFA-based fiber ring laser and a balanced Sagnac interferometer for acoustic sensing of the partial discharge (PD in power transformers is proposed and demonstrated. As a technical background, an experimental investigation on how the variations of the fiber birefringence affect the sensor performances was carried out, and the results are discussed. The operation principles are described, and the relevant formulas are derived. The analytical results show that an EDFA-based fiber ring laser operating in chaotic mode can provide a degree of polarization (DOP tunable light beam for effectively suppressing polarization fading noises. The balanced Sagnac interferometer can eliminate command intensity noises and enhance the signal-to-noise ratio (SNR. Furthermore, it inherently operates at the quadrature point of the response curve without any active stabilizations. Several experiments are conducted for evaluating the performances of the sensor system, as well as for investigating the ability of the detection of high-frequency acoustic emission signals. The experimental results demonstrate that the DOP of the laser beam can be continuously tuned from 0.2% to 100%, and the power fluctuation in the whole DOP tuning range is less than 0.05 dBm. A high-frequency response up to 300 kHz is reached, and the high sensing sensitivity for detections of weak corona discharges, as well as partial discharges also is verified.

  2. A Fiber Optic PD Sensor Using a Balanced Sagnac Interferometer and an EDFA-Based DOP Tunable Fiber Ring Laser

    Science.gov (United States)

    Wang, Lutang; Fang, Nian; Wu, Chunxu; Qin, Haijuan; Huang, Zhaoming

    2014-01-01

    A novel fiber-optic acoustic sensor using an erbium-doped fiber amplifier (EDFA)-based fiber ring laser and a balanced Sagnac interferometer for acoustic sensing of the partial discharge (PD) in power transformers is proposed and demonstrated. As a technical background, an experimental investigation on how the variations of the fiber birefringence affect the sensor performances was carried out, and the results are discussed. The operation principles are described, and the relevant formulas are derived. The analytical results show that an EDFA-based fiber ring laser operating in chaotic mode can provide a degree of polarization (DOP) tunable light beam for effectively suppressing polarization fading noises. The balanced Sagnac interferometer can eliminate command intensity noises and enhance the signal-to-noise ratio (SNR). Furthermore, it inherently operates at the quadrature point of the response curve without any active stabilizations. Several experiments are conducted for evaluating the performances of the sensor system, as well as for investigating the ability of the detection of high-frequency acoustic emission signals. The experimental results demonstrate that the DOP of the laser beam can be continuously tuned from 0.2% to 100%, and the power fluctuation in the whole DOP tuning range is less than 0.05 dBm. A high-frequency response up to 300 kHz is reached, and the high sensing sensitivity for detections of weak corona discharges, as well as partial discharges also is verified. PMID:24824371

  3. High Speed 1.55 μm Lasers for Fiber Optic Transmission

    Science.gov (United States)

    Morton, Paul A.

    This paper describes the essential elements for creating a practical wide bandwidth directly modulated laser source. This includes considerations of the intrinsic limitations of the laser structure, due to the resonant frequency and damping of the laser output, together with carrier transport issues to allow carriers in the device active region to be efficiently modulated at high speeds. The use of a P-doped compressively strained multiple-quantum well active region to provide high intrinsic speed and remove transport limitations is described, together with record setting results of 25 GHz modulation bandwidth for a 1.55 μm Fabry-Perot laser and 26 GHz bandwidth for a 1.55 μm DFB laser. The challenges of providing high bandwidth electrical connections to the laser on a suitable submount, together with fiber attachment and microwave packaging are discussed. Results of fully packaged 1.55 μm DFB lasers with 25 GHz modulation bandwidth are shown. Digital modulation of the packaged 1.55 μm DFB including impedance matching is described, and the transient wavelength chirp is presented. This low chirp is reduced further using an optical filter, to provide a 10 GBit/s source that can transmit error free over 38.5 km of standard optical fiber.

  4. Novel laser machining of optical fibers for long cavities with low birefringence.

    Science.gov (United States)

    Takahashi, Hiroki; Morphew, Jack; Oručević, Fedja; Noguchi, Atsushi; Kassa, Ezra; Keller, Matthias

    2014-12-15

    We present a novel method of machining optical fiber surfaces with a CO₂ laser for use in Fiber-based Fabry-Perot Cavities (FFPCs). Previously FFPCs were prone to large birefringence and limited to relatively short cavity lengths (≤ 200 μm). These characteristics hinder their use in some applications such as cavity quantum electrodynamics with trapped ions. We optimized the laser machining process to produce large, uniform surface structures. This enables the cavities to achieve high finesse even for long cavity lengths. By rotating the fibers around their axis during the laser machining process the asymmetry resulting from the laser's transverse mode profile is eliminated. Consequently we are able to fabricate fiber mirrors with a high degree of rotational symmetry, leading to remarkably low birefringence. Through measurements of the cavity finesse over a range of cavity lengths and the polarization dependence of the cavity linewidth, we confirmed the quality of the produced fiber mirrors for use in low-birefringence FFPCs.

  5. Roof Polishing of Optical Fibers

    Science.gov (United States)

    Dholakia, A. R.

    1985-01-01

    Bevealed tip gives optimum coupling efficiency. Abrasive tape used to grind tip of optical fiber. Grinding force depends on stiffness of optical fiber. "Roof" shape on end of optical glass fiber increases efficiency which couples laser light. End surface angle of 65 degrees with perpendicular required for optimum coupling. Since fiber and tape are light in weight and compliant, ridge defect-free, and chipping on fiber edge totally eliminated.

  6. Fiber optic spanner

    Science.gov (United States)

    Black, Bryan; Mohanty, Samarendra

    2011-10-01

    Rotation is a fundamental function in nano/biotechnology and is being useful in a host of applications such as pumping of fluid flow in microfluidic channels for transport of micro/nano samples. Further, controlled rotation of single cell or microscopic object is useful for tomographic imaging. Though conventional microscope objective based laser spanners (based on transfer of spin or orbital angular momentum) have been used in the past, they are limited by the short working distance of the microscope objective. Here, we demonstrate development of a fiber optic spanner for rotation of microscopic objects using single-mode fiber optics. Fiber-optic trapping and simultaneous rotation of pin-wheel structure around axis perpendicular to fiber-optic axis was achieved using the fiber optic spanner. By adjusting the laser beam power, rotation speed of the trapped object and thus the microfluidic flow could be controlled. Since this method does not require special optical or structural properties of the sample to be rotated, three-dimensional rotation of a spherical cell could also be controlled. Further, using the fiber optic spanner, array of red blood cells could be assembled and actuated to generate vortex motion. Fiber optical trapping and spinning will enable physical and spectroscopic analysis of microscopic objects in solution and also find potential applications in lab- on-a-chip devices.

  7. Fiber-optic temperature sensor using a liquid crystal film for laser-induced interstitial thermotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong-Soo; Tack, Gye-Rae; Chung, Soon-Cheol; Yi, Jeong-Han [Konkuk University, Chungju (Korea, Republic of); Kim, Sin [Cheju National University, Cheju (Korea, Republic of); Cho, Hyo-Sung [Yonsei University, Wonju (Korea, Republic of)

    2005-06-15

    In this paper, we describe the feasibility of developing a new fiber-optic temperature sensor using a thermo-sensitive liquid crystal (LC) film for laser-induced interstitial thermotherapy (LITT). The temperature change in the tissue or the tumor causes the color of the LC film in contacted with the tissue to change, and that change alters the reflectivity of the LC film. The light with a selected wavelength that is transmitted to the LC film and the optical power of the reflected light are measured using transmitting and receiving optical fibers, respectively. Also, the relationship between the temperature and the optical power of reflected light is determined using the characteristics of the LC films.

  8. Optical Coupling Structures of Fiber-Optic Mach-Zehnder Interferometers Using CO2 Laser Irradiation

    Directory of Open Access Journals (Sweden)

    Chien-Hsing Chen

    2014-01-01

    Full Text Available The Mach-Zehnder interferometer (MZI can be used to test changes in the refractive index of sucrose solutions at different concentrations. However, the popularity of this measurement tool is limited by its substantial size and portability. Therefore, the MZI was integrated with a small fiber-optic waveguide component to develop an interferometer with fiber-optic characteristics, specifically a fiber-optic Mach-Zehnder interferometer (FO-MZI. Optical fiber must be processed to fabricate two optical coupling structures. The two optical coupling structures are a duplicate of the beam splitter, an optical component of the interferometer. Therefore, when the sensor length and the two optical coupling structures vary, the time or path for optical transmission in the sensor changes, thereby influencing the back-end interference signals. The researchers successfully developed an asymmetrical FO-MZI with sensing abilities. The spacing value between the troughs of the sensor length and interference signal exhibited an inverse relationship. In addition, image analysis was employed to examine the size-matching relationship between various sensor lengths and the coupling and decoupling structure. Furthermore, the spectral wavelength shift results measured using a refractive index sensor indicate that FO-MZIs with a sensor length of 38 mm exhibited excellent sensitivity, measuring 59.7 nm/RIU.

  9. The feasibility of a fiber optic laser approach to relieving lymphedematous syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Palmieri B

    2013-02-01

    Full Text Available Beniamino Palmieri,1,2 Alessandro Di Cerbo,1,2 Valentina Rottigni,1,2 Gregorio Fistetto,2 Tommaso Iannitti2,31University of Modena, Department of General Surgery and Surgical Specialties, 2Poliambulatorio del Secondo Parere, Modena, Italy; 3University of Kentucky, Department of Physiology, Lexington, KY, USAAbstract: Here we report a case of successful fiber optic laser treatment of lymphedema in a swollen arm post mastectomy. At the moment, this procedure has only anecdotal evidence to justify its use, but in our experience is a feasible, minimally invasive day-stay procedure which has been demonstrated to be safe and effective. Further nonhomogeneous case pooling and follow-up would enable guidelines and definite surgical protocols for its use to be implemented.Keywords: fiber optic, lymphedema, Nd:YAG, laser, mastectomy

  10. Microfluidic cell counter with embedded optical fibers fabricated by femtosecond laser ablation and anodic bonding.

    Science.gov (United States)

    Schafer, Dawn; Gibson, Emily A; Salim, Evan A; Palmer, Amy E; Jimenez, Ralph; Squier, Jeff

    2009-04-13

    A simple fabrication technique to create all silicon/glass microfluidic devices is demonstrated using femtosecond laser ablation and anodic bonding. In a first application, we constructed a cell counting device based on small angle light scattering. The counter featured embedded optical fibers for multiangle excitation and detection of scattered light and/or fluorescence. The performance of the microfluidic cell counter was benchmarked against a commercial fluorescence-activated cell sorter.

  11. Characterization of novel microsphere chain fiber optic tips for potential use in ophthalmic laser surgery

    Science.gov (United States)

    Hutchens, Thomas C.; Darafsheh, Arash; Fardad, Amir; Antoszyk, Andrew N.; Ying, Howard S.; Astratov, Vasily N.; Fried, Nathaniel M.

    2012-06-01

    Ophthalmic surgery may benefit from use of more precise fiber delivery systems during laser surgery. Some current ophthalmic surgical techniques rely on tedious mechanical dissection of tissue layers. In this study, chains of sapphire microspheres integrated into a hollow waveguide distal tip are used for erbium:YAG laser ablation studies in contact mode with ophthalmic tissues, ex vivo. The laser's short optical penetration depth combined with the small spot diameters achieved with this fiber probe may provide more precise tissue removal. One-, three-, and five-microsphere chain structures were characterized, resulting in FWHM diameters of 67, 32, and 30 μm in air, respectively, with beam profiles comparable to simulations. Single Er:YAG pulses of 0.1 mJ and 75-μs duration produced ablation craters with average diameters of 44, 30, and 17 μm and depths of 26, 10, and 8 μm, for one-, three-, and five-sphere structures, respectively. Microsphere chains produced spatial filtering of the multimode Er:YAG laser beam and fiber, providing spot diameters not otherwise available with conventional fiber systems. Because of the extremely shallow treatment depth, compact focused beam, and contact mode operation, this probe may have potential for use in dissecting epiretinal membranes and other ophthalmic tissues without damaging adjacent retinal tissue.

  12. Characterization of novel microsphere chain fiber optic tips for potential use in ophthalmic laser surgery.

    Science.gov (United States)

    Hutchens, Thomas C; Darafsheh, Arash; Fardad, Amir; Antoszyk, Andrew N; Ying, Howard S; Astratov, Vasily N; Fried, Nathaniel M

    2012-06-01

    Ophthalmic surgery may benefit from use of more precise fiber delivery systems during laser surgery. Some current ophthalmic surgical techniques rely on tedious mechanical dissection of tissue layers. In this study, chains of sapphire microspheres integrated into a hollow waveguide distal tip are used for erbium:YAG laser ablation studies in contact mode with ophthalmic tissues, ex vivo. The laser's short optical penetration depth combined with the small spot diameters achieved with this fiber probe may provide more precise tissue removal. One-, three-, and five-microsphere chain structures were characterized, resulting in FWHM diameters of 67, 32, and 30 μm in air, respectively, with beam profiles comparable to simulations. Single Er:YAG pulses of 0.1 mJ and 75-μs duration produced ablation craters with average diameters of 44, 30, and 17 μm and depths of 26, 10, and 8 μm, for one-, three-, and five-sphere structures, respectively. Microsphere chains produced spatial filtering of the multimode Er:YAG laser beam and fiber, providing spot diameters not otherwise available with conventional fiber systems. Because of the extremely shallow treatment depth, compact focused beam, and contact mode operation, this probe may have potential for use in dissecting epiretinal membranes and other ophthalmic tissues without damaging adjacent retinal tissue.

  13. Fiber Optically Coupled Eyesafe Laser Threat Warning System

    Science.gov (United States)

    2000-05-11

    LIGHTWEIGHT, MUST BE CONFORMAL TO AIRCRAFT SKIN, MUST HAVE A HIGH DEGREE OF RFI/EMI INMUNITY AND SHOULD BE LOW COST. PERFORMANCE REQUIREMENTS SIMILAR...CONTINUOUS) LARGE OPTICAL DYNAMIC RANGES (60-70 dB) DEMONSTRATED WITH LARGE TEMPORAL BANDWIDTHS RFI/EMI IMMUNITY ACHIEVED WITH 100% PASSIVE OPTICAL

  14. Glass-ceramic optical fiber containing Ba2TiSi2O8 nanocrystals for frequency conversion of lasers

    Science.gov (United States)

    Fang, Zaijin; Xiao, Xusheng; Wang, Xin; Ma, Zhijun; Lewis, Elfed; Farrell, Gerald; Wang, Pengfei; Ren, Jing; Guo, Haitao; Qiu, Jianrong

    2017-01-01

    A glass-ceramic optical fiber containing Ba2TiSi2O8 nanocrystals fabricated using a novel combination of the melt-in-tube method and successive heat treatment is reported for the first time. For the melt-in-tube method, fibers act as a precursor at the drawing temperature for which the cladding glass is softened while the core glass is melted. It is demonstrated experimentally that following heat treatment, Ba2TiSi2O8 nanocrystals with diameters below 10 nm are evenly distributed throughout the fiber core. Comparing to the conventional rod-in-tube method, the melt-in-tube method is superior in terms of controllability of crystallization to allow for the fabrication of low loss glass-ceramic fibers. When irradiated using a 1030 nm femtosecond laser, an enhanced green emission at a wavelength of 515 nm is observed in the glass-ceramic fiber, which demonstrates second harmonic generation of a laser action in the fabricated glass-ceramic fibers. Therefore, this new glass-ceramic fiber not only provides a highly promising development for frequency conversion of lasers in all optical fiber based networks, but the melt-in-tube fabrication method also offers excellent opportunities for fabricating a wide range of novel glass-ceramic optical fibers for multiple future applications including fiber telecommunications and lasers. PMID:28358045

  15. High-resolution flying-PIV with optical fiber laser delivery

    Science.gov (United States)

    Weichselbaum, Noah A.; André, Matthieu A.; Rahimi-Abkenar, Morteza; Manzari, Majid T.; Bardet, Philippe M.

    2016-05-01

    Implementation of non-intrusive optical measurement techniques, such as particle image velocimetry (PIV), in harsh environments requires specialized techniques for introducing controlled laser sheets to the region of interest. Large earthquake shake tables are a particularly challenging environment. Lasers must be mounted away from the table, and the laser sheet has to be delivered precisely and stably to the measurement station. Here, high-power multi-mode step-index fiber optics enable introduction of light from an Nd:YLF pulsed laser to a remote test section. Such lasers are suitable for coupling to optical fibers, which presents a portable, flexible, and safe manner to deliver a PIV light sheet. Best practices for their implementation are reviewed. Particular attention is focused on obtaining a collimated beam of acceptable quality at the output of the fiber. To achieve high spatial resolution, the PIV camera is directly mounted on the moving shake table with care to minimize its vibrations. A special arrangement of PIV planes is deployed for precise in-situ PIV alignment and to monitor and account for residual structure vibrations and beam wandering. The design of the instruments is detailed. Here, an experimental facility for the study of nuclear fuel bundle response to seismic forcing near prototypical conditions is instrumented. Only through integration of a high-resolution flying-PIV system can velocity fields be acquired. Data indicate that in the presence of a mean axial flow, a secondary oscillatory flow develops as the bundle oscillates. Instantaneous, phase-averaged, and fluctuating velocity fields illustrate this phenomenon.

  16. Recent developments in laser-driven and hollow-core fiber optic gyroscopes

    Science.gov (United States)

    Digonnet, M. J. F.; Chamoun, J. N.

    2016-05-01

    Although the fiber optic gyroscope (FOG) continues to be a commercial success, current research efforts are endeavoring to improve its precision and broaden its applicability to other markets, in particular the inertial navigation of aircraft. Significant steps in this direction are expected from the use of (1) laser light to interrogate the FOG instead of broadband light, and (2) a hollow-core fiber (HCF) in the sensing coil instead of a conventional solid-core fiber. The use of a laser greatly improves the FOG's scale-factor stability and eliminates the source excess noise, while an HCF virtually eliminates the Kerr-induced drift and significantly reduces the thermal and Faraday-induced drifts. In this paper we present theoretical evidence that in a FOG with a 1085-m coil interrogated with a laser, the two main sources of noise and drift resulting from the use of coherent light can be reduced below the aircraft-navigation requirement by using a laser with a very broad linewidth, in excess of 40 GHz. We validate this concept with a laser broadened with an external phase modulator driven with a pseudo-random bit sequence at 2.8 GHz. This FOG has a measured noise of 0.00073 deg/√h, which is 30% below the aircraft-navigation requirement. Its measured drift is 0.03 deg/h, the lowest reported for a laser-driven FOG and only a factor of 3 larger than the navigation-grade specification. To illustrate the potential benefits of a hollow-core fiber in the FOG, this review also summarizes the previously reported performance of an experimental FOG utilizing 235 m of HCF and interrogated with broadband light.

  17. Delivery of 10-MW Nd:YAG laser pulses by large-core optical fibers: Dependence of the laser-intensity profile on beam propagation

    Energy Technology Data Exchange (ETDEWEB)

    Richou, B.; Richou, J. [Laboratoire d` Optoelectronique, Faculte des Sciences, Universite de Toulon et du Var, BP 132, La Garde 83957 (France); Schertz, I.; Gobin, I. [Commissariat a l`Energie Atomique/Vaujours, Moronvilliers, BP 7, Courtry 77181 (France)

    1997-03-01

    A large-core multimode optical fiber of a few meters length is studied as a 10-MW beam delivery system for a 15-ns pulsed Nd:YAG laser. A laser-to-fiber vacuum coupler is used to inhibit air breakdown and reduce the probability of dielectric breakdown on the fiber front surface. Laser-induced damage inside the fiber core is observed behind the fiber front surface. An explanation based on a high power density is illustrated by a ray trace. Damaged spots and measurements of fiber output energies are reported for two laser beam distributions: a flat-hat type and a near-Gaussian type. Experiments have been performed to deliver a 100-pulse mean energy between 100 and 230 mJ without catastrophic damage. {copyright} 1997 Optical Society of America

  18. Fiber optic laser Doppler anemometry in swirling jets

    Science.gov (United States)

    Taghavi, R.; Rice, E. J.

    1991-01-01

    Time-averaged and fluctuating quantities are measured in a free turbulent swirling jet. Data from a two-component laser Doppler anemometry (LDA) are compared to the measurements via hot-wire and 5-hole pitot probes. To acquire the proper seeding density near the axis of a swirling jet for LDA measurements proved difficult. This is due to an imbalance of the centrifugal force and radial pressure gradient, which throws the seeding material off the axis. Despite this problem, close agreement between various measurement techniques is obtained.

  19. Bragg grating photo-inscription in doped microstructured polymer optical fiber by 400 nm femtosecond laser pulses

    DEFF Research Database (Denmark)

    Hu, X.; Woyessa, Getinet; Kinet, D.;

    2016-01-01

    In this paper, we report the manufacturing of high-quality endlessly single-mode doped microstructured poly(methyl methacrylate) (PMMA) optical fibers. Bragg gratings are photo-inscribed in such fibers by means of 400 nm femtosecond laser pulses through a 1060-nm-period uniform phase mask...

  20. Vector Soliton Fiber Lasers

    CERN Document Server

    Zhang, Han

    2011-01-01

    Solitons, as stable localized wave packets that can propagate long distance in dispersive media without changing their shapes, are ubiquitous in nonlinear physical systems. Since the first experimental realization of optical bright solitons in the anomalous dispersion single mode fibers (SMF) by Mollenauer et al. in 1980 and optical dark solitons in the normal dispersion SMFs by P. Emplit et al. in 1987, optical solitons in SMFs had been extensively investigated. In reality a SMF always supports two orthogonal polarization modes. Taking fiber birefringence into account, it was later theoretically predicted that various types of vector solitons, including the bright-bright vector solitons, dark-dark vector solitons and dark-bright vector solitons, could be formed in SMFs. However, except the bright-bright type of vector solitons, other types of vector solitons are so far lack of clear experimental evidence. Optical solitons have been observed not only in the SMFs but also in mode locked fiber lasers. It has be...

  1. Fiber laser development for LISA

    Energy Technology Data Exchange (ETDEWEB)

    Numata, Kenji [Department of Astronomy, University of Maryland, College Park, Maryland, 20742 (United States); Chen, Jeffrey R [NASA Goddard Space Flight Center, Laser and electro-optics branch, Code 554, Greenbelt, Maryland, 20771 (United States); Camp, Jordan, E-mail: kenji.numata@nasa.go [NASA Goddard Space Flight Center, Gravitational astrophysics branch, Code 663, Greenbelt, Maryland, 20771 (United States)

    2010-05-01

    We have developed a linearly-polarized Ytterbium-doped fiber ring laser with single longitudinal-mode output at 1064 nm for LISA and other space applications. Single longitudinal-mode selection was achieved by using a fiber Bragg grating (FBG) and a fiber Fabry-Perot (FFP). The FFP also serves as a frequency-reference within our ring laser. Our laser exhibits comparable low frequency and intensity noise to Non-Planar Ring Oscillator (NPRO). By using a fiber-coupled phase modulator as a frequency actuator, the laser frequency can be electro-optically tuned at a rate of 100 kHz. It appears that our fiber ring laser is promising for space applications where robustness of fiber optics is desirable.

  2. Fiber laser development for LISA

    CERN Document Server

    Numata, Kenji; Camp, Jordan

    2010-01-01

    We have developed a linearly-polarized Ytterbium-doped fiber ring laser with single longitudinal-mode output at 1064nm for LISA and other space applications. Single longitudinal-mode selection was achieved by using a fiber Bragg grating (FBG) and a fiber Fabry-Perot (FFP). The FFP also serves as a frequency-reference within our ring laser. Our laser exhibits comparable low frequency and intensity noise to Non-Planar Ring Oscillator (NPRO). By using a fiber-coupled phase modulator as a frequency actuator, the laser frequency can be electro-optically tuned at a rate of 100kHz. It appears that our fiber ring laser is promising for space applications where robustness of fiber optics is desirable.

  3. Fiber Laser Development for LISA

    Science.gov (United States)

    Numata, Kenji; Chen, Jeffrey R.

    2009-01-01

    We have developed a linearly-polarized Ytterbium-doped fiber ring laser with single longitudinal-mode output at 1064nm for LISA and other space applications. Single longitudinal-mode selection was achieved by using a fiber Bragg grating (FBG) and a fiber Fabry-Perot (FFP). The FFP also serves as a frequency-reference within our ring laser. Our laser exhibits comparable low frequency and intensity noise to Non-Planar Ring Oscillator (NPRO). By using a fiber-coupled phase modulator as a frequency actuator, the laser frequency can be electro-optically tuned at a rate of 100kHz. It appears that our fiber ring laser is promising for space applications where robustness of fiber optics is desirable.

  4. Optical Material Researches for Frontier Optical Ceramics and Visible Fiber Laser Technologies

    Science.gov (United States)

    2016-07-07

    AM2A.2, 27 October - 01 November 2013, Paris Marriott Rive Gauche Hotel and Convention Center, Paris, France. 2) “ Development on advanced functional...DISTRIBUTION/AVAILABILITY STATEMENT A DISTRIBUTION UNLIMITED: PB Public Release 13. SUPPLEMENTARY NOTES 14. ABSTRACT We have successfully developed a new...are very useful for scientific and industrial applications. 15. SUBJECT TERMS Fibre Lasers, Laser Dynamics, Nonlinear Optical Materials 16. SECURITY

  5. Femtosecond Fiber Lasers

    Science.gov (United States)

    Bock, Katherine J.

    This thesis focuses on research I have done on ytterbium-doped femtosecond fiber lasers. These lasers operate in the near infrared region, lasing at 1030 nm. This wavelength is particularly important in biomedical applications, which includes but is not limited to confocal microscopy and ablation for surgical incisions. Furthermore, fiber lasers are advantageous compared to solid state lasers in terms of their cost, form factor, and ease of use. Solid state lasers still dominate the market due to their comparatively high energy pulses. High energy pulse generation in fiber lasers is hindered by either optical wave breaking or by multipulsing. One of the main challenges for fiber lasers is to overcome these limitations to achieve high energy pulses. The motivation for the work done in this thesis is increasing the output pulse peak power and energy. The main idea of the work is that decreasing the nonlinearity that acts on the pulse inside the cavity will prevent optical wave breaking, and thus will generate higher energy pulses. By increasing the output energy, ytterbium-doped femtosecond fiber lasers can be competitive with solid state lasers which are used commonly in research. Although fiber lasers tend to lack the wavelength tuning ability of solid state lasers, many biomedical applications take advantage of the 1030 microm central wavelength of ytterbium-doped fiber lasers, so the major limiting factor of fiber lasers in this field is simply the output power. By increasing the output energy without resorting to external amplification, the cavity is optimized and cost can remain low and economical. During verification of the main idea, the cavity was examined for possible back-reflections and for components with narrow spectral bandwidths which may have contributed to the presence of multipulsing. Distinct cases of multipulsing, bound pulse and harmonic mode-locking, were observed and recorded as they may be of more interest in the future. The third

  6. Coherent combining of fiber-laser-pumped frequency converters using all fiber electro-optic modulator for active phase control

    Science.gov (United States)

    Bourdon, P.; Durécu, A.; Canat, G.; Le Gouët, J.; Goular, D.; Lombard, L.

    2015-03-01

    Coherent beam combining (CBC) by active phase control could be useful for power scaling fiber-laser-pumped optical frequency converters like OPOs. However, a phase modulator operating at the frequency-converted wavelength is needed, which is non standard component. Fortunately, nonlinear conversion processes rely on a phase-matching condition correlating, not only the wave vectors of the coupled waves, but also their phases. This paper demonstrates that, using this phase correlation for indirect control of the phase, coherent combining of optical frequency converters is feasible using standard all-fibered electro-optic modulators. For the sake of demonstration, this new technique is experimentally applied twice for continuous wave second-harmonic-generator (SHG) combination: i) combining 2 SHG of 1.55-μm erbium-doped fiber amplifiers in PPLN crystals generating 775-nm beams; ii) combining 2 SHG of 1.064-μm ytterbium-doped fiber amplifiers in LBO crystals generating 532-nm beams. Excellent CBC efficiency is achieved on the harmonic waves in both these experiments, with λ/20 and λ/30 residual phase error respectively. In the second experiment, I/Q phase detection is added on fundamental and harmonic waves to measure their phase variations simultaneously. These measurements confirm the theoretical expectations and formulae of correlation between the phases of the fundamental and harmonic waves. Unexpectedly, in both experiments, when harmonic waves are phase-locked, a residual phase difference remains between the fundamen tal waves. Measurements of the spectrum of these residual phase differences locate them above 50 Hz, revealing that they most probably originate in fast-varying optical path differences induced by turbulence and acoustic-waves on the experimental breadboard.

  7. Dual-frequency Brillouin fiber laser for optical generation of tunable low-noise radio frequency/microwave frequency.

    Science.gov (United States)

    Geng, Jihong; Staines, Sean; Jiang, Shibin

    2008-01-01

    We demonstrate a new approach, i.e., a cw dual-frequency Brillouin fiber laser pumped by two independent single-frequency Er-doped fiber lasers, for the generation of tunable low-noise rf/microwave optical signals. Its inherent features of both linewidth narrowing effect in a Brillouin fiber cavity and common mode noise cancellation between two laser modes sharing a common cavity allow us to achieve high frequency stability without using a supercavity. Beat frequency of the dual-frequency Brillouin fiber laser can be tuned from tens of megahertz up to 100 GHz by thermally tuning the wavelengths of the two pump lasers with tuning sensitivity of approximately 1.4 GHz/ degrees C. Allan variance measurements show the beat signals have the hertz-level frequency stability.

  8. Four-Wave Mixing of a Laser and Its Frequency-Doubled Version in a Multimode Optical Fiber

    Directory of Open Access Journals (Sweden)

    Hamed Pourbeyram

    2015-08-01

    Full Text Available It is shown that it is possible to couple a laser beam and its frequency-doubled daughter into a multimode optical fiber through the four-wave mixing nonlinear process and generate a new wavelength. The frequency-doubled daughter can be generated in an external crystal with a large second order nonlinearity. It is argued that while this possibility is within the design parameter range of conventional multimode optical fibers, it necessitates a lower-bound for the core-cladding refractive index contrast of the multimode optical fiber.

  9. Ultrahigh resolution optical coherence tomography with femtosecond Ti:sapphire laser and photonic crystal fiber

    Institute of Scientific and Technical Information of China (English)

    XUE Ping; James G FUJIMOTO

    2008-01-01

    Optical coherence tomography (OCT) with ultrahigh axial resolution was achieved by the super-contin- uum generated by coupling femtosecond pulses from a commercial Ti :sapphire laser into an air-silica microstructure fiber. The visible spectrum of the super-continuum from 450 to 700 nm centered at 540 nm can be generated. A free-space axial OCT resolution of 0.64 IJm was achieved. The sensitivity of OCT system was 108 dB with incident light power 3 mW at sample, only 7dB below the theoretical limit. Subcellular OCT imaging was also demonstrated, showing great potential for biomedical application.

  10. Fiber-optic laser-Doppler anemometer microscope applied to the cerebral microcirculation in rats.

    Science.gov (United States)

    Seki, J; Sasaki, Y; Oyama, T; Yamamoto, J

    1996-01-01

    We have applied our developed fiber-optic laser-Doppler anemometer microscope (FLDAM) for the study of the cerebral microcirculation in the rat. The red cell velocity in single pial microvessels was successfully measured through a closed cranial window for the vessel diameter range from 7.8 to 230 microns. The temporal resolution of the FLDAM was sufficiently high to detect the pulsation in the arterioles. Arterio-venous distributions of the temporal mean red cell velocity and wall shear rate are also described.

  11. Delivery of 10-MW Nd:YAG laser pulses by large-core optical fibers: dependence of the laser-intensity profile on beam propagation.

    Science.gov (United States)

    Richou, B; Schertz, I; Gobin, I; Richou, J

    1997-03-01

    A large-core multimode optical fiber of a few meters length is studied as a 10-MW beam delivery system for a 15-ns pulsed Nd:YAG laser. A laser-to-fiber vacuum coupler is used to inhibit air breakdown and reduce the probability of dielectric breakdown on the fiber front surface. Laser-induced damage inside the fiber core is observed behind the fiber front surface. An explanation based on a high power density is illustrated by a ray trace. Damaged spots and measurements of fiber output energies are reported for two laser beam distributions: a flat-hat type and a near-Gaussian type. Experiments have been performed to deliver a 100-pulse mean energy between 100 and 230 mJ without catastrophic damage.

  12. Optically induced mode conversion in graded-index fibers using ultra-short laser pulses

    CERN Document Server

    Hellwig, Tim; Fallnich, Carsten

    2013-01-01

    We propose the use of graded-index few-mode fibers for mode-conversion by long-period gratings (LPG) transiently written by ultrashort laser pulses using the optical Kerr effect. The mode inter- action is studied by numerically solving the multi-mode coupled nonlinear Schroedinger equations. We present highly efficient conversion of the LP 01 - into the LP 11 -mode preserving the pulse shape in contrast to previous results in step-index fibers. Furthermore, mode conversion using different wavelengths for inducing and probing the LPG is shown. Due to the flat phase-matching curve of the examined modes in the graded-index fiber, mode-conversion can be observed for probe center wavelengths of 1100nm up to 1800nm with a write beam centered around 1030nm. Therefore, a complete separation of the probe from the write beam should be possible as well as the application of optically induced guided mode conversion for all optical modulation across a broad wavelength range.

  13. Comparison of LASER and LED illumination for fiber optic fringe projection

    Science.gov (United States)

    Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

    2016-04-01

    The inspection of functional elements is a crucial part of modern production cycles. However, with higher integration of production machinery and products, the accessibility for measurement systems is more and more limited. A solution for this problem can be found in endoscopy techniques, which are able to transport the image information for optical measurement methods. In this paper, an optical inspection system based on the fringe projection profilometry technique is presented. The fiber-optic fringe projection system uses two high-resolution image fibers to connect a compact sensor head to the pattern generation and camera unit. In order to keep inspection times low, the system is developed with particular focus on fast projection times. This can be achieved by using a digital micro-mirror device, which is capable of projecting grey-scale patterns at a rate of more than 10 images per second. However, due to the low numerical aperture of the optical fibers, a limiting factor for the pattern rate is the illumination path of the pattern generator. Two different designs of the illumination path are presented, which are based on a LASER light source as well as a LED light source. Due to low beam divergence and high intensities LASERs are well suited for fiber coupling. Unfortunately, the coherent property of the light has negative effects in certain measurement applications, as interference patterns, the so called speckle, appear on rough surfaces. Although speckle reducing methods are employed in the LASER beam path, the emergence of interference cannot be prevented completely. As an alternative, an illumination path based on a LED light source is demonstrated. To compare the effects of the speckle, based on measurements on a planar calibration standard both designs are compared in terms of phase noise, which is directly related to the noise in the reconstructed 3-D point data. Additionally, optical power measurements of both methods are compared to give an

  14. Fiber Transmission Stabilization by Optical Heterodyning Techniques and Synchronization of Mode-Locked Lasers Using Two Spectral Lines

    CERN Document Server

    Staples, J W

    2005-01-01

    Stabilization of the transit time through a glass fiber using an optical heterodyne technique promises to provide jitter reduction down to the few femtosecond level using inexpensive commodity hardware. An acousto-optical frequency shifter provides the optical frequency offset that is used to downconvert phase shifts at optical frequency to equivalent phase shifts at radio frequency which are used to close a phase-lock loop driving a piezoelectric phase shifter. Using the stabilized fiber transmission medium, two spectral lines of a mode locked laser lock two low-power CW lasers which are transmitted to a receiver which phase locks the same spectral lines of a second mode-locked laser to the first. The optical transmission system operates at low power and is linear, providing excellent signal-to-noise ratio and allows many signals to be transmitted without mutual interference. Experimental results will be presented.

  15. Wideband digitally tunable lasers based on fiber Bragg grating external cavity array and 1×N optical switch

    Institute of Scientific and Technical Information of China (English)

    Haiwen Cai(蔡海文); Jianxin Geng(耿建新); Zuoren Dong(董作人); Gaoting Chen(陈高庭); Zujie Fang(方祖捷)

    2003-01-01

    A novel wideband digitally tunable laser based on fiber Bragg grating external cavities and 1 × N optical switch provides 5 ms fast tuning time with output power more than 1 dBm over whole C-band that is only limited by the laser emission bandwidth. Less than 50 pm wavelength drift over -10 to 55℃ temperature range make that the wavelength locker and monitor are not necessary in this tunable laser.

  16. Nanostructuring an erbium local environment inside sol-gel silica glasses: toward efficient erbium optical fiber lasers

    Science.gov (United States)

    Savelii, Inna; El Hamzaoui, Hicham; Bigot, Laurent; Bouwmans, Géraud; Fsaifes, Ihsan; Capoen, Bruno; Bouazaoui, Mohamed

    2016-02-01

    To extend the use of erbium- (Er-)/aluminum- (Al-) codoped optical fibers in hostile environments, the reduction of the Al amount has been identified as a serious way to harden them against harsh radiation. In this work, sol-gel monolithic Er3+-doped and Er3+/Al3+-codoped silica glasses were prepared from nanoporous silica xerogels soaked in a solution containing an Er salt together or not with an Al salt. After sintering, these glasses were used as the core material of microstructured optical fibers made by the stack-and-draw method. The influence of Al incorporation on the optical properties of Er3+-doped silica glasses and fibers is investigated. This approach enabled the preparation of silica glasses containing dispersed Er3+ ions with low Al content. The obtained fibers have been tested in an all-fibered cavity laser architecture. The Er3+/Al3+-codoped fiber laser presents a maximum efficiency of 27% at 1530 nm. We show that without Al doping, the laser exhibits lower performances that depend on Er content inside the doped fiber core. The effect of Er pair-induced quenching also has been investigated through nonsaturable absorption experiments, which clearly indicate that the fraction of Er ion pairs is significantly reduced in the Al-codoped fiber.

  17. Fiber optic and laser sensors VIII; Proceedings of the Meeting, San Jose, CA, Sept. 17-19, 1990

    Science.gov (United States)

    Depaula, Ramon P. (Editor); Udd, Eric (Editor)

    1991-01-01

    This issue presents topics on the advances in fiber-optic sensor technology, fiber-optic gyroscope, fiber-optic position and pressure sensors, fiber-optic magnetic and temperature sensors, and generic fiber-optic sensors. Papers included are on a novel analog phase tracker for interferometric fiber-optic sensor applications, recent development status of fiber-optic sensors in China, the magnetic-field sensitivity of depolarized fiber-optic gyros, a depolarized fiber-optic gyro for future tactical applications, fiber-optic position transducers for aircraft controls, and a metal embedded optical-fiber pressure sensor. Attention is also given to a fiber-optic magnetic field sensor using spectral modulation encoding, a bare-fiber temperature sensor, an interferometric fiber-optic accelerometer, improvement of specular reflection pyrometer, a theoretical analysis of two-mode elliptical-core optical fiber sensors, and a fiber probe for ring pattern.

  18. Generating 2 micron continuous-wave ytterbium-doped fiber laser-based optical parametric effect

    Science.gov (United States)

    Paul, M. C.; Latiff, A. A.; Hisyam, M. B.; Rusdi, M. F. M.; Harun, S. W.

    2016-10-01

    We report an efficient method for generating a 2 micron laser based on an optical parametric oscillator (OPO). It uses a long piece of a newly developed double-clad ytterbium-doped fiber (YDF), which is obtained by doping multi-elements of ZrO2, CeO2 and CaO in a phospho-alumina-silica glass as a gain medium. The efficient 2 micron laser generation is successful due to the presence of partially crystalline Yb-doped ZrO2 nano-particles that serve as a nonlinear material in a linear cavity configuration and high watt-level pump power. Stable self-wavelength double lasing at 2122 nm with an efficiency of 7.15% is successfully recorded. At a maximum pump power of 4.1 W, the output power is about 201 mW.

  19. Optical fiber synaptic sensor

    Science.gov (United States)

    Pisarchik, A. N.; Jaimes-Reátegui, R.; Sevilla-Escoboza, R.; García-Lopez, J. H.; Kazantsev, V. B.

    2011-06-01

    Understanding neuron connections is a great challenge, which is needed to solve many important problems in neurobiology and neuroengineering for recreation of brain functions and efficient biorobotics. In particular, a design of an optical synapse capable to communicate with neuron spike sequences would be crucial to improve the functionality of neuromimmetic networks. In this work we propose an optical synaptic sensor based on an erbium-doped fiber laser driven by a FitzHung-Nagumo electronic neuron, to connect with another electronic neuron. Two possible optical synaptic configurations are analyzed for optoelectronic coupling between neurons: laser cavity loss modulation and pump laser modulation. The control parameters of the proposed optical synapse provide additional degrees of flexibility to the neuron connection traditionally controlled only by coupling strengths in artificial networks.

  20. Multiwavelength Erbium-doped fiber laser employing nonlinear polarization rotation in a symmetric nonlinear optical loop mirror.

    Science.gov (United States)

    Tian, Jiajun; Yao, Yong; Sun, Yunxu; Yu, Xuelian; Chen, Deying

    2009-08-17

    A new multiwavelength Erbium-doped fiber laser is proposed and demonstrated. The intensity-dependent loss induced by nonlinear polarization rotation in a power-symmetric nonlinear optical loop mirror (NOLM) suppresses the mode competition of an Erbium-doped fiber and ensures stable multiwavelength operation at room temperature. The polarization state and its evolution conditions for stable multiwavelength operation in the ring laser cavity are discussed. The number and spectra region of output wavelength can be controlled by adjusting the work states of NOLM. (c) 2009 Optical Society of America

  1. Generation of 8-nJ pulses from a dissipative-soliton fiber laser with a nonlinear optical loop mirror

    Science.gov (United States)

    Zhao, L. M.; Bartnik, A. C.; Tai, Q. Q.; Wise, F. W.

    2013-01-01

    Theoretical and experimental investigations of the behavior of normal-dispersion fiber lasers with nonlinear-optical loop mirrors are presented. The use of a loop mirror causes the laser to generate relatively long, flat-topped pulses. The pulse energy can be high, but the pulse duration is limited to greater than 300 fs. Experimentally, 8-nJ pulses that can be dechirped to 340 fs duration are obtained. The laser is a step toward an all-fiber, environmentally-stable design. PMID:23722797

  2. An actively Q-switched single-longitudinal-mode fiber laser with an optically pumped saturable absorber

    Science.gov (United States)

    Yun, Hyo-Geun; Lee, Seoung Hun; Lee, Min Hee; Kim, Kyong Hon

    2013-09-01

    We have demonstrated an actively Q-switched single-longitudinal-mode (SLM) erbium-doped fiber (EDF) ring laser by using an EDF saturable absorber modulated under an external laser pulse injection. A laser output of 1531.9 nm wavelength from a distributed-feedback laser diode was amplified with an EDF amplifier and modulated with an external electro-optical modulator, and the modulated signals were used as control pulses to saturate the EDF saturable absorber for the actively Q-switched ring-type fiber laser operation. Actively Q-switched 1542 nm wavelength laser pulses of 4.5 nJ pulse energy and of 4.0μs pulse width were achieved at a repetition rate of 100 Hz. When the Q-switched laser pulse energy was reduced to about 0.54 nJ by decreasing the gain-pump power used for exciting the ring cavity and the control-pulse beam power used for bleaching out the saturable absorber, the SLM laser pulses were achieved. Further improvement of the Q-switched SLM laser pulse output can be achieved simply by using an external laser amplifier and by shortening the cavity length with short pigtailed-fiber laser components, and thus the SLM laser pulses can be useful for various applications.

  3. Experimental Results of the Superluminescent Fiber Laser Sources for Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    E. F. Pinzón-Escobar

    2012-03-01

    Full Text Available We are presenting experimental work on an erbium-doped fiber operating in the superluminescent regime. Experimental results for different pump power levels and fiber length show that the theoretical and numerical model could render useful information for predicting the total output power as a function of fiber doped length and the input pump power. These types of sources could have direct application in wavelength multiplexed arrangements of fiber sensors, fiber gyroscopes or, in general, in any sensors in which a broad wavelength and stable light source is required.

  4. Long-cavity all-fiber ring laser actively mode locked with an in-fiber bandpass acousto-optic modulator.

    Science.gov (United States)

    Cuadrado-Laborde, C; Bello-Jiménez, M; Díez, A; Cruz, J L; Andrés, M V

    2014-01-01

    We demonstrate low-frequency active mode locking of an erbium-doped all-fiber ring laser. As the mode locker, we used a new in-fiber bandpass acousto-optic modulator showing 74% modulation depth, 3.7 dB power insertion losses, 4.5 nm of optical bandwidth, and 20 dB of nonresonant light suppression. The laser generates 330 ps mode-locked pulses over a 10 ns pedestal, at a 1.538 MHz frequency, with 130 mW of pump power.

  5. Nonlinear switching in a two-concentric-core chalcogenide glass optical fiber for passively mode-locking a fiber laser.

    Science.gov (United States)

    Nazemosadat, Elham; Mafi, Arash

    2014-08-15

    We propose an all-fiber mode-locking device, which operates based on nonlinear switching in a novel two-concentric-core fiber structure. The design is particularly attractive given the ease of fabrication and coupling to other components in a mode-locked fiber laser cavity. The nonlinear switching in this coupler is studied, and the relative power transmission is obtained. The analysis shows that this nonlinear switch is practical for mode-locking fiber lasers and is forgiving to fabrication errors.

  6. An ultrafast optics undergraduate advanced laboratory with a mode-locked fiber laser

    Science.gov (United States)

    Schaffer, Andrew; Fredrick, Connor; Hoyt, Chad; Jones, Jason

    2015-05-01

    We describe an ultrafast optics undergraduate advanced laboratory comprising a mode-locked erbium fiber laser, auto-correlation measurements, and an external, free-space parallel grating dispersion compensation apparatus. The simple design of the stretched pulse laser uses nonlinear polarization rotation mode-locking to produce pulses at a repetition rate of 55 MHz and average power of 5.5 mW. Interferometric and intensity auto-correlation measurements are made using a Michelson interferometer that takes advantage of the two-photon nonlinear response of a common silicon photodiode for the second order correlation between 1550 nm laser pulses. After a pre-amplifier and compression, pulse widths as narrow as 108 fs are measured at 17 mW average power. A detailed parts list includes previously owned and common components used by the telecommunications industry, which may decrease the cost of the lab to within reach of many undergraduate and graduate departments. We also describe progress toward a relatively low-cost optical frequency comb advanced laboratory. NSF EIR #1208930.

  7. Chromium:forsterite laser frequency comb stabilization and development of portable frequency references inside a hollow optical fiber

    Science.gov (United States)

    Thapa, Rajesh

    We have made significant accomplishments in the development of portable frequency standard inside hollow optical fibers. Such standards will improve portable optical frequency references available to the telecommunications industry. Our approach relies on the development of a stabilized Cr:forsterite laser to generate the frequency comb in the near-IR region. This laser is self referenced and locked to a CW laser which in turn is stabilized to a sub-Doppler feature of a molecular transition. The molecular transition is realized using a hollow core fiber filled with acetylene gas. We finally measured the absolute frequency of these molecular transitions to characterize the references. In this thesis, the major ideas, techniques and experimental results for the development and absolute frequency measurement of the portable frequency references are presented. A prism-based Cr:forsterite frequency comb is stabilized. We have effectively used the prism modulation along with power modulation inside the cavity in order to actively stabilize the frequency comb. We have also studied the carrier-envelope-offset frequency (f0) dynamics of the laser and its effect on laser stabilization. A reduction of f0 linewidth from ˜2 MHz to ˜20 kHz has also been observed. Both our in-loop and out-of-loop measurements of the comb stability showed that the comb is stable within a part in 1011 at 1-s gate time and is currently limited by our reference signal. In order to develop this portable frequency standard, saturated absorption spectroscopy is performed on the acetylene v1 + v3 band near 1532 nm inside different kinds of hollow optical fibers. The observed linewidths are a factor 2 narrower in the 20 mum fiber as compared to 10 mum fiber, and vary from 20-40 MHz depending on pressure and power. The 70 mum kagome fiber shows a further reduction in linewidth to less than 10 MHz. In order to seal the gas inside the hollow optical fiber, we have also developed a technique of splicing the

  8. All-Optical envelope detection and fiber transmission of wireless signals by external injection of a DFB laser

    DEFF Research Database (Denmark)

    Prince, Kamau; Tafur Monroy, Idelfonso

    2008-01-01

    We outline a novel method for all-optical envelope detection of wireless signals by exploiting cross-gain modulation effects in a distributed feedback laser operating with optical injection. We successfully demonstrate envelope detection of a 20-GHz carrier amplitude-shift-keying modulated signal...... at 2.5 Gb/s and its transmission over a 70-km optical fiber link. We present results including bit-error-rate measurements, signal waveforms, and receiver sensitivity penalties associated with envelope detection and fiber transmission....

  9. Determination of femtosecond-laser-induced refractive-index changes in an optical fiber from far-field measurements

    DEFF Research Database (Denmark)

    Savolainen, Juha-Matti; Grüner-Nielsen, Lars; Kristensen, Poul

    2014-01-01

    A new method for direct writing of localized, circularly symmetric refractive-index changes in optical fibers with a femtosecond laser is demonstrated. The refractive-index changes are characterized using a novel approach employing comparison of numerical simulations to the measured far......-field profiles of unmodified and modified fibers. From the analysis, a negative refractive-index change of −0.015 0.005 within a radius of 0.6 0.1 μm is determined....

  10. Suppresion of Self-Phase Modulation in a Laser Transfer System using Optical Fiber on the Subaru Telescope

    CERN Document Server

    Ito, Meguru; Saito, Yoshihiko; Takami, Hideki; Saito, Norihito; Akagawa, Kazuyuki; Iye, Masanori

    2012-01-01

    We are developing the Laser Guide Star Adaptive Optics (LGS/AO188) system for the Subaru Telescope at Mauna Kea, Hawaii. This system utilizes a combination of an all-solid-state mode-locked sum-frequency generation (SFG) laser (1.7-GHz bandwidth, 0.7-ns pulse width) as a light source and a single-mode optical fiber for beam transference. However, optical fibers induce nonlinear effects, especially self-phase modulation (SPM). We studied SPM in our photonic crystal fiber (PCF). SPM broadens the spectrum of a laser beam and decrease the efficiency of bright laser guide star generation. We measured the spectrum width using a spectrum analyzer. We found a spectrum width of 8.4 GHz at full width at half maximum (FWHM). The original FWHM of our laser spectrum was 1.4 GHz. This was equivalent to a 70 % loss in laser energy. We also measured the brightness of the sodium cell and evaluated its performance as a function of laser wavelength. The cell's brightness showed a peculiar tendency; specifically, it did not exti...

  11. Continuous-wave supercontinuum laser based on an erbium-doped fiber ring cavity incorporating a highly nonlinear optical fiber

    Science.gov (United States)

    Lee, Ju Han; Takushima, Yuichi; Kikuchi, Kazuro

    2005-10-01

    We experimentally demonstrate a novel erbium-doped fiber based continuous-wave (cw) supercontinuum laser. The laser has a simple ring-cavity structure incorporating an erbium-doped fiber and a highly nonlinear dispersion-shifted fiber (HNL-DSF). Differently from previously demonstrated cw supercontinuum sources based on single propagation of a strong Raman pump laser beam through a highly nonlinear fiber, erbium gain inside the cavity generates a seed light oscillation, and the oscillated light subsequently evolves into a supercontinuum by nonlinear effects such as modulation instability and stimulated Raman scattering in the HNL-DSF. High quality of the depolarized supercontinuum laser output with a spectral bandwidth larger than 250 nm is readily achieved.

  12. Frequency-doubled telecom fiber laser for a cold atom interferometer using optical lattices

    Science.gov (United States)

    Theron, Fabien; Bidel, Yannick; Dieu, Emily; Zahzam, Nassim; Cadoret, Malo; Bresson, Alexandre

    2017-06-01

    A compact and robust frequency-doubled telecom laser system at 780 nm is presented for a rubidium cold atom interferometer using optical lattices. Adopting an optical switch at 1.5 μm and a dual-wavelength second harmonic generation system, only one laser amplifier is required for the laser system. Our system delivers a 900 mW laser beam with a detuning of 110 GHz for the optical lattice and a 650 mW laser beam with an adjustable detuning between 0 and -1 GHz for the laser cooling, the detection and the Raman transitions.

  13. Frequency doubled telecom fiber laser for a cold atom interferometer using optical lattices

    CERN Document Server

    Theron, Fabien; Dieu, Emily; Zahzam, Nassim; Cadoret, Malo; Zahzam, Nassim; Bresson, Alexandre

    2016-01-01

    A compact and robust laser system, based on a frequency-doubled telecom laser, providing all the lasers needed for a rubidium cold atom interferometer using optical lattices is presented. Thanks to an optical switch at 1.5 \\mu m and a dual-wavelength second harmonic generation system, only one laser amplifier is needed for all the laser system. Our system delivers at 780 nm a power of 900 mW with a detuning of 110 GHz for the optical lattice and a power of 650 mW with an adjustable detuning between 0 and -1 GHz for the laser cooling, the detection and the Raman transitions.

  14. Investigations of repetition rate stability of a mode-locked quantum dot semiconductor laser in an auxiliary optical fiber cavity

    DEFF Research Database (Denmark)

    Breuer, Stefan; Elsässer, Wolfgang; McInerney, J.G.

    2010-01-01

    We have investigated experimentally the pulse train (mode beating) stability of a monolithic mode-locked multi-section quantum-dot laser with an added passive auxiliary optical fiber cavity. Addition of the weakly coupled (¿ -24dB) cavity reduces the current-induced shift d¿/dI of the principal...

  15. Retinal nerve fiber layer thickness in subgroups of multiple sclerosis, measured by optical coherence tomography and scanning laser polarimetry

    NARCIS (Netherlands)

    T.A.M. Siepman (Theodora); M. Wefers Bettink-Remeijer (Marijke); R.Q. Hintzen (Rogier)

    2010-01-01

    textabstractOptical coherence tomography (OCT) and scanning laser polarimetry (GDx ECC) are non-invasive methods used to assess retinal nerve fiber layer (RNFL) thickness, which may be a reliable tool used to monitor axonal loss in multiple sclerosis (MS). The objectives of this study are (1) to com

  16. Optical arbitrary waveform generation based on multi-wavelength semiconductor fiber ring laser

    Science.gov (United States)

    Li, Peili; Ma, Xiaolu; Shi, Weihua; Xu, Enming

    2017-09-01

    A new scheme of generating optical arbitrary waveforms based on multi-wavelength semiconductor fiber ring laser (SFRL) is proposed. In this novel scheme, a wide and flat optical frequency comb (OFC) is provided directly by multi-wavelength SFRL, whose central frequency and comb spacing are tunable. OFC generation, de-multiplexing, amplitude and phase modulation, and multiplexing are implementing in an intensity and phase tunable comb filter, as induces the merits of high spectral coherence, satisfactory waveform control and low system loss. By using the mode couple theory and the transfer matrix method, the theoretical model of the scheme is established. The impacts of amplitude control, phase control, number of spectral line, and injection current of semiconductor optical amplifier (SOA) on the waveform similarity are studied using the theoretical model. The results show that, amplitude control and phase control error should be smaller than 1% and 0.64% respectively to achieve high similarity. The similarity of the waveform is improved with the increase of the number of spectral line. When the injection current of SOA is in a certain range, the optical arbitrary waveform reaches a high similarity.

  17. Novel Applications of Chirp Managed Laser in Optical Fiber Communication Systems

    Science.gov (United States)

    Jia, Wei

    Nowadays, with the dramatically growing bandwidth requirement of Internet, the number of wavelength division multiplexing (WDM) channels of the optical fiber communication systems is increasing rapidly. Hence, optical transmitters with cost effectiveness, high power efficiency, and excellent transmission performance are necessary. Especially, for access and metropolitan applications, simple configuration is the essential factor. The conventional optical transmitter is composed of a laser as continuous-wave (CW) source and one or more external modulators for modulation. However, the high insertion loss, large driving voltage, and extra cost of external modulator make it relatively bulky and power-hungry. Chirp managed laser (CML), comprising a directly modulated semiconductor laser (DML) and a passive optical filter, is an alternative promising transmitter candidate. It has the merits of smaller device size, lower cost, less power consumption, and higher fiber chromatic dispersion (CD) tolerance, compared with that based on external modulator. In this thesis, we have investigated several novel applications of CML in optical fiber communication systems, taking advantage of its unique phase modulating and spectral reshaping properties. These topics include optical return-to-zero (RZ) pulses generation using CML, M-ary RZ differential phase-shift-keying (RZ-DPSK) signals generation using CML, and enhanced CD tolerance of CML with pre-emphasis. These CML-based designs consume low power for less electrical pre-coding, require reduced or no external modulator, and show notable transmission performances. Optical RZ pulses generation using CML: RZ pulses have been widely used in optical fiber communication systems together with on-off-keying (OOK) and DPSK modulation formats, for its high robustness towards inter symbol interference (ISI) and nonlinear distortions. In this thesis, we propose and experimentally demonstrate the technique of 10-Gb/s optical RZ pulses

  18. 200-fs mode-locked Erbium-doped fiber laser by using mechanically exfoliated MoS2 saturable absorber onto D-shaped optical fiber.

    Science.gov (United States)

    Aiub, Eduardo J; Steinberg, David; Thoroh de Souza, Eunézio A; Saito, Lúcia A M

    2017-05-01

    For the first time, we demonstrated the fabrication of mechanically exfoliated molybdenum disulfide (MoS2) samples deposited onto a D-shaped optical fiber. The MoS2 exfoliated flakes were deposited onto a stacked of 1.2 µm PVA (polyvinyl alcohol) and 300 nm PMMA (polymethyl methacrylate) layers and then transferred directly onto a side polished surface of D-shaped optical fiber with polishing length of 17 mm and no distance from the fiber core. The sample exhibited a high polarization performance as a polarizer with relative polarization extinction ratio of 97.5%. By incorporating the sample as a saturable absorber in the Erbium-doped fiber laser (EDFL), bandwidth of 20.5 nm and pulse duration of 200 fs were generated, which corresponded to the best mode-locking results obtained for all-fiber MoS2 saturable absorber at 1.5 µm wavelength.

  19. Effects of laser frequency drift in phase-sensitive optical time-domain reflectometry fiber sensors

    CERN Document Server

    Zhirnov, Andrey; Stepanov, Konstantin; Nesterov, Evgeny; Karasik, Valery; Svelto, Cesare; Pnev, Alexey

    2016-01-01

    The present work studies the influence of laser frequency drifts on operating of phase-sensitive optical time-domain reflectometry ($\\Phi$-OTDR) fiber sensors. A mathematical model and numerical simulations are employed to highlight the influence of frequency drifts of light sources on two characteristic scales: large-time (minutes) and short-time (milliseconds) frequency drifts. Numerical simulation results are compared with predictions given by the fluctuation ratio coefficient (FRC), and they are in a qualitative agreement. In addition to qualitative criteria for light sources given by the FRC, quantitive requirements for optimal light sources for $\\Phi$-OTDR sensors are obtained. Numerical simulation results are verified by comparison with experimental data for three significantly different types of light source.

  20. Fiber laser optical frequency standard at 1.54 μm.

    Science.gov (United States)

    Hald, Jan; Nielsen, Lars; Petersen, Jan C; Varming, Poul; Pedersen, Jens E

    2011-01-31

    A 32 mW fiber laser is stabilized to the (13)C(2)H(2) P(16) (ν1 + ν3) transition at 1542 nm using saturated absorption. The short-term shot-noise limited fractional frequency instability is 5.0 × 10(-13)(τ/s)-½ for averaging times τ up to about 100 s. The relative lock-point repeatability over 2½ month is 4.3 × 10(-13) corresponding to 83 Hz. The simple setup includes a 21 cm long gas cell, but it does not require an enhancement cavity or external modulators. The spectroscopic lineshape is analyzed with respect to optical power and acetylene pressure. Narrow linewidths of 300 kHz FWHM are observed with a signal to noise ratio of 35 dB in a 9 Hz bandwidth.

  1. Hollow fiber optics with improved durability for high-peak-power pulses of Q-switched Nd:YAG lasers.

    Science.gov (United States)

    Matsuura, Yuji; Tsuchiuchi, Akio; Noguchi, Hiroshi; Miyagi, Mitsunobu

    2007-03-10

    To improve the damage threshold of hollow optical waveguides for transmitting Q-switched Nd:YAG laser pulses, we optimize the metallization processes for the inner coating of fibers. For silver-coated hollow fiber as the base, second, and third Nd:YAG lasers, drying silver films at a moderate temperature and with inert gas flow is found to be effective. By using this drying process, the resistance to high-peak-power optical pulse radiation is drastically improved for fibers fabricated with and without the sensitizing process. The maximum peak power transmitted in the fiber is greater than 20 MW. To improve the energy threshold of aluminum-coated hollow fibers for the fourth and fifth harmonics of Nd:YAG lasers, a thin silver film is added between the aluminum film and the glass substrate to increase adhesion of the aluminum coating. By using this primer layer, the power threshold improves to 3 MW for the fourth harmonics of a Q-switched Nd:YAG laser light.

  2. Coherence transfer of subhertz-linewidth laser light via an optical fiber noise compensated by remote users.

    Science.gov (United States)

    Wu, Lifei; Jiang, Yanyi; Ma, Chaoqun; Yu, Hongfu; Bi, Zhiyi; Ma, Longsheng

    2016-09-15

    We present a technique for the coherence transfer of laser light through a fiber link, where the optical phase noise induced by environmental perturbation via the fiber link is compensated by remote users. When compensating the fiber noise by remote users, the time base at the remote site independent from that at the local site does not destroy the performance of the fiber output light. Using this technique, we demonstrate the transfer of subhertz-linewidth laser light through a 25-km-long, lab-based spooled fiber. After being compensated, the relative linewidth between the fiber input and output light is 1 mHz, and the relative frequency instability is 4×10-17 at 1 s averaging time and scales down to 2×10-19 at 800 s averaging time. The frequency uncertainty of the light after transferring through the fiber relative to that of the input light is 3.0×10-19. This system is suitable for the simultaneous transfer of an optical signal to a number of end users within a city.

  3. Fiber-based multiple-beam reflection interferometer for single-longitudinal-mode generation in fiber laser based on semiconductor optical amplifier

    Science.gov (United States)

    Terentyev, V. S.; Simonov, V. A.; Babin, S. A.

    2017-02-01

    A technique of single-longitudinal-mode selection in a fiber laser by means of a fiber multiple-beam reflection interferometer (FRI) has been experimentally demonstrated for the first time. The laser is based on a semiconductor optical amplifier placed in a linear fiber cavity formed by a fiber Bragg grating (FBG), and the FRI generates at 1529.24 nm with output power of 1 mW in single-frequency regime with a linewidth of about 217 kHz and polarization extinction ratio of  >30 dB. The FRI technique potentially enables fast tuning (within the FBG bandwidth of ~0.9 nm in our case) by varying the base length of the FRI that can be used in a number of practical applications.

  4. Optical coherence tomography, scanning laser polarimetry and confocal scanning laser ophthalmoscopy in retinal nerve fiber layer measurements of glaucoma patients.

    Science.gov (United States)

    Fanihagh, Farsad; Kremmer, Stephan; Anastassiou, Gerasimos; Schallenberg, Maurice

    2015-01-01

    To determine the correlations and strength of association between different imaging systems in analyzing the retinal nerve fiber layer (RNFL) of glaucoma patients: optical coherence tomography (OCT), scanning laser polarimetry (SLP) and confocal scanning laser ophthalmoscopy (CSLO). 114 eyes of patients with moderate open angle glaucoma underwent spectral domain OCT (Topcon SD-OCT 2000 and Zeiss Cirrus HD-OCT), SLP (GDx VCC and GDx Pro) and CSLO (Heidelberg Retina Tomograph, HRT 3). Correlation coefficients were calculated between the structural parameters yielded by these examinations. The quantitative relationship between the measured RNFL thickness globally and for the four regions (superior, inferior, nasal, temporal) were evaluated with different regression models for all used imaging systems. The strongest correlation of RNFL measurements was found between devices using the same technology like GDx VCC and GDx Pro as well as Topcon OCT and Cirrus OCT. In glaucoma patients, the strongest associations (R²) were found between RNFL measurements of the two optical coherence tomography devices Topcon OCT and Cirrus OCT (R² = 0.513) and between GDx VCC and GDx Pro (R² = 0.451). The results of the OCTs and GDX Pro also had a strong quantitative relationship (Topcon OCT R² = 0.339 and Cirrus OCT R² = 0.347). GDx VCC and the OCTs showed a mild to moderate association (Topcon OCT R² = 0.207 and Cirrus OCT R² = 0.258). The confocal scanning laser ophthalmoscopy (HRT 3) had the lowest association to all other devices (Topcon OCT R² = 0.254, Cirrus OCT R² = 0.158, GDx Pro R² = 0.086 and GDx VCC R² = 0.1). The measurements of the RNFL in glaucoma patients reveal a high correlation of OCT and GDx devices because OCTs can measure all major retinal layers and SLP can detect nerve fibers allowing a comparison between the results of this devices. However, CSLO by means of HRT topography can only measure height values of the retinal surface but it cannot distinguish

  5. Ultralow-frequency-noise stabilization of a laser by locking to an optical fiber-delay line.

    Science.gov (United States)

    Kéfélian, Fabien; Jiang, Haifeng; Lemonde, Pierre; Santarelli, Giorgio

    2009-04-01

    We report the frequency stabilization of an erbium-doped fiber distributed-feedback laser using an all-fiber-based Michelson interferometer of large arm imbalance. The interferometer uses a 1 km SMF-28 optical fiber spool and an acousto-optic modulator allowing heterodyne detection. The frequency-noise power spectral density is reduced by more than 40 dB for Fourier frequencies ranging from 1 Hz to 10 kHz, corresponding to a level well below 1 Hz2/Hz over the entire range; it reaches 10(-2) Hz2/Hz at 1 kHz. Between 40 Hz and 30 kHz, the frequency noise is shown to be comparable to the one obtained by Pound-Drever-Hall locking to a high-finesse Fabry-Perot cavity. Locking to a fiber delay line could consequently represent a reliable, simple, and compact alternative to cavity stabilization for short-term linewidth reduction.

  6. A Large Area Fiber Optic Gyroscope on multiplexed fiber network

    CERN Document Server

    Clivati, Cecilia; Costanzo, Giovanni A; Mura, Alberto; Pizzocaro, Marco; Levi, Filippo

    2012-01-01

    We describe a fiber optical gyroscope based on the Sagnac effect realized on a multiplexed telecom fiber network. Our loop encloses an area of 20 km^2 and coexists with Internet data traffic. This Sagnac interferometer achieves a sensitivity of about 1e-8 (rad/s)/sqrt(Hz), thus approaching ring laser gyroscopes without using narrow-linewidth laser nor sophisticated optics. The proposed gyroscope is sensitive enough for seismic applications, opening new possibilities for this kind of optical fiber sensors

  7. Optical Fiber Link with 1E-19 frequency stability using a Planar-Waveguide External Cavity Laser Diode

    CERN Document Server

    Clivati, Cecilia; Calonico, Davide; Levi, Filippo; Costanzo, Giovanni A; Calosso, Claudio E; Godone, Aldo

    2011-01-01

    We compare the performances of a compact planar-waveguide external cavity laser (ECL) and a traditional fiber laser (FL) frequency locked to a Fabry-P\\'erot cavity and demonstrate the possibility to use such ECL in an optical link for ultra stable frequency dissemination. A relative stability of the ECL of 1E-14 is obtained and an optical link of 100 km based on fiber spools has been realized, that reaches 2E-19 relative stability, limited by the system noise floor. The performances of ECL and FL are shown to be comparable. Thus, ECLs could be a better choice than FLs in longer optical links with amplification and regenerating stations, thanks to their cost-effectiveness, robustness and small size.

  8. POINT-BY-POINT INSCRIPTION OF FIBER BRAGG GRATINGS INTO BIREFRINGENT OPTICAL FIBER THROUGH PROTECTIVE ACRYLATE COATING BY TI:SA FEMTOSECOND LASER

    Directory of Open Access Journals (Sweden)

    S. V. Arkhipov,

    2016-05-01

    Full Text Available The paper deals withpoint-by-point inscriptionof fiber Bragg gratings by the 800 nm Ti:Sa femtosecond laser pulses into a unique birefringent fiber with elliptical stress cladding of home manufacture. The proposed inscriptionmethod has advantages over the conventional phase mask method. The possibility to create complex grating structures and relatively high transparency of acrylate coating to the Ti:Sa femtosecond laser radiation of 800 nm gives the possibility for inscriptionof phase shifting gratings, chirped grating and superstructures without stripping the fiber. Also, this method makes it possible to inscribethese diffractive structures with and without co-doping of GeO2 in the fiber core. Achieved reflectance was 10%. The microscopic image of the diffractive structure in the fiber core is presented. The grating of 1.07 µm is realized by pulling the fiber with constant speed while the laser pulses are applied with a repetition frequency of 1 kHz. The results are usable in the sphere of creation of different fiber optic sensitive elements based on Bragg gratings.

  9. Laser phase and frequency noise measurement by Michelson interferometer composed of a 3 × 3 optical fiber coupler.

    Science.gov (United States)

    Xu, Dan; Yang, Fei; Chen, Dijun; Wei, Fang; Cai, Haiwen; Fang, Zujie; Qu, Ronghui

    2015-08-24

    A laser phase and frequency noise measurement method by an unbalanced Michelson interferometer composed of a 3 × 3 optical fiber coupler is proposed. The relations and differences of the power spectral density (PSD) of differential phase and frequency fluctuation, PSD of instantaneous phase and frequency fluctuation, phase noise and linewidth are derived strictly and discussed carefully. The method obtains the noise features of a narrow linewidth laser conveniently without any specific assumptions or noise models. The technique is also used to characterize the noise features of a narrow linewidth external-cavity semiconductor laser, which confirms the correction and robustness of the method.

  10. Fiber Coupled Laser Diodes with Even Illumination Pattern

    Science.gov (United States)

    Howard, Richard T. (Inventor)

    2007-01-01

    An optical fiber for evenly illuminating a target. The optical fiber is coupled to a laser emitting diode and receives laser light. The la ser light travels through the fiber optic and exits at an exit end. T he exit end has a diffractive optical pattern formed thereon via etch ing, molding or cutting, to reduce the Gaussian profile present in co nventional fiber optic cables The reduction of the Gaussian provides an even illumination from the fiber optic cable.

  11. Transverse UV-laser irradiation-induced defects and absorption in a single-mode erbium-doped optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Tortech, B.; Ouerdane, Y.; Boukenter, A.; Meunier, J. P. [Univ St Etienne, Lab Hubert Curien, CNRS, UMR 5516, F-42000 St Etienne (France); Girard, S. [CEA Bruyeres le Chatel, DIF, 91 (France); Van Uffelen, M.; Berghmans, F. [CEN SCK, B-2400 Mol (Belgium); Regnier, E. [Draka Comteq France, Data Ctr 4, F-91460 Marcoussis (France); Berghmans, F.; Thienpont, H. [Vrije Univ Brussels, B-1050 Brussels, (Belgium)

    2009-07-15

    Near UV-visible absorption coefficients of an erbium-doped optical fiber were investigated through an original technique based on a transverse cw UV-laser irradiation operating at 244 nm. Such irradiation leads to the generation of a quite intense guided luminescence signal in near UV spectral range. This photoluminescence probe source combined with a longitudinal translation of the fiber sample (at a constant velocity) along the UV-laser irradiation, presents several major advantages: (i) we bypass and avoid the procedures classically used to study the radiation induced attenuation which are not adapted to our case mainly because the samples present a very strong absorption with significant difficulties due to the injection of adequate UV-light levels in a small fiber diameter: (ii) the influence of the laser irradiation on the host matrix of the optical fiber is directly correlated to the evolution of the generated photoluminescence signal and (iii) in our experimental conditions, short fiber sample lengths (typically 20-30 cm) suffice to determine the associated absorption coefficients over the entire studied spectral domain. The generated photoluminescence signal is also used to characterize the absorption of the erbium ions in the same wavelength range with no cut-back method needed. (authors)

  12. Incorporation of a Redfern Integrated Optics ORION Laser Module with an IPG Photonics Erbium Fiber Laser to Create a Frequency Conversion Photon Doppler Velocimeter for US Army Research Laboratory Measurements: Hardware, Data Analysis, and Error Quantification

    Science.gov (United States)

    2017-04-01

    ARL-MR-0953● Apr 2017 US Army Research Laboratory Incorporation of a Redfern Integrated Optics ORION Laser Module with an IPG...Photonics Erbium Fiber Laser to Create a Frequency- Conversion Photon Doppler Velocimeter for US Army Research Laboratory Measurements: Hardware...Laboratory Incorporation of a Redfern Integrated Optics ORION Laser Module with an IPG Photonics Erbium Fiber Laser to Create a Frequency- Conversion

  13. Effect of low intensity laser interaction with human skin fibroblast cells using fiber-optic nano-probes.

    Science.gov (United States)

    Pal, Gopalendu; Dutta, Ashim; Mitra, Kunal; Grace, Michael S; Amat, Albert; Romanczyk, Tara B; Wu, Xingjia; Chakrabarti, Kristi; Anders, Juanita; Gorman, Erik; Waynant, Ronald W; Tata, Darrell B

    2007-03-01

    Over the past forty years, many efforts have been devoted to study low power laser light interactions with biological systems. Some of the investigations were performed in-vitro, on bulk cell populations. Our present work was undertaken to apply specially engineered fiber-optic based nano-probes for the precise delivery of laser light on to a single cell and to observe production of low power laser light induced reactive oxygen species (ROS). A normal human skin fibroblast (NHF) cell line was utilized in this investigation and the cells were irradiated under two different schemes of exposure: (1) an entire NHF cell population within a Petri dish using a fan beam methodology, and (2) through the precise delivery of laser energy on to a single NHF cell using fiber-optic nano-probe. Photobiostimulative studies were conducted through variation of laser intensity, exposure time, and the energy dose of exposure. Laser irradiation induced enhancement in the rate of cell proliferation was observed to be dependent on laser exposure parameters and the method of laser delivery. The total energy dose (fluence) had a greater influence on the enhancement in the rate of cellular proliferation than compared to laser intensity. The enhancement in the growth rate was observed to have a finite life-time of several days after the initial laser exposure. Fluorescent life-time imaging of ROS was performed during the nano-based single cell exposure method. The kinetics of ROS generation was found to depend strongly on the laser fluence and not on the laser intensity.

  14. Optical fiber-based devices and applications

    Institute of Scientific and Technical Information of China (English)

    Perry Ping SHUM; Jonathan C. KNIGHT; Jesper LAEGSGAARD; Dora Juan Juan HU

    2010-01-01

    @@ Optical fiber technology has undergone tremendous growth and development over the last 40 years. Optical fibers constitute an information super highway and are vital in enabling the proliferating use of the Internet. Optical fiber is also an enabling technology which can find applications in sensing, imaging, biomedical, machining, etc. There have been a few milestones in the advancement of optical fiber technology. Firstly, the invention and development of the laser some 50 years ago made optical communications possible. Secondly, the fabrication of low-loss optical fibers has been a key element to the success of optical communication.

  15. Fiber-coupling efficiency simulation of Gaussian Schell Model laser in space-to-ground optical communication link

    Science.gov (United States)

    Tan, Liying; Li, Mengnan; Wu, Jiajie; Ma, Jing; Yang, Qingbo

    2015-08-01

    In practice, due to reasons related to the laser device and the inevitable error of the processing technique, a laser source emitted from a communication terminal is partially coherent, which is represented by the Gaussian Schell Model (GSM). In a space-to-ground optical communication link, the cross-spectral density function, based on the Gaussian Model in previous research, is replaced by GSM; thus, the fiber-coupling efficiency equation of the GSM laser source is deduced. The GSM equation presents the effects of the source coherent parameter ζ and the zenith angle θ on the fiber-coupling efficiency, which were not included previously. The effects on the fiber-coupling efficiency are numerically simulated and analyzed. The results manifest that the fiber-coupling efficiency invariably degrades with increasing ζ or θ. The hope of this work is to improve the redundancy design of fiber-coupling receiver systems by analyzing the fiber-coupling efficiency with the source coherent parameter.

  16. Fiber Optics Technology.

    Science.gov (United States)

    Burns, William E.

    1986-01-01

    Discusses various applications of fiber optics technology: information systems, industrial robots, medicine, television, transportation, and training. Types of jobs that will be available with fiber optics training (such as electricians and telephone cable installers and splicers) are examined. (CT)

  17. Fiber Optics Instrumentation Development

    Science.gov (United States)

    Chan, Patrick Hon Man; Parker, Allen R., Jr.; Richards, W. Lance

    2010-01-01

    This is a general presentation of fiber optics instrumentation development work being conducted at NASA Dryden for the past 10 years and recent achievements in the field of fiber optics strain sensors.

  18. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber-laser...... cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  19. Real-time fiber-optic anemometer based on a laser-heated few-layer graphene in an aligned graded-index fiber.

    Science.gov (United States)

    Gao, Ran; Lu, Danfeng; Cheng, Jin; Qi, Zhi-Mei

    2017-07-15

    A real-time all-fiber anemometer based on laser-heated few-layer graphene in aligned graded-index fibers has been proposed and experimentally demonstrated. The proposed fiber-optic anemometer was composed of a pair of all-fiber collimators by using aligned graded-index fibers that was coated with the few-layer graphene. The few-layer graphene was heated through a heating light from a 532-nm laser, which changed the optical transmittance of signal light with the wavelength of 1550 nm. The wind speed can be measured through the transmission power of the signal light based on the wind cooling effects on the heated few-layer graphene, acting as a "hot-wire" anemometer. The experimental results show that the maximum sensitivity of the anemometer reaches -22.03  μW/(m/s), and a fast response time of as 0.064 s can be achieved. The proposed fiber sensor can be used for the real-time measurement of wind speed in the fields of environmental monitoring, oil exploration, oceanography research, etc.

  20. Fiber Lasers V

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2008-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last five years, and many of the traditional manufactures of gas and solid-state lasers are pursuing the attractive fiber-based systems, which are now displacing the old technology in many areas. High-power fiber laser...... laser system. We present the latest advancements within airclad fiber technology including a new 70 μm single-mode polarization-maintaining rod-type fiber capable of amplifying to MW power levels. Furthermore we describe the novel airclad based pump combiners and their use in a completely monolithic 350...... W CW fiber laser system with an M2 of less than 1.1. Finally, we briefly touch upon the subject of photo darkening and its origin....

  1. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2008-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last five years, and many of the traditional manufactures of gas and solid-state lasers are pursuing the attractive fiber-based systems, which are now displacing the old technology in many areas. High-power fiber laser...... laser system. We present the latest advancements within airclad fiber technology including a new 70 μm single-mode polarization-maintaining rod-type fiber capable of amplifying to MW power levels. Furthermore we describe the novel airclad based pump combiners and their use in a completely monolithic 350...... W CW fiber laser system with an M2 of less than 1.1. Finally, we briefly touch upon the subject of photo darkening and its origin....

  2. Integration of an optical fiber taper with an optical microresonator fabricated in glass by femtosecond laser 3D micromachining

    CERN Document Server

    Song, Jiangxin; Tang, Jialei; Qiao, Lingling; Cheng, Ya

    2014-01-01

    We report on fabrication of a microtoroid resonator of a high-quality factor (i. e., Q-factor of ~3.24x10^6 measured under the critical coupling condition) using femtosecond laser three-dimensional (3D) micromachining. Coupling of light into and out of the microresonator has been realized with a fiber taper that is reliably assembled with the microtoroid. The assembly of the fiber taper to the microtoroid is achieved by welding the fiber taper onto the sidewall of the microtoroid using CO2 laser irradiation. The integrated microresonator maintains a high Q-factor of 3.21x10^5 as measured in air.

  3. Two Fiber Optical Fiber Thermometry

    Science.gov (United States)

    Jones, Mathew R.; Farmer, Jeffery T.; Breeding, Shawn P.

    2000-01-01

    An optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber is essentially an isothermal cavity, so the emission from this cavity will be approximately equal to the emission from a blackbody. Temperature readings are obtained by measuring the spectral radiative heat flux at the end of the fiber at two wavelengths. The ratio of these measurements and Planck's Law are used to infer the temperature at the sensing tip. Optical fiber thermometers have high accuracy, excellent long-term stability and are immune to electromagnetic interference. In addition, they can be operated for extended periods without requiring re-calibration. For these reasons. it is desirable to use optical fiber thermometers in environments such as the International Space Station. However, it has recently been shown that temperature readings are corrupted by emission from the fiber when extended portions of the probe are exposed to elevated temperatures. This paper will describe several ways in which the reading from a second fiber can be used to correct the corrupted temperature measurements. The accuracy and sensitivity to measurement uncertainty will be presented for each method.

  4. Active Q-switching in an erbium-doped fiber laser using an ultrafast silicon-based variable optical attenuator.

    Science.gov (United States)

    Chang, You Min; Lee, Junsu; Jhon, Young Min; Lee, Ju Han

    2011-12-19

    Presented herein is the use of an ultrafast Si-based variable optical attenuator (VOA) as a Q-switch for rare earth-doped fiber lasers. The ultrafast VOA is based on a forward-biased p-i-n diode integrated with a ridge waveguide, which was originally designed and optimized for WDM channel power equalization in optical communication systems. By incorporating a Si-based VOA with a transient time of ~410 ns into an erbium-doped fiber-based Fabry-Perot cavity it has been shown that stable Q-switched pulses possessing a temporal width of less than ~86 ns can be readily obtained at a repetition rate of up to ~1 MHz. The laser's peak power of ~38 W is shown to be obtainable at 20 kHz with a slope efficiency of ~21%.

  5. Cladded single crystal fibers for high power fiber lasers

    Science.gov (United States)

    Kim, W.; Shaw, B.; Bayya, S.; Askins, C.; Peele, J.; Rhonehouse, D.; Meyers, J.; Thapa, R.; Gibson, D.; Sanghera, J.

    2016-09-01

    We report on the recent progress in the development of cladded single crystal fibers for high power single frequency lasers. Various rare earth doped single crystal YAG fibers with diameters down to 17 μm with length > 1 m have been successfully drawn using a state-of-the-art Laser Heated Pedestal Growth system. Single and double cladding on rare earth doped YAG fibers have been developed using glasses where optical and physical properties were precisely matched to doped YAG core single crystal fiber. The double clad Yb:YAG fiber structures have dimensions analogous to large mode area (LMA) silica fiber. We also report successful fabrications of all crystalline core/clad fibers where thermal and optical properties are superior over glass cladded YAG fibers. Various fabrication methods, optical characterization and gain measurements on these cladded YAG fibers are reported.

  6. Hollow Core Optical Fiber Gas Lasers: Toward Novel and Practical Systems in Fused Silica

    Science.gov (United States)

    2017-05-18

    Nampoothiri, University of New Mexico Fetah Benabid, GPPMM group, Xlim, CNRS Research Institute, Limoges, France Project Summary/Abstract Abstract (>500...Kagome lattice fiber has been demonstrated: 8 dB/km at 1 um. Furthermore, we have pushed the state-of-the art in tubular lattice fiber; a loss of...Laser, University of New Mexico .................................................................................. 4  E.2.  Acetylene HOFGLAS, Kansas

  7. Comparison of fiber lasers based on distributed side-coupled cladding-pumped fibers and double-cladding fibers.

    Science.gov (United States)

    Huang, Zhihe; Cao, Jianqiu; Guo, Shaofeng; Chen, Jinbao; Xu, Xiaojun

    2014-04-01

    We compare both analytically and numerically the distributed side-coupled cladding-pumped (DSCCP) fiber lasers and double cladding fiber (DCF) lasers. We show that, through optimization of the coupling and absorbing coefficients, the optical-to-optical efficiency of DSCCP fiber lasers can be made as high as that of DCF lasers. At the same time, DSCCP fiber lasers are better than the DCF lasers in terms of thermal management.

  8. Carbon Nanotube-Poly(vinylalcohol) Nanocomposite Film Devices: Applications for Femtosecond Fiber Laser Mode Lockers and Optical Amplifier Noise Suppressors

    Science.gov (United States)

    Sakakibara, Youichi; Rozhin, Aleksey G.; Kataura, Hiromichi; Achiba, Yohji; Tokumoto, Madoka

    2005-04-01

    We fabricated single-wall carbon nanotube (SWNT)/poly(vinylalcohol) (PVA) nanocomposite freestanding films and examined their application in devices in which the saturable absorption of SWNTs at near-infrared optical telecommunication wavelengths can be utilized. In a passively mode-locked fiber laser, we integrated a 30-μm-thick SWNT/PVA film into a fiber connection adaptor with the film sandwiched by a pair of fiber ferrules. A ring fiber laser with a SWNT/PVA saturable absorber was operated very easily in the mode-locked short-pulse mode with a pulse width of about 500 fs. Reproducible stable device performance was confirmed. In examining noise suppression for optical amplifiers, mixed light of semiconductor amplified spontaneous emission (ASE) source and 370 fs laser pulses was passed through a 100-μm-thick SWNT/PVA film. The transmission loss of the femtosecond pulse light was smaller than that of the ASE light. This proved that the SWNT/PVA film has the ability to suppress ASE noise.

  9. Bundled hollow optical fibers for transmission of high-peak-power Q-switched Nd:YAG laser pulses.

    Science.gov (United States)

    Yilmaz, Ozgur; Miyagi, Mitsunobu; Matsuura, Yuji

    2006-09-20

    A hollow-fiber bundle was designed and used to deliver high-peak-power pulses from a Q-switched Nd:YAG laser. An 80 cm long bundle with a total diameter of 5.5 mm was composed of 37 glass capillaries with bore diameters of 0.7 mm. Beam-resizing optics with two lenses were used to couple the laser beam into the bundle. The measured coupling loss due to the limited aperture ratio of the bundle was 2.3 dB, and the transmission loss at wavelengths of 1064 and 532 nm was 0.3 dB. When an inert gas flowed through the bores of the capillaries, the maximum output pulse energy was 200 mJ, which was the limit of the laser used in the experiment. Hollow-fiber bundles withstand irradiation better than single hollow fibers and silica-glass optical fibers do. They are suitable for many dermatological applications because they can be used to irradiate a large area.

  10. Optical Fiber Spectroscopy

    Science.gov (United States)

    Buoncristiani, A. M.

    1999-01-01

    This is the final report of work done on NASA Grant NAG-1-443. The work covers the period from July 1, 1992 to December 1, 1998. During this period several distinct but related research studies and work tasks were undertaken. These different subjects are enumerated below with a description of the work done on each of them. The focus of the research was the development of optical fibers for use as distributed temperature and stress sensors. The initial concept was to utilize the utilize the temperature and stress dependence of emission from rare earth and transition metal ions substitutionally doped into crystalline or glass fibers. During the course of investigating this it became clear that fiber Bragg gratings provided a alternative for making the desired measurements and there was a shift of research focus on to include the photo-refractive properties of germano-silicate glasses used for most gratings and to the possibility of developing fiber laser sources for an integrated optical sensor in the research effort. During the course of this work several students from Christopher Newport University and other universities participated in this effort. Their names are listed below. Their participation was an important part of their education.

  11. Determination of femtosecond-laser-induced refractive-index changes in an optical fiber from far-field measurements.

    Science.gov (United States)

    Savolainen, Juha-Matti; Grüner-Nielsen, Lars; Kristensen, Poul; Balling, Peter

    2014-06-15

    A new method for direct writing of localized, circularly symmetric refractive-index changes in optical fibers with a femtosecond laser is demonstrated. The refractive-index changes are characterized using a novel approach employing comparison of numerical simulations to the measured far-field profiles of unmodified and modified fibers. From the analysis, a negative refractive-index change of -0.015±0.005 within a radius of (0.6±0.1)  μm is determined.

  12. Scanning Laser Polarimetry and Optical Coherence Tomography for Detection of Retinal Nerve Fiber Layer Defects

    Science.gov (United States)

    Oh, Jong-Hyun

    2009-01-01

    Purpose To compare the ability of scanning laser polarimetry with variable corneal compensation (GDx-VCC) and Stratus optical coherence tomography (OCT) to detect photographic retinal nerve fiber layer (RNFL) defects. Methods This retrospective cross-sectional study included 45 eyes of 45 consecutive glaucoma patients with RNFL defects in red-free fundus photographs. The superior and inferior temporal quadrants in each eye were included for data analysis separately. The location and presence of RNFL defects seen in red-free fundus photographs were compared with those seen in GDx-VCC deviation maps and OCT RNFL analysis maps for each quadrant. Results Of the 90 quadrants (45 eyes), 31 (34%) had no apparent RNFL defects, 29 (32%) had focal RNFL defects, and 30 (33%) had diffuse RNFL defects in red-free fundus photographs. The highest agreement between GDx-VCC and red-free photography was 73% when we defined GDx-VCC RNFL defects as a cluster of three or more color-coded squares (p<5%) along the traveling line of the retinal nerve fiber in the GDx-VCC deviation map (kappa value, 0.388; 95% confidence interval (CI), 0.195 to 0.582). The highest agreement between OCT and red-free photography was 85% (kappa value, 0.666; 95% CI, 0.506 to 0.825) when a value of 5% outside the normal limit for the OCT analysis map was used as a cut-off value for OCT RNFL defects. Conclusions According to the kappa values, the agreement between GDx-VCC deviation maps and red-free photography was poor, whereas the agreement between OCT analysis maps and red-free photography was good. PMID:19794943

  13. Scanning laser polarimetry and optical coherence tomography for detection of retinal nerve fiber layer defects.

    Science.gov (United States)

    Oh, Jong-Hyun; Kim, Yong Yeon

    2009-09-01

    To compare the ability of scanning laser polarimetry with variable corneal compensation (GDx-VCC) and Stratus optical coherence tomography (OCT) to detect photographic retinal nerve fiber layer (RNFL) defects. This retrospective cross-sectional study included 45 eyes of 45 consecutive glaucoma patients with RNFL defects in red-free fundus photographs. The superior and inferior temporal quadrants in each eye were included for data analysis separately. The location and presence of RNFL defects seen in red-free fundus photographs were compared with those seen in GDx-VCC deviation maps and OCT RNFL analysis maps for each quadrant. Of the 90 quadrants (45 eyes), 31 (34%) had no apparent RNFL defects, 29 (32%) had focal RNFL defects, and 30 (33%) had diffuse RNFL defects in red-free fundus photographs. The highest agreement between GDx-VCC and red-free photography was 73% when we defined GDx-VCC RNFL defects as a cluster of three or more color-coded squares (p<5%) along the traveling line of the retinal nerve fiber in the GDx-VCC deviation map (kappa value, 0.388; 95% confidence interval (CI), 0.195 to 0.582). The highest agreement between OCT and red-free photography was 85% (kappa value, 0.666; 95% CI, 0.506 to 0.825) when a value of 5% outside the normal limit for the OCT analysis map was used as a cut-off value for OCT RNFL defects. According to the kappa values, the agreement between GDx-VCC deviation maps and red-free photography was poor, whereas the agreement between OCT analysis maps and red-free photography was good.

  14. Fiber-laser-based green-pumped picosecond MgO:sPPLT optical parametric oscillator.

    Science.gov (United States)

    Chaitanya Kumar, S; Ebrahim-Zadeh, M

    2013-12-15

    We report a stable, high-power, picosecond optical parametric oscillator (OPO) at 160 MHz repetition rate synchronously pumped by a frequency-doubled mode-locked Yb-fiber laser at 532 nm and tunable in the near-infrared, across 874-1008 nm (signal) and 1126-1359 nm (idler). Using a 30-mm-long MgO:sPPLT crystal, the OPO provides average output power up to 780 mW in the signal at 918.58 nm and 600 mW in the idler at 1242 nm. The device operates stably over many days, even close to degeneracy, exhibiting passive long-term power stability better than 1.8% rms in the signal and 2.4% rms in the idler over 2.5 h at a temperature of 55°C. We investigate spectral and temporal characteristics of the signal pulses under different conditions and demonstrate cavity-length tuning enabled by the dispersion properties of MgO:sPPLT. The output signal pulses have a duration of 2.4 ps at 967 nm.

  15. Continuously tunable wideband semiconductor fiber-ring laser

    Science.gov (United States)

    Mao, Xuefeng; Zhao, Shiwei; Yuan, Suzhen; Wang, Xiaofa; Zheng, Peichao

    2017-08-01

    We demonstrate a wideband tunable semiconductor fiber-ring laser that can be continuously tuned from 1498 nm to 1623 nm. The proposed laser uses a semiconductor optical amplifier (SOA) as a gain medium and a fiber Fabry-Perot tunable filter as a selective wavelength filter. The optimized drive current of the SOA and the output coupling ratio are obtained by experimental research. This laser has a simple configuration, low threshold, flat laser output power and high optical signal-to-noise ratio.

  16. Fiber optics engineering

    CERN Document Server

    Azadeh, Mohammad

    2009-01-01

    Covering fiber optics from an engineering perspective, this text emphasizes data conversion between electrical and optical domains. Techniques to improve the fidelity of this conversion (from electrical to optical domain, and vice versa) are also covered.

  17. Optical fiber crossbar switch

    Science.gov (United States)

    Kilcoyne, Michael K.; Beccue, Stephen M.; Brar, Berinder; Robinson, G.; Pedrotti, Kenneth D.; Haber, William A.

    1990-07-01

    Advances in high performance computers and signal processing systems have led to parallel system architectures. The main limitation in achieving the performance expected of these parallel systems has been the realization of an efficient means to interconnect many processors into a effective parallel system. Electronic interconnections have proved cumbersome, costly and ineffective. The Optical Fiber Crossbar Switch (OFCS) is a compact low power, multi-gigahertz bandwidth multi-channel switch which can be used in large scale computer and telecommunication applications. The switch operates in the optical domain using GaAs semiconductor lasers to transmit wideband multiple channel optical data over fiber optic cables. Recently, a 32 X 32 crossbar switching system was completed and demonstrated. Error free performance was obtained at a data bandwidth of 410 MBPS, using a silicon switch IC. The switch can be completely reconfigured in less than 50 nanoseconds under computer control. The fully populated OFCS has the capability to handle 12.8 gigabits per second (GBPS) of data while switching this data over 32 channels without the loss of a single bit during switching. GaAs IC technology has now progressed to the point that 16 X 16 GaAs based crossbar switch Ics are available which have increased the data bandwidth capability to 2.4 GBPS. The present optical interfaces are integrated GaAs transmitter drivers, GaAs lasers, and integrated GaAs optical receivers with data bandwidths exceeding 2.4 GBPS. A system using all Ill-V switching and optoelectronic components is presently under development for both NASA and DoD programs. The overall system is designed to operate at 1.3 GBPS. It is expected that these systems will find wide application in high capacity computing systems based on parallel microprocessor architecture which require high data bandwidth communication between processors. The OFCS will also have application in commercial optical telecommunication systems

  18. Laser of optical fiber composed by two coupled cavities: application as optical fiber sensor; Laser de fibra optica compuesto por dos cavidades acopladas: aplicacion como sensor de fibra optica

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez S, R.A.; Kuzin, E.A.; Ibarra E, B. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), A.P. 51 y 216, 72000 Puebla (Mexico); May A, M. [Universidad Autonoma del Carmen (UNACAR) Av. 56 No. 4 por Av. Concordia, Campeche (Mexico); Shlyagin, M.; Marquez B, I. [Centro de Investigacion Cientifica y de Ensenanza Superior de Ensenada (CICESE), 22860 Ensenada, Baja California (Mexico)]. e-mail: ravsa100@hotmail.com

    2004-07-01

    We show an optical fiber laser sensor which consist of two cavities coupled and three fiber Bragg gratings. We used one Bragg grating (called reference) and two Bragg gratings (called sensors), which have the lower reflection wavelength. The reference grating with the two sensors grating make two cavities: first one is the internal cavity which has 4230 m of length and the another one is the external cavity which has 4277 m of length. Measuring the laser beating frequency for a resonance cavity and moving the frequency peaks when the another cavity is put in resonance, we prove that the arrangement can be used as a two points sensor for determining the difference of temperature or stress between these two points. (Author)

  19. Active Optical Fibers Doped with Ceramic Nanocrystals

    Directory of Open Access Journals (Sweden)

    Jan Mrazek

    2014-01-01

    Full Text Available Erbium-doped active optical fiber was successfully prepared by incorporation of ceramic nanocrystals inside a core of optical fiber. Modified chemical vapor deposition was combined with solution-doping approach to preparing preform. Instead of inorganic salts erbium-doped yttrium-aluminium garnet nanocrystals were used in the solution-doping process. Prepared preform was drawn into single-mode optical fiber with a numerical aperture 0.167. Optical and luminescence properties of the fiber were analyzed. Lasing ability of prepared fiber was proofed in a fiber-ring set-up. Optimal laser properties were achieved for a fiber length of 20~m. The slope efficiency of the fiber-laser was about 15%. Presented method can be simply extended to the deposition of other ceramic nanomaterials.

  20. The Fiber Optic Connection.

    Science.gov (United States)

    Reese, Susan

    2003-01-01

    Describes the fiber optics programs at the Career and Technical Center in Berlin, Pennsylvania and the Charles S. Monroe Technology Center in Loudoun County, Virginia. Discusses the involvement of the Fiber Optic Association with education, research and development, manufacturing, sales, distribution, installation, and maintenance of fiber optic…

  1. A Fundamental Study of Laser-Induced Breakdown Spectroscopy Using Fiber Optics for Remote Measurements Of Trace Metals

    Energy Technology Data Exchange (ETDEWEB)

    Scott Goode; S. Michael Angel

    2004-01-20

    Develop a fiber-optic imaging probe for microanalysis of solid samples; Design a time-resolved plasma imaging system to measure the development of the LIBS signal; Setup a laboratory system capable of timing two lasers independently, for optimizing and characterizing dual-pulse LIBS; Compare the development of laser-induced plasmas generated with a single laser pulse to the development of laser-induced plasmas generated with a pre-ablation spark prior to sample ablation; Examine the effect of sample matrix on the LIBS signals of elements in different sample matrices; Investigate the effect of excitation wavelength of the ablation beam in pre-ablation spark dual-pulse LIBS experiments; Determine the effect of the physical properties of the sample on the mass of materials ablated.

  2. A Large Area Fiber Optic Gyroscope on multiplexed fiber network

    OpenAIRE

    Clivati, Cecilia; Calonico, Davide; Costanzo, Giovanni A.; Mura, Alberto; Pizzocaro, Marco; Levi, Filippo

    2012-01-01

    We describe a fiber optical gyroscope based on the Sagnac effect realized on a multiplexed telecom fiber network. Our loop encloses an area of 20 km^2 and coexists with Internet data traffic. This Sagnac interferometer achieves a sensitivity of about 1e-8 (rad/s)/sqrt(Hz), thus approaching ring laser gyroscopes without using narrow-linewidth laser nor sophisticated optics. The proposed gyroscope is sensitive enough for seismic applications, opening new possibilities for this kind of optical f...

  3. Generation of acoustic waves by cw laser radiation at the tip of an optical fiber in water

    Science.gov (United States)

    Yusupov, V. I.; Konovalov, A. N.; Ul'yanov, V. A.; Bagratashvili, V. N.

    2016-09-01

    We investigate the specific features of acoustic signals generated in water under the action of cw laser radiation with a power of 3 W at wavelengths of 0.97, 1.56, and 1.9 μm, emerging from an optical fiber. It is established that when a fiber tip without an absorbing coating is used, quasi-periodic pulse signals are generated according to the thermocavitation mechanism due to the formation and collapse of vapor-gas bubbles of millimeter size. In this case, the maximum energy of a broadband (up to 10 MHz) acoustic signal generated only at wavelengths of 1.56 and 1.9 μm is concentrated in the range of 4-20 kHz. It is shown that when there is no absorbing coating, an increase in the laser-radiation absorption coefficient in water leads to an increase in the frequency of generated acoustic pulses, while the maximum pressure amplitudes in them remain virtually constant. If there is an absorbing coating on the laser-fiber tip, a large number of small vapor-gas bubbles are generated at all laser-radiation wavelengths used. This leads to the appearance of a continuous amplitude-modulated acoustic signal, whose main energy is concentrated in the range of 8-15 kHz. It is shown that in this case, increasing the absorption coefficient of laser radiation in water leads to an increase in the power of an acoustic emission signal. The results can be used to explain the high therapeutic efficiency of moderate-power laser-fiber apparatus.

  4. Photonic crystal distributed feedback fiber lasers with Bragg gratings

    DEFF Research Database (Denmark)

    Søndergaard, Thomas

    2000-01-01

    Two new types of optical fibers, where air-holes are running down their length, are considered for making fiber lasers with Bragg gratings. The mode areas for pump and signal in these fiber lasers may be either larger or smaller compared to the corresponding mode areas for fiber lasers based on s...... on standard step index fibers. This makes possible realization of fiber lasers with a low pump threshold (small mode area), and fiber lasers suitable for high-power applications (large mode area)......Two new types of optical fibers, where air-holes are running down their length, are considered for making fiber lasers with Bragg gratings. The mode areas for pump and signal in these fiber lasers may be either larger or smaller compared to the corresponding mode areas for fiber lasers based...

  5. Random Fiber Laser

    CERN Document Server

    de Matos, Christiano J S; Brito-Silva, Antônio M; Gámez, M A Martinez; Gomes, Anderson S L; de Araújo, Cid B

    2007-01-01

    We investigate the effects of two dimensional confinement on the lasing properties of a classical random laser system operating in the incoherent feedback (diffusive) regime. A suspension of 250nm rutile (TiO2) particles in a Rhodamine 6G solution was inserted into the hollow core of a photonic crystal fiber (PCF) generating the first random fiber laser and a novel quasi-one-dimensional RL geometry. Comparison with similar systems in bulk format shows that the random fiber laser presents an efficiency that is at least two orders of magnitude higher.

  6. Optical Fiber Fusion Splicing

    CERN Document Server

    Yablon, Andrew D

    2005-01-01

    This book is an up-to-date treatment of optical fiber fusion splicing incorporating all the recent innovations in the field. It provides a toolbox of general strategies and specific techniques that the reader can apply when optimizing fusion splices between novel fibers. It specifically addresses considerations important for fusion splicing of contemporary specialty fibers including dispersion compensating fiber, erbium-doped gain fiber, polarization maintaining fiber, and microstructured fiber. Finally, it discusses the future of optical fiber fusion splicing including silica and non-silica based optical fibers as well as the trend toward increasing automation. Whilst serving as a self-contained reference work, abundant citations from the technical literature will enable readers to readily locate primary sources.

  7. RF Fiber Optic Link.

    Science.gov (United States)

    1984-06-01

    CONTENTS (Continued) 0 o p- Paragraph Title Page 4.6.3 Laser Diode and Single Mode Fiber Interface ....... 68 0 4.6.4 Laser Noise Discussion...A111-4. 2. 0. Marcuse and C. L. Lin, "Low Dispersion Single-Mode Fiber Transmission - The Question of Practical Versus Theoretical Maxlimum...001/0161A 68 ,.-. .- ,-... -. ..- , .. -............. . ............... • :q

  8. In-Vivo functional optical-resolution photoacoustic microscopy with stimulated Raman scattering fiber-laser source.

    Science.gov (United States)

    Hajireza, Parsin; Forbrich, Alexander; Zemp, Roger

    2014-02-01

    In this paper a multi-wavelength optical-resolution photoacoustic microscopy (OR-PAM) system using stimulated Raman scattering is demonstrated for both phantom and in vivo imaging. A 1-ns pulse width ytterbium-doped fiber laser is coupled into a single-mode polarization maintaining fiber. Discrete Raman-shifted wavelength peaks extending to nearly 800 nm are generated with pulse energies sufficient for OR-PAM imaging. Bandpass filters are used to select imaging wavelengths. A dual-mirror galvanometer system was used to scan the focused outputs across samples of carbon fiber networks, 200μm dye-filled tubes, and Swiss Webster mouse ears. Photoacoustic signals were collected in transmission mode and used to create maximum amplitude projection C-scan images. Double dye experiments and in vivo oxygen saturation estimation confirmed functional imaging potential.

  9. Low-Complexity Tracking of Laser and Nonlinear Phase Noise in WDM Optical Fiber Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Fehenberger, Tobias; Barletta, Luca;

    2015-01-01

    In this paper, the wavelength division multiplexed (WDM) fiber optic channel is considered. It is shown that for ideal distributed Raman amplification (IDRA), the Wiener process model is suitable for the non-linear phase noise due to cross phase modulation from neighboring channels. Based...

  10. Fiber Ring Optical Gyroscope (FROG)

    Science.gov (United States)

    1979-01-01

    The design, construction, and testing of a one meter diameter fiber ring optical gyro, using 1.57 kilometers of single mode fiber, are described. The various noise components: electronic, thermal, mechanical, and optical, were evaluated. Both dc and ac methods were used. An attempt was made to measure the Earth rotation rate; however, the results were questionable because of the optical and electronic noise present. It was concluded that fiber ring optical gyroscopes using all discrete components have many serious problems that can only be overcome by discarding the discrete approach and adapting an all integrated optic technique that has the laser source, modulator, detector, beamsplitters, and bias element on a single chip.

  11. Efficient, high-power, ytterbium-fiber-laser-pumped picosecond optical parametric oscillator.

    Science.gov (United States)

    Kokabee, O; Esteban-Martin, A; Ebrahim-Zadeh, M

    2010-10-01

    We report a high-power picosecond optical parametric oscillator (OPO) synchronously pumped by a Yb fiber laser at 1.064 μm, providing 11.7 W of total average power in the near to mid-IR at 73% extraction efficiency. The OPO, based on a 50 mm MgO:PPLN crystal, is pumped by 20.8 ps pulses at 81.1 MHz and can simultaneously deliver 7.1 W of signal at 1.56 μm and 4.6 W of idler at 3.33 μm for 16 W of pump power. The oscillator has a threshold of 740 mW, with maximum signal power of 7.4 W at 1.47 μm and idler power of 4.9 W at 3.08 μm at slope efficiencies of 51% and 31%, respectively. Wavelength coverage across 1.43-1.63 μm (signal) and 4.16-3.06 μm (idler) is obtained, with a total power of ~11 W and an extraction efficiency of ~68%, with pump depletion of ~78% maintained over most of the tuning range. The signal and idler output have a single-mode spatial profile and a peak-to-peak power stability of ±1.8% and ±2.9% over 1 h at the highest power, respectively. A signal pulse duration of 17.3 ps with a clean single-peak spectrum results in a time-bandwidth product of ~1.72, more than four times below the input pump pulses.

  12. Nonlinear High-Energy Pulse Propagation in Graded-Index Multimode Optical Fibers for Mode-Locked Fiber Lasers

    Science.gov (United States)

    2014-12-23

    bels or specify how to translate the μ index into the p;m index pair. jAμzj2 represents the optical power in the LGpm mode. Fig. 1. GIMF of...crystal fiber,” Opt. Lett. 31, 1480–1482 (2006). 19. T. F. S. Büttner, D. D. Hudson, E. C. Mägi, A. Casas Bedoya, T. Taunay, and B. J. Eggleton

  13. Laser-optical fiber Bragg grating anemometer for measuring gas flows: application to measuring the electric wind.

    Science.gov (United States)

    Lamb, David W; Hooper, Adam

    2006-04-15

    A novel laser-optical fiber Bragg grating anemometer (FBGA) has been devised for measuring the speed of a moving gas in the range 0-1.5 m s(-1). As a test, the FBGA was applied to measuring the speed of the electric wind generated in the particularly harsh, high-voltage environment of a dc, negative-polarity, partial (corona) discharge in atmospheric air. The instrument proved more stable and yielded an order-of-magnitude improvement in sensitivity (deltav approximately 4 x 10(-3) ms(-1)) compared with other optical-fiber-based anemometers. On-axis wind speeds ranging from zero to 1.1 m s(-1) were measured in the vicinity of the corona discharge.

  14. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind P

    2001-01-01

    The Optical Society of America (OSA) and SPIE - The International Society for Optical Engineering have awarded Govind Agrawal with an honorable mention for the Joseph W. Goodman Book Writing Award for his work on Nonlinear Fiber Optics, 3rd edition.Nonlinear Fiber Optics, 3rd Edition, provides a comprehensive and up-to-date account of the nonlinear phenomena occurring inside optical fibers. It retains most of the material that appeared in the first edition, with the exception of Chapter 6, which is now devoted to the polarization effects relevant for light propagation in optical

  15. Optical fiber sensors measurement system and special fibers improvement

    Science.gov (United States)

    Jelinek, Michal; Hrabina, Jan; Hola, Miroslava; Hucl, Vaclav; Cizek, Martin; Rerucha, Simon; Lazar, Josef; Mikel, Bretislav

    2017-06-01

    of the splicing process has to be prepared for any new optical fibers and new fibers combinations. The splicing of the same types of fibers from different manufacturers can be adjusted by several tested changes in the splicing process. We are able to splice PCF with standard telecommunication fiber with attenuation up to 2 dB. The method is also presented. Development of these new techniques and methods of the optical fibers splicing are made with respect to using these fibers to another research and development in the field of optical fibers sensors, laser frequency stabilization and laser interferometry based on optical fibers. Especially for the field of laser frequency stabilization we developed and present new techniques to closing microstructured fibers with gases inside.

  16. Analysis of Laser & Detector Placement in MIMO Multimode Optical Fiber Systems

    CERN Document Server

    Appaiah, Kumar; Vishwanath, Sriram; Bank, Seth R

    2011-01-01

    Multimode fibers (MMFs) offer a cost-effective connection solution for small and medium length networks. However, data rates through multimode fibers are traditionally limited by modal dispersion. Signal processing and Multiple-Input Multiple-Output (MIMO) have been shown to be effective at combating these limitations, but device design for the specific purpose of MIMO in MMFs is still an open issue. This paper utilizes a statistical field propagation model for MMFs to aid the analysis and designs of MMF laser and detector arrays, and aims to improve data rates of the fiber. Simulations reveal that optimal device designs could possess 2-3 times the data carrying capacity of suboptimal ones.

  17. Bragg gratings inscription in step-index PMMA optical fiber by femtosecond laser pulses at 400 nm

    Science.gov (United States)

    Hu, X.; Kinet, D.; Chah, K.; Mégret, P.; Caucheteur, C.

    2016-05-01

    In this paper, we report photo-inscription of uniform Bragg gratings in trans-4-stilbenemethanol-doped photosensitive step-index polymer optical fiber. Gratings were produced at ~1575 nm by the phase mask technique with a femtosecond laser emitting at 400 nm with different average optical powers (8 mW, 13 mW and 20 mW). The grating growth dynamics in transmission were monitored during the manufacturing process, showing that the grating grows faster with higher power. Using 20 mW laser beam power, the reflectivity reaches 94 % (8 dB transmission loss) in 70 seconds. Finally, the gratings were characterized in temperature in the range 20 - 45 °C. The thermal sensitivity has been computed equal to - 86.6 pm/°C.

  18. A unidirectional Er3+-doped fiber ring laser without isolator

    DEFF Research Database (Denmark)

    Shi, Yuan; Sejka, Milan; Poulsen, Ove

    1995-01-01

    An Er3+-doped fiber ring laser with unidirectional operation without optical isolator has been investigated for different cavity conditions. The fiber ring laser cavity is built in such a way that the optical fields propagating in the two directions suffer different losses. As a consequence, the ......, the laser oscillation appears in a quasi-unidirectional form. By incorporating a fiber pigtailed bandpass filter to enhance mode competition, a purely unidirectional tunable fiber ring laser is obtained with high efficiency and broad tunability...

  19. EFFECT OF OPTICAL FIBER HYDROGEN LOADING ON THE INSCRIPTION EFFICIENCY OF CHIRPED BRAGG GRATINGS BY MEANS OF KrF EXCIMER LASER RADIATION

    Directory of Open Access Journals (Sweden)

    Sergey V. Varzhel

    2016-11-01

    Full Text Available Subject of Research.We present comparative results of the chirped Bragg gratings inscription efficiency in optical fiber of domestic production with and without low-temperature hydrogen loading. Method. Chirped fiber Bragg gratings inscription was made by the Talbot interferometer with chirped phase mask having a chirp rate of 2.3 nm/cm used for the laser beam amplitude separation. The excimer laser system Coherent COMPexPro 150T, working with the gas mixture KrF (248 nm, was used as the radiation source. In order to increase the UV photosensitivity, the optical fiber was placed in a chamber with hydrogen under a pressure of 10 MPa and kept there for 14 days at 40 °C. Main Results. The usage of the chirped phase mask in a Talbot interferometer scheme has made it possible to get a full width at half-maximum of the fiber Bragg grating reflection spectrum of 3.5 nm with induced diffraction structure length of 5 mm. By preliminary hydrogen loading of optical fiber the broad reflection spectrum fiber Bragg gratings with a reflectivity close to 100% has been inscribed. Practical Relevance. The resulting chirped fiber Bragg gratings can be used as dispersion compensators in optical fiber communications, as well as the reflective elements of distributed fiber-optic phase interferometric sensors.

  20. Fast-light Enhanced Brillouin Laser Based Active Fiber Optics Sensor for Simultaneous Measurement of Rotation and Acceleration

    CERN Document Server

    Zhou, Minchuan; Fouda, Mohamed; Condon, Nicholas; Scheuer, Jacob; Shahriar, Selim M

    2016-01-01

    We have developed a conceptual design for an Active Fast Light Fiber Optic Sensor (AFLIFOS) that can perform simultaneously or separately as a gyroscope (differential mode effect) and a sensor for acceleration, strain, and other common mode effects. Two Brillouin lasers in opposite directions and separated in frequency by several free spectral ranges are used for this sensor. By coupling two auxiliary resonators to the primary fiber resonator, we produce superluminal effects for two laser modes. We develop a detailed theoretical model for optimizing the design of the AFLIFOS, and show that the enhancement factor of the sensitivity is $\\sim{187}$ and $\\sim{-187}$, respectively for the two Brillouin lasers under the optimized condition, when the effective change in perimeter of the primary fiber resonator is 0.1nm, corresponding to a rotation rate of 0.4 deg/sec for a ring resonator with radius 1m. It may be possible to get much higher enhancement by adjusting the parameters such as the perimeters and the coupl...

  1. Stable dual-wavelength single-longitudinal-mode ring erbium-doped fiber laser for optical generation of microwave frequency

    Science.gov (United States)

    Wang, T.; Liang, G.; Miao, X.; Zhou, X.; Li, Q.

    2012-05-01

    We demonstrate a simple dual-wavelength ring erbium-doped fiber laser operating in single-longitudinal-mode (SLM) at room temperature. A pair of reflection type short-period fiber Bragg gratings (FBGs), which have two different center wavelengths of 1545.072 and 1545.284 nm, are used as the wavelength-selective component of the laser. A segment of unpumped polarization maintaining erbium-doped fiber (PM-EDF) is acted as a narrow multiband filter. By turning the polarization controller (PC) to enhance the polarization hole burning (PHB), the single-wavelength and dual-wavelength laser oscillations are observed at 1545.072 and 1545.284 nm. The output power variation is less than 0.6 dB for both wavelengths over a five-minute period and the optical signal to noise ratio (OSNR) is greater than 50 dB. By beating the dual-wavelengths at a photodetector (PD), a microwave signal at 26.44 GHz is demonstrated.

  2. The influence on biotissue laser resection of a strongly absorbing layer at the optical fiber tip

    Directory of Open Access Journals (Sweden)

    Daria Kuznetsova

    2016-09-01

    Full Text Available In this paper, we consider a method of laser resection using the silica glass core from which the cladding layer has been removed as the cutting part of a laser scalpel. An absorbing layer coating the silica fiber tip markedly alters its biotissue cutting characteristics. The results of histological studies of skin after exposure to a laser scalpel with and without a strongly absorbing coating (SAC at a wavelength of 0.97μm show that resection using a coated scalpel is more sparing. When an uncoated scalpel was used, skin injury was more apparent in both its surface spread and the depth of structural damage, resulting in poorer tissue regeneration.

  3. Fiber optic and laser sensors IV; Proceedings of the Meeting, Cambridge, MA, Sept. 22-24, 1986

    Science.gov (United States)

    De Paula, Ramon P. (Editor); Udd, Eric (Editor)

    1987-01-01

    The conference presents papers on industrial uses of fiber optic sensors, point and distributed polarimetric optical fiber sensors, fiber optic electric field sensor technology, micromachined resonant structures, single-mode fibers for sensing applications, and measurement techniques for magnetic field gradient detection. Consideration is also given to electric field meter and temperature measurement techniques for the power industry, the calibration of high-temperature fiber-optic microbend pressure transducers, and interferometric sensors for dc measurands. Other topics include the recognition of colors and collision avoidance in robotics using optical fiber sensors, the loss compensation of intensity-modulating fiber-optic sensors, and an embedded optical fiber strain tensor for composite structure applications.

  4. Fiber optic and laser sensors IV; Proceedings of the Meeting, Cambridge, MA, Sept. 22-24, 1986

    Science.gov (United States)

    De Paula, Ramon P. (Editor); Udd, Eric (Editor)

    1987-01-01

    The conference presents papers on industrial uses of fiber optic sensors, point and distributed polarimetric optical fiber sensors, fiber optic electric field sensor technology, micromachined resonant structures, single-mode fibers for sensing applications, and measurement techniques for magnetic field gradient detection. Consideration is also given to electric field meter and temperature measurement techniques for the power industry, the calibration of high-temperature fiber-optic microbend pressure transducers, and interferometric sensors for dc measurands. Other topics include the recognition of colors and collision avoidance in robotics using optical fiber sensors, the loss compensation of intensity-modulating fiber-optic sensors, and an embedded optical fiber strain tensor for composite structure applications.

  5. Microsecond pulsed optical parametric oscillator pumped by a Q-switched fiber laser

    NARCIS (Netherlands)

    Klein, M.E.; Adel, P.; Auerbach, M.; Fallnich, C.; Gross, P.; Boller, Klaus J.

    2003-01-01

    We report on what is to our knowledge the first optical parametric oscillator (OPO) pumped by microsecond pulses from a wavelength-tunable solid-state laser. The singly resonant OPO (SRO) is based on a periodically poled LiNbO3 crystal and pumped with 2.1-ms-long pulses from an actively Q-switched Y

  6. High Power Fiber Lasers

    Science.gov (United States)

    2012-08-02

    Optics, Information and Photonics, University of Erlangen- Nuremberg , Germany, June 2007. INVITED 14. A. Siegman, “Index Antiguided Optical Fibers and...Lasers” seminar given at the Institute for Optics, Information and Photonics, University of Erlangen- Nuremberg , Germany, June 2007. INVITED 14. A

  7. A novel 852-nm tunable fiber laser

    Institute of Scientific and Technical Information of China (English)

    Yanlong Shen; Chun Gu; LixinXu; Anting Wang; Hai Ming; Yang Liu; Xiaobing Wang

    2009-01-01

    @@ We report a novel fiber laser operating at 850-nm band by using semiconductor optical amplifier and fiber grating.The laser system is stable, compact, and the operating wavelength can be tuned continuously from about 851 to 854 nm for Cs atomic clock system by stretching the fiber grating.An output power up to 20 mW is obtained with a signal-to-background ratio beyond 30 dB.

  8. Method of targeted delivery of laser beam to isolated retinal rods by fiber optics.

    Science.gov (United States)

    Sim, Nigel; Bessarab, Dmitri; Jones, C Michael; Krivitsky, Leonid

    2011-11-01

    A method of controllable light delivery to retinal rod cells using an optical fiber is described. Photo-induced current of the living rod cells was measured with the suction electrode technique. The approach was tested with measurements relating the spatial distribution of the light intensity to photo-induced current. In addition, the ion current responses of rod cells to polarized light at two different orientation geometries of the cells were studied.

  9. Method of targeted delivery of laser beam to isolated retinal rods by fiber optics

    CERN Document Server

    Sim, Nigel; Jones, C Michael; Krivitsky, Leonid

    2013-01-01

    A method of controllable light delivery to retinal rod cells using an optical fiber is described. Photo-induced current of the living rod cells was measured with the suction electrode technique. The approach was tested with measurements relating the spatial distribution of the light intensity to photo-induced current. In addition, the ion current responses of rod cells to polarized light at two different orientation geometries of the cells were studied.

  10. Fiber optics principles and practices

    CERN Document Server

    Al-Azzawi, Abdul

    2007-01-01

    Since the invention of the laser, our fascination with the photon has led to one of the most dynamic and rapidly growing fields of technology. New advances in fiber optic devices, components, and materials make it more important than ever to stay current. Comprising chapters drawn from the author's highly anticipated book Photonics: Principles and Practices, Fiber Optics: Principles and Practices offers a detailed and focused treatment for anyone in need of authoritative information on this critical area underlying photonics.Using a consistent approach, the author leads you step-by-step throug

  11. Python fiber optic seal

    Energy Technology Data Exchange (ETDEWEB)

    Ystesund, K.; Bartberger, J.; Brusseau, C.; Fleming, P.; Insch, K.; Tolk, K.

    1993-08-01

    Sandia National Laboratories has developed a high security fiber optic seal that incorporates tamper resistance features that are not available in commercial fiber optic seals. The Python Seal is a passive fiber optic loop seal designed to give indication of unauthorized entry. The seal includes a fingerprint feature that provides seal identity information in addition to the unique fiber optic pattern created when the seal is installed. The fiber optic cable used for the seal loop is produced with tamper resistant features that increase the difficulty of attacking that component of a seal. A Seal Reader has been developed that will record the seal signature and the fingerprint feature of the seal. A Correlator software program then compares seal images to establish a match or mismatch. SNL is also developing a Polaroid reader to permit hard copies of the seal patterns to be obtained directly from the seal.

  12. Degradation of optical properties of a film-type single-wall carbon nanotubes saturable absorber (SWNT-SA) with an Er-doped all-fiber laser.

    Science.gov (United States)

    Ryu, Sung Yoon; Kim, Kyung-Soo; Kim, Jungwon; Kim, Soohyun

    2012-06-04

    Single-wall carbon nanotubes (SWNTs) are promising materials for saturable absorbers (SAs) in mode-locked lasers. However it has been widely recognized that the degradation of optical properties of film-type SWNTs used in femtosecond mode-locked lasers limits the achievable long-term stability of such lasers. In this paper, we study the degradation of optical properties of SWNT-SA fabricated as sandwich type using HiPCO SWNTs with an Er-doped all-fiber laser. The thresholds of laser pump power are examined to avoid the damage of the SWNT-SA. Based on the proposed analysis, it is shown that all-fiber laser pulses of 300 fs pulse width, 3.85 mW average output power, 211.7 MW/cm² peak intensity and 69.9 MHz repetition rate can be reliably generated without any significant damage to the SWNT-SA film.

  13. Effects of underwater turbulence on laser beam propagation and coupling into single-mode optical fiber.

    Science.gov (United States)

    Hanson, Frank; Lasher, Mark

    2010-06-01

    We characterize and compare the effects of turbulence on underwater laser propagation with theory. Measurements of the coupling efficiency of the focused beam into a single-mode fiber are reported. A simple tip-tilt control system, based on the position of the image centroid in the focal plane, was shown to maintain good coupling efficiency for a beam radius equal to the transverse coherence length, r(0). These results are relevant to high bandwidth communication technology that requires good spatial mode quality.

  14. Multispot fiber laser welding

    DEFF Research Database (Denmark)

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...... in the weld causing expulsion of the melt pool. Trailing beams were applied to melt additional material and ensure a melt pool. The method showed good results for increasing tolerances to impurities and reduction of scrapped parts from blowouts during laser welding....

  15. Development of fiber optic laser Doppler velocimeter for measurement of local blood velocity

    Science.gov (United States)

    Ohba, Kenkich; Fujiwara, Noboru

    1993-08-01

    In order to measure the local velocity field in opaque fluid flows like blood flow, a new laser Doppler velocimeter having a pickup consisting of a small distributed index lens attached to the tips of two fibers which are joined side by side in parallel has been newly developed. The distributed index lens is the shape of a truncated cone. The flow field around this sensor has been measured very precisely by means of an ordinary LDV. The effect of turbidity of fluid on the quality of the laser Doppler signal from this sensor has been examined by experiments. As a result, it has been shown that this LDV sensor has a high signal-to-noise ratio, and that the disturbance against flow by the sensor is very small, and it is very promising as a velocity sensor for opaque or semi-opaque fluid flow like blood flow.

  16. Measurement of axial neutral density profiles in a microwave discharge ion thruster by laser absorption spectroscopy with optical fiber probes.

    Science.gov (United States)

    Tsukizaki, Ryudo; Koizumi, Hiroyuki; Nishiyama, Kazutaka; Kuninaka, Hitoshi

    2011-12-01

    In order to reveal the physical processes taking place within the "μ10" microwave discharge ion thruster, internal plasma diagnosis is indispensable. However, the ability of metallic probes to access microwave plasmas biased at a high voltage is limited from the standpoints of the disturbance created in the electric field and electrical isolation. In this study, the axial density profiles of excited neutral xenon were successfully measured under ion beam acceleration by using a novel laser absorption spectroscopy system. The target of the measurement was metastable Xe I 5p(5)((2)P(0) (3/2))6s[3/2](0) (2) which absorbed a wavelength of 823.16 nm. Signals from laser absorption spectroscopy that swept a single-mode optical fiber probe along the line of sight were differentiated and converted into axial number densities of the metastable neutral particles in the plasma source. These measurements revealed a 10(18) m(-3) order of metastable neutral particles situated in the waveguide, which caused two different modes during the operation of the μ10 thruster. This paper reports a novel spectroscopic measurement system with axial resolution for microwave plasma sources utilizing optical fiber probes.

  17. Wavelength-tunable 10 GHz actively harmonic mode-locked fiber laser based on semiconductor optical amplifier

    Science.gov (United States)

    Mao, Yan; Tong, Xinglin; Wang, Zhiqiang; Zhan, Li; Hu, Pan; Chen, Liang

    2015-12-01

    We demonstrate a widely wavelength-tunable actively mode-locked fiber laser based on semiconductor optical amplifier. Beneficiating from the actively mode-locking operation and the wavelength-tunable characteristics of a Fabry-Perot filter, different harmonic mode-locking orders, from the fundamental mode-locking order (18.9 MHz) to the 520th order (9.832 GHz), can be easily achieved. The spectral bandwidth corresponding to the fundamental repetition rate is 0.12 nm with the pulse duration of 9.8 ns, leading to the TBP value of 146, which is about 460 times the transform-limited value for soliton pulse. The highest repetition rate of the mode-locked pulses we obtained is 9.832 GHz, with a signal-to-noise ratio up to 50 dB. The theoretical transform-limited pulse duration is 21 ps. Meanwhile, the central wavelength can be continuously tuned over 43.4 nm range (1522.8-1566.2 nm). The higher repetition rate and the widely tuning wavelength range make the fiber laser to own great potential and promising prospects in areas such as optical communication and photonic analog-to-digital conversion (ADC).

  18. Remote laser generation of narrow-band surface waves through optical fibers.

    Science.gov (United States)

    Di Scalea, F L; Berndt, T P; Spicer, J B; Djordjevic, B B

    1999-01-01

    This paper demonstrates the use of a fiberoptic bundle for flexible, compact, remote, and noncontact laser generation of surface ultrasonic waves in materials. The bundle is able to deliver Nd:YAG pulsed light with a 60% delivery efficiency up to an average energy of 55 mJ/pulse for a pulse duration on the order of 10 ns and a pulse repetition rate of 20 Hz without signs of fiber damage. Details of the bundle construction and surface preparation are given, and pulsed light delivery tests performed with single tapered fibers are discussed. The high-power light delivery capabilities of the bundle are demonstrated for the generation of narrow-band surface waves in a Carbon/PEEK composite laminate by a spatial modulation technique that employs a periodic transmission mask. Single laser pulse ultrasonic tonebursts are clearly detectable using a small aperture piezoelectric transducer while ensuring thermoelastic generation conditions. The theory of narrow-band generation of surface acoustic waves is improved by accounting for the strength nonuniformity of the illumination sources. In addition, the effect of the number of illumination sources on the bandwidth of the generated surface wave is assessed experimentally, and excellent agreement is shown with the theoretical results predicted by the improved model.

  19. Gain engineering for all-optical microwave and high speed pulse generation in mode-locked fiber lasers

    Science.gov (United States)

    Li, Fangxin; Helmy, Amr S.

    2014-03-01

    Pulsed sources based on approaches that employ only photonic components and no RF components will be discussed in this talk. Several technologies have been explored to generate actively mode-locked sources using electronically driven fiber ring cavities. However, for these sources the pulse repetition rate is usually limited by the bandwidth of the intracavity modulator. Filtering of highly-stable low repetition rate optical combs utilizing cavities such as Fabry-Perot etalons can be used to overcome this limitation. This scheme is not flexible as it requires highly precise control of ultrahigh finesse etalons which limits the repetition rate to the free spectral range of the filter. Pulsed sources based on semiconductor devices offer many advantages, including large gain bandwidth, rapid tunability, long-term stability. In this work we introduce a novel, simple method to generate optical clock with wavelength tunability using two continuous wave (CW) lasers. The lasers are injected into a conventional SOAs-based fiber ring laser. The beating signal generated by these two lasers causes the modulation of the SOA gain saturation inside the cavity. Thus, the SOA provides gain and functions as the modulator as well as the gain medium. When the lasing mode inside the cavity is amplified, it also results in gain-induced four wave mixing. The proposed technique is particularly versatile, overcoming the bandwidth limitation of other techniques, which require RF sources. Moreover, this technique provides the possibility for hybrid integration as it is comprised of semiconductor chips that can be heterogeneously integrated on a Si platform.

  20. Fiber optics standard dictionary

    CERN Document Server

    Weik, Martin H

    1997-01-01

    Fiber Optics Vocabulary Development In 1979, the National Communications System published Technical InfonnationBulle­ tin TB 79-1, Vocabulary for Fiber Optics and Lightwave Communications, written by this author. Based on a draft prepared by this author, the National Communications System published Federal Standard FED-STD-1037, Glossary of Telecommunications Terms, in 1980 with no fiber optics tenns. In 1981, the first edition of this dictionary was published under the title Fiber Optics and Lightwave Communications Standard Dictionary. In 1982, the then National Bureau of Standards, now the National Institute of Standards and Technology, published NBS Handbook 140, Optical Waveguide Communications Glossary, which was also published by the General Services Admin­ istration as PB82-166257 under the same title. Also in 1982, Dynamic Systems, Inc. , Fiberoptic Sensor Technology Handbook, co-authored and edited by published the this author, with an extensive Fiberoptic Sensors Glossary. In 1989, the handbook w...

  1. Ultrahigh resolution optical coherence tomography using high power fiber laser supercontinuum at 1.7 μm wavelength region

    Science.gov (United States)

    Ishida, S.; Kawagoe, H.; Aramaki, M.; Sakakibara, Y.; Omoda, E.; Kataura, H.; Nishizawa, N.

    2013-03-01

    Optical coherence tomography (OCT) is a non-invasive optical imaging technology for micron-scale cross-sectional imaging of biological tissue and materials. We have been investigating ultrahigh resolution optical coherence tomography (UHR-OCT) using fiber based supercontinuum (SC) source. Although UHR-OCT has many advantages in medical equipments, low penetration depth is a serious limitation for wider applications. Recently, we have demonstrated high penetration depth UHR-OCT by use of fiber based Gaussian shaped SC source at 1.7 μm center wavelength. However, the penetration depth has been limited by the low power of SC source. In this paper, to realize deeper penetration imaging, we have developed the high power Gaussian shaped SC source at 1.7 μm wavelength region based on the custom-made Er-doped ultrashort pulse fiber laser with single-wall carbon nanotube and nonlinear phenomena in fibers. This SC source has 43.3 mW output power, 242 nm full-width at half maximum bandwidth, and 109 MHz repetition rate. The repetition rate and average power were almost twice as large as those of previous SC source. Using this light source, 105 dB sensitivity and ultrahigh resolution of 4.3 μm in tissue were achieved simultaneously. We have demonstrated the UHR-OCT imaging of pig thyroid gland and hamster's cheek pouch with this developed SC source and compared the images with those measured by the previous SC source. We have observed the fine structures such as round or oval follicles, epithelium, connective tissue band, and muscular layer. From the comparison of the UHR-OCT images and signals, we confirmed the improvement of imaging contrast and penetration depth with the developed SC source.

  2. Cleaning of endodontic root canal by ultrasonics and Nd:YAG laser beam with fiber optic delivery: scanning electron microscopy, endoscopic and microradiographic analysis

    Science.gov (United States)

    Berna, Norberto; Melis, Marco; Benvenuti, Alessandro; Tosto, Sebastiano; Pierdominici, Fabrizio

    1997-05-01

    12 teeth have been extracted and treated 'in vitro' by ultrasonics and Nd:YAG pulsed laser with fiber optic delivery to compare the cleaning efficiency of the root canal. The optic fiber was equipped with a water-air coaxial cooling system. The ultrasonic device was equipped with a 3 percent NaCl solution douche system. The samples have been prepared according to the technical specifications of the suppliers of laser and ultrasonics and observed by an endodontic endoscope. Cross sections of the samples have been utilized for microradiographic investigations and scanning electron microscopy observations. Local melting has been observed after laser irradiation.Also, vitrification preferentially occurred in the apical zones. The occurrence of vitrification was found strongly dependent on the translation velocity of the laser beam inside the root canal. The laser beam has shown a cleaning efficiency greater than that obtained by ultrasonic procedure.

  3. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA.......Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  4. Fiber Optic Microphone

    Science.gov (United States)

    Cho, Y. C.; George, Thomas; Norvig, Peter (Technical Monitor)

    1999-01-01

    Research into advanced pressure sensors using fiber-optic technology is aimed at developing compact size microphones. Fiber optic sensors are inherently immune to electromagnetic noise, and are very sensitive, light weight, and highly flexible. In FY 98, NASA researchers successfully designed and assembled a prototype fiber-optic microphone. The sensing technique employed was fiber optic Fabry-Perot interferometry. The sensing head is composed of an optical fiber terminated in a miniature ferrule with a thin, silicon-microfabricated diaphragm mounted on it. The optical fiber is a single mode fiber with a core diameter of 8 micron, with the cleaved end positioned 50 micron from the diaphragm surface. The diaphragm is made up of a 0.2 micron thick silicon nitride membrane whose inner surface is metallized with layers of 30 nm titanium, 30 nm platinum, and 0.2 micron gold for efficient reflection. The active sensing area is approximately 1.5 mm in diameter. The measured differential pressure tolerance of this diaphragm is more than 1 bar, yielding a dynamic range of more than 100 dB.

  5. A new fiber-optic non-contact compact laser-ultrasound scanner for fast non-destructive testing and evaluation of aircraft composites.

    Science.gov (United States)

    Pelivanov, Ivan; Buma, Takashi; Xia, Jinjun; Wei, Chen-Wei; O'Donnell, Matthew

    2014-03-21

    Laser ultrasonic (LU) inspection represents an attractive, non-contact method to evaluate composite materials. Current non-contact systems, however, have relatively low sensitivity compared to contact piezoelectric detection. They are also difficult to adjust, very expensive, and strongly influenced by environmental noise. Here, we demonstrate that most of these drawbacks can be eliminated by combining a new generation of compact, inexpensive fiber lasers with new developments in fiber telecommunication optics and an optimally designed balanced probe scheme. In particular, a new type of a balanced fiber-optic Sagnac interferometer is presented as part of an all-optical LU pump-probe system for non-destructive testing and evaluation of aircraft composites. The performance of the LU system is demonstrated on a composite sample with known defects. Wide-band ultrasound probe signals are generated directly at the sample surface with a pulsed fiber laser delivering nanosecond laser pulses at a repetition rate up to 76 kHz rate with a pulse energy of 0.6 mJ. A balanced fiber-optic Sagnac interferometer is employed to detect pressure signals at the same point on the composite surface. A- and B-scans obtained with the Sagnac interferometer are compared to those made with a contact wide-band polyvinylidene fluoride transducer.

  6. Polymer optical fiber fuse

    CERN Document Server

    Mizuno, Yosuke; Tanaka, Hiroki; Nakamura, Kentaro

    2013-01-01

    Although high-transmission-capacity optical fibers are in demand, the problem of the fiber fuse phenomenon needs to be resolved to prevent the destruction of fibers. As polymer optical fibers become more prevalent, clarifying their fuse properties has become important. Here, we experimentally demonstrate a fuse propagation velocity of 21.9 mm/s, which is 1 to 2 orders of magnitude slower than that in standard silica fibers. The achieved threshold power density and proportionality constant between the propagation velocity and the power density are respectively 1/186 of and 16.8 times the values for silica fibers. An oscillatory continuous curve instead of periodic voids is formed after the passage of the fuse. An easy fuse termination method is presented herein, along with its potential plasma applications.

  7. Phase-locking of commercial DFB lasers for distributed optical fiber sensing applications

    Science.gov (United States)

    Rouse, Chris D.; Brown, Anthony W.; Wylie, Michael T. V.; Colpitts, Bruce G.

    2011-05-01

    The design of a phase/frequency detector-based optical phase-locked loop (PFD-OPLL) capable of locking two commercial semiconductor distributed feedback (DFB) lasers for the purpose of making Brillouin Optical Time-Domain Analysis (BOTDA) measurements is presented. Due to the aperiodic nature of the PFD transfer characteristic, the PFDOPLL offers strong acquisition performance without requiring additional acquisition hardware. Design constraints due to laser linewidths are relaxed by choosing a damping factor of 3.5 instead of 0.707. Loop stability is ensured by reducing the loop propagation delay by as much as possible in hardware, and choosing the loop natural frequency such that the loop bandwidth is below the FM phase reversal frequency of the laser. Results show stable lock performance at 11 GHz with a phase noise of -70dBc/Hz at a 100 Hz offset, a capture range of 2.5 GHz and a tuning range of 3.3 GHz. These specifications exceed the performance requirements of a BOTDA system.

  8. Fiber Optics: No Illusion.

    Science.gov (United States)

    American School and University, 1983

    1983-01-01

    A campus computer center at Hofstra University (New York) that holds 70 terminals for student use was first a gymnasium, then a language laboratory. Strands of fiber optics are used for the necessary wiring. (MLF)

  9. Observation of laser pulse propagation in optical fibers with a SPAD camera

    Science.gov (United States)

    Warburton, Ryan; Aniculaesei, Constantin; Clerici, Matteo; Altmann, Yoann; Gariepy, Genevieve; McCracken, Richard; Reid, Derryck; McLaughlin, Steve; Petrovich, Marco; Hayes, John; Henderson, Robert; Faccio, Daniele; Leach, Jonathan

    2017-03-01

    Recording processes and events that occur on sub-nanosecond timescales poses a difficult challenge. Conventional ultrafast imaging techniques often rely on long data collection times, which can be due to limited device sensitivity and/or the requirement of scanning the detection system to form an image. In this work, we use a single-photon avalanche detector array camera with pico-second timing accuracy to detect photons scattered by the cladding in optical fibers. We use this method to film supercontinuum generation and track a GHz pulse train in optical fibers. We also show how the limited spatial resolution of the array can be improved with computational imaging. The single-photon sensitivity of the camera and the absence of scanning the detection system results in short total acquisition times, as low as a few seconds depending on light levels. Our results allow us to calculate the group index of different wavelength bands within the supercontinuum generation process. This technology can be applied to a range of applications, e.g., the characterization of ultrafast processes, time-resolved fluorescence imaging, three-dimensional depth imaging, and tracking hidden objects around a corner.

  10. Tapered Optical Fiber Functionalized with Palladium Nanoparticles by Drop Casting and Laser Radiation for H2 and Volatile Organic Compounds Sensing Purposes

    Science.gov (United States)

    González-Sierra, Nancy Elizabeth; Gómez-Pavón, Luz del Carmen; Pérez-Sánchez, Gerardo Francisco; Luis-Ramos, Arnulfo; Zaca-Morán, Plácido; Chávez-Ramírez, Fernando

    2017-01-01

    A comparative study on the sensing properties of a tapered optical fiber pristine and functionalized with the palladium nanoparticles to hydrogen and volatile organic compounds (VOCs), is presented. The sensor response and, response/recovery times were extracted from the measurements of the transient response of the device. The tapered optical fiber sensor was fabricated using a single-mode optical fiber by the flame-brushing technique. Functionalization of the optical fiber was performed using an aqueous solution of palladium chloride by drop-casting technique assisted for laser radiation. The detection principle of the sensor is based on the changes in the optical properties of palladium nanoparticles when exposed to reducing gases, which causes a variation in the absorption of evanescent waves. A continuous wave laser diode operating at 1550 nm is used for the sensor characterization. The sensor functionalized with palladium nanoparticles by this technique is viable for the sensing of hydrogen and VOCs, since it shows an enhancement in sensor response and response time compared to the sensor based on the pristine optical microfiber. The results show that the fabricated sensor is competitive with other fiber optic sensors functionalized with palladium nanoparticles to the hydrogen. PMID:28878161

  11. Miniaturized optical fiber endoscope without inertial scan for simultaneous imaging and laser microsurgery

    Science.gov (United States)

    Adam, Jost; Metz, Philipp; Gerken, Martina; Jalali, Bahram

    2013-09-01

    The current autostereoscopic projection system is accomplished by array projectors. It is easy to realize optically but has a drawback with size. Another type is to place the shutter on the screen. It saves the volume but reduces the efficiency depending on how many views are produced. The shutter in the lens aperture has the same efficiency problem, too. To overcome these problems, a full HD autostereoscopic projector based on the lens aperture switching type is proposed. It has RGB laser sources and can produce 16-views or even higher stereoscopic images. This system removes the shutter in the lens aperture by the opti-mechanism itself. The specific light on the lens aperture coming from the point on the DMD is reflected to different angles. The proper angle of light is generated in the object side by the relay and folding system. The UHP lamps or the LED rays are difficult to constrain in a relative small cone angle. For this reason, the laser is applied to the design. The very small etendue of the laser is good for this architecture. The rays are combined by dichroic filter from RGB laser sources then forming and expanding to the mirror. The mirror is synchronized with DMD by the DSP control system. The images of different views are generated by DMD and specific position of the mirror. By the double lenticular screen, the lens aperture is imaged to the observer's viewing zone and the 3D scene is created.

  12. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  13. Fiber optics welder

    Science.gov (United States)

    Higgins, R.W.; Robichaud, R.E.

    A system is described for welding fiber optic waveguides together. The ends of the two fibers to be joined together are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 45/sup 0/ angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation.

  14. Gas-Filled Hollow Core Fiber Lasers Based on Population Inversion

    Science.gov (United States)

    2013-12-05

    levels of C2H2 with the pump ( optical parametric oscillator in the telecom C band) and observed lasing transitions. The fiber ends were housed in...FA9550-10-1-0515 FA9550-10-1-0515 AFOSR unlimited Hollow-core Optical Fiber Gas LASer (HOFGLAS) have been created, and explored in pulsed mode with...were created. HOFGLAS, Optically -pumped gas lasers, photonic crystal fiber , microstructured fiber , hollow-core fiber , mid-IR lasers, IR lasers, fiber

  15. Continuously Tunable Erbium-Doped Fiber Ring Laser Using Fiber Bragg Grating

    Directory of Open Access Journals (Sweden)

    S. W. Harun H. Ahmad and P. Poopalan

    2012-08-01

    Full Text Available An efficient tunable erbium-doped fiber (EDF ring laser utilizing a single fiber Bragg grating (FBG and an optical circulator is investigated. The laser demonstrates a threshold of 3.43 mW and a slope efficiency of 12.5%. Tunability of the fiber laser is obtained by thermal tuning of the FBG. Simultaneous temperature tuning demonstrates a 0.01 nm/oC variation in laser wavelength.Key Words:  Fiber Bragg grating, fiber laser, tunable laser, ring laser, thermal tuning

  16. Diode Pumped Fiber Laser

    Science.gov (United States)

    1983-07-01

    numerical aperture is assumed to be small, the fiber modes are taken to be of the LP-type, described for example by Marcuse (Reference 11). In an (x...Fort Washington, PA. 11. D. Marcuse in Theory of Dielectric Optical Waveguides, Quantum Electronics, Principles and Applications, (Academic...10, 2252-2258, October 1971. 17. D. Marcuse , "Gaussian approximation of the fundamental modes of graded- index fibers," J. Opt. Soc. Am., Vol

  17. Nonlinear effects in optical fibers

    CERN Document Server

    Ferreira, Mario F

    2011-01-01

    Cutting-edge coverage of nonlinear phenomena occurring inside optical fibers Nonlinear fiber optics is a specialized part of fiber optics dealing with optical nonlinearities and their applications. As fiber-optic communication systems have become more advanced and complex, the nonlinear effects in optical fibers have increased in importance, as they adversely affect system performance. Paradoxically, the same nonlinear phenomena also offer the promise of addressing the bandwidth bottleneck for signal processing for future ultra-high speed optical networks. Nonlinear Effects in Optical Fiber

  18. Effective generation of optical quadruple frequency millimeter-wave based on fiber laser using injection rational harmonic mode-locked technique

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Xue Feng; Fei Huang; Xiaoming Liu

    2009-01-01

    A method to generate the optical quadruple frequency millimeter-wave with high power efficiency is pro-posed and demonstrated based on the combination of the injection 2nd-order rational harmonic mode-locked fiber ring laser technique and the fiber grating notch filter. In this approach, the fiber Bragg grating notch filter is inserted into the laser cavity to prevent the undesired optical carrier, so that the pump power can be converted to 2nd-order harmonic wave more efficiently. In our experiment, the power efficiency of optical quadruple frequency millimeter-wave (40 GHz) generation is ten folds of that of our previous method based only on the rational harmonic mode-locked technique.

  19. A fiber-optic water flow sensor based on laser-heated silicon Fabry-Pérot cavity

    Science.gov (United States)

    Liu, Guigen; Sheng, Qiwen; Resende Lisboa Piassetta, Geraldo; Hou, Weilin; Han, Ming

    2016-05-01

    A hot-wire fiber-optic water flow sensor based on laser-heated silicon Fabry-Pérot interferometer (FPI) has been proposed and demonstrated in this paper. The operation of the sensor is based on the convective heat loss to water from a heated silicon FPI attached to the cleaved enface of a piece of single-mode fiber. The flow-induced change in the temperature is demodulated by the spectral shifts of the reflection fringes. An analytical model based on the FPI theory and heat transfer analysis has been developed for performance analysis. Numerical simulations based on finite element analysis have been conducted. The analytical and numerical results agree with each other in predicting the behavior of the sensor. Experiments have also been carried to demonstrate the sensing principle and verify the theoretical analysis. Investigations suggest that the sensitivity at low flow rates are much larger than that at high flow rates and the sensitivity can be easily improved by increasing the heating laser power. Experimental results show that an average sensitivity of 52.4 nm/(m/s) for the flow speed range of 1.5 mm/s to 12 mm/s was obtained with a heating power of ~12 mW, suggesting a resolution of ~1 μm/s assuming a wavelength resolution of 0.05 pm.

  20. Tunable femtosecond Cherenkov fiber laser

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Svane, Ask Sebastian; Lægsgaard, Jesper

    2014-01-01

    We demonstrate electrically-tunable femtosecond Cherenkov fiber laser output at the visible range. Using an all-fiber, self-starting femtosecond Yb-doped fiber laser as the pump source and nonlinear photonic crystal fiber link as the wave-conversion medium, ultrafast, milliwatt-level, tunable...... and spectral isolated Cherenkov radiation at visible wavelengths are reported. Such a femtosecond Cherenkov laser source is promising for practical biophotonics applications....

  1. Low-Complexity Tracking of Laser and Nonlinear Phase Noise in WDM Optical Fiber Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Fehenberger, Tobias; Barletta, Luca

    2015-01-01

    In this paper, the wavelength division multiplexed (WDM) fiber optic channel is considered. It is shown that for ideal distributed Raman amplification (IDRA), the Wiener process model is suitable for the non-linear phase noise due to cross phase modulation from neighboring channels. Based...... compared to previous trellis-based approaches, which require numerical integration. Further, the proposed method performs very well in low-to-moderate signal-to-noise ratio (SNR), where standard decision directed (DD) methods, especially for high-order modulation, fail. The proposed algorithm does not rely...... on this model, a phase noise tracking algorithm is presented. We approximate the distribution of the phase noise at each time instant by a mixture of Tikhonov distributions, and derive a closed form expression for the posterior probabilities of the input symbols. This reduces the complexity dramatically...

  2. Moldable AR microstructures for improved laser transmission and damage resistance in CIRCM fiber optic beam delivery systems

    Science.gov (United States)

    MacLeod, Bruce D.; Hobbs, Douglas S.; Sabatino, Ernest, III

    2011-06-01

    Anti-reflecting (AR) surface relief microstructures (ARMs) are being developed as a replacement for thin-film AR coatings in laser-based systems to improve light transmission, power handling, operational bandwidth, and system reliability. Because ARMs textures have the potential to be replicated using simple embossing methods, the performance advantage and robustness of ARMs can be extended to moldable mid-infrared transmitting materials such as chalcogenide optical fibers. In this work, the optical performance of mid-infrared transparencies incorporating ARMs textures replicated from a master template has been modeled, and multiple master stamping tools have been fabricated in materials such as diamond, silicon carbide, nickel, silicon, and sapphire. Images from ARMs texture embossing trials using arsenic sulfide and arsenic selenide (AMTIR2) glasses, and fluoride glasses such as ZBLAN and indium fluoride provided by IRPhotonics, show excellent pattern transfer and fidelity. Transmission measurements of ARMs textures stamped into arsenic sulfide and arsenic selenide windows show broadband infrared performance equivalent to ARMs textured windows processed by direct patterning and etch methods. A system for molding ARMs textures directly into the end facets of multi-mode mid-infrared transmitting fibers is yielding promising initial results.

  3. Visible fiber lasers excited by GaN laser diodes

    Science.gov (United States)

    Fujimoto, Yasushi; Nakanishi, Jun; Yamada, Tsuyoshi; Ishii, Osamu; Yamazaki, Masaaki

    2013-07-01

    This paper describes and discusses visible fiber lasers that are excited by GaN laser diodes. One of the attractive points of visible light is that the human eye is sensitive to it between 400 and 700 nm, and therefore we can see applications in display technology. Of course, many other applications exist. First, we briefly review previously developed visible lasers in the gas, liquid, and solid-state phases and describe the history of primary solid-state visible laser research by focusing on rare-earth doped fluoride media, including glasses and crystals, to clarify the differences and the merits of primary solid-state visible lasers. We also demonstrate over 1 W operation of a Pr:WPFG fiber laser due to high-power GaN laser diodes and low-loss optical fibers (0.1 dB/m) made by waterproof fluoride glasses. This new optical fiber glass is based on an AlF3 system fluoride glass, and its waterproof property is much better than the well known fluoride glass of ZBLAN. The configuration of primary visible fiber lasers promises highly efficient, cost-effective, and simple laser systems and will realize visible lasers with photon beam quality and quantity, such as high-power CW or tunable laser systems, compact ultraviolet lasers, and low-cost ultra-short pulse laser systems. We believe that primary visible fiber lasers, especially those excited by GaN laser diodes, will be effective tools for creating the next generation of research and light sources.

  4. Optical fiber laser sensor with a cavity of 8.6 Km formed by two fiber Bragg gratings used as mirrors

    Energy Technology Data Exchange (ETDEWEB)

    May A, M.; Kuzin, E.A.; Vazquez S, R.A. [Instituto Nacional de Astrofisica, Optica y Electronica, A. P. 51 y 216, C.P. 72000 Puebla (Mexico); Basurto P, M.A. [Universidad Autonoma del Estado de Morelos, Av. Universidad No. 1001, Col. Chamilpa, C.P. 62210 Cuernavaca, Morelos (Mexico); Shlyagin, M.G.; Marquez B, I. [Centro de Investigacion Cientifica y de Ensenanza Superior de Ensenada, C.P. 22860 Ensenada, Baja California (Mexico)

    2002-07-01

    We report the operation of a fiber laser sensor made by an Erbium Doped Fiber pumped at 980 nm, an 8.67 km passive fiber and two fiber Bragg gratings placed at the ends of the laser cavity. Under normal conditions, the Bragg gratings have different reflection wavelengths and laser emission is not generated. The two Bragg gratings can be placed at the same reflection wavelength when the Bragg grating with the lowest reflective wavelength is strained which can be used as a sensor element. The laser generation thus shows that the Bragg grating is under strain. Furthermore, our configuration give us the possibility for knowing the distance between two Bragg gratings when the laser beating frequency is measured. A measurement precision better than 25 m in 8.67 Km is shown to be feasible. (Author)

  5. A long-term frequency-stabilized erbium-fiber-laser-based optical frequency comb with an intra-cavity electro-optic modulator

    CERN Document Server

    Zhang, Y; Zhao, W; Meng, S; Fan, S; Zhang, L; Guo, G; Zhang, S; Jiang, H

    2014-01-01

    We demonstrate a home-made optical frequency comb based on an erbium-doped-fiber femtosecond laser with a ring cavity. The repetition rate of the laser is about 209 MHz determined by optical length of the laser cavity. By controlling an intra-cavity electro-optic modulator and a Piezo-transducer, the repetition rate can be stabilized with megahertz bandwidth in a range of 3 kilohertz, enabling long-term repetition rate phase-locking. The in-loop frequency instability of the repetition rate, limited by measurement system, is 1.3E-13 at 1 second integration time and inversely proportional to integration time for short terms. Using a common path f-2f interferometer, the carrier envelope offset (CEO) frequency of the frequency comb is obtained with a signal-to-noise ratio of 40 dB for 3 megahertz resolution spectrum. Stabilized CEO frequency exhibits a deviation of 0.6 milihertz at 1 second integration time.

  6. Multi-channel laser Doppler velocimetry using a two-dimensional optical fiber array for obtaining instantaneous velocity distribution characteristics

    Science.gov (United States)

    Kyoden, Tomoaki; Yasue, Youichi; Ishida, Hiroki; Akiguchi, Shunsuke; Andoh, Tsugunobu; Takada, Yogo; Teranishi, Tsunenobu; Hachiga, Tadashi

    2015-01-01

    A laser Doppler velocimeter (LDV) has been developed that is capable of performing two-dimensional (2D) cross-sectional measurements. It employs two horizontal laser light sheets that intersect at an angle of 13.3°. Since the intersection region is thin, it can be used to approximately determine the 2D flow field. An 8 × 8 array of optical fibers is used to simultaneously measure Doppler frequencies at 64 points. Experiments were conducted to assess the performance of the LDV, and it was found to be capable of obtaining spatial and temporal velocity information at multiple points in a flow field. The technique is fast, noninvasive, and accurate over long sampling periods. Furthermore, its applicability to an actual flow field was confirmed by measuring the temporal velocity distribution of a pulsatile flow in a rectangular flow channel with an obstruction. The proposed device is thus a useful, compact optical instrument for conducting simultaneous 2D cross-sectional multipoint measurements.

  7. Electrospun amplified fiber optics.

    Science.gov (United States)

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-03-11

    All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ∼20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics.

  8. Multi-wavelength narrow linewidth fiber laser based on distributed feedback fiber lasers

    Science.gov (United States)

    Lv, Jingsheng; Qi, Haifeng; Song, Zhiqiang; Guo, Jian; Ni, Jiasheng; Wang, Chang; Peng, Gangding

    2016-09-01

    A narrow linewidth laser configuration based on distributed feedback fiber lasers (DFB-FL) with eight wavelengths in the international telecommunication union (ITU) grid is presented and realized. In this laser configuration, eight phase-shifted gratings in series are bidirectionally pumped by two 980-nm laser diodes (LDs). The final laser output with over 10-mW power for each wavelength can be obtained, and the maximum power difference within eight wavelengths is 1.2 dB. The laser configuration with multiple wavelengths and uniform power outputs can be very useful in large scaled optical fiber hydrophone fields.

  9. Amplitude-modulated fiber-ring laser

    DEFF Research Database (Denmark)

    Caputo, J. G.; Clausen, Carl A. Balslev; Sørensen, Mads Peter

    2000-01-01

    Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self-starting......Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self......-starting of stable solitonic pulses from small random noise, provided the modulation depth is small. The perturbative analysis leads to a nonlinear coupled return map for the amplitude, phase, and position of the soliton pulses circulating in the fiber-ring laser. We established the validity of this approach...

  10. Amplitude-modulated fiber-ring laser

    DEFF Research Database (Denmark)

    Caputo, J. G.; Clausen, Carl A. Balslev; Sørensen, Mads Peter

    2000-01-01

    Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self-starting......Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self......-starting of stable solitonic pulses from small random noise, provided the modulation depth is small. The perturbative analysis leads to a nonlinear coupled return map for the amplitude, phase, and position of the soliton pulses circulating in the fiber-ring laser. We established the validity of this approach...

  11. Measurement of retinal nerve fiber layer thickness in eyes with optic disc swelling by using scanning laser polarimetry and optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Hata M

    2013-12-01

    Full Text Available Masayuki Hata, Kazuaki Miyamoto, Akio Oishi, Yugo Kimura, Satoko Nakagawa, Takahiro Horii, Nagahisa Yoshimura Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan Background: The retinal nerve fiber layer thickness (RNFLT in patients with optic disc swelling of different etiologies was compared using scanning laser polarimetry (SLP and spectral-domain optical coherence tomography (OCT. Methods: Forty-seven patients with optic disc swelling participated in the cross-sectional study. Both GDx SLP (enhanced corneal compensation and Spectralis spectral-domain OCT measurements of RNFLT were made in 19 eyes with papilledema (PE, ten eyes with optic neuritis (ON, and 18 eyes with nonarteritic anterior ischemic optic neuropathy (NAION at the neuro-ophthalmology clinic at Kyoto University Hospital. Differences in SLP (SLP-RNFLT and OCT (OCT-RNFLT measurements among different etiologies were investigated. Results: No statistical differences in average OCT-RNFLT among PE, ON, and NAION patients were noted. Average SLP-RNFLT in NAION patients was smaller than in PE (P<0.01 or ON (P=0.02 patients. When RNFLT in each retinal quadrant was compared, no difference among etiologies was noted on OCT, but on SLP, the superior quadrant was thinner in NAION than in PE (P<0.001 or ON (P=0.001 patients. Compared with age-adjusted normative data of SLP-RNFLT, average SLP-RNFLT in PE (P<0.01 and ON (P<0.01 patients was greater. Superior SLP-RNFLT in NAION patients was smaller (P=0.026. The ratio of average SLP-RNFLT to average OCT-RNFLT was smaller in NAION than in PE (P=0.001 patients. Conclusion: In the setting of RNFL thickening, despite increased light retardance in PE and ON eyes, SLP revealed that NAION eyes have less retardance, possibly associated with ischemic axonal loss. Keywords: optic disc swelling, scanning laser polarimetry, optical coherence tomography

  12. Ultra Small Integrated Optical Fiber Sensing System

    Directory of Open Access Journals (Sweden)

    Peter Van Daele

    2012-09-01

    Full Text Available This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 μm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL, fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.

  13. Tunable laser optics

    CERN Document Server

    Duarte, FJ

    2015-01-01

    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

  14. Narrow linewidth comb realized with a mode-locked fiber laser using an intra-cavity waveguide electro-optic modulator for high-speed control.

    Science.gov (United States)

    Iwakuni, Kana; Inaba, Hajime; Nakajima, Yoshiaki; Kobayashi, Takumi; Hosaka, Kazumoto; Onae, Atsushi; Hong, Feng-Lei

    2012-06-18

    We have developed an optical frequency comb using a mode-locked fiber ring laser with an intra-cavity waveguide electro-optic modulator controlling the optical length in the laser cavity. The mode-locking is achieved with a simple ring configuration and a nonlinear polarization rotation mechanism. The beat note between the laser and a reference laser and the carrier envelope offset frequency of the comb were simultaneously phase locked with servo bandwidths of 1.3 MHz and 900 kHz, respectively. We observed an out-of-loop beat between two identical combs, and obtained a coherent δ-function peak with a signal to noise ratio of 70 dB/Hz.

  15. Fiber optic sensing and imaging

    CERN Document Server

    2013-01-01

    This book is designed to highlight the basic principles of fiber optic imaging and sensing devices. The editor has organized the book to provide the reader with a solid foundation in fiber optic imaging and sensing devices. It begins with an introductory chapter that starts from Maxwell’s equations and ends with the derivation of the basic optical fiber characteristic equations and solutions (i.e. fiber modes). Chapter 2 reviews most common fiber optic interferometric devices and Chapter 3 discusses the basics of fiber optic imagers with emphasis on fiber optic confocal microscope. The fiber optic interferometric sensors are discussed in detail in chapter 4 and 5. Chapter 6 covers optical coherence tomography and goes into the details of signal processing and systems level approach of the real-time OCT implementation. Also useful forms of device characteristic equations are provided so that this book can be used as a reference for scientists and engineers in the optics and related fields.

  16. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  17. Optical fiber rotation sensing

    CERN Document Server

    Burns, William K; Kelley, Paul

    1993-01-01

    Optical Fiber Rotation Sensing is the first book devoted to Interferometric Fiber Optic Gyros (IFOG). This book provides a complete overview of IFOGs, beginning with a historical review of IFOG development and including a fundamental exposition of basic principles, a discussion of devices and components, and concluding with industry reports on state-of-the-art activity. With several chapters contributed by principal developers of this solid-state device, the result is an authoritative work which will serve as the resource for researchers, students, and users of IFOGs.* * State-of-t

  18. Optical fiber telecommunications IIIb

    CERN Document Server

    Koch, Thomas L

    2012-01-01

    Updated to include the latest information on light wave technology, Optical Fiber Telecommunication III, Volumes A & B are invaluable for scientists, students, and engineers in the modern telecommunications industry. This two-volume set includes the most current research available in optical fiber telecommunications, light wave technology, and photonics/optoelectronics. The authors cover important background concepts such as SONET, coding device technology, andWOM components as well as projecting the trends in telecommunications for the 21st century.Key Features* One of the hottest subjects of

  19. Highly Efficient Fiber Lasers for Wireless Power Transmission Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop ytterbium (Yb) fiber lasers with an electrical-to-optical efficiency of nominally 64% by directly coupling 80%-efficient diode lasers with Yb...

  20. Multi-wavelength Operation of an Er3+-doped Fiber Laser at Room Temperature with a Novel Optical Fiber Mach-Zehnder Interferometer

    Institute of Scientific and Technical Information of China (English)

    AN Hong-Lin; LIN Xiang-Zhi; LIU Hong-Du

    2000-01-01

    A novel multi-wavelength erbium-doped fiber laser with a double-pass Mach-Zehnder fiber interferometer acting both as a comb filter and as a reflection mirror is demonstrated. The spatial hole burning effect introduced by the standing wave cavity configuration enables the simultaneous operation of multiple wavelengths in the homogeneously broadened erbium-doped fiber at room temperature. In the experiment, simultaneous oscillation of four wavelengths at room temperature has been obtained.

  1. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  2. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  3. Optical fiber communications

    CERN Document Server

    Keiser, Gerd

    2008-01-01

    The fourth edition of this popular text and reference book presents the fundamental principles for understanding and applying optical fiber technology to sophisticated modern telecommunication systems. Optical-fiber-based telecommunication networks have become a major information-transmission-system, with high capacity links encircling the globe in both terrestrial and undersea installations. Numerous passive and active optical devices within these links perform complex transmission and networking functions in the optical domain, such as signal amplification, restoration, routing, and switching. Along with the need to understand the functions of these devices comes the necessity to measure both component and network performance, and to model and stimulate the complex behavior of reliable high-capacity networks.

  4. Applications of nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind

    2008-01-01

    * The only book describing applications of nonlinear fiber optics * Two new chapters on the latest developments: highly nonlinear fibers and quantum applications* Coverage of biomedical applications* Problems provided at the end of each chapterThe development of new highly nonlinear fibers - referred to as microstructured fibers, holey fibers and photonic crystal fibers - is the next generation technology for all-optical signal processing and biomedical applications. This new edition has been thoroughly updated to incorporate these key technology developments.The bo

  5. Application of ABCD Formalism in Theoretical and Experimental Analysis of Actively Modelocked Fiber Laser

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Time domain ABCD matrix formalism is a useful model for analyzing the characteristics of actively modelocked fiber laser. Based on this model and given more consideration on the influences of optical fiber dispersion and optical fiber nonlinearity, the laser characteristic of actively modelocked fiber laser is analyzed, and the comparision of the theoretical analysis results with experimental ones is given.

  6. Electrospun Polymer Fiber Lasers for Applications in Vapor Sensing

    DEFF Research Database (Denmark)

    Krämmer, Sarah; Laye, Fabrice; Friedrich, Felix

    2017-01-01

    A sensing approach based on laser emissionfrom polymer fiber networks is presented. Poly(methyl methacrylate) (PMMA) fibers doped with a laser dye are fabricated by electrospinning. They form random loop resonators, which show laser emission upon optical pumping. The shift of the spectral position...

  7. Widely tunable, narrow line width and low optical noise continuous-wave all fiber Er:Yb co-doped double-clad ring laser

    Science.gov (United States)

    Guesmi, Khmaies; Bahloul, Faouzi; Semaan, Georges; Meng, Yichang; Salhi, Mohamed; Sanchez, François

    2017-01-01

    In this paper, we report a widely tunable, narrow linewidth, low noise continuous-wave double-clad Er:Yb doped fiber ring laser. Tunability is demonstrated in wide range spanning from 1520 to almost 1620 nm covering the C and L spectral bands. The cavity design is optimized in order to achieve the largest tuning range with very high optical signal-to-noise ratio (SNR). The output coupling ratio greatly influences the tuning range of the laser while the position of the spectral filter determines the SNR. The obtained laser exhibits a tuning range over 98 nm with a nearly constant SNR of about 58.5 dB.

  8. Compact fiber optic accelerometer

    Institute of Scientific and Technical Information of China (English)

    Feng Peng; Jun Yang; Bing Wu; Yonggui Yuan; Xingliang Li; Ai Zhou; Libo Yuan

    2012-01-01

    A compact fiber optic accelerometer based on a Michelson interferometer is proposed and demonstrated.In the proposed system,the sensing element consists of two single-mode fibers glued together by epoxy,which then act as a simple supported beam.By demodulating the optical phase shift,the acceleration is determined as proportional to the force applied on the central position of the two single-mode fibers.This simple model is able to calculate the sensitivity and the resonant frequency of the compact accelerometer.The experimental results show that the sensitivity and the resonant frequency of the accelerometer are 0.42 rad/g and 600 Hz,respectively.

  9. Infrared Fiber Optic Sensors

    Science.gov (United States)

    1997-01-01

    Successive years of Small Business Innovation Research (SBIR) contracts from Langley Research Center to Sensiv Inc., a joint venture between Foster-Miller Inc. and Isorad, Ltd., assisted in the creation of remote fiber optic sensing systems. NASA's SBIR interest in infrared, fiber optic sensor technology was geared to monitoring the curing cycles of advanced composite materials. These funds helped in the fabrication of an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. Foster-Miller ingenuity allowed infrared transmitting optical fibers to combine with Fourier Transform Infrared spectroscopy to enable remote sensing. Sensiv probes operate in the mid-infrared range of the spectrum, although modifications to the instrument also permits its use in the near-infrared region. The Sensiv needle-probe is built to be placed in a liquid or powder and analyze the chemicals in the mixture. Other applications of the probe system include food processing control; combustion control in furnaces; and maintenance problem solving.

  10. Optical Fiber Protection

    Science.gov (United States)

    1999-01-01

    F&S Inc. developed and commercialized fiber optic and microelectromechanical systems- (MEMS) based instrumentation for harsh environments encountered in the aerospace industry. The NASA SBIR programs have provided F&S the funds and the technology to develop ruggedized coatings and coating techniques that are applied during the optical fiber draw process. The F&S optical fiber fabrication facility and developed coating methods enable F&S to manufacture specialty optical fiber with custom designed refractive index profiles and protective or active coatings. F&S has demonstrated sputtered coatings using metals and ceramics and combinations of each, and has also developed techniques to apply thin coatings of specialized polyimides formulated at NASA Langley Research Center. With these capabilities, F&S has produced cost-effective, reliable instrumentation and sensors capable of withstanding temperatures up to 800? C and continues building commercial sales with corporate partners and private funding. More recently, F&S has adapted the same sensing platforms to provide the rapid detection and identification of chemical and biological agents

  11. Performance analysis of CO2 laser polished angled ribbon fiber

    Science.gov (United States)

    Sohn, Ik-Bu; Choi, Hun-Kook; Noh, Young-Chul; Lee, Man-Seop; Oh, Jin-Kyoung; Kim, Seong-min; Ahsan, Md. Shamim

    2017-01-01

    This paper demonstrates CO2 laser assisted simultaneous polishing of angled ribbon fibers consisting eight set of optical fibers. The ribbon fibers were rotated vertically at an angle of 12° and polished by repetitive irradiation of CO2 laser beam at the end faces of the fibers. Compared to mechanically polished sharp edged angled fibers, CO2 laser polishing forms curve edged angled fibers. Increase in the curvature of the end faces of the ribbon fibers causes the increase of the fibers' strength, which in turn represents great robustness against fiber connections with other devices. The CO2 laser polished angled fibers have great smoothness throughout the polished area. The smoothness of the fiber end faces have been controlled by varying the number of laser irradiation. After CO2 laser polishing, the average value of the fiber angle of the ribbon fibers is ∼8.28°. The laser polished ribbon fibers show low insertion and return losses when connecting with commercial optical communication devices. The proposed technique of polishing the angled ribbon fibers is highly replicable and reliable and thus suitable for commercial applications.

  12. Fiber Optics and Library Technology.

    Science.gov (United States)

    Koenig, Michael

    1984-01-01

    This article examines fiber optic technology, explains some of the key terminology, and speculates about the way fiber optics will change our world. Applications of fiber optics to library systems in three major areas--linkage of a number of mainframe computers, local area networks, and main trunk communications--are highlighted. (EJS)

  13. Buying Fiber-Optic Networks.

    Science.gov (United States)

    Fickes, Michael

    2003-01-01

    Describes consortia formed by college and university administrators to buy, manage, and maintain their own fiber-optic networks with the goals of cutting costs of leasing fiber-optic cable and planning for the future. Growth capacity is the real advantage of owning fiber-optic systems. (SLD)

  14. Aerogel-clad optical fiber

    Science.gov (United States)

    Sprehn, Gregory A.; Hrubesh, Lawrence W.; Poco, John F.; Sandler, Pamela H.

    1997-01-01

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency.

  15. Vacuum ultraviolet argon excimer laser excited by optical-field-induced ionized electrons produced in an argon-filled hollow fiber

    Science.gov (United States)

    Kubodera, Shoichi; Kaku, Masanori; Katto, Masahito

    2011-10-01

    Short-wavelength lasers in the vacuum ultraviolet (VUV) spectral region between 100 and 200 nm have not yet been developed to the same degree as visible and infrared lasers. We have demonstrated the production of argon excimers via an optical-field-induced ionization (OFI) process by using a high-intensity infrared laser. We here report optical amplification of argon excimers at the wavelength of 126 nm by producing an extended OFI plasma inside an argon-filled hollow fiber with an inner diameter of 250 microns with a length of 5.0 cm. A gain-length product of 4.3 through the use of single-pass amplification with VUV optics was observed, indicating a small signal gain coefficient of 0.86 cm-1 with an uncertainty of 0.03. It was found that the hollow fiber served to extend the OFI plasma length and to guide the excitation of the infrared laser and the produced VUV emissions at 126 nm, but did not affect the OFI plasma conditions to produce argon excimer molecules. Short-wavelength lasers in the vacuum ultraviolet (VUV) spectral region between 100 and 200 nm have not yet been developed to the same degree as visible and infrared lasers. We have demonstrated the production of argon excimers via an optical-field-induced ionization (OFI) process by using a high-intensity infrared laser. We here report optical amplification of argon excimers at the wavelength of 126 nm by producing an extended OFI plasma inside an argon-filled hollow fiber with an inner diameter of 250 microns with a length of 5.0 cm. A gain-length product of 4.3 through the use of single-pass amplification with VUV optics was observed, indicating a small signal gain coefficient of 0.86 cm-1 with an uncertainty of 0.03. It was found that the hollow fiber served to extend the OFI plasma length and to guide the excitation of the infrared laser and the produced VUV emissions at 126 nm, but did not affect the OFI plasma conditions to produce argon excimer molecules. Part of this work has been supported by

  16. Switchable dual-wavelength single-longitudinal-mode erbium-doped fiber laser using an inverse-Gaussian apodized fiber Bragg grating filter and a low-gain semiconductor optical amplifier.

    Science.gov (United States)

    Lin, Bo; Tjin, Swee Chuan; Zhang, Han; Tang, Dingyuan; Hao, Jianzhong; Dong, Bo; Liang, Sheng

    2010-12-20

    We present a stable and switchable dual-wavelength erbium-doped fiber laser. In the ring cavity, an inverse-Gaussian apodized fiber Bragg grating serves as an ultranarrow dual-wavelength passband filter, a semiconductor optical amplifier biased in the low-gain regime reduces the gain competition of the two wavelengths, and a feedback fiber loop acts as a mode filter to guarantee a stable single-longitudinal-mode operation. Two lasing lines with a wavelength separation of approximately 0.1 nm are obtained experimentally. A microwave signal at 12.51 GHz is demonstrated by beating the dual wavelengths at a photodetector.

  17. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind

    2012-01-01

    Since the 4e appeared, a fast evolution of the field has occurred. The 5e of this classic work provides an up-to-date account of the nonlinear phenomena occurring inside optical fibers, the basis of all our telecommunications infastructure as well as being used in the medical field. Reflecting the big developments in research, this new edition includes major new content: slow light effects, which offers a reduction in noise and power consumption and more ordered network traffic-stimulated Brillouin scattering; vectorial treatment of highly nonlinear fibers; and a brand new chapter o

  18. Curved Piezoelectric Actuators for Stretching Optical Fibers

    Science.gov (United States)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    Assemblies containing curved piezoceramic fiber composite actuators have been invented as means of stretching optical fibers by amounts that depend on applied drive voltages. Piezoceramic fiber composite actuators are conventionally manufactured as sheets or ribbons that are flat and flexible, but can be made curved to obtain load-carrying ability and displacement greater than those obtainable from the flat versions. In the primary embodiment of this invention, piezoceramic fibers are oriented parallel to the direction of longitudinal displacement of the actuators so that application of drive voltage causes the actuator to flatten, producing maximum motion. Actuator motion can be transmitted to the optical fiber by use of hinges and clamp blocks. In the original application of this invention, the optical fiber contains a Bragg grating and the purpose of the controlled stretching of the fiber is to tune the grating as part of a small, lightweight, mode-hop-free, rapidly tunable laser for demodulating strain in Bragg-grating strain-measurement optical fibers attached to structures. The invention could also be used to apply controllable tensile force or displacement to an object other than an optical fiber.

  19. Temperature monitoring and control of CO2 laser tissue welding in the urinary tract using a silver halide fiber optic radiometer

    Science.gov (United States)

    Shenfeld, Ofer; Eyal, Ophir; Goldwasser, Benad; Katzir, Abraham

    1993-07-01

    Laser welding of tissues is an experimental surgical technique for the binding of tissues. The difficulty in the clinical implementation of this technique arises from the difficulty in defining the optimal conditions under which a satisfactory weld is formed. Temperature measurements of laser irradiated tissues are difficult to perform and experiments have produced conflicting results. Fiber optic radiometry allows temperature measurement of laser irradiated tissues by remote sensing of emitted infra red (IR) radiation. We developed an IR radiometer capable of accurate temperature measurements (+/- 0.2 degree(s)C). Utilizing this radiometer for the monitoring and control of CO2 laser irradiated tissues we achieved temperature control of +/- 2.5 degree(s)C of tissues during welding. This system was used to perform laser welds on the urinary bladders of rats. The strength of the welds was recorded for different welding temperatures, and maximal strength was obtained at 55 degree(s)C and 12 sec.

  20. Rugged passively cooled high power laser fiber optic connectors and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.; McKay, Ryan P.

    2016-06-07

    There are provided high power laser connectors and couplers and methods that are capable of providing high laser power without the need for active cooling to remote, harsh and difficult to access locations and under difficult and harsh conditions and to manage and mitigate the adverse effects of back reflections.

  1. Rugged passively cooled high power laser fiber optic connectors and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.; McKay, Ryan P.

    2016-06-07

    There are provided high power laser connectors and couplers and methods that are capable of providing high laser power without the need for active cooling to remote, harsh and difficult to access locations and under difficult and harsh conditions and to manage and mitigate the adverse effects of back reflections.

  2. Intra-pulse Raman frequency shift versus conventional Stokes generation of diode laser pulses in optical fibers.

    Science.gov (United States)

    Kuzin, Evgeny; Mendoza-Vazquez, Sergio; Gutierrez-Gutierrez, Jaime; Ibarra-Escamilla, Baldemar; Haus, Joseph; Rojas-Laguna, Roberto

    2005-05-02

    We report experimental observations of stimulated Raman scattering in a standard fiber using a directly modulated DFB semiconductor laser amplified by two erbium-doped fibers. The laser pulse width was variably controlled on a nanosecond-scale; the laser emission was separated into two distinct regimes: an initial transient peak regime, followed by a quasi steady-state plateau regime. The transient leading part of the pump pulse containing fast amplitude modulation generated a broadband Raman-induced spectral shift through the modulation instability and subsequent intra-pulse Raman frequency shift. The plateau regime amplified the conventional Stokes shifted emission expected from the peaks of the gain distribution. The output signal spectrum at the end of a 9.13 km length of fiber for the transient part extends from 1550 nm to 1700 nm for a pump pulse peak power of 65 W. We found that the Raman-induced spectral shift is measurable about 8 W for every fiber length examined, 0.6 km, 4.46 km, and 9.13 km. All spectral components of the broadband scattering appear to be generated in the initial kilometer of the fiber span. The Stokes shifted light generation threshold was higher than the threshold for the intra-pulse Raman-induced broadened spectra. This fact enables the nonlinear spectral filtering of pulses from directly modulated semiconductor lasers.

  3. Intra-pulse Raman frequency shift versus conventional Stokes generation of diode laser pulses in optical fibers

    Science.gov (United States)

    Kuzin, Evgeny A.; Mendoza-Vazquez, Sergio; Gutierrez-Gutierrez, Jaime; Ibarra-Escamilla, Baldemar; Haus, Joseph W.; Rojas-Laguna, Roberto

    2005-05-01

    We report experimental observations of stimulated Raman scattering in a standard fiber using a directly modulated DFB semiconductor laser amplified by two erbium-doped fibers. The laser pulse width was variably controlled on a nanosecond-scale; the laser emission was separated into two distinct regimes: an initial transient peak regime, followed by a quasi steady-state plateau regime. The transient leading part of the pump pulse containing fast amplitude modulation generated a broadband Raman-induced spectral shift through the modulation instability and subsequent intra-pulse Raman frequency shift. The plateau regime amplified the conventional Stokes shifted emission expected from the peaks of the gain distribution. The output signal spectrum at the end of a 9.13 km length of fiber for the transient part extends from 1550 nm to 1700 nm for a pump pulse peak power of 65 W. We found that the Raman-induced spectral shift is measurable about 8 W for every fiber length examined, 0.6 km, 4.46 km, and 9.13 km. All spectral components of the broadband scattering appear to be generated in the initial kilometer of the fiber span. The Stokes shifted light generation threshold was higher than the threshold for the intra-pulse Raman-induced broadened spectra. This fact enables the nonlinear spectral filtering of pulses from directly modulated semiconductor lasers.

  4. The analytical investigation of the super-Gaussian pump source on the thermal, stress and thermo-optics properties of double-clad Yb:glass fiber lasers

    Indian Academy of Sciences (India)

    H Nadgaran; P Elahi

    2005-07-01

    Fiber lasers have attracted considerable attention when their power can realistically be scaled to kilowatt level and beyond. In this paper, we assumed that the fiber core and first clad are exposed to a pump source with a super-Gaussian profile of order four. The effects of this non-uniform heat deposition on thermal, stress and thermo-optics properties such as temperature-dependent change of refractive index and thermally induced stress have been comprehensively studied and their equations analytically derived.

  5. Hermetic optical-fiber iodine frequency standard.

    Science.gov (United States)

    Light, Philip S; Anstie, James D; Benabid, Fetah; Luiten, Andre N

    2015-06-15

    We have built an optical-frequency standard based on interrogating iodine vapor that has been trapped within the hollow core of a hermetically sealed kagome-lattice photonic crystal fiber. A frequency-doubled Nd:YAG laser locked to a hyperfine component of the P(142)37-0 I2127 transition using modulation transfer spectroscopy shows a frequency stability of 3×10(-11) at 100 s. We discuss the impediments in integrating this all-fiber standard into a fully optical-fiber-based system, and suggest approaches that could improve performance of the frequency standard substantially.

  6. Mechanical reliability of double clad fibers in typical fiber laser deployment conditions

    Science.gov (United States)

    Walorny, Michael; Abramczyk, Jaroslaw; Jacobson, Nick; Tankala, Kanishka

    2016-03-01

    With the rapid acceptance of fiber lasers and amplifiers for various materials processing and defense applications the long term optical and mechanical reliability of the fiber laser, and therefore the components that make up the laser, is of significant interest to the industrial and defense communities. The double clad fiber used in a fiber laser is a key component whose lifetime in typical deployment conditions needs to be understood. The optical reliability of double clad fiber has recently been studied and a predictive model of fiber lifetime has been published. In contrast, a rigorous model for the mechanical reliability of the fiber and an analysis of the variables affecting the lifetime of the fiber in typical deployment conditions has not been studied. This paper uses the COST-218 model which is widely used for analyzing the mechanical lifetime of fiber used in the telecom industry. The factors affecting lifetime are analyzed to make the reader aware of the design choices a laser manufacturer can make, and the information they must seek from fiber suppliers, to ensure excellent lifetime for double clad fiber and consequently for the fiber laser. It is shown that the fiber's stress corrosion susceptibility, its proof strength, the coil diameter and the length of fiber coiled to achieve good beam quality all have important implications on fiber lifetime.

  7. Shedding Light on Fiber Optics.

    Science.gov (United States)

    Bunch, Robert M.

    1994-01-01

    Explains the principles of fiber optics as a medium for light-wave communication. Current uses of fiber systems on college campuses include voice, video, and local area network applications. A group of seven school districts in Minnesota are linked via fiber-optic cables. Other uses are discussed. (MLF)

  8. Optical fibers for FTTH application

    Science.gov (United States)

    Guzowski, Bartlomiej; Tosik, Grzegorz; Lisik, Zbigniew; Bedyk, Michal; Kubiak, Andrzej

    2013-07-01

    In this paper the specifics of FTTH (Fiber To The Home) networks in terms of requirements for optical fibers has been presented. Optical fiber samples used in FTTH applications acquired from the worldwide leading manufacturers were subjected to small diameter mandrel wraps tests. The detailed procedures of performed tests and the measurement results has been presented.

  9. Fiber-laser-based, green-pumped, picosecond optical parametric oscillator using fan-out grating PPKTP.

    Science.gov (United States)

    Chaitanya Kumar, S; Parsa, S; Ebrahim-Zadeh, M

    2016-01-01

    We report a stable, Yb-fiber-laser-based, green-pumped, picosecond optical parametric oscillator (OPO) for the near-infrared based on periodically poled potassium titanyl phosphate (PPKTP) nonlinear crystal, using fan-out grating design and operating near room temperature. The OPO is continuously tunable across 726-955 nm in the signal and 1201-1998 nm in the idler, resulting in a total signal plus idler wavelength coverage of 1026 nm by grating tuning at a fixed temperature. The device generates up to 580 mW of average power in the signal at 765 nm and 300 mW in the idler at 1338 nm, with an overall extraction efficiency of up to 52% and a pump depletion >76%. The extracted signal at 765 nm and idler at 1746 nm exhibit excellent passive power stability better than 0.5% and 0.8% rms, respectively, over 1 h with good beam quality in TEM00 mode profile. The output signal pulses have a Gaussian temporal duration of 13.2 ps, with a FWHM spectral bandwidth of 3.4 nm at 79.5 MHz repetition rate. Power scaling limitations of the OPO due to the material properties of PPKTP are studied.

  10. Optimally efficient, high power, Yb:fiber laser pumped, near- to mid-infrared picosecond optical parametric oscillator

    CERN Document Server

    Kokabee, Omid

    2014-01-01

    Absolute output power optimization and performance of a near- to mid-infrared picosecond optical parametric oscillator (OPO) is studied at two high pump powers using a widely-tunable output coupling (OC) technique which provides 15% to 68% OC. The MgO:PPLN-based OPO is synchronously pumped at 81.1 MHz by an Yb:fiber laser with double-peak spectrum. At 2 W pump power, maximum signal (at 1.46 $\\mu$m) and idler (at 3.92 $\\mu$m) power of 670 mW and 270 mW are obtained at 27% OC at 47% total extraction efficiency and 58% pump power depletion where at 15.5 W pump power, 7.4 W signal and 2.7 W idler power are extracted at 53% OC at 65% total extraction efficiency and 80% pump depletion. With respect to non-optimum points, OPO provides signal pulses with narrower single-peak spectrum, smaller time-bandwidth product, much better circular single-mode TEM00 spatial profile and passive peak-to-peak power stability of $\\pm$4.6% at 2 W and $\\pm$1% at 15.5 W pump power in optimum power extraction points.

  11. High-power, fiber-laser-pumped, picosecond optical parametric oscillator based on MgO:sPPLT.

    Science.gov (United States)

    Kumar, S Chaitanya; Ebrahim-Zadeh, M

    2011-12-19

    We report a stable, high-power, mid-infrared synchronously-pumped optical parametric oscillator (SPOPO) based on MgO:sPPLT, pumped by a 1064 nm, picosecond Yb-fiber laser operating at a repetition rate of 81.1 MHz. The singly resonant SPOPO is tunable over 1531-1642 nm (111 nm) in the near-infrared signal and 3022-3488 nm (466 nm) in the mid-infrared idler, providing a total tuning range of 577 nm. Careful optimization of output coupling results in a signal output power as high as 4.3 W at 1593 nm and a mid-infrared idler power of 2 W at 3204 nm for 13.4 W of pump power at a total extraction efficiency of 47%. The SPOPO can be operated near room temperature, down to 30 °C, and exhibits passive peak-to-peak power stability better than 8.6% at 1568 nm (signal) and 8.2% at 3310 nm (idler) over 13 hours at full power. The output signal pulses have duration of 17.5 ps, with a FWHM spectral bandwidth of 1.4 nm centered at 1568 nm.

  12. A multi-wavelength fiber-optic temperature-controlled laser soldering system for upper aerodigestive tract reconstruction: an animal model.

    Science.gov (United States)

    Abergel, Avraham; Gabay, Ilan; Fliss, Dan M; Katzir, Abraham; Gil, Ziv

    2011-06-01

    Laser soldering of a thick multilayer organ using conventional CO(2) lasers is ineffective. The purpose of this work was to develop a method for bonding the multilayer tissue of the upper aerodigestive tracts (UADT) without the need of sutures or stapling. Animal model. Academic research laboratory. The authors developed a multi-wavelength laser system, based on 2 fiber-optic lasers applied simultaneously. A highly absorbable CO(2) laser interacts with the muscular layer, and a nonabsorbable GaAs laser interacts with indocyanine-green solid albumin, placed between the mucosa and the muscular layer. The authors used an ex vivo porcine model to examine the capability of this system to effectively correct esophageal tears. The soldered esophagi burst pressure was >175 cm H(2)O (98% success rate) in 88 of the 90 experiments. A conventional CO(2) laser soldering resulted in insufficient bonding (mean burst pressure of 40 ± 7 cm H(2)O, n = 5), while the multi-wavelength laser system provided an ~9-fold tighter seal (359 ± 75.4 cm H(2)O, P system. Bonding of the UADT mucosa using a multi-wavelength, temperature-controlled laser soldering system can support significantly higher pressures then conventional CO(2) laser soldering and suture repair. The mean bonding pressure was 3.5-fold higher than the maximal swallowing pressure. Our findings provide a basis for implementation of new surgical tools for repair of esophageal perforations.

  13. Measurement of retinal nerve fiber layer thickness in eyes with optic disc swelling by using scanning laser polarimetry and optical coherence tomography.

    Science.gov (United States)

    Hata, Masayuki; Miyamoto, Kazuaki; Oishi, Akio; Kimura, Yugo; Nakagawa, Satoko; Horii, Takahiro; Yoshimura, Nagahisa

    2014-01-01

    The retinal nerve fiber layer thickness (RNFLT) in patients with optic disc swelling of different etiologies was compared using scanning laser polarimetry (SLP) and spectral-domain optical coherence tomography (OCT). Forty-seven patients with optic disc swelling participated in the cross-sectional study. Both GDx SLP (enhanced corneal compensation) and Spectralis spectral-domain OCT measurements of RNFLT were made in 19 eyes with papilledema (PE), ten eyes with optic neuritis (ON), and 18 eyes with nonarteritic anterior ischemic optic neuropathy (NAION) at the neuro-ophthalmology clinic at Kyoto University Hospital. Differences in SLP (SLP-RNFLT) and OCT (OCT-RNFLT) measurements among different etiologies were investigated. No statistical differences in average OCT-RNFLT among PE, ON, and NAION patients were noted. Average SLP-RNFLT in NAION patients was smaller than in PE (P<0.01) or ON (P=0.02) patients. When RNFLT in each retinal quadrant was compared, no difference among etiologies was noted on OCT, but on SLP, the superior quadrant was thinner in NAION than in PE (P<0.001) or ON (P=0.001) patients. Compared with age-adjusted normative data of SLP-RNFLT, average SLP-RNFLT in PE (P<0.01) and ON (P<0.01) patients was greater. Superior SLP-RNFLT in NAION patients was smaller (P=0.026). The ratio of average SLP-RNFLT to average OCT-RNFLT was smaller in NAION than in PE (P=0.001) patients. In the setting of RNFL thickening, despite increased light retardance in PE and ON eyes, SLP revealed that NAION eyes have less retardance, possibly associated with ischemic axonal loss.

  14. Ultrafast nonlinear optical properties of thin-solid DNA film and their application as a saturable absorber in femtosecond mode-locked fiber laser

    Science.gov (United States)

    Khazaeinezhad, Reza; Hosseinzadeh Kassani, Sahar; Paulson, Bjorn; Jeong, Hwanseong; Gwak, Jiyoon; Rotermund, Fabian; Yeom, Dong-Il; Oh, Kyunghwan

    2017-01-01

    A new extraordinary application of deoxyribonucleic acid (DNA) thin-solid-film was experimentally explored in the field of ultrafast nonlinear photonics. Optical transmission was investigated in both linear and nonlinear regimes for two types of DNA thin-solid-films made from DNA in aqueous solution and DNA-cetyltrimethylammonium chloride (CTMA) in an organic solvent. Z-scan measurements revealed a high third-order nonlinearity with n2 exceeding 10-9 at a wavelength of 1570 nm, for a nonlinarity about five orders of magnitude larger than that of silica. We also demonstrated ultrafast saturable absorption (SA) with a modulation depth of 0.43%. DNA thin solid films were successfully deposited on a side-polished optical fiber, providing an efficient evanescent wave interaction. We built an organic-inorganic hybrid all-fiber ring laser using DNA film as an ultrafast SA and using Erbium-doped fiber as an efficient optical gain medium. Stable transform-limited femtosecond soliton pulses were generated with full width half maxima of 417 fs for DNA and 323 fs for DNA-CTMA thin-solid-film SAs. The average output power was 4.20 mW for DNA and 5.46 mW for DNA-CTMA. Detailed conditions for DNA solid film preparation, dispersion control in the laser cavity and subsequent characteristics of soliton pulses are discussed, to confirm unique nonlinear optical applications of DNA thin-solid-film.

  15. Peripapillary retinal nerve fiber layer assessment of spectral domain optical coherence tomography and scanning laser polarimetry to diagnose preperimetric glaucoma.

    Directory of Open Access Journals (Sweden)

    Harsha L Rao

    Full Text Available To compare the abilities of peripapillary retinal nerve fiber layer (RNFL parameters of spectral domain optical coherence tomograph (SDOCT and scanning laser polarimeter (GDx enhanced corneal compensation; ECC in detecting preperimetric glaucoma.In a cross-sectional study, 35 preperimetric glaucoma eyes (32 subjects and 94 control eyes (74 subjects underwent digital optic disc photography and RNFL imaging with SDOCT and GDx ECC. Ability of RNFL parameters of SDOCT and GDx ECC to discriminate preperimetric glaucoma eyes from control eyes was compared using area under receiver operating characteristic curves (AUC, sensitivities at fixed specificities and likelihood ratios (LR.AUC of the global average RNFL thickness of SDOCT (0.786 was significantly greater (p<0.001 than that of GDx ECC (0.627. Sensitivities at 95% specificity of the corresponding parameters were 20% and 8.6% respectively. AUCs of the inferior, superior and temporal quadrant RNFL thickness parameters of SDOCT were also significantly (p<0.05 greater than the respective RNFL parameters of GDx ECC. LRs of outside normal limits category of SDOCT parameters ranged between 3.3 and 4.0 while the same of GDx ECC parameters ranged between 1.2 and 2.1. LRs of within normal limits category of SDOCT parameters ranged between 0.4 and 0.7 while the same of GDx ECC parameters ranged between 0.7 and 1.0.Abilities of the RNFL parameters of SDOCT and GDx ECC to diagnose preperimetric glaucoma were only moderate. Diagnostic abilities of the RNFL parameters of SDOCT were significantly better than that of GDx ECC in preperimetric glaucoma.

  16. Peripapillary retinal nerve fiber layer assessment of spectral domain optical coherence tomography and scanning laser polarimetry to diagnose preperimetric glaucoma.

    Science.gov (United States)

    Rao, Harsha L; Yadav, Ravi K; Addepalli, Uday K; Chaudhary, Shashikant; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

    2014-01-01

    To compare the abilities of peripapillary retinal nerve fiber layer (RNFL) parameters of spectral domain optical coherence tomograph (SDOCT) and scanning laser polarimeter (GDx enhanced corneal compensation; ECC) in detecting preperimetric glaucoma. In a cross-sectional study, 35 preperimetric glaucoma eyes (32 subjects) and 94 control eyes (74 subjects) underwent digital optic disc photography and RNFL imaging with SDOCT and GDx ECC. Ability of RNFL parameters of SDOCT and GDx ECC to discriminate preperimetric glaucoma eyes from control eyes was compared using area under receiver operating characteristic curves (AUC), sensitivities at fixed specificities and likelihood ratios (LR). AUC of the global average RNFL thickness of SDOCT (0.786) was significantly greater (p<0.001) than that of GDx ECC (0.627). Sensitivities at 95% specificity of the corresponding parameters were 20% and 8.6% respectively. AUCs of the inferior, superior and temporal quadrant RNFL thickness parameters of SDOCT were also significantly (p<0.05) greater than the respective RNFL parameters of GDx ECC. LRs of outside normal limits category of SDOCT parameters ranged between 3.3 and 4.0 while the same of GDx ECC parameters ranged between 1.2 and 2.1. LRs of within normal limits category of SDOCT parameters ranged between 0.4 and 0.7 while the same of GDx ECC parameters ranged between 0.7 and 1.0. Abilities of the RNFL parameters of SDOCT and GDx ECC to diagnose preperimetric glaucoma were only moderate. Diagnostic abilities of the RNFL parameters of SDOCT were significantly better than that of GDx ECC in preperimetric glaucoma.

  17. FIBER LASER CONSTRUCTION AND THEORY INCLUDING FIBER BRAGG GRATINGS Photonic Crystal Fibers (PCFs) and applications of gas filled PCFs

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, Jacob O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-08

    The principles used in fiber lasers have been around for a while but it is only within the past few years that fiber lasers have become commercially available and used in high power laser applications. This paper will focus on the basic design principles of fiber lasers, including fiber Bragg gratings, principles of operation, and forms of non-linear effects. It will describe the type and associated doping of the fiber used and difficult designs used to guide energy from the pump to the active medium. Topics covered include fiber laser design, fiber Bragg gratings, materials used, differences in quantum energy loss, thermo-optical effects, stimulated Raman scattering, Brillouin scattering, photonic crystal fibers and applications of gas filled Photonic Crystal Fibers (PCFs). Thanks to fiber lasers, the energy required to produce high power lasers has greatly dropped and as such we can now produce kW power using a standard 120V 15A circuit. High power laser applications are always requiring more power. The fiber laser can now deliver the greater power that these applications demand. Future applications requiring more power than can be combined using standard materials or configurations will need to be developed to overcome the high energy density and high non-linear optical scattering effects present during high power operations.

  18. Templated Chemically Deposited Semiconductor Optical Fiber Materials

    Science.gov (United States)

    Sparks, Justin R.; Sazio, Pier J. A.; Gopalan, Venkatraman; Badding, John V.

    2013-07-01

    Chemical deposition is a powerful technology for fabrication of planar microelectronics. Optical fibers are the dominant platform for telecommunications, and devices such as fiber lasers are forming the basis for new industries. High-pressure chemical vapor deposition (HPCVD) allows for conformal layers and void-free wires of precisely doped crystalline unary and compound semiconductors inside the micro-to-nanoscale-diameter pores of microstructured optical fibers (MOFs). Drawing the fibers to serve as templates into which these semiconductor structures can be fabricated allows for geometric design flexibility that is difficult to achieve with planar fabrication. Seamless coupling of semiconductor optoelectronic and photonic devices with existing fiber infrastructure thus becomes possible, facilitating all-fiber technological approaches. The deposition techniques also allow for a wider range of semiconductor materials compositions to be exploited than is possible by means of preform drawing. Gigahertz bandwidth junction-based fiber devices can be fabricated from doped crystalline semiconductors, for example. Deposition of amorphous hydrogenated silicon, which cannot be drawn, allows for the exploitation of strong nonlinear optical function in fibers. Finally, crystalline compound semiconductor fiber cores hold promise for high-power infrared light-guiding fiber devices and subwavelength-resolution, large-area infrared imaging.

  19. All-Fiber Configuration Laser Self-Mixing Doppler Velocimeter Based on Distributed Feedback Fiber Laser.

    Science.gov (United States)

    Wu, Shuang; Wang, Dehui; Xiang, Rong; Zhou, Junfeng; Ma, Yangcheng; Gui, Huaqiao; Liu, Jianguo; Wang, Huanqin; Lu, Liang; Yu, Benli

    2016-07-27

    In this paper, a novel velocimeter based on laser self-mixing Doppler technology has been developed for speed measurement. The laser employed in our experiment is a distributed feedback (DFB) fiber laser, which is an all-fiber structure using only one Fiber Bragg Grating to realize optical feedback and wavelength selection. Self-mixing interference for optical velocity sensing is experimentally investigated in this novel system, and the experimental results show that the Doppler frequency is linearly proportional to the velocity of a moving target, which agrees with the theoretical analysis commendably. In our experimental system, the velocity measurement can be achieved in the range of 3.58 mm/s-2216 mm/s with a relative error under one percent, demonstrating that our novel all-fiber configuration velocimeter can implement wide-range velocity measurements with high accuracy.

  20. Towards biochips using microstructured optical fiber sensors

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Hoiby, Poul Erik; Jensen, Jesper Bo

    2006-01-01

    In this paper we present the first incorporation of a microstructured optical fiber (MOF) into biochip applications. A 16-mm-long piece of MOF is incorporated into an optic-fluidic coupler chip, which is fabricated in PMMA polymer using a CO2 laser. The developed chip configuration allows...... the continuous control of liquid flow through the MOF and simultaneous optical characterization. While integrated in the chip, the MOF is functionalized towards the capture of a specific single-stranded DNA string by immobilizing a sensing layer on the microstructured internal surfaces of the fiber. The sensing...

  1. Development of a fiber-optic laser delivery system capable of delivering 213 and 266 nm pulsed Nd:YAG laser radiation for tissue ablation in a fluid environment.

    Science.gov (United States)

    Miller, Joe; Yu, Xiao-Bo; Yu, Paula K; Cringle, Stephen J; Yu, Dao-Yi

    2011-02-20

    Ultraviolet (UV) lasers have the capability to precisely remove tissue via ablation; however, due to strong absorption of the applicable portion the UV spectrum, their surgical use is currently limited to extraocular applications at the air/tissue boundary. Here we report the development and characterization of a fiber-optic laser delivery system capable of outputting high-fluence UV laser pulses to internal tissue surfaces. The system has been developed with a view to intraocular surgical applications and has been demonstrated to ablate ocular tissue at the fluid/tissue boundary. The fifth (213 nm) and fourth(266 nm) harmonics of a Nd:YAG laser were launched into optical fibers using a hollow glass taper to concentrate the beam. Standard and modified silica/silica optical fibers were used, all commercially available. The available energy and fluence as a function of optical fiber length was evaluated and maximized. The maximum fluence available to ablate tissue was affected by the wavelength dependence of the fiber transmission; this maximum fluence was greater for 266 nm pulses (8.4 J/cm2) than for 213 nm pulses (1.4 J/cm2). The type of silica/silica optical fiber used did not affect the transmission efficiency of 266 nm pulses, but transmission of 213 nm pulses was significantly greater through modified silica/silica optical fiber. The optical fiber transmission efficiency of 213 nm pulses decreased as a function of number of pulses transmitted, whereas the transmission efficiency of 266 nm radiation was unchanged. Single pulses have been used to ablate fresh porcine ocular tissue. In summary, we report a method for delivering the fifth (213 nm) and fourth (266 nm) harmonics of a Nd:YAG laser to the surface of immersed tissue, the reliability and stability of the system has been characterized, and proof of concept via tissue ablation of porcine ocular tissue demonstrates the potential for the intraocular surgical application of this

  2. Carbonization of a radicular cyst using fiber-optic diode laser: a case report

    Science.gov (United States)

    Kafas, Panagiotis; Kalfas, Sotirios

    2008-01-01

    A female patient, 51 years old, complaint of painful swelling on the anatomical area of the upper left lateral incisor. The diagnosis of radicular cyst was confirmed histo-pathologically. Nowadays, radicular cysts may be treated using conventional root canal methods or surgical apicectomy. The possible soft-laser reaction to radicular cysts after contact application has not been investigated. We present an in vitro case of a diagnosed radicular cyst which carbonized after contact application of diode laser. The need for future clinical trials will be essential to prove the sensitivity of this procedure in humans. PMID:18713459

  3. Polarization dependence of laser interaction with carbon fibers and CFRP.

    Science.gov (United States)

    Freitag, Christian; Weber, Rudolf; Graf, Thomas

    2014-01-27

    A key factor for laser materials processing is the absorptivity of the material at the laser wavelength, which determines the fraction of the laser energy that is coupled into the material. Based on the Fresnel equations, a theoretical model is used to determine the absorptivity for carbon fiber fabrics and carbon fiber reinforced plastics (CFRP). The surface of each carbon fiber is considered as multiple layers of concentric cylinders of graphite. With this the optical properties of carbon fibers and their composites can be estimated from the well-known optical properties of graphite.

  4. Ultrafast fiber lasers for homeland security

    Science.gov (United States)

    Okhotnikov, O. G.

    2005-09-01

    Detecting weapons concealed underneath clothing, analyzing the contents of suspicious-looking envelopes, or even spotting the onset of cancer: these are just some of the exciting prospects that have been turning terahertz wave research into one of the most important topics in photonics. Most broadband pulsed THz sources are based on the excitation of different materials with ultrashort laser pulses. So far, generation of tunable narrow-band THz radiation has been demonstrated using ultrafast solid state lasers as a source of high-intensity optical pulses. The lack of a high-power, low-cost, portable room-temperature THz source is the most significant limitation of modern THz systems. Advances in fiber laser technology can be used to further the capabilities of the homeland security. Using semiconductor saturable absorber mirrors allows for reliable mode-locked operation with different values of cavity dispersion in a broad spectrum ranged from 900 to 1600 nm. Semiconductor saturable absorbers mirrors have been used successfully to initiate and to sustain mode-locking in a wide range of core-pumped fiber lasers. The main advantage of the semiconductor saturable absorber mirrors (SESAM) is the possibility to control important parameters such as absorption recovery time, saturation fluence and modulation depth through the device design, growth conditions and post-growth processing. The SESAM as a cavity mirror in the fiber laser results in compact size, environmentally stable and simple ultrashort pulse lasers that can cover wide wavelength range and generate optical pulses with durations from picoseconds to femtoseconds. Employing SESAM technology for mode-locking, the double-clad fiber laser promises superior pulse quality, high stability and pulse energy without need for power booster that eventually degrades the pulse quality due to nonlinear distortions in the amplifier fiber. We give an overview of recent achievements in ultrafast fiber lasers; discuss basic

  5. Interferometric Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    Hae Young Choi

    2012-02-01

    Full Text Available Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  6. Interferometric fiber optic sensors.

    Science.gov (United States)

    Lee, Byeong Ha; Kim, Young Ho; Park, Kwan Seob; Eom, Joo Beom; Kim, Myoung Jin; Rho, Byung Sup; Choi, Hae Young

    2012-01-01

    Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG) is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  7. Stabilized Optical Fiber Links for the XFEL

    CERN Document Server

    Winter, Axel; Grawert, Felix J; Ilday, Fatih O; Kaertner, Franz X; Kim, Jung-Won; Schlarb, Holger; Schmidt, Bernhard

    2005-01-01

    The timing synchronization scheme for the European X-Ray free electron laser facility (XFEL) is based on the generation and distribution of sub-picosecond laser pulses with actively stabilized repetition rate which are used to synchronize local RF oscillators. An integral part of the scheme is the distribution of the optical pulse stream to parts of the facility via optical fiber links. The optical path length of the fiber has to be stabilized against short-term and long-term timing jitter due to environmental effects, such as temperature drifts and acoustic vibrations, to better than 10 fs for distances ranging from tens of meters to several kilometers. In this paper, we present first experimental results for signal transmission through a km-long fiber link with femtosecond stability.

  8. 100 W all fiber picosecond MOPA laser.

    Science.gov (United States)

    Chen, Sheng-Ping; Chen, Hong-Wei; Hou, Jing; Liu, Ze-Jin

    2009-12-21

    A high power picosecond laser is constructed in an all fiber master oscillator power amplifier (MOPA) configuration. The seed source is an ytterbium-doped single mode fiber laser passively mode-locked by a semiconductor saturable absorber mirror (SESAM). It produces 20 mW average power with 13 ps pulse width and 59.8 MHz repetition rate. A direct amplification of this seed source encounters obvious nonlinear effects hence serious spectral broadening at only ten watt power level. To avoid these nonlinear effects, we octupled the repetition rate to about 478 MHz though a self-made all fiber device before amplification. The ultimate output laser exhibits an average power of 96 W, a pulse width of 16 ps, a beam quality M2 of less than 1.5, and an optical conversion efficiency of 61.5%.

  9. Carbonization of a radicular cyst using fiber-optic diode laser: a case report

    OpenAIRE

    Kafas, Panagiotis; Kalfas, Sotirios

    2008-01-01

    A female patient, 51 years old, complaint of painful swelling on the anatomical area of the upper left lateral incisor. The diagnosis of radicular cyst was confirmed histo-pathologically. Nowadays, radicular cysts may be treated using conventional root canal methods or surgical apicectomy. The possible soft-laser reaction to radicular cysts after contact application has not been investigated. We present an in vitro case of a diagnosed radicular cyst which carbonized after contact application ...

  10. Optical Fiber Pressure Sensor with Reference channel①

    Institute of Scientific and Technical Information of China (English)

    YUZhijing; TIANWei

    1997-01-01

    The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of the system by means of taking the techniques of reference light channel and ratio measurement.

  11. Optical system components for navigation grade fiber optic gyroscopes

    Science.gov (United States)

    Heimann, Marcus; Liesegang, Maximilian; Arndt-Staufenbiel, Norbert; Schröder, Henning; Lang, Klaus-Dieter

    2013-10-01

    Interferometric fiber optic gyroscopes belong to the class of inertial sensors. Due to their high accuracy they are used for absolute position and rotation measurement in manned/unmanned vehicles, e.g. submarines, ground vehicles, aircraft or satellites. The important system components are the light source, the electro optical phase modulator, the optical fiber coil and the photodetector. This paper is focused on approaches to realize a stable light source and fiber coil. Superluminescent diode and erbium doped fiber laser were studied to realize an accurate and stable light source. Therefor the influence of the polarization grade of the source and the effects due to back reflections to the source were studied. During operation thermal working conditions severely affect accuracy and stability of the optical fiber coil, which is the sensor element. Thermal gradients that are applied to the fiber coil have large negative effects on the achievable system accuracy of the optic gyroscope. Therefore a way of calculating and compensating the rotation rate error of a fiber coil due to thermal change is introduced. A simplified 3 dimensional FEM of a quadrupole wound fiber coil is used to determine the build-up of thermal fields in the polarization maintaining fiber due to outside heating sources. The rotation rate error due to these sources is then calculated and compared to measurement data. A simple regression model is used to compensate the rotation rate error with temperature measurement at the outside of the fiber coil. To realize a compact and robust optical package for some of the relevant optical system components an approach based on ion exchanged waveguides in thin glass was developed. This waveguides are used to realize 1x2 and 1x4 splitter with fiber coupling interface or direct photodiode coupling.

  12. Fiber-Optic Sensor Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Constructs and evaluates fiber-optic sensors for a variety of measurands. These measurands include acoustic, pressure, magnetic, and electric field as well...

  13. Technology and applications of ultrafast fiber lasers

    Science.gov (United States)

    Lang, Marion; Hellerer, Thomas; Stuhler, Juergen

    2012-03-01

    We briefly review the key technology of modern fiber based femtosecond laser sources summarizing advantages and disadvantages of different mode-locking solutions. A description of possible extensions of a FemtoFiber-type modelocked Er-doped fiber laser oscillator (1560 nm) reveals the flexibility with respect to wavelength coverage (488 nm .. 2200 nm) and pulse duration (10 fs .. 10 ps). The resulting FemtoFiber family and its versions for instrument integration allow one to use these state-of-the-art light sources in many important applications, e.g. THz spectroscopy and microscopy. We show that, depending on the fiber laser model and the THz emitter, THz radiation can be produced with 4-10 THz bandwidth and detected with up to 60 dB signal-to-noise ratio (SNR). Electronically controlled optical scanning (ECOPS) - a unique method for fast, precise and comfortable sampling of the THz pulse or other pump-probe experiments - is described and recommended for efficient data acquisition. As examples for modern microscopy with ultrafast fiber lasers we present results of two-photon fluorescence, coherent microscopy techniques (SHG/THG/CARS) and fluorescence lifetime imaging (FLIM).

  14. Noise caused by semiconductor lasers in high-speed fiber-optic links

    DEFF Research Database (Denmark)

    Olsen, C. M.; Stubkjær, Kristian; Olesen, H.

    1989-01-01

    Theoretical and experimental results are presented for the signal-to-noise (S/N) ratio caused by mode partition noise, intensity noise, and reflection-induced noise in optical data links. Under given conditions an additional noise source with a S /N ratio of 20 dB will cause a power penalty of 1 d...

  15. Fiber-Optic Vibration Sensor Based on Multimode Fiber

    Directory of Open Access Journals (Sweden)

    I. Lujo

    2008-06-01

    Full Text Available The purpose of this paper is to present a fiberoptic vibration sensor based on the monitoring of the mode distribution in a multimode optical fiber. Detection of vibrations and their parameters is possible through observation of the output speckle pattern from the multimode optical fiber. A working experimental model has been built in which all used components are widely available and cheap: a CCD camera (a simple web-cam, a multimode laser in visible range as a light source, a length of multimode optical fiber, and a computer for signal processing. Measurements have shown good agreement with the actual frequency of vibrations, and promising results were achieved with the amplitude measurements although they require some adaptation of the experimental model. Proposed sensor is cheap and lightweight and therefore presents an interesting alternative for monitoring large smart structures.

  16. Fiber-optic laser-Doppler anemometer microscope developed for the measurement of microvascular red cell velocity.

    Science.gov (United States)

    Seki, J

    1990-11-01

    A fiber-optic laser-Doppler anemometer microscope (FLDAM) was developed and its applicability to the study of microvascular blood flow was examined by measuring red cell velocities in vivo and in vitro. The FLDAM consists of an intravital microscope equipped with a fringe-mode back-scatter LDA. A data processing method of the Doppler signal which used frequency averaging over the entire frequency range of the power spectrum was developed. Spatial resolution of the FLDAM varied from 17 to 200 microns with 50X to 5X objectives. In vitro experiments showed that the red cell velocity obtained by the FLDAM was equal to the mean flow velocity, within the accuracy of the measurements, for tube diameters from 35 to 100 microns, mean velocity from 0.7 to 17 mm/sec, and feed hematocrit of 20%, when 10X or 20X objectives were used. In vivo red cell velocity measurements conducted with the FLDAM in microvessels of rat mesentery with diameters from 6.5 to 49 microns showed that red cell velocities were about 1/1.6 times smaller than those obtained by the two-slit technique, which also suggests that the velocity obtained by the FLDAM corresponds to the mean flow velocity. This relationship was also established from theoretical considerations for the case where the FLDAM sampling volume covers the entire vessel cross section. Furthermore the frequency response of the FLDAM was established to be about 20 Hz, which was sufficient for measurement of pulsatile velocities in rat mesenteric microvessels.

  17. Comparison of optical coherence tomography and scanning laser polarimetry for detection of localized retinal nerve fiber layer defects.

    Science.gov (United States)

    Yoo, Young Cheol; Park, Ki Ho

    2010-01-01

    To compare the ability of Stratus optical coherence tomography (Stratus OCT) and scanning laser polarimetry with variable corneal compensator (GDx VCC) in recognizing a localized retinal nerve fiber layer (RNFL) defect identified on red-free fundus photography. Fifty-three patients with only 1 localized RNFL defect in either eye were taken RNFL thickness analysis using Stratus OCT and GDx VCC. Thirty-nine healthy subjects were used as controls and only 1 eye per subject was considered. Using red-free photography as the standard reference test, sensitivity and specificity for photographic defects, and topographic correlation with photographic defects were compared between Stratus OCT (sector average graph) and GDx VCC (deviation from normal map). Abnormal sectors at P<5% compared with their internal normative database were evaluated. After excluding eyes with unacceptable scan images, 38 healthy eyes and 47 glaucomatous eyes were finally included. Stratus OCT and GDx VCC showed moderate sensitivity (78.7%) and high specificity (94.7% and 89.5%, respectively), and there was no significant difference (P=1.00 and P=0.69, respectively). RNFL defects determined by Stratus OCT and GDx VCC were correlated well with photographic RNFL defects in terms of peripapillary localization and clock-hour size, and there was no significant difference between 2 imaging devices (P=0.20 and P=0.27, respectively). In recognizing a localized RNFL defect, overall diagnostic performance of Stratus OCT and GDx VCC with regard to their internal normative database was not significantly different. As both Stratus OCT and GDx VCC showed only moderate sensitivity, these imaging devices may not substitute red-free fundus photography in clinical practice of glaucoma diagnosis.

  18. Fiber optic to integrated optical chip coupler

    Science.gov (United States)

    Pikulski, Joseph I. (Inventor); Ramer, O. Glenn (Inventor)

    1987-01-01

    Optical fibers are clamped by a block onto a substrate. Thereupon, metal is plated over the fibers to hold them in place upon the substrate. The clamp block is removed and the opening, resulting from the clamp block's presence, is then plated in. The built-up metallic body is a coupling which holds the fibers in position so that the ends can be polished for coupling to an integrated optical chip upon a coupling fixture.

  19. Highly spatially resolved velocity measurements of a turbulent channel flow by a fiber-optic heterodyne laser-Doppler velocity-profile sensor

    Energy Technology Data Exchange (ETDEWEB)

    Shirai, K.; Pfister, T.; Buettner, L.; Czarske, J. [Dresden University of Technology (TU Dresden), Department of Electrical Engineering and Information Technology, Chair for Measurement and Testing Techniques, Dresden (Germany); Mueller, H. [Physikalisch-Technische Bundesanstalt Braunschweig (PTB), Department 1.4 Gas Flow, Braunschweig (Germany); Becker, S.; Lienhart, H.; Durst, F. [Institute of Fluid Mechanics (LSTM), Friedrich-Alexander-University Erlangen-Nuernberg, Erlangen (Germany)

    2006-03-15

    Velocity measurements with a high spatial resolution are important in turbulent flow research. In this paper, we report on the development of a new fiber-optic laser-Doppler velocity-profile sensor exhibiting a spatial resolution of up to 5 {mu}m and its application to turbulent boundary layers. The sensor developed in the present work employs a frequency-division-multiplexing technique in order to separate two measurement signals from the two fringe systems. Velocity measurements close to zero at the solid wall were realized using heterodyne technique. The use of fiber optics improved a robustness of the sensor. The measurement accuracy of the sensor was experimentally investigated with respect to the spatial resolution and velocity. Universal velocity profile of a turbulent flow was obtained in a fully developed channel flow. Mean and fluctuating velocity are presented with a high spatial resolution. (orig.)

  20. Fundamentals of plastic optical fibers

    CERN Document Server

    Koike, Yasuhiro

    2014-01-01

    Polymer photonics is an interdisciplinary field which demands excellence both in optics (photonics) and materials science (polymer). However, theses disciplines have developed independently, and therefore the demand for a comprehensive work featuring the fundamentals of photonic polymers is greater than ever.This volume focuses on Polymer Optical Fiber and their applications. The first part of the book introduces typical optical fibers according to their classifications of material, propagating mode, and structure. Optical properties, the high bandwidth POF and transmission loss are discussed,

  1. Efficient Ho:YLF laser pumped by a Tm:fiber laser

    CSIR Research Space (South Africa)

    Koen, W

    2013-10-01

    Full Text Available A thulium fiber laser pumped Ho:YLF laser delivering 45.1 W in a near diffraction limited beam when pumped with 84.7 W is demonstrated. The optical-to-optical efficiency of 53 % compares favorably with similar Ho:YAG lasers....

  2. Fabrication of Optical Fiber Devices

    Science.gov (United States)

    Andres, Miguel V.

    In this paper we present the main research activities of the Laboratorio de Fibras Opticas del Instituto de Ciencia de los Materiales de la Universidad de Valencia. We show some of the main results obtained for devices based on tapered fibers, fiber Bragg gratings, acousto-optic effects and photonic crystal fibers.

  3. Laser-induced fluorescence fiber optic probe measurement of oil dilution by fuel

    Science.gov (United States)

    Parks, II, James E [Knoxville, TN; Partridge, Jr., William P [Oak Ridge, TN

    2010-11-23

    Apparatus for detecting fuel in oil includes an excitation light source in optical communication with an oil sample for exposing the oil sample to excitation light in order to excite the oil sample from a non-excited state to an excited state and a spectrally selective device in optical communication with the oil sample for detecting light emitted from the oil sample as the oil sample returns from the excited state to a non-excited state to produce spectral indicia that can be analyzed to determine the presence of fuel in the oil sample. A method of detecting fuel in oil includes the steps of exposing a oil sample to excitation light in order to excite the oil sample from a non-excited state to an excited state, as the oil sample returns from the excited state to a non-excited state, detecting light emitted from the oil sample to produce spectral indicia; and analyzing the spectral indicia to determine the presence of fuel in the oil sample.

  4. Nonlinear distortion evaluation in a directly modulated distributed feedback laser diode-based fiber-optic cable television transport system

    Science.gov (United States)

    Li, Chung-Yi; Ying, Cheng-Ling; Lin, Chun-Yu; Chu, Chien-An

    2015-12-01

    This study evaluated a directly modulated distributed feedback (DFB) laser diode (LD) for cable TV systems with respect to carrier-to-nonlinear distortion of LDs. The second-order distortion-to-carrier ratio is found to be proportional to that of the second-order coefficient-to-first-order coefficient of the DFB laser diode driving current and to the optical modulation index (OMI). Furthermore, the third-order distortion-to-carrier ratio is proportional to that of the third-order coefficient-to-first-order coefficient of the DFB laser diode driving current, and to the OMI2.

  5. Optical-Fiber Leak Detector

    Science.gov (United States)

    Workman, Gary L.; Kosten, Susan E.

    1994-01-01

    Proposed optical-fiber sensor detects small changes in pressure in elastomeric O-ring or similar pressure seal, which may indicate deterioration of seal and interpreted as indications of incipient failure. According to concept, length of optical fiber embedded in seal. Light-emitting diode illuminates one end of fiber; photodetector measures intensity of light emerging from other end. Pressure-induced changes in seal bend fiber slightly, altering microbending-induced loss of light from fiber and alter intensity of light at photodetector. Change in intensity approximately proportional to change in pressure.

  6. Advanced ultrafast fiber laser sources enabled by fiber nonlinearities

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei

    2017-05-15

    Development of high power/energy ultrafast fiber lasers for scientific research and industrial applications is one of the most exciting fields in ultrafast optics. This thesis demonstrated new means to improve two essential properties - which are indispensable for novel applications such as high-harmonic generation (HHG) and multiphoton microscopy (MPM) - of an ultrafast fiber laser system: energy scaling capability and wavelength tunability. High photon-flux extreme ultraviolet sources enabled by HHG desire high power (>100 W), high repetition-rate (>1 MHz) ultrafast driving laser sources. We have constructed from scratch a high-power Yb-fiber laser system using the well-known chirped-pulse amplification (CPA) technique. Such a CPA system capable of producing ∝200-W average power consists of a monolithic Yb-fiber oscillator, an all-fiber stretcher, a pre-amplifier chain, a main amplifier constructed from rode-type large pitch fiber, and a diffraction-grating based compressor. To increase the HHG efficiency, ultrafast pulses with duration <60 fs are highly desired. We proposed and demonstrated a novel amplification technique, named as pre-chirp managed amplification (PCMA). We successfully constructed an Yb-fiber based PCMA system that outputs 75-MHz spectrally broadened pulses with >130-W average power. The amplified pulses are compressed to 60-fs pulses with 100-W average power, constituting a suitable HHG driving source. MPM is a powerful biomedical imaging tool, featuring larger penetration depth while providing the capability of optical sectioning. Although femtosecond solid-state lasers have been widely accepted as the standard option as MPM driving sources, fiber-based sources have received growing research efforts due to their superior performance. In the second part of this thesis, we both theoretically and experimentally demonstrated a new method of producing wavelength widely tunable femtosecond pulses for driving MPM. We employed self-phase modulation

  7. Tunable microwave output over a wide RF region generated by an optical dual-wavelength fiber laser

    Science.gov (United States)

    Soltanian, M. R. K.; Ahmad, H.; Pua, C. H.; Harun, S. W.

    2014-10-01

    The dual-wavelength fiber laser provides a compact, robust and stable platform for the generation of microwave signals. Two approaches towards generating microwave emissions using dual wavelengths are explored in this work, with both exploiting the heterodyning beat technique. Both approaches are based on a ring fiber laser with an erbium-doped fiber, having absorption coefficients of 16.0-20.0 dBm at 1531 nm and 11.0-13.0 dBm at 980 nm, serving as the active gain medium. A 10 cm long photonic crystal fiber with a solid core diameter of 4.37 μm and surrounded by air holes of 5.06 μm diameter with a separation of 5.52 μm between them serves to create the desired dual-wavelength output. A tunable band pass filter with bandwidth of 0.8 nm serves as a tuning mechanism together with a polarization controller. Channel spacings as narrow as 0.00043 nm can be realized, giving a microwave output of about 671.9 MHz. Furthermore, the channel spacing can be extended to as large as 0.03631 nm, giving a microwave emission in excess of 4.59 GHz. The output is highly stable, with little change in power or wavelength observed over a test period of 22 min.

  8. Numerical modeling of mode-locked fiber lasers with a fiber-based saturable-absorber

    Science.gov (United States)

    Wang, Long; Chong, Andy; Haus, Joseph W.

    2017-01-01

    We report fiber laser simulations with a fiber compatible, self-focusing, saturable absorber (SA) device. The SA device consists of two tapered fiber ends separated by a bulk, nonlinear medium. An optical beam transmitted from one tapered fiber end, propagate through the nonlinear medium (chalcogenide glass As40 S e60) and couples back into the other tapered fiber end. Pulse propagation in the fiber laser cavity is performed using the Split Step Method. Stable pulses are generated with energies around 0.3 nJ and a transform limited pulse width around 200 fs.

  9. Fiber-Optic Optical-Microwave Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Used to conduct programs of basic science and applied research in the development of laser sources, high-power fiber amplifiers, photonic control of phased...

  10. A fiber laser pumped dual-wavelength mid-infrared laser based on optical parametric oscillation and intracavity difference frequency generation

    Science.gov (United States)

    Wang, Peng; Shang, Yaping; Li, Xiao; Shen, Meili; Xu, Xiaojun

    2017-02-01

    We report a dual-wavelength mid-infrared laser based on intracavity difference frequency generation (DFG) in an MgO-doped periodically poled LiNbO3, which was pumped by a dual-wavelength fiber MOPA consisting of two parts: a dual-wavelength seed and a power amplifier. The maximum pump power was 74.1 W and the wavelengths were 1060 nm and 1090 nm. The wavelengths of the mid-infrared output were 3.1 µm and 3.4 µm under maximum pump power with a total idler power of 6.57 W. The corresponding pump-to-idler slope efficiency reached 12%. The contrast for the peak intensity of the emissions for the two idlers was 0.6. A power preamplifier was added in a further experiment to enhance the contrast. The idler output reached 4.45 W under the maximum pump power of 70 W, which was lower than before. However, the contrast for the idler emission peak intensity was increased to 1.18. The signal wave generated in the experiment only had a single wavelength around 1.6 µm, indicating that two kinds of nonlinear processes occurred in the experiment, namely optical parametric oscillation and intracavity DFG.

  11. Erbium 3-µm fiber lasers

    NARCIS (Netherlands)

    Pollnau, Markus; Jackson, Stuart D.

    2001-01-01

    With its recent breakthrough in terms of output power, the erbium 3- mfiber laser has become an object of intense scientific research and an increasingly attractive tool for medical applications. This paper reviews the research on the erbium 3-um fiber laser since its first demonstration. Its develo

  12. Quantum cryptography using optical fibers.

    Science.gov (United States)

    Franson, J D; Lives, H

    1994-05-10

    Quantum cryptography permits the transmission of secret information whose security is guaranteed by the uncertainty principle. An experimental system for quantum crytography is implemented based on the linear polarization of single photons transmitted by an optical fiber. Polarization-preserving optical fiber and a feedback loop are employed to maintain the state of polarization. Error rates of less than 0.5% are obtained.

  13. Development of measurement simulation of the laser dew-point hygrometer using an optical fiber cable

    Science.gov (United States)

    Matsumoto, Shigeaki

    2005-02-01

    In order to improve the initial and the response times of the Laser Dew-Point Hygrometer (LDH), the measurement simulation was developed on the basis of the loop computation of the surface temperature of a gold plate for dew depostition, the quantity of deposited dew and the intensity of scattered light from the surface of the plate at time interval of 5 sec during measurement. A more detailed relationship between the surface temperature of the plate and the cooling current, and the time constant of the integrator in the control circuit of the LDH were introduced in the simulation program as a function of atmospheric temperature. The simulation was more close to the actual measurement by the LDH. The simulation results indicated the possibility of improving both the times of teh LDH by the increase of the sensitivity of dew and that of the mass transfer coefficient of dew deposited on the plate surface. It was concluded that the initial and the response times could be improved to below 100sec and 120 sec, respectively in the dew-point range at room temperature, that are almost half of the those times of the original LDH.

  14. Lasers for bio-optics

    Science.gov (United States)

    Sona, Alberto

    1992-03-01

    Lasers are being increasingly used in bioptics and in life sciences in general, especially for medical applications for therapy and diagnostics. Lasers are also broadly used in environment sciences to monitor atmospheric parameters and concentrations of molecular species of natural origin or coming from human activities such as the various kind of pollutants. The peculiar features of lasers exploited in these areas are mainly the capability of developing an action or performing a measurement without physical contact with the target and, if required, from a remote position with the assistance of suitable beam delivery systems such as telescopes, microscopes, or optical fibers. These features are directly related to the space and time coherence of the laser light and to the energy storage capability of the laser material which allow an extremely effective concentration of the beam energy in space, direction frequency, or time. A short description of the principle of operation and relevant properties of lasers are given and the most significant properties of the laser emission are briefly reviewed. Lasers for medical applications (mainly for therapy) will be mentioned, pointing out the specific property exploited for the various applications. Finally, examples of laser applications to the environmental sciences will be reported. A summary of the properties exploited in the various bio-optical applications is shown.

  15. Fiber optic sensor and method for making

    Science.gov (United States)

    Vartuli, James Scott; Bousman, Kenneth Sherwood; Deng, Kung-Li; McEvoy, Kevin Paul; Xia, Hua

    2010-05-18

    A fiber optic sensor including a fiber having a modified surface integral with the fiber wherein the modified surface includes an open pore network with optical agents dispersed within the open pores of the open pore network. Methods for preparing the fiber optic sensor are also provided. The fiber optic sensors can withstand high temperatures and harsh environments.

  16. Fiber-optic technology review

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, P.B.

    1980-01-01

    A history of fiber technology is presented. The advantages of fiber optics are discussed (bandwidth, cost, weight and size, nonmetallic construction and isolation). Some aspects of the disadvantages of fiber systems briefly discussed are fiber and cable availability, fiber components, radiation effects, receivers and transmitters, and material dispersion. Particular emphasis over the next several years will involve development of fibers and systems optimized for use at wavelengths near 1.3 ..mu..m and development of wavelengths multiplexers for simultaneous system operation at several wavelengths.

  17. Monolithic, High-Speed Fiber-Optic Switching Array for Lidar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed optical device is a fiber-based multi-channel switch to quickly switch a fiber-coupled laser among many possible output channels to create a fiber-based...

  18. High-temperature diode laser pumps for directed energy fiber lasers (Conference Presentation)

    Science.gov (United States)

    Kanskar, Manoj; Bao, Ling; Chen, Zhigang; DeVito, Mark; Dong, Weimin; Grimshaw, Mike P.; Guan, Xinguo; Hemenway, David M.; Martinsen, Robert; Zhang, Jim; Zhang, Shiguo

    2017-05-01

    Kilowatt-class fiber lasers and amplifiers are becoming increasingly important building blocks for power-scaling laser systems in various different architectures for directed energy applications. Currently, state-of-the-art Yb-doped fiber lasers operating near 1060 nm operate with optical-to-optical power-conversion efficiency of about 66%. State-of-the-art fiber-coupled pump diodes near 975 nm operate with about 50% electrical-to-fiber-coupled optical power conversion efficiency at 25C heatsink temperature. Therefore, the total system electrical-to-optical power conversion efficiency is about 33%. As a result, a 50-kW fiber laser will generate 75 kW of heat at the pump module and 25 kW at the fiber laser module with a total waste heat of 100 kW. It is evident that three times as much waste heat is generated at the pump module. While improving the efficiency of the diodes primarily reduces the input power requirement, increasing the operating temperature primarily reduces the size and weight for thermal management systems. We will discuss improvement in diode laser design, thermal resistance of the package as well as improvement in fiber-coupled optical-to-optical efficiency to achieve high efficiency at higher operating temperature. All of these factors have a far-reaching implication in terms of significantly improving the overall SWAP requirements thus enabling DEW-class fiber lasers on airborne and other platforms.

  19. Study on All Fiber-optic Laser Doppler Velocimeter%全光纤多普勒测速系统的研究

    Institute of Scientific and Technical Information of China (English)

    谭朝勇; 叶欣; 胡永明

    2011-01-01

    A fiber-optic laser Doppler velocimeter based on Michelson interferometer was described and constructed with fiber laser and fiber collimator. In the experiment of measuring the weak vibration of loudspeaker, good agreement was observed between the fiber-velocimeter and the driving signal. The experiment data dealt with FFT method shows that this system is capable of resolving the velocity less than 1 mm/s,and the resolution is about 0.1 mm/s.%为了验证全光纤多普勒测速系统的低速响应能力,采用窄带光纤激光器、准直透镜等器件搭建了一套迈克尔逊干涉仪结构的全光纤多普勒测速系统,分析了其测速的基本原理,并对喇叭振动进行了测试.采用快速傅里叶变换对信号进行处理,解调结果表明,该系统对低速响应灵敏,能够有效地测量出喇叭膜片振动速度,最低可测速度在1 mm/s以下,速度分辨率可达0.1mm/s.

  20. Nondestructive thickness measurement system for multiple layers of paint based on femtosecond fiber laser technologies

    Science.gov (United States)

    Sudo, Masaaki; Takayanagi, Jun; Ohtake, Hideyuki

    2016-11-01

    Because optical fiber-based optical systems are generally robust against external interference, they can be used as reliable systems in industrial applications in various fields. This paper describes fiber lasers generating femtosecond pulses that use optical fibers as gain media and optical paths. Additionally, the nondestructive paint multilayer thickness measurement of automotive parts using terahertz waves generated and detected by femtosecond fiber laser systems was conducted.

  1. High-sensitivity fiber optic acoustic sensors

    Science.gov (United States)

    Lu, Ping; Liu, Deming; Liao, Hao

    2016-11-01

    Due to the overwhelming advantages compared with traditional electronicsensors, fiber-optic acoustic sensors have arisen enormous interest in multiple disciplines. In this paper we present the recent research achievements of our group on fiber-optic acoustic sensors. The main point of our research is high sensitivity interferometric acoustic sensors, including Michelson, Sagnac, and Fabry-Pérot interferometers. In addition, some advanced technologies have been proposed for acoustic or acoustic pressure sensing such as single-mode/multimode fiber coupler, dual FBGs and multi-longitudinal mode fiber laser based acoustic sensors. Moreover, our attention we have also been paid on signal demodulation schemes. The intensity-based quadrature point (Q-point) demodulation, two-wavelength quadrature demodulation and symmetric 3×3 coupler methodare discussed and compared in this paper.

  2. Fiber optic hydrogen sensor

    Energy Technology Data Exchange (ETDEWEB)

    Butler, M.A.; Sanchez, R.; Dulleck, G.R.

    1996-05-01

    This report covers the development of fiber optic hydrogen and temperature sensors for monitoring dissolved hydrogen gas in transformer oil. The concentration of hydrogen gas is a measure of the corona and spark discharge within the transformer and reflects the state of health of the transformer. Key features of the instrument include use of palladium alloys to enhance hydrogen sensitivity, a microprocessor controlled instrument with RS-232, liquid crystal readout, and 4-20 ma. current loop interfaces. Calibration data for both sensors can be down loaded to the instrument through the RS-232 interface. This project was supported by the Technology Transfer Initiative in collaboration with J. W. Harley, Inc. through the mechanism of a cooperative research and development agreement (CRADA).

  3. Innovations in high power fiber laser applications

    Science.gov (United States)

    Beyer, Eckhard; Mahrle, Achim; Lütke, Matthias; Standfuss, Jens; Brückner, Frank

    2012-02-01

    Diffraction-limited high power lasers represent a new generation of lasers for materials processing, characteristic traits of which are: smaller, cost-effective and processing "on the fly". Of utmost importance is the high beam quality of fiber lasers which enables us to reduce the size of the focusing head incl. scanning mirrors. The excellent beam quality of the fiber laser offers a lot of new applications. In the field of remote cutting and welding the beam quality is the key parameter. By reducing the size of the focusing head including the scanning mirrors we can reach scanning frequencies up to 1.5 kHz and in special configurations up to 4 kHz. By using these frequencies very thin and deep welding seams can be generated experienced so far with electron beam welding only. The excellent beam quality of the fiber laser offers a high potential for developing new applications from deep penetration welding to high speed cutting. Highly dynamic cutting systems with maximum speeds up to 300 m/min and accelerations up to 4 g reduce the cutting time for cutting complex 2D parts. However, due to the inertia of such systems the effective cutting speed is reduced in real applications. This is especially true if complex shapes or contours are cut. With the introduction of scanner-based remote cutting systems in the kilowatt range, the effective cutting speed on the contour can be dramatically increased. The presentation explains remote cutting of metal foils and sheets using high brightness single mode fiber lasers. The presentation will also show the effect of optical feedback during cutting and welding with the fiber laser, how those feedbacks could be reduced and how they have to be used to optimize the cutting or welding process.

  4. Coherent fiber supercontinuum laser for nonlinear biomedical imaging

    Science.gov (United States)

    Tu, Haohua; Liu, Yuan; Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry; Boppart, Stephen A.

    2012-12-01

    Nonlinear biomedical imaging has not benefited from the well-known techniques of fiber supercontinuum generation for reasons such as poor coherence (or high noise), insufficient controllability, low spectral power intensity, and inadequate portability. Fortunately, a few techniques involving nonlinear fiber optics and femtosecond fiber laser development have emerged to overcome these critical limitations. These techniques pave the way for conducting point-of-care nonlinear biomedical imaging by a low-maintenance cost-effective coherent fiber supercontinuum laser, which covers a broad emission wavelength of 350-1700 nm. A prototype of this laser has been demonstrated in label-free multimodal nonlinear imaging of cell and tissue samples.

  5. Gold island fiber optic sensor

    Science.gov (United States)

    Meriaudeau, Fabrice; Wig, A. G.; Passian, A.; Downey, Todd R.; Buncick, Milan; Ferrell, Trinidad L.

    1999-12-01

    A fiber optic chemical sensor based on gold-island surface plasmon excitation is presented. The sensing part of the fiber is the end of the fiber onto which a thin layer of gold has been deposited to form a particulate surface. Annealing the gold reshapes the particles and produces an optical absorbance near 535 nm with the fiber in air. The optical absorption resonance of the gold particles is shifted if the fiber is immersed in a medium other than air. These resonance shifts are examined by transmission spectroscopy through the fiber. Experimental results for the sensitivity and dynamic range in the measurement of liquid solutions are in agreement with a basic theoretical model which characterizes the surface plasmon using nonretarded electrodynamics.

  6. Fiber optic-based biosensor

    Science.gov (United States)

    Ligler, Frances S.

    1991-01-01

    The NRL fiber optic biosensor is a device which measures the formation of a fluorescent complex at the surface of an optical fiber. Antibodies and DNA binding proteins provide the mechanism for recognizing an analyze and immobilizing a fluorescent complex on the fiber surface. The fiber optic biosensor is fast, sensitive, and permits analysis of hazardous materials remote from the instrumentation. The fiber optic biosensor is described in terms of the device configuration, chemistry for protein immobilization, and assay development. A lab version is being used for assay development and performance characterization while a portable device is under development. Antibodies coated on the fiber are stable for up to two years of storage prior to use. The fiber optic biosensor was used to measure concentration of toxins in the parts per billion (ng/ml) range in under a minute. Immunoassays for small molecules and whole bacteria are under development. Assays using DNA probes as the detection element can also be used with the fiber optic sensor, which is currently being developed to detect biological warfare agents, explosives, pathogens, and toxic materials which pollute the environment.

  7. Dark pulse generation in fiber lasers incorporating carbon nanotubes.

    Science.gov (United States)

    Liu, H H; Chow, K K

    2014-12-01

    We demonstrate the generation of dark pulses from carbon nanotube (CNT) incorporated erbium-doped fiber ring lasers with net anomalous dispersion. A side-polished fiber coated with CNT layer by optically-driven deposition method is embedded into the laser in order to enhance the birefringence and nonlinearity of the laser cavity. The dual-wavelength domain-wall dark pulses are obtained from the developed CNT-incorporated fiber laser at a relatively low pump threshold of 50.6 mW. Dark pulses repeated at the fifth-order harmonic of the fundamental cavity frequency are observed by adjusting the intra-cavity polarization state.

  8. Springer handbook of lasers and optics

    CERN Document Server

    2012-01-01

    The Springer Handbook of Lasers and Optics provides fast, up-to-date, comprehensive and authoritative coverage of the wide fields of optics and lasers. It is written for daily use in the office or laboratory and offers explanatory text, data, and references needed for anyone working with lasers and optical instruments. This second edition features numerous updates and additions. Especially four new chapters on Fiber Optics, Integrated Optics, Frequency Combs, and Interferometry reflect the major changes. In addition, chapters Optical Materials and Their Properties, Optical Detectors, Nanooptics, and Optics far Beyond the Diffraction Limit have been thoroughly revised and updated. The now 25 chapters are grouped into four parts which cover basic principles and materials, fabrication and properties of optical components, coherent and incoherent light sources, and, finally, selected applications and special fields such as terahertz photonics, x-ray optics and holography. Each chapter is authored by respected exp...

  9. 2 micron femtosecond fiber laser

    Science.gov (United States)

    Liu, Jian; Wan, Peng; Yang, Lihmei

    2014-07-29

    Methods and systems for generating femtosecond fiber laser pulses are disclose, including generating a signal laser pulse from a seed laser oscillator; using a first amplifier stage comprising an input and an output, wherein the signal laser pulse is coupled into the input of the first stage amplifier and the output of the first amplifier stage emits an amplified and stretched signal laser pulse; using an amplifier chain comprising an input and an output, wherein the amplified and stretched signal laser pulse from the output of the first amplifier stage is coupled into the input of the amplifier chain and the output of the amplifier chain emits a further amplified, stretched signal laser pulse. Other embodiments are described and claimed.

  10. Switchable dual-mode all-fiber laser with few-mode fiber Bragg grating

    Science.gov (United States)

    Jin, Wenxing; Qi, Yanhui; Yang, Yuguang; Jiang, Youchao; Wu, Yue; Xu, Yao; Yao, Shuzhi; Jian, Shuisheng

    2017-09-01

    We propose a new approach to realize switchable mode operation in a few-mode erbium-doped fiber laser. The ring fiber laser structure is constructed with a core-offset splicing between single-mode fiber and dual-mode fiber. Stable operating on the fundamental mode laser and second-order mode laser individually or simultaneously is realized by appropriately adjusting the state of the polarization controller and bending status of the few-mode fiber Bragg grating. The narrow 3 dB linewidth less than 0.02 nm and high optical signal to noise ratio more than 42 dB are obtained for both modes in either separate laser or simultaneous laser operating conditions.

  11. SURFACE MORPHOLOGY OF CARBON FIBER POLYMER COMPOSITES AFTER LASER STRUCTURING

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL; Chen, Jian [ORNL; Jones, Jonaaron F. [University of Tennessee (UT); Alexandra, Hackett [University of Tennessee (UT); Jellison Jr, Gerald Earle [ORNL; Daniel, Claus [ORNL; Warren, Charles David [ORNL; Rehkopf, Jackie D. [Plasan Carbon Composites

    2015-01-01

    The increasing use of Carbon Fiber Polymer Composite (CFPC) as a lightweight material in automotive and aerospace industries requires the control of surface morphology. In this study, the composites surface was prepared by ablating the resin in the top fiber layer of the composite using an Nd:YAG laser. The CFPC specimens with T700S carbon fiber and Prepreg - T83 resin (epoxy) were supplied by Plasan Carbon Composites, Inc. as 4 ply thick, 0/90o plaques. The effect of laser fluence, scanning speed, and wavelength was investigated to remove resin without an excessive damage of the fibers. In addition, resin ablation due to the power variation created by a laser interference technique is presented. Optical property measurements, optical micrographs, 3D imaging, and high-resolution optical profiler images were used to study the effect of the laser processing on the surface morphology.

  12. Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

    Science.gov (United States)

    Lanin, Aleksandr A.; Fedotov, Il'ya V.; Sidorov-Biryukov, Dmitrii A.; Doronina-Amitonova, Lyubov V.; Ivashkina, Olga I.; Zots, Marina A.; Sun, Chi-Kuang; Ömer Ilday, F.; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

    2012-03-01

    Large-core hollow photonic-crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-μm-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding.

  13. High-Power ZBLAN Glass Fiber Lasers: Review and Prospect

    Directory of Open Access Journals (Sweden)

    Xiushan Zhu

    2010-01-01

    Full Text Available ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF, considered as the most stable heavy metal fluoride glass and the excellent host for rare-earth ions, has been extensively used for efficient and compact ultraviolet, visible, and infrared fiber lasers due to its low intrinsic loss, wide transparency window, and small phonon energy. In this paper, the historical progress and the properties of fluoride glasses and the fabrication of ZBLAN fibers are briefly described. Advances of infrared, upconversion, and supercontinuum ZBLAN fiber lasers are addressed in detail. Finally, constraints on the power scaling of ZBLAN fiber lasers are analyzed and discussed. ZBLAN fiber lasers are showing promise of generating high-power emissions covering from ultraviolet to mid-infrared considering the recent advances in newly designed optical fibers, beam-shaped high-power pump diodes, beam combining techniques, and heat-dissipating technology.

  14. Germanate Glass Fiber Lasers for High Power

    Science.gov (United States)

    2016-01-04

    evidence of crystallisation after thermal cycling, and is of a low enough loss to realize a fiber laser. The glass stability is demonstrated by...2low-loss fiber can be realized . 15. SUBJECT TERMS Germanate fiber Laser, Fiber Laser, Structured Fiber 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...the profile of bare fibres and the loss value at 630 matches with the spot loss measurement done by Naveed. DISTRIBUTION A: Distribution

  15. Fiber optics that fly

    Science.gov (United States)

    Wilcox, Michael J.; Thelen, Donald C., Jr.

    1996-11-01

    analog integrated circuit using photodiodes and fiber optic waveguides as the nonlinear light sensing devices, current mirrors and opamp circuits for the processing. The outputs of this circuit will go to other artificial neural networks for further processing.

  16. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  17. Fiber-Optic Terahertz Data-Communication Networks

    Science.gov (United States)

    Chua, Peter L.; Lambert, James L.; Morookian, John M.; Bergman, Larry A.

    1994-01-01

    Network protocols implemented in optical domain. Fiber-optic data-communication networks utilize fully available bandwidth of single-mode optical fibers. Two key features of method: use of subpicosecond laser pulses as carrier signals and spectral phase modulation of pulses for optical implementation of code-division multiple access as multiplexing network protocol. Local-area network designed according to concept offers full crossbar functionality, security of data in transit through network, and capacity about 100 times that of typical fiber-optic local-area network in current use.

  18. Gigashot Optical Laser Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Deri, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-13

    The Gigashot Optical Laser Demonstrator (GOLD) project has demonstrated a novel optical amplifier for high energy pulsed lasers operating at high repetition rates. The amplifier stores enough pump energy to support >10 J of laser output, and employs conduction cooling for thermal management to avoid the need for expensive and bulky high-pressure helium subsystems. A prototype amplifier was fabricated, pumped with diode light at 885 nm, and characterized. Experimental results show that the amplifier provides sufficient small-signal gain and sufficiently low wavefront and birefringence impairments to prove useful in laser systems, at repetition rates up to 60 Hz.

  19. Application of Fiber Optic Instrumentation

    Science.gov (United States)

    Richards, William Lance; Parker, Allen R., Jr.; Ko, William L.; Piazza, Anthony; Chan, Patrick

    2012-01-01

    Fiber optic sensing technology has emerged in recent years offering tremendous advantages over conventional aircraft instrumentation systems. The advantages of fiber optic sensors over their conventional counterparts are well established; they are lighter, smaller, and can provide enormous numbers of measurements at a fraction of the total sensor weight. After a brief overview of conventional and fiber-optic sensing technology, this paper presents an overview of the research that has been conducted at NASA Dryden Flight Research Center in recent years to advance this promising new technology. Research and development areas include system and algorithm development, sensor characterization and attachment, and real-time experimentally-derived parameter monitoring for ground- and flight-based applications. The vision of fiber optic smart structure technology is presented and its potential benefits to aerospace vehicles throughout the lifecycle, from preliminary design to final retirement, are presented.

  20. Fiber Optics: A Bright Future.

    Science.gov (United States)

    Rice, James, Jr.

    1980-01-01

    Presents an overview of the impact of fiber optics on telecommunications and its application to information processing and library services, including information retrieval, news services, remote transmission of library services, and library networking. (RAA)

  1. Fast phase switching within the bunch train of the PHIN photo-injector at CERN using fiber-optic modulators on the drive laser

    CERN Document Server

    Divall Csatari, M; Bolzon, B; Bravin, E; Chevallay, E; Dobert, S; Drozdy, A; Fedosseev, V; Hessler, C; Lefevre, T; Livesley, S; Losito, R; Mete, O; Petrarca, M; Rabiller, A N

    2011-01-01

    The future Compact Linear Collider (CLIC) e^-/e^+ collider is based on the two-beam acceleration concept, whereby interleaving electron bunches of the drive beam through a delay loop and combiner rings as well as high peak RF power at 12GHz are created locally to accelerate a second beam, the main beam. One of the main objectives of the currently operational CLIC Test Facility (CTF3) is to demonstrate beam combination from 1.5GHz to 12GHz, which requires satellite-free fast phase-switching of the drive beam with sub-ns speed. The PHIN photo-injector, with the photo-injector laser, provides flexibility in the time structure of the electron bunches produced, by direct manipulation of the laser pulses. A novel fiber modulator-based phase-switching technique allows clean and fast phase-switch at 1.5GHz. This paper describes the switching system based on fiber-optic modulators, and the measurements carried out on both the laser and the electron beam to verify the scheme.

  2. Recent development on high-power tandem-pumped fiber laser

    Science.gov (United States)

    Zhou, Pu; Xiao, Hu; Leng, Jinyong; Zhang, Hanwei; Xu, Jiangmin; Wu, Jian

    2016-11-01

    High power fiber laser is attracting more and more attention due to its advantage in excellent beam quality, high electricto- optical conversion efficiency and compact system configuration. Power scaling of fiber laser is challenged by the brightness of pump source, nonlinear effect, modal instability and so on. Pumping active fiber by using high-brightness fiber laser instead of common laser diode may be the solution for the brightness limitation. In this paper, we will present the recent development of various kinds of high power fiber laser based on tandem pumping scheme. According to the absorption property of Ytterbium-doped fiber, Thulium-doped fiber and Holmium-doped fiber, we have theoretically studied the fiber lasers that operate at 1018 nm, 1178 nm and 1150 nm, respectively in detail. Consequently, according to the numerical results we have optimized the fiber laser system design, and we have achieved (1) 500 watt level 1018nm Ytterbium-doped fiber laser (2) 100 watt level 1150 nm fiber laser and 100 watt level random fiber laser (3) 30 watt 1178 nm Ytterbium-doped fiber laser, 200 watt-level random fiber laser. All of the above-mentioned are the record power for the corresponded type of fiber laser to the best of our knowledge. By using the high-brightness fiber laser operate at 1018 nm, 1178 nm and 1150 nm that we have developed, we have achieved the following high power fiber laser (1) 3.5 kW 1090 nm Ytterbium-doped fiber amplifier (2) 100 watt level Thulium-doped fiber laser and (3) 50 watt level Holmium -doped fiber laser.

  3. All fiber passively Q-switched laser

    Science.gov (United States)

    Soh, Daniel B. S.; Bisson, Scott E

    2015-05-12

    Embodiments relate to an all fiber passively Q-switched laser. The laser includes a large core doped gain fiber having a first end. The large core doped gain fiber has a first core diameter. The laser includes a doped single mode fiber (saturable absorber) having a second core diameter that is smaller than the first core diameter. The laser includes a mode transformer positioned between a second end of the large core doped gain fiber and a first end of the single mode fiber. The mode transformer has a core diameter that transitions from the first core diameter to the second core diameter and filters out light modes not supported by the doped single mode fiber. The laser includes a laser cavity formed between a first reflector positioned adjacent the large core doped gain fiber and a second reflector positioned adjacent the doped single mode fiber.

  4. A Noninvasive Miniaturized-Wireless Laser-Doppler Fiber-Optic Sensor for Understanding Distal Fingertip Injuries in Astronauts

    Science.gov (United States)

    Ansari, Rafat R.; Jones, Jeffrey A.; Pollonini, Luca; Rodriquez, Mikael; Opperman, Roedolph; Hochstein, Jason

    2009-01-01

    During extra-vehicular activities (EVAs) or spacewalks astronauts over use their fingertips under pressure inside the confined spaces of gloves/space suits. The repetitive hand motion is a probable cause for discomfort and injuries to the fingertips. We describe a new wireless fiber-optic probe that can be integrated inside the astronaut glove for noninvasive blood perfusion measurements in distal fingertips. In this preliminary study, we present blood perfusion measurements while performing hand-grip exercises simulating the use of space tools.

  5. A non-invasive miniaturized-wireless laser-Doppler fiber optic sensor for understanding distal fingertip injuries in astronauts

    Science.gov (United States)

    Ansari, Rafat R.; Jones, Jeffrey A.; Pollonini, Luca; Rodriguez, Mikael; Opperman, Roedolph; Hochstein, Jason

    2009-02-01

    During extra-vehicular activities (EVAs) or space walks astronauts over use their fingertips under pressure inside the confined spaces of gloves/space-suite. The repetitive hand motion is a probable cause for discomfort and injuries to the finger-tips. We describe a new wireless fiber-optic probe that can be integrated inside the astronaut glove for non-invasive blood perfusion measurements in distal finger tips. In this preliminary study, we present blood perfusion measurements while performing hand-grip exercises simulating the use of space tools.

  6. Achromatic optical diode in fiber optics

    CERN Document Server

    Berent, Michal; Vitanov, Nikolay V

    2013-01-01

    We propose a broadband optical diode, which is composed of one achromatic reciprocal quarter-wave plate and one non-reciprocal quarter-wave plate, both placed between two crossed polarizers. The presented design of achromatic wave plates relies on an adiabatic evolution of the Stokes vector, thus, the scheme is robust and efficient. The possible simple implementation using fiber optics is suggested.

  7. Laser-jamming analysis of combined fiber lasers to imaging CCD

    Science.gov (United States)

    Jie, Xu; Shanghong, Zhao; Rui, Hou; Xiaoliang, Li; Jili, Wu; Yunxia, Li; Wen, Meng; Yanhui, Ni; Lihua, Ma

    2009-07-01

    To complete a successful laser jamming to imaging charge coupled device (CCD) based on combined fiber lasers, the interactions between CCD and combined fiber lasers were analyzed in detail. The saturation and crosstalk thresholds of CCD were achieved, which are lower than 10 mW/cm 2. Through theoretical analysis and numerical simulations, the thermal processes under single pulse, multi-pulses and continuous laser irradiations were developed. The simulation results have proved the possibility of hard damage caused by multi-pulses and continuous laser irradiations. The combined fiber lasers is suitable to deploy optical saturation jamming at present. The further applications of combined fiber lasers need a more powerful laser source and a more accurate tracking and pointing system.

  8. Optics, light and lasers

    CERN Document Server

    Meschede, Dieter

    2008-01-01

    Starting from the concepts of classical optics, Optics, Light and Lasers introduces in detail the phenomena of linear and nonlinear light matter interaction, the properties of modern laser sources, and the concepts of quantum optics. Several examples taken from the scope of modern research are provided to emphasize the relevance of optics in current developments within science and technology. The text has been written for newcomers to the topic and benefits from the author's ability to explain difficult sequences and effects in a straightforward and easily comprehensible way. To this second, c

  9. Large-area fiber-optic gyroscope on a multiplexed fiber network.

    Science.gov (United States)

    Clivati, C; Calonico, D; Costanzo, G A; Mura, A; Pizzocaro, M; Levi, F

    2013-04-01

    We describe a fiber-optic gyroscope based on the Sagnac effect, realized on a multiplexed telecom fiber network. Our loop encloses an area of 20 km² and coexists with Internet data traffic. This Sagnac interferometer is capable of detecting signals that are larger than 10(-8) (rad/s)/√Hz, thus approaching ring laser gyroscopes without using a narrow-linewidth laser or sophisticated optics. The proposed gyroscope could be useful for seismic applications, opening new possibilities for this kind of optical fiber sensor.

  10. Fiber optic Adaline neural networks

    Science.gov (United States)

    Ghosh, Anjan K.; Trepka, Jim; Paparao, Palacharla

    1993-02-01

    Optoelectronic realization of adaptive filters and equalizers using fiber optic tapped delay lines and spatial light modulators has been discussed recently. We describe the design of a single layer fiber optic Adaline neural network which can be used as a bit pattern classifier. In our realization we employ as few electronic devices as possible and use optical computation to utilize the advantages of optics in processing speed, parallelism, and interconnection. The new optical neural network described in this paper is designed for optical processing of guided lightwave signals, not electronic signals. We analyzed the convergence or learning characteristics of the optically implemented Adaline in the presence of errors in the hardware, and we studied methods for improving the convergence rate of the Adaline.

  11. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam

    2011-01-01

    This book provides an in-depth treatment of both linear fiber-optic systems and their key enabling devices. It presents a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers. To the second edition of this book important new aspects of linear fiber-optic transmission technologies are added, such as high level system architectural issues, algorithms for deriving the optimal frequency assignment, directly modulated or externally modulated laser t...

  12. Microfabrication of fiber optic scanners

    Science.gov (United States)

    Fauver, Mark; Crossman-Bosworth, Janet L.; Seibel, Eric J.

    2002-06-01

    A cantilevered optical fiber is micromachined to function as a miniature resonant opto-mechanical scanner. By driving the base of the cantilevered fiber at a resonance frequency using a piezoelectric actuator, the free end of the cantilever beam becomes a scanned light source. The fiber scanners are designed to achieve wide field-of-view (FOV) and high scan frequency. We employ a non-linearly tapered profile fiber to achieve scan amplitudes of 1 mm at scan frequencies above 20 KHz. Scan angles of over 120 degree(s) (full angle) have been achieved. Higher order modes are also employed for scanning applications that require compactness while maintaining large angular FOV. Etching techniques are used to create the non-linearly tapered sections in single mode optical fiber. Additionally, micro-lenses are fabricated on the tips of the etched fibers, with lens diameters as small as 15 microns. Such lenses are capable of reducing the divergence angle of the emitted light to 5 degree(s) (full angle), with greater reduction expected by employing novel lens shaping techniques. Microfabricated optical fiber scanners have display applications ranging from micro-optical displays to larger panoramic displays. Applications for micro-image acquisition include small barcode readers to medical endoscopes.

  13. Numerical simulation of a DFB - fiber laser sensor (part 1

    Directory of Open Access Journals (Sweden)

    Dan SAVASTRU

    2010-06-01

    Full Text Available This paper presents the preliminary results obtained in developing a numerical simulationanalysis of fiber optic bending sensitivity aiming to improve the design of fiber lasers. The developednumerical simulation method relies on an analysis of both the fundamental mode propagation alongan optical fiber and of how bending of this fiber influence the optical radiation losses. The cases ofsimple, undoped and of doped with Er3+ ions optical fibers are considered. The presented results arebased on numerical simulation of eigen-modes of a laser intensity distribution by the use of finiteelement method (FEM developed in the frame of COMSOL software package. The numericalsimulations are performed by considering the cases of both normal, non-deformed optic fiber and ofsymmetrically deformed optic fiber resembling micro-bending of it. Both types of fiber optic bendinglosses are analyzed, namely: the transition loss, associated with the abrupt or rapid change incurvature at the beginning and the end of a bend, and pure bend loss is associated with the loss fromthe bend of constant curvature in between.

  14. Advanced Components For Fiber-Optical Systems

    Science.gov (United States)

    Depaula, Ramon; Stowe, David W.

    1989-01-01

    Paper reviews statuses of some advanced passive and active optical components for use with optical fibers. Emphasis on highly birefringent components controling polarization, because control of polarization critical in applications as fiber-optical gyroscopes, interferometric sensors, and coherent communications.

  15. On-chip optical detection of laser cooled atoms.

    Science.gov (United States)

    Quinto-Su, P; Tscherneck, M; Holmes, M; Bigelow, N

    2004-10-18

    We have used an optical fiber based system to implement optical detection of atoms trapped on a reflective "atom-chip". A fiber pair forms an emitter-detector setup that is bonded to the atom-chip surface to optically detect and probe laser cooled atoms trapped in a surface magneto-optical trap. We demonstrate the utility of this scheme by measuring the linewidth of the Cs D2 line at different laser intensities.

  16. Completely monolithic linearly polarized high-power fiber laser oscillator

    Science.gov (United States)

    Belke, Steffen; Becker, Frank; Neumann, Benjamin; Ruppik, Stefan; Hefter, Ulrich

    2014-03-01

    We have demonstrated a linearly polarized cw all-in-fiber oscillator providing 1 kW of output power and a polarization extinction ratio (PER) of up to 21.7 dB. The design of the laser oscillator is simple and consists of an Ytterbium-doped polarization maintaining large mode area (PLMA) fiber and suitable fiber Bragg gratings (FBG) in matching PLMA fibers. The oscillator has nearly diffraction-limited beam quality (M² high power 6+1:1 pump coupler. The slope efficiency of the laser is 75 %. The electro/optical efficiency of the complete laser system is ~30 % and hence in the range of Rofin's cw non-polarized fiber lasers. Choosing an adequate bending diameter for the Yb-doped PLMA fiber, one polarization mode as well as higher order modes are sufficiently supressed1. Resulting in a compact and robust linearly polarized high power single mode laser without external polarizing components. Linearly polarized lasers are well established for one dimensional cutting or welding applications. Using beam shaping optics radially polarized laser light can be generated to be independent from the angle of incident to the processing surface. Furthermore, high power linearly polarized laser light is fundamental for nonlinear frequency conversion of nonlinear materials.

  17. Optical Measurement Techniques for Optical Fiber and Waveguide Devices

    Institute of Scientific and Technical Information of China (English)

    D.Y.; Kim; Y.; Park; N.H.; Seong; Y.C.Youk; J.Y.; Lee; S.; Moon; I.H.; Shin; H.S.; Ryu

    2003-01-01

    We describe three major optical characterization methods for fiber and fiber devices. A simple servo controlled scanning fiber-optic confocal microscope is proposed for determining the refractive index profile of an optical fiber. To measure the chromatic dispersion of a short length fiber a Mach-Zehnder fiber interferometer with a novel interferometric distance meter is introduced. At the end, a tomographic method is demonstrated for determining the 2-D stress profile of a fiber.

  18. Multi-wavelength fiber ring laser based on semiconductor optical amplifier and sampled fiber Bragg grating in a Sagnac loop interferometer%基于半导体光放大器和取样光纤光栅结合Sagnac环的多波长光纤激光器

    Institute of Scientific and Technical Information of China (English)

    冯素春; 许鸥; 鲁韶华; 宁提纲; 简水生

    2009-01-01

    Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.

  19. 122-W high-power single-frequency MOPA fiber laser in all-fiber format

    Institute of Scientific and Technical Information of China (English)

    Xiaolin Dong; Hu Xiao; Shanhui Xu; Zhiyong Pan; Yanxing Ma; Xiaolin Wang; Pu Zhou; Zhongmin Yang

    2011-01-01

    High-power single-frequency lasers have been found widespread applications in science and industries,such as gravitational wave detection,coherent and spectrum beam combining,range finding,and lidar[1- 7].In such cases,the localization of high-power single-frequency fiber laser is extremely important for domestic researchers.The power of single-frequency fiber lasers has increased dramatically in recent years.Most previously presented high-power single-frequency fiber lasers are based on bulk optics configuration,which have big sizes and massive weights.The use of aIl-fiber-based components can significantly simplify the system configuration and make the system more compact and robust[8-10].In this letter,we report a high-power single-frequency master oscillator power amplifier (MOPA) fiber laser in all-fiber format.The MOPA fiber laser consists of twostage amplification architecture.The maximum output power is 122 W,with slope efficiency of 72%.%We demonstrate a high-power single-frequency master oscillator power amplifier (MOPA) fiber laser. The central wavelength of the single-frequency fiber lager seed is 1 063.8 nm, with a linewidth narrower than 20 kHz and output power of 120 mW. By using two-stage amplification, a single-frequency fiber laser with an output power of 122 W is obtained, and the optical-optical conversion efficiency is 72%. No significant amplified spontaneous emission (ASE) or stimulated Brillouin scattering (SBS) is observed. The output power can be further increased by launching more pump power.

  20. Multiwavelength erbium-doped fiber laser exploiting intracavity polarization inhomogeneity

    Institute of Scientific and Technical Information of China (English)

    孙军强; 丘军林; 黄德修

    2000-01-01

    Simultaneous multiwavelength lasing is demonstrated exploiting intracavity polarization in-homogeneity in an erbium-doped fiber laser. Experiments indicate that polarization hole burning can be enhanced by the changes of optical MQW waveguide bias current and the polarization states in the laser cavity. Ten wavelengths with 0.9 nm spacing are generated at room temperature.

  1. Multiwavelength erbium-doped fiber laser exploiting intracavity polarization inhomogeneity

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Simultaneous multiwavelength lasing is demonstrated exploiting intracavity polarization inhomogeneity in an erbium-doped fiber laser. Experiments indicate that polarization hole burning can be enhanced by the changes of optical MQW waveguide bias current and the polarization states in the laser cavity. Ten wavelengths with 0.9 nm spacing are generated at room temperature.

  2. Optical diagnostics integrated with laser spark delivery system

    Science.gov (United States)

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-09-02

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  3. Fiber inline Michelson interferometer fabricated by a femtosecond laser.

    Science.gov (United States)

    Yuan, Lei; Wei, Tao; Han, Qun; Wang, Hanzheng; Huang, Jie; Jiang, Lan; Xiao, Hai

    2012-11-01

    A fiber inline Michelson interferometer was fabricated by micromachining a step structure at the tip of a single-mode optical fiber using a femtosecond laser. The step structure splits the fiber core into two reflection paths and produces an interference signal. A fringe visibility of 18 dB was achieved. Temperature sensing up to 1000°C was demonstrated using the fabricated assembly-free device.

  4. Photochromic glass optical fiber

    Science.gov (United States)

    Alvi, Bilal A.; Israr, Amber; Asif, Muhammad; Aamir, Muhammad; Rehan, Muhammad

    2016-02-01

    This paper describes the fabrication and analysis of novel twin cored fiber which contains a transparent and silver halide doped photochromic core in same cladding. The Photochromic core fibers were fabricated in twin cored structure by rode and tube method. The diameter of photochromic core and transparent core is around 15 m. The distance between two cores is 1.5m. The transparent core was used to guide the probe beam and photochromic core was excited by UV source. The interaction of the probe beam with the excited photochromic core showed the photochromic behavior of the fiber.

  5. The truth about laser fiber diameters.

    Science.gov (United States)

    Kronenberg, Peter; Traxer, Olivier

    2014-12-01

    To measure the various diameters of laser fibers from various manufacturers and compare them with the advertised diameter. Fourteen different unused laser fibers from 6 leading manufacturers with advertised diameters of 200, 270, 272, 273, 365, and 400 μm were measured by light microscopy. The outer diameter (including the fiber coating, cladding, and core), cladding diameter (including the cladding and the fiber core), and core diameter were measured. Industry representatives of the manufacturers were interviewed about the diameter of their fibers. For all fibers, the outer and cladding diameters differed significantly from the advertised diameter (P cladding, and core diameters of fibers with equivalent advertised diameters differed by up to 180, 100, and 78 μm, respectively. Some 200-μm fibers had larger outer diameters than the 270- to 273-μm fibers. All packaging material and all laser fibers lacked clear and precise fiber diameter information labels. Of 12 representatives interviewed, 8, 3, and 1 considered the advertised diameter to be the outer, the cladding, and the core diameter, respectively. Representatives within the same company frequently gave different answers. This study suggests that, at present, there is a lack of uniformity between laser fiber manufacturers, and most of the information conveyed to urologists regarding laser fiber diameter may be incorrect. Because fibers larger than the advertised laser fibers are known to influence key interventional parameters, this misinformation can have surgical repercussions. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Design of graded refractive index profile for silica multimode optical fibers with improved effective modal bandwidth for short-distance laser-based multi-Gigabit data transmission over "O"-band

    Science.gov (United States)

    Bourdine, Anton V.; Zhukov, Alexander E.

    2017-04-01

    High bit rate laser-based data transmission over silica optical fibers with enlarged core diameter in comparison with standard singlemode fibers is found variety infocommunication applications. Since IEEE 802.3z standard was ratified on 1998 this technique started to be widely used for short-range in-premises distributed multi-Gigabit networks based on new generation laser optimized multimode fibers 50/125 of Cat. OM2…OM4. Nowadays it becomes to be in demand for on-board cable systems and industrial network applications requiring 1Gps and more bit rates over fibers with extremely enlarged core diameter up to 100 μm. This work presents an alternative method for design the special refractive index profiles of silica few-mode fibers with extremely enlarged core diameter, that provides modal bandwidth enhancing under a few-mode regime of laser-based data optical transmission. Here some results are presented concerning with refractive index profile synthesis for few-mode fibers with reduced differential mode delay for "O"-band central region, as well as computed differential mode delay spectral curves corresponding to profiles for fibers 50/125 and 100/125 for in-premises and on-board/industrial cable systems.

  7. Izmerenie vektora skorosti lazernym dopplerovskim anemometrom (LDA s volokonno-opticheskimi traktami[Measurement of the velocity vector of the laser Doppler anemometer (LDA with fiber-optic tracts

    Directory of Open Access Journals (Sweden)

    S. N. Khotyaintsev

    1982-12-01

    Full Text Available The problems encountered in the development of laser Doppler velocity vector meter optical fiber paths. The scheme of the meter, including three-dimensional velocity meter made by differential circuit. Describes the experimental setup and the results of the experiment by measuring the two projections of the velocity vector.

  8. Intrinsic Fabry-Perot optical fiber sensors and their multiplexing

    Science.gov (United States)

    Wang, Anbo

    2007-12-11

    An intrinsic Fabry-Perot optical sensor includes a thin film sandwiched between two fiber ends. When light is launched into the fiber, two reflections are generated at the two fiber/thin film interfaces due to a difference in refractive indices between the fibers and the film, giving rise to the sensor output. In another embodiment, a portion of the cladding of a fiber is removed, creating two parallel surfaces. Part of the evanescent fields of light propagating in the fiber is reflected at each of the surfaces, giving rise to the sensor output. In a third embodiment, the refractive index of a small portion of a fiber is changed through exposure to a laser beam or other radiation. Interference between reflections at the ends of the small portion give rise to the sensor output. Multiple sensors along a single fiber are multiplexed using an optical time domain reflectometry method.

  9. Fiber optic anemometer based on metal infiltrated microstructured optical fiber inscribed with Bragg grating

    Science.gov (United States)

    Wang, Jie; Gao, Shaorui; Liu, Zhengyong; Zhang, A. Ping; Shen, Yonghang; Tam, Hwayaw

    2015-09-01

    An all-fiber optical anemometer with high light-heat conversion efficiency by using an in-house microstructured optical fiber Bragg grating (MOFBG) is presented. Low-molten-temperature BiSnIn alloy was successfully infiltrated into 11- cm length of a six-hole microstructured optical fiber which was inscribed with a fibre Bragg grating (FBG) centered at ~848 nm. Light launched into the MOFBG was strongly absorbed by the metal to generate heat, while the FBG was utilized to monitor temperature change due to surrounding wind speed. The sensitivity of the laser-heated MOFBG anemometer was measured to be ~0.1 nm/(m/s) for wind speed ranged from 0.5 m/s to 2 m/s. The efficiency of the anemometer, defined as effective sensitivity per pump power, is 8.7 nm/(m/s*W).

  10. Fiber-Optic Temperature Sensor

    Science.gov (United States)

    Maram, Jonathan M.

    1987-01-01

    Proposed sensor measures temperatures over wide range, from cryogenic liquids to burning gases. Made in part of optical fibers, sensor lighter in weight than thermocouple and immune to electromagnetic interference. Device does not respond to temperatures elsewhere than at sensing tip. Thermal expansion and contraction of distance between fiber end and mirror alters interference between light reflected from those two surfaces, thereby giving interferometric indication of temperatures.

  11. Cyclodestructive procedures. II. Optical fibers, endoscopy, physics: a review.

    Science.gov (United States)

    Fankhauser, Franz; Kwasniewska, Sylwia

    2004-01-01

    Methods used in laser destructive procedures are detailed. While in noncontact procedures laser energy is delivered via the optics of a slitlamp, often enhanced by contact lenses, the contact method takes advantage of optical fibers for the delivery of energy. Endpieces such as hemispherical or microlens probes enhance the cyclodestructive effect and/or allow the dose of laser energy to be reduced. Laser energy may also be delivered under direct view by endoscopic systems. Advances in laser cyclodestruction are possible by studying the physical effects.

  12. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long......-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two...

  13. Campus fiber optic enterprise networks

    Science.gov (United States)

    Weeks, Richard A.

    1991-02-01

    The proliferation of departmental LANs in campus environments has driven network technology to the point where construction of token ring fiber-optic backbone systems is now a cost-effective alternative. This article will discuss several successful real life case history applications of token ring fiber in a campus setting each with unique distance and load factor requirements. It is hoped that these examples will aid in the understanding planning and implementation of similar installations. It will also attempt to provide important information on the emerging Fiber Distributed Data Interface (FDDI) standard.

  14. Tunable Fiber Bragg Grating Ring Lasers using Macro Fiber Composite Actuators

    Science.gov (United States)

    Geddis, Demetris L.; Allison, Sidney G.; Shams, Qamar A.

    2006-01-01

    The research reported herein includes the fabrication of a tunable optical fiber Bragg grating (FBG) fiber ring laser (FRL)1 from commercially available components as a high-speed alternative tunable laser source for NASA Langley s optical frequency domain reflectometer (OFDR) interrogator, which reads low reflectivity FBG sensors. A Macro-Fiber Composite (MFC) actuator invented at NASA Langley Research Center (LaRC) was selected to tune the laser. MFC actuators use a piezoelectric sheet cut into uniaxially aligned rectangular piezo-fibers surrounded by a polymer matrix and incorporate interdigitated electrodes to deliver electric fields along the length of the piezo-fibers. This configuration enables MFC actuators to produce displacements larger than the original uncut piezoelectric sheet. The FBG filter was sandwiched between two MFC actuators, and when strained, produced approximately 3.62 nm of wavelength shift in the FRL when biasing the MFC actuators from 500 V to 2000 V. This tunability range is comparable to that of other tunable lasers and is adequate for interrogating FBG sensors using OFDR technology. Three different FRL configurations were studied. Configuration A examined the importance of erbium-doped fiber length and output coupling. Configuration B demonstrated the importance of the FBG filter. Configuration C added an output coupler to increase the output power and to isolate the filter. Only configuration C was tuned because it offered the best optical power output of the three configurations. Use of Plastic Optical Fiber (POF) FBG s holds promise for enhanced tunability in future research.

  15. A novel differential optical fiber accelerometer

    Science.gov (United States)

    Pi, Shaohua; Zhao, Jiang; Hong, Guangwei; Jia, Bo

    2013-08-01

    The development of sensitive fiber-optic accelerometers is a subject of continuing interest. To acquire high resolution, Michelson phase interferometric techniques are widely adopted. Among the variety structures, the compliant cylinder approach is particularly attractive due to its high sensitivity that is defined as the induced phase shift per applied acceleration. While the two arms of Michelson interferometer should be at the same optical path, it is inconvenient to adjust the two arms' length to equal, also the polarization instability and phase random drift will cause a signal decline. To overcome these limitations, a novel optical fiber accelerometer based on differential interferometric techniques is proposed and investigated. The interferometer is a Sagnac-like white light interferometer, which means the bandwidth of laser spectrum can be as wide as tens nanometers. This interferometer was firstly reported by Levin in 1990s. Lights are divided to two paths before entering the coupler. To induce time difference, one passes through a delay arm and another goes a direct arm. After modulated by the sensing component, they reflect to opposite arm. The sensing part is formed by a seismic mass that is held to only one compliant cylinder, where the single-mode optical fiber is wrapped tightly. When sticking to vibrations, the cylinder compresses or stretches as a spring. The corresponding changes in cylinder circumference lead to strain in the sensing fibers, which is detected as an optical phase shift by the interferometer. The lights from two arms reach the vibration source at different time, sensing a different accelerate speed; produce a different optic path difference. Integrating the dissimilarity of the accelerated speed by time can obtain the total acceleration graph. A shaker's vibration has been tested by the proposed accelerometer referring to a standard piezoelectric accelerometer. A 99.8% linearity of the optical phase shift to the ground acceleration

  16. Enabling technologies for fiber optic sensing

    Science.gov (United States)

    Ibrahim, Selwan K.; Farnan, Martin; Karabacak, Devrez M.; Singer, Johannes M.

    2016-04-01

    In order for fiber optic sensors to compete with electrical sensors, several critical parameters need to be addressed such as performance, cost, size, reliability, etc. Relying on technologies developed in different industrial sectors helps to achieve this goal in a more efficient and cost effective way. FAZ Technology has developed a tunable laser based optical interrogator based on technologies developed in the telecommunication sector and optical transducer/sensors based on components sourced from the automotive market. Combining Fiber Bragg Grating (FBG) sensing technology with the above, high speed, high precision, reliable quasi distributed optical sensing systems for temperature, pressure, acoustics, acceleration, etc. has been developed. Careful design needs to be considered to filter out any sources of measurement drifts/errors due to different effects e.g. polarization and birefringence, coating imperfections, sensor packaging etc. Also to achieve high speed and high performance optical sensing systems, combining and synchronizing multiple optical interrogators similar to what has been used with computer/processors to deliver super computing power is an attractive solution. This path can be achieved by using photonic integrated circuit (PIC) technology which opens the doors to scaling up and delivering powerful optical sensing systems in an efficient and cost effective way.

  17. Development and evaluation of fiber optic probe-based helium-neon low-level laser therapy system for tissue regeneration--an in vivo experimental study.

    Science.gov (United States)

    Prabhu, Vijendra; Rao, Satish B S; Rao, Nageshwara B; Aithal, Kiran B; Kumar, Pramod; Mahato, Krishna K

    2010-01-01

    We report the design and development of an optical fiber probe-based Helium-Neon (He-Ne) low-level laser therapy system for tissue regeneration. Full thickness excision wounds on Swiss albino mice of diameter 15 mm were exposed to various laser doses of 1, 2, 3, 4, 6, 8 and 10 J cm(-2) of the system with appropriate controls, and 2 J cm(-2) showing optimum healing was selected. The treatment schedule for applying the selected laser dose was also standardized by irradiating the wounds at different postwounding times (0, 24 and 48 h). The tissue regeneration potential was evaluated by monitoring the progression of wound contraction and mean wound healing time along with the hydroxyproline and glucosamine estimation on wound ground tissues. The wounds exposed to 2 J cm(-2) immediately after wounding showed considerable contraction on days 5, 9, 12, 14, 16 and 19 of postirradiation compared with the controls and other treatment schedules, showing significant (P < 0.001) decrease in the healing time. A significant increase in hydroxyproline and glucosamine levels was observed for the 2 J cm(-2) irradiation group compared with the controls and other treatment groups. In conclusion, the wounds treated with 2 J cm(-2) immediately after the wounding show better healing compared with the controls.

  18. Optical fiber strain sensor using fiber resonator based on frequency comb Vernier spectroscopy

    DEFF Research Database (Denmark)

    Zhang, Liang; Lu, Ping; Chen, Li;

    2012-01-01

    A novel (to our best knowledge) optical fiber strain sensor using a fiber ring resonator based on frequency comb Vernier spectroscopy is proposed and demonstrated. A passively mode-locked optical fiber laser is employed to generate a phased-locked frequency comb. Strain applied to the optical fiber...... be proportionally improved by increasing the length of the optical fiber ring resonator....... of the fiber ring resonator can be measured with the transmission spectrum. A good linearity is obtained between displacement and the inverse of wavelength spacing with an R2 of 0.9989, and high sensitivities better than 40  pm/με within the range of 0 to 10  με are achieved. The sensitivity can...

  19. 10 Watts Double-Cladding Fiber Laser

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Considering the wavelength characteristics of the pump high-power laser diode, a modified Fabry-Perot fiber laser resonator is designed. And a fiber laser with more than 10Watts output, near diffraction-limited and operating in the 1110nm region is developed.

  20. Development of ceramic fibers for high-energy laser applications

    Science.gov (United States)

    Fair, Geoff E.; Kim, Hyun Jun; Lee, HeeDong; Parthasarathy, Triplicane A.; Keller, Kristin A.; Miller, Zachary D.

    2011-06-01

    Polycrystalline ceramics offer a number of advantages relative to single crystal materials such as lower processing temperatures, improved mechanical properties, and higher doping levels with more uniform distribution of dopants for improved laser performance. Ceramic YAG (Y3Al5O12) and rare earth sesquioxide (RE2O3) fibers promise to enable a number of high power laser devices via high thermal conductivity and higher allowable dopant concentration; however, these materials are not currently available as fine diameter optical-quality fibers. Powder processing approaches for laser quality polycrystalline ceramic fibers are in development at AFRL. Current processing techniques will be reviewed. The effects of a number of processing variables on the resulting fibers as well as preliminary optical characterization will also be presented.

  1. Coherent fiber supercontinuum laser for nonlinear biomedical imaging

    DEFF Research Database (Denmark)

    Tu, Haohua; Liu, Yuan; Liu, Xiaomin;

    2012-01-01

    Nonlinear biomedical imaging has not benefited from the well-known techniques of fiber supercontinuum generation for reasons such as poor coherence (or high noise), insufficient controllability, low spectral power intensity, and inadequate portability. Fortunately, a few techniques involving...... nonlinear fiber optics and femtosecond fiber laser development have emerged to overcome these critical limitations. These techniques pave the way for conducting point-of-care nonlinear biomedical imaging by a low-maintenance cost-effective coherent fiber supercontinuum laser, which covers a broad emission...... wavelength of 350-1700 nm. A prototype of this laser has been demonstrated in label-free multimodal nonlinear imaging of cell and tissue samples.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only....

  2. Thermal characterization of optical fibers using wavelength-sweeping interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Perret, Luc; Pfeiffer, Pierre; Serio, Bruno; Twardowski, Patrice

    2010-06-20

    In this paper, we report a new method of thermal characterization of optical fibers using wavelength-sweeping interferometry and discuss its advantages compared to other techniques. The setup consists of two temperature-stabilized interferometers, a reference Michelson and a Mach-Zehnder, containing the fiber under test. The wavelength sweep is produced by an infrared tunable laser diode. We obtained the global phase shift coefficients of a large effective area fiber and gold-coated fiber optics with a 10{sup -7} accuracy.

  3. Eliminating Crystals in Non-Oxide Optical Fiber Preforms and Optical Fibers

    Science.gov (United States)

    Tucker, Dennis S.; LaPointe, Michael R.

    2012-01-01

    Non ]oxide fiber optics such as heavy metal fluoride and chalcogenide glasses are extensively used in infrared transmitting applications such as communication systems, chemical sensors, and laser fiber guides for cutting, welding and medical surgery. The addition of rare earths such as erbium, enable these materials to be used as fiber laser and amplifiers. Some of these glasses however are very susceptible to crystallization. Even small crystals can lead to light scatter and a high attenuation coefficient, limiting their usefulness. Previously two research teams found that microgravity suppressed crystallization in heavy metal fluoride glasses. Looking for a less expensive method to suppress crystallization, ground based research was performed utilizing an axial magnetic field. The experiments revealed identical results to those obtained via microgravity processing. This research then led to a patented process for eliminating crystals in optical fiber preforms and the resulting optical fibers. In this paper, the microgravity results will be reviewed as well as patents and papers relating to the use of magnetic fields in various material and glass processing applications. Finally our patent to eliminate crystals in non ]oxide glasses utilizing a magnetic field will be detailed.

  4. Normal dispersion femtosecond fiber optical parametric oscillator.

    Science.gov (United States)

    Nguyen, T N; Kieu, K; Maslov, A V; Miyawaki, M; Peyghambarian, N

    2013-09-15

    We propose and demonstrate a synchronously pumped fiber optical parametric oscillator (FOPO) operating in the normal dispersion regime. The FOPO generates chirped pulses at the output, allowing significant pulse energy scaling potential without pulse breaking. The output average power of the FOPO at 1600 nm was ∼60  mW (corresponding to 1.45 nJ pulse energy and ∼55% slope power conversion efficiency). The output pulses directly from the FOPO were highly chirped (∼3  ps duration), and they could be compressed outside of the cavity to 180 fs by using a standard optical fiber compressor. Detailed numerical simulation was also performed to understand the pulse evolution dynamics around the laser cavity. We believe that the proposed design concept is useful for scaling up the pulse energy in the FOPO using different pumping wavelengths.

  5. High power wavelength-defined all-fiber Yb3+-doped double clad fiber laser

    Institute of Scientific and Technical Information of China (English)

    Hongxin Su(苏红新); Kecheng Lü(吕可诚); Peiguang Yan(闫培光); Yigang Li(李乙钢); Xiaoyi Dong(董孝义)

    2003-01-01

    An all-fiber Yb3+-doped double-clad fiber laser using FBGs as cavity mirrors is investigated in this paper.Continuous-wave (CW) output power of 1.18 W with defined wavelength at 1.06 μm and narrow line-widthof less than 0.1 nm is obtained. The slope efficiency and the maximum optical-to-optical efficiency of laseroutput are 68% and 51%, respectively, with respect to absorbed pump power.

  6. Handbook of fiber optics theory and applications

    CERN Document Server

    Yeh, Chai

    2013-01-01

    Dr. Yeh supplies a firm theoretical foundation in such topics as propagation of light through fibers, fiber fabrication, loss mechanisms, and dispersion properties. He then expands from this into such practical areas as fiber splicing, measuring loss in fibers, fiber-based communications networks, remote fiber sensors, and integrated optics. Whether involved in fiber optics research, design, or practical implementation of systems, this handbook will be extremely useful.Key Features* Here is a comprehensive, ""one-stop"" reference with state-of-the-art information on fiber optics Included is da

  7. Soliton-similariton switchable ultrafast fiber laser

    CERN Document Server

    Peng, Junsong; Guo, Pan; Gu, Zhaochang; Zou, Weiwen; Luo, Shouyu; Shen, Qishun

    2012-01-01

    For the first time, we demonstrated alternative generation of dispersion-managed (DM) solitons or similaritons in an all-fiber Erbium-doped laser. DM solitons or similaritons can be chosen to emit at the same output port by controlling birefringence in the cavity. The pulse duration of 87-fs for DM solitons and 248-fs for similaritons have been observed. For proof of similaritons, we demonstrate that the spectral width depends exponentially on the pump power, consistent with theoretical studies. Besides, the phase profile measured by a frequency-resolved optical gating (FROG) is quadratic corresponding to linear chirp. In contrast, DM solitons show non-quadratic phase profile.

  8. Fiber optical assembly for fluorescence spectrometry

    Science.gov (United States)

    Carpenter, II, Robert W.; Rubenstein, Richard; Piltch, Martin; Gray, Perry

    2010-12-07

    A system for analyzing a sample for the presence of an analyte in a sample. The system includes a sample holder for containing the sample; an excitation source, such as a laser, and at least one linear array radially disposed about the sample holder. Radiation from the excitation source is directed to the sample, and the radiation induces fluorescent light in the sample. Each linear array includes a plurality of fused silica optical fibers that receive the fluorescent light and transmits a fluorescent light signal from the first end to an optical end port of the linear array. An end port assembly having a photo-detector is optically coupled to the optical end port. The photo-detector detects the fluorescent light signal and converts the fluorescent light signal into an electrical signal.

  9. Development of a fiber-optic laser velocimeter for the study of unsteady rotating flows in spinning rocket motors

    Science.gov (United States)

    Chen, K.; Shorthill, R. W.; Flandro, G. A.

    1986-08-01

    The development of a Laser Doppler Velocimeter (LDV) designed to measure two orthogonal velocity components in a complex rotating flow is described; this flow simulates the unsteady flows encountered in spinning rocket motor operations as well as such time-dependent phenomena as low frequency acoustic oscillations. The LDV is a three watt, two color, three beam system with a velocity measurement device that follows the flow continuously without any disturbance. The focusing optics, photo multipliers, amplifiers and test chamber are mounted on a precision Genisco C-181 rate-of-return table and spun to about 60 RPM. The silicon carbide particles used for seeding follow velocity fluctuations up to several hundred KHz. Two-dimensional unsteady velocity measurement systems for water flow rotating in the horizontal direction and tilting in the vertical direction are presented and discussed.

  10. Stimulated Brillouin Scattering Suppression in Fiber Amplifiers via Chirped Diode Lasers

    Science.gov (United States)

    2011-09-01

    1.55-µm diode laser at 1014 Hz/s using a phase-locked loop and a fiber -optic Michelson interferometer (9). The chirp has now been extended to 5×1015...diode lasers. By incorporating a fiber interferometer , the technique has been extended to chirp a (single) laser diode at 1015 Hz/s in an extremely...Stimulated Brillouin Scattering Suppression in Fiber Amplifiers via Chirped Diode Lasers by Jeffrey O. White, George Rakuljic, and Carl E

  11. Photonics and Fiber Optics Processor Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Photonics and Fiber Optics Processor Lab develops, tests and evaluates high speed fiber optic network components as well as network protocols. In addition, this...

  12. Optical Fiber Devices in WDM Networks

    Institute of Scientific and Technical Information of China (English)

    Shan Jiang; Yong Luo; Xinda Yin; Wei Shi; Qianggao Hu

    2003-01-01

    Crystal optics and fiber grating technology are two of the most important optical fiber device technologies.In this paper, we report several new devices developed in Accelink for WDM networks application.

  13. Optical Fiber Devices in WDM Networks

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Crystal optics and fiber grating technology are two of the most important optical fiber device technologies. In this paper, we report several new devices developed in Accelink for WDM networks application.

  14. Integrated optical fiber lattice accumulators

    OpenAIRE

    Atherton, Adam F

    1997-01-01

    Approved for public release; distribution is unlimited. Sigma-delta modulators track a signal by accumulating the error between an input signal and a feedback signal. The accumulated energy is amplitude analyzed by a comparator. The comparator output signal is fed back and subtracted from the input signal. This thesis is primarily concerned with designing accumulators for inclusion in an optical sigma-delta modulator. Fiber lattice structures with optical amplifiers are used to perform the...

  15. Fiber optic evanescent wave biosensor

    Science.gov (United States)

    Duveneck, Gert L.; Ehrat, Markus; Widmer, H. M.

    1991-09-01

    The role of modern analytical chemistry is not restricted to quality control and environmental surveillance, but has been extended to process control using on-line analytical techniques. Besides industrial applications, highly specific, ultra-sensitive biochemical analysis becomes increasingly important as a diagnostic tool, both in central clinical laboratories and in the doctor's office. Fiber optic sensor technology can fulfill many of the requirements for both types of applications. As an example, the experimental arrangement of a fiber optic sensor for biochemical affinity assays is presented. The evanescent electromagnetic field, associated with a light ray guided in an optical fiber, is used for the excitation of luminescence labels attached to the biomolecules in solution to be analyzed. Due to the small penetration depth of the evanescent field into the medium, the generation of luminescence is restricted to the close proximity of the fiber, where, e.g., the luminescent analyte molecules combine with their affinity partners, which are immobilized on the fiber. Both cw- and pulsed light excitation can be used in evanescent wave sensor technology, enabling the on-line observation of an affinity assay on a macroscopic time scale (seconds and minutes), as well as on a microscopic, molecular time scale (nanoseconds or microseconds).

  16. Catching Attention in Fiber Optics Class

    OpenAIRE

    Kezerashvili, R. Ya.; Leng, L

    2004-01-01

    Following a brief review on the history and the current development of fiber optics, the significance of teaching fiber optics for science and non-science major college students is addressed. Several experimental demonstrations designed to aid the teaching and learning process in fiber optics lectures are presented. Sample laboratory projects are also proposed to help the students to understand the physical principles of fiber optics.

  17. High pressure fiber optic sensor system

    Science.gov (United States)

    Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N

    2013-11-26

    The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

  18. Optical Manipulation of Symbiotic Chlorella in Paramecium Bursaria Using a Fiber Axicon Microlens

    Science.gov (United States)

    Taguchi, K.; Hirota, S.; Nakayama, H.; Kunugihara, D.; Mihara, Y.

    2012-03-01

    In this paper, chemically etched axicon fiber was proposed for laser trapping of symbiotic chlorella from paramecium bursaria. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a symbiotic chlorella. From experimental results, it was found that our proposed fiber axicon microlens was a promising tool for cell trapping without physical contact.

  19. Infrared Fiber Optics.

    Science.gov (United States)

    1979-12-01

    solid lubricants (anthacene, p-terphenyl). To date, the best lubricants have been Parafilm and beeswax . Using these materials to coat the KC1 billets...fabrication involves both extruding KCl fibers and also preparing the starting billet used in the extrusion. The billets are then usually coated with a...8217C) and be removable after extrusion. This has limited the choice of lubricants to waxes (parafin, beeswax ), polyethelene mixtures (Parafilm M), and

  20. Crystal-free Formation of Non-Oxide Optical Fiber

    Science.gov (United States)

    Nabors, Sammy A.

    2015-01-01

    Researchers at NASA Marshall Space Flight Center have devised a method for the creation of crystal-free nonoxide optical fiber preforms. Non-oxide fiber optics are extensively used in infrared transmitting applications such as communication systems, chemical sensors, and laser fiber guides for cutting, welding and medical surgery. However, some of these glasses are very susceptible to crystallization. Even small crystals can lead to light scatter and a high attenuation coefficient, limiting their usefulness. NASA has developed a new method of non-oxide fiber formation that uses axial magnetic fields to suppress crystallization. The resulting non-oxide fibers are crystal free and have lower signal attenuation rates than silica based optical fibers.

  1. Fiber Optics: Deregulate and Deploy.

    Science.gov (United States)

    Suwinski, Jan H.

    1993-01-01

    Describes fiber optic technology, explains its use in education and commercial settings, and recommends regulations and legislation that will speed its use to create broadband information networks. Topics discussed include distance learning; interactive video; costs; and the roles of policy makers, lawmakers, public advocacy groups, and consumers.…

  2. Fiber Optic Magnetic Sensor Research.

    Science.gov (United States)

    1983-02-28

    Michelson inter- ferometric fiber optical point temperature sensor (Appendix B). The sensor has potential applicntion to non-invnsive and high...3roeniheaingUsing similar techniques, to for monolithic circuits. Lange couplers have been fabricated on alumina substrates. The: re- Fig 3 illustrates

  3. Nonlinear fiber optics formerly quantum electronics

    CERN Document Server

    Agrawal, Govind

    1995-01-01

    The field of nonlinear fiber optics has grown substantially since the First Edition of Nonlinear Fiber Optics, published in 1989. Like the First Edition, this Second Edition is a comprehensive, tutorial, and up-to-date account of nonlinear optical phenomena in fiber optics. It synthesizes widely scattered research material and presents it in an accessible manner for students and researchers already engaged in or wishing to enter the field of nonlinear fiber optics. Particular attention is paid to the importance of nonlinear effects in the design of optical fiber communication systems. This is

  4. Optical fibers and RF a natural combination

    CERN Document Server

    Romeiser, Malcolm

    2004-01-01

    The optical fiber industry has experienced a period of consolidation and reorganization and is now poised for a new surge in growth. To take advantage of that growth, and to respond to the demand to use fiber more efficiently, designers need a better understanding of fiber optics. Taking the approach that optical fibers are an extension of RF-based communications, the author explains basic optical concepts, applications, and systems; the nature and performance characteristics of optical fibers; and optical sources, connectors and splices. Subsequent chapters explore current applications of fib

  5. Fiber lasers and their applications [Invited].

    Science.gov (United States)

    Shi, Wei; Fang, Qiang; Zhu, Xiushan; Norwood, R A; Peyghambarian, N

    2014-10-01

    Fiber lasers have seen progressive developments in terms of spectral coverage and linewidth, output power, pulse energy, and ultrashort pulse width since the first demonstration of a glass fiber laser in 1964. Their applications have extended into a variety of fields accordingly. In this paper, the milestones of glass fiber laser development are briefly reviewed and recent advances of high-power continuous wave, Q-switched, mode-locked, and single-frequency fiber lasers in the 1, 1.5, 2, and 3 μm regions and their applications in such areas as industry, medicine, research, defense, and security are addressed in detail.

  6. Fiber-diffraction Interferometer using Coherent Fiber Optic Taper

    CERN Document Server

    Kihm, Hagyong

    2010-01-01

    We present a fiber-diffraction interferometer using a coherent fiber optic taper for optical testing in an uncontrolled environment. We use a coherent fiber optic taper and a single-mode fiber having thermally-expanded core. Part of the measurement wave coming from a test target is condensed through a fiber optic taper and spatially filtered from a single-mode fiber to be reference wave. Vibration of the cavity between the target and the interferometer probe is common to both reference and measurement waves, thus the interference fringe is stabilized in an optical way. Generation of the reference wave is stable even with the target movement. Focus shift of the input measurement wave is desensitized by a coherent fiber optic taper.

  7. Overview of Fiber-Optical Sensors

    Science.gov (United States)

    Depaula, Ramon P.; Moore, Emery L.

    1987-01-01

    Design, development, and sensitivity of sensors using fiber optics reviewed. State-of-the-art and probable future developments of sensors using fiber optics described in report including references to work in field. Serves to update previously published surveys. Systems incorporating fiber-optic sensors used in medical diagnosis, navigation, robotics, sonar, power industry, and industrial controls.

  8. Career Directions--Fiber Optic Installer

    Science.gov (United States)

    Tech Directions, 2012

    2012-01-01

    Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber that is roughly the diameter of a human hair. The light forms an electromagnetic carrier wave that is modulated to carry information. Each optical fiber is capable of carrying an enormous amount of…

  9. 10 Gb/s 16-quadrature amplitude modulation signal delivery over a wireless fiber system by using a directly modulated laser for electrical/optical conversion

    Institute of Scientific and Technical Information of China (English)

    Lun Zhao; Jianguo Yu

    2015-01-01

    We propose and experimentally demonstrate a novel scheme to realize electrical/optical (E/O) conversion on the receiver side of a wireless fiber integration system at the W band.At the receiver,a directly modulated laser (DML) is used to realize E/O conversion.The received 85 GHz wireless millimeter-wave (mm-wave) signal is first down-converted into a 10 GHz electrical intermediate-frequency (IF) signal to overcome the insufficient bandwidth of the subsequent DML.Then,two cascaded electrical amplifiers (EAs) are employed to boost the electrical IF signal before it is used to drive a DML.By using this scheme,we transmit a 10 Gb/s 16 quadrature amplitude modulation (16QAM) signal over a 10 m wireless link,and then deliver it over a 2 km single-mode fiber-28 (SMF-28) wire link with a bit error ratio (BER) that is less than the hard-decision forward error correction threshold of 3.8 × 10-3.Our experimental results show that the DML is good device to be used for the E/O conversion of a 16QAM signal.

  10. PM Raman fiber laser at 1679 nm

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    2012-01-01

    We demonstrate a PM Raman fiber laser emitting light at 1679 nm. The laser has an slope efficiency of 67 % and an output power of more than 275mWwith a 27 pm linewidth.......We demonstrate a PM Raman fiber laser emitting light at 1679 nm. The laser has an slope efficiency of 67 % and an output power of more than 275mWwith a 27 pm linewidth....

  11. Switchable multiwavelength fiber laser using erbium-doped twin-core fiber and nonlinear polarization rotation

    Science.gov (United States)

    Lian, Yudong; Ren, Guobin; Zhu, Bofeng; Gao, Yixiao; Jian, Wei; Ren, Wenhua; Jian, Shuisheng

    2017-05-01

    We propose and demonstrate a switchable multiwavelength fiber laser using erbium-doped twin-core fiber (ED-TCF) and nonlinear polarization rotation (NPR). The number switchability of lasing wavelengths being switched from 1 to 4 and wavelength location switchability could be achieved simultaneously in the proposed configuration with a wavelength spacing of 1.1 nm and an optical signal to noise ratio (OSNR) larger than 43 dB. The output laser powers at different wavelengths are nearly the same with a fluctuation less than 2 dB. The proposed fiber laser shows good stability with wavelength shift within 0.01 nm and peak power fluctuation less than 5 dB. The proposed fiber laser has the advantages of simple structure and stable operation.

  12. 1.2W laser amplification at 1427nm on the 4Fsub>3/2sub> to 4Isub>13/2sub> spectral line in an Nd3+ doped fused silica optical fiber.

    Science.gov (United States)

    Dawson, Jay W; Pax, Paul H; Allen, Graham S; Drachenberg, Derrek R; Khitrov, Victor V; Schenkel, Nick; Messerly, Michael J

    2016-12-12

    A 9.3dB improvement in optical gain and a 100x improvement in total optical power over prior published experimental results from the 4Fsub>3/2sub> to 4Isub>13/2sub> transition in an Nd3+ doped fused silica optical fiber is demonstrated. This is enabled via an optical fiber waveguide design that creates high spectral attenuation in the 1050-1120nm-wavelength range, a continuous spectral filter for the primary 4Fsub>3/2sub> to 4Isub>11/2sub> optical transition. A maximum output power at 1427nm of 1.2W was attained for 43mW coupled seed laser power and 22.2W of coupled pump diode laser power at 880nm a net optical gain of 14.5dB. Reducing the coupled seed laser power to 2.5mW enabled the system to attain 19.3dB of gain for 16.5W of coupled pump power. Four issues limited results; non-optimal seed laser wavelength, amplified spontaneous emission on the 4Fsub>3/2sub> to 4Isub>9/2sub> optical transition, low absorption of pump light from the cladding and high spectral attenuation in the 1350-1450nm range. Future fibers that mitigate these issues should lead to significant improvements in the efficiency of the laser amplifier, though the shorter wavelength region of the transition from 1310nm to >1350nm is still expected to be limited by excited state absorption.

  13. Hight Energy Fiber Laser Based Lidar Transmitter for Topographic Mapping Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR will develop core Yb laser technology that is higher than 50% optical to optical efficient with pulse energies up to 300uJ/pulse in the all fiber...

  14. Comparative assessment of erbium fiber ring lasers and reflective SOA linear lasers for fiber Bragg grating dynamic strain sensing.

    Science.gov (United States)

    Wei, Heming; Krishnaswamy, Sridhar

    2017-05-01

    Fiber Bragg grating (FBG) dynamic strain sensors using both an erbium-based fiber ring laser configuration and a reflective semiconductor optical amplifier (RSOA)-based linear laser configuration are investigated theoretically and experimentally. Fiber laser models are first presented to analyze the output characteristics of both fiber laser configurations when the FBG sensor is subjected to dynamic strains at high frequencies. Due to differences in the transition times of erbium and the semiconductor (InP/InGaAsP), erbium-doped fiber amplifier (EDFA)- and RSOA-based fiber lasers exhibit different responses and regimes of stability when the FBG is subjected to dynamic strains. The responses of both systems are experimentally verified using an adaptive photorefractive two-wave mixing (TWM) spectral demodulation technique. The experimental results show that the RSOA-FBG fiber linear cavity laser is stable and can stably respond to dynamic strains at high frequencies. An example application using a multiplexed TWM interferometer to demodulate multiple FBG sensors is also discussed.

  15. Experimental study on kilowatt fiber laser in an all-fiber configuration

    Institute of Scientific and Technical Information of China (English)

    Hu Xiao; Yanxing Ma; Pu Zhou; Lei Si; Jinbao Chen

    2012-01-01

    A high-power fiber laser in an all-fiber format is reported.The system consists of 36 pump ports,which use both counter and forward pump configuration.In the experiment,1 008-W output power is obtained when 24 pump ports are used with a total pump power of 1 477 W.The optical-to-optical conversion efficiency is 68% and the 3-dB bandwidth of laser output increases with output power.Presently,the output power is only limited by the pump source.It can be predicted that the laser power can be further scaled if more pump sources are utilized.%A high-power fiber laser in an all-fiber format is reported. The system consists of 36 pump ports, which use both counter and forward pump configuration. In the experiment, 1008-W output power is obtained when 24 pump ports are used with a total pump power of 1 477 W. The optical-to-optical conversion efficiency is 68% and the 3-dB bandwidth of laser output increases with output power. Presently, the output power is only limited by the pump source. It can be predicted that the laser power can be further scaled if more pump sources are utilized.

  16. Lab-on-fiber electrophoretic trace mixture separating and detecting an optofluidic device based on a microstructured optical fiber.

    Science.gov (United States)

    Yang, Xinghua; Guo, Xiaohui; Li, Song; Kong, Depeng; Liu, Zhihai; Yang, Jun; Yuan, Libo

    2016-04-15

    We report an in-fiber integrated electrophoretic trace mixture separating and detecting an optofluidic optical fiber sensor based on a specially designed optical fiber. In this design, rapid in situ separation and simultaneous detection of mixed analytes can be realized under electro-osmotic flow in the microstructured optical fiber. To visually display the in-fiber separating and detecting process, two common fluorescent indicators are adopted as the optofluidic analytes in the optical fiber. Results show that a trace amount of the mixture (0.15 μL) can be completely separated within 3.5 min under a high voltage of 5 kV. Simultaneously, the distributed information of the separated analytes in the optical fiber can be clearly obtained by scanning along the optical fiber using a 355 nm laser. The emission from the analytes can be efficiently coupled into the inner core and guides to the remote end of the optical fiber. In addition, the thin cladding around the inner core in the optical fiber can prevent the fluorescent cross talk between the analytes in this design. Compared to previous optical fiber optofluidic devices, this device first realizes simultaneously separating treatment and the detection of the mixed samples in an optical fiber. Significantly, such an in-fiber integrated separating and detecting optofluidic device can find wide applications in various analysis fields involves mixed samples, such as biology, chemistry, and environment.

  17. Fiber optic stress-independent helical torsion sensor.

    Science.gov (United States)

    Fernandes, Luís A; Grenier, Jason R; Aitchison, J Stewart; Herman, Peter R

    2015-02-15

    Femtosecond laser-fabricated waveguides have been formed into helical paths throughout the cladding of single-mode optical fibers to demonstrate a strain-independent fiber torsion sensor. A comparison between a Bragg grating sensor and a Mach-Zehnder based on helical waveguides (HWs) showed a much weaker twist sensitivity of 1.5 pm/(rad/m) for the grating in contrast with a value of 261 pm/(rad/m) for the interferometer. The HW geometry provided an unambiguous determination of the rotational direction of the twist while facilitating a convenient and efficient means for optical coupling into the single-mode core of the fiber. The flexible three-dimensional writing by the femtosecond laser fabrication method enabled the direct inscription of compact and robust optical cladding devices without the need for combining or splicing multiple-fiber segments.

  18. Polydimethylsiloxane fibers for optical fiber sensor of displacement

    Science.gov (United States)

    Martincek, Ivan; Pudis, Dusan; Gaso, Peter

    2013-09-01

    The paper describes the preparation of polydimethylsiloxane (PDMS) fiber integrated on the conventional optical fibers and their use for optical fiber displacement sensor. PDMS fiber was made of silicone elastomer Sylgard 184 (Dow Corning) by drawing from partially cured silicone. Optical fiber displacement sensor using PDMS fiber is based on the measurement of the local minimum of optical signal in visible spectral range generated by intermodal interference of circularly symmetric modes. Position of the local minimum in spectral range varies by stretching the PDMS fiber of 230 μm in the wavelength range from 688 to 477 nm. In the stretched PDMS fiber is possible to determine the longitudinal displacement with an accuracy of approximately 1 micrometer.

  19. Delivering dispersion-managed soliton and Q-switched pulse in fiber laser based on graphene and nonlinear optical loop mirror

    Science.gov (United States)

    Wang, W. B.; Wang, F.; Yu, Q.; Zhang, X.; Lu, Y. X.; Gu, J.

    2016-11-01

    We propose and experimentally demonstrate a bidirectional erbium-doped fiber laser delivering dispersion-managed soliton (DMS) and Q-switched pulse based on a graphene-polyvinyl alcohol (PVA) and nonlinear optical loop mirror (NOLM) saturable absorbers (SAs). In proposed structure, the DMS is achieved in clockwise (CW) direction and Q-switched pulse is obtained in counter-clockwise (CCW) direction. By properly adjusting the intracavity attenuators (ATT) and polarizer controllers (PCs), DMS in the CW direction and Q-switched pulse in the CCW direction can be obtained, respectively or simultaneously. The DMS with full width at half maximum (FWHM) of ~480 fs, signal to noise ratio (SNR) of ~60 dB and repetition frequency about 3.907 MHz is obtained. The Q-switched pulse is established at a pump power of 180 mW with a repetition rate of ~43.5 kHz and FWHM of ~8.18 μs. When the pump power is increased to 700 mW, Q-switched pulse with a repetition rate of ~107.1 kHz and FWHM of ~2.15 μs is generated. When the two type pulses are formed simultaneously, the maximum repetition rate of Q-switched pulse is 55.8 kHz and minimum FWHM is 2.81 μs, the DMS can be formed by properly adjusting PC and ATT in this case. To the best of our knowledge, it is the first time that Q-switched pulse and DMS have been acquired respectively or simultaneously in a fiber laser.

  20. NOVEL SPECTRUM ABSORPTION OPTICAL FIBER METHANE SENSOR

    Institute of Scientific and Technical Information of China (English)

    Wang Shutao; Che Rensheng

    2005-01-01

    Based on spectrum principle and analyzing the infrared absorption spectrum of methane, a kind of optical fiber methane gas sensor and its system are developed. DFBLD(Distributed feedback laser diode) in 1 300 nm waveband is used as illuminant and phase-detecting technology is used to carry out harmonic wave detecting the concentration of methane. The sensitivity can arrive at 10-5.Experiments results show that the performance targets of the sensor such as sensitivity can basically satisfy the requests of methane detection.

  1. Erbium doped random fiber laser and fiber mixing effect

    OpenAIRE

    Yao, Can; Thévenaz, Luc; Brès, Camille Sophie

    2017-01-01

    We demonstrate an active random fiber laser by directly pumping a 100 m erbium-doped fiber at 980 nm wavelength, with a fiber loop mirror forming a half-open cavity. Random lasing with competing spectral modes in the range from 1535 nm to 1560 nm is achieved, with the maximum lasing slope efficiency around 10%. We also study the effect of combining a dispersion compensated fiber with the erbium-doped fiber. The kilometers long dispersion compensated fiber reduces the random lasing threshold a...

  2. Fiber optic ionizing radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Suter, J.J. (Johns Hopkins Univ., Applied Physics Lab., Laurel, MD (United States)); Poret, J.C.; Rosen, M. (Johns Hopkins Univ., Dept. of Materials Science and Engineering, Baltimore, MD (United States))

    1992-08-01

    Radiation detection can be done by various types of devices, such as Geiger counters, thermoluminescent detectors, and electric field sensors. This paper reports on a noel design for an ionizing radiation sensor using coiled optical fibers, which can be placed within or near a radioactive source. This design has several features that make it different from sensors proposed in the past. In order to evaluate this sensor, coiled fiber samples were placed inside metallic and metal-matrix composite cylinders to evaluate the sensitivity of the detector as well as the shielding effectiveness of the materials.

  3. Distributed optical fiber surface plasmon resonance sensors

    Institute of Scientific and Technical Information of China (English)

    Zhenxin Cao; Lenan Wu; Dayong Li

    2006-01-01

    @@ The relationships of the resonant wavelength of optical fiber surface plasmon resonance (SPR) sensors to the modulation layer refractive index, thickness and the refractive index of the bulk medium are obtained by using theoretical calculation model of optical fiber SPR sensors under certain conditions, which indicates that resonant wavelength of the sensors is approximately linear with modulation layer thickness. Based on the linear relationship, multiple SPR sensors with different resonant wavelengths can be fabricated in a single optical fiber named as distributed optical fiber surface plasmon resonance sensors (DOFSPRSs).Experimental results are presented, showing that it is practical to fabricate more than one SPR sensors in a single optical fiber.

  4. Spectroscopic and laser properties of Er{sup 3+} doped fluoro-phosphate glasses as promising candidates for broadband optical fiber lasers and amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Babu, S. [Department of Physics, Sri Venkateswara University, Tirupati 517 502, A.P. (India); Seshadri, M. [Institute of Physics, University of Campinas, UNICAMP, P.O. Box 6165, Campinas 13083-970 (Brazil); Reddy Prasad, V. [Department of Physics, Sri Venkateswara University, Tirupati 517 502, A.P. (India); Ratnakaram, Y.C., E-mail: ratnakaramsvu@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati 517 502, A.P. (India)

    2015-10-15

    Highlights: • Erbium doped different fluoro-phosphate glasses are prepared and characterized. • Spectroscopic properties have been determined using Judd–Ofelt and Mc-Cumber theory. • Prominent laser transition Er{sup 3+}:{sup 4}I{sub 13/2} → {sup 4}I{sub 15/2} is observed at 1.53 μm. - Abstract: Different fluoro-phosphate glasses doped with 0.5 mol% Er{sup 3+} doped are prepared by melt quenching method. Both structural and spectroscopic properties have been characterized in order to evaluate their potential as both laser source and amplifier materials. Optical absorption measurements are carried out and analyzed through Judd–Ofelt and Mc-Cumber theories where spectroscopic parameters such as intensity parameters Ω{sub l} (λ = 2,4,6), transition probabilities, radiative lifetimes, stimulated absorption cross-sections and emission cross-sections at 1.5 μm have been evaluated for Er{sup 3+} doped different fluorophosphate glasses. The various luminescence and gain properties are explained from photoluminescence studies. The decay curve analysis have been done for obtaining the decay time constants of Er{sup 3+} excited level {sup 4}I{sub 13/2} in all the fluoro-phosphate glasses. The obtained results of each glass matrix are compared with the equivalent parameters for several other host glasses. These fluoro-phosphate glasses are found to be suitable candidates for laser and amplifier applications.

  5. Generalized fiber Fourier optics.

    Science.gov (United States)

    Cincotti, Gabriella

    2011-06-15

    A twofold generalization of the optical schemes that perform the discrete Fourier transform (DFT) is given: new passive planar architectures are presented where the 2 × 2 3 dB couplers are replaced by M × M hybrids, reducing the number of required connections and phase shifters. Furthermore, the planar implementation of the discrete fractional Fourier transform (DFrFT) is also described, with a waveguide grating router (WGR) configuration and a properly modified slab coupler.

  6. The power of fiber optics

    Energy Technology Data Exchange (ETDEWEB)

    Roy, C.

    1999-03-01

    The latest technology in optical groundwire (OPGW), involving a single cable serving as a communications network, providing high-speed data and voice transmission, and as a conventional groundwire, part of a power transmission grid, is described. The first-ever symposium devoted to OPGW was held at Hydro-Quebec`s IREQ facility in Montreal, a fitting venue, considering that Hydro-Quebec has installed an extensive network of some 3,500 km of OPGW cables since 1992. The international symposium was attended by over 130 interested experts mainly from North America, but with delegates as far away as Australia, Japan, Libya, Brazil and the UK. The three-day event showcased a number of presentations and demonstrations concerning OPGW splicing requirements, the live-line installation process, the merits of using fiber optics in a power situation, comparison of international standards in OPGW and fiber optics applications, and future developments in fiber optics technology. Demonstration of IREQ`s OPGW type-testing and manufacturer`s exhibits provided an opportunity for hands-on experience.

  7. Adaptive fiber optics collimator based on flexible hinges.

    Science.gov (United States)

    Zhi, Dong; Ma, Yanxing; Ma, Pengfei; Si, Lei; Wang, Xiaolin; Zhou, Pu

    2014-08-20

    In this manuscript, we present a new design for an adaptive fiber optics collimator (AFOC) based on flexible hinges by using piezoelectric stacks actuators for X-Y displacement. Different from traditional AFOC, the new structure is based on flexible hinges to drive the fiber end cap instead of naked fiber. We fabricated a real AFOC based on flexible hinges, and the end cap's deviation and resonance frequency of the device were measured. Experimental results show that this new AFOC can provide fast control of tip-tilt deviation of the laser beam emitting from the end cap. As a result, the fiber end cap can support much higher power than naked fiber, which makes the new structure ideal for tip-tilt controlling in a high-power fiber laser system.

  8. Subhertz linewidth laser by locking to a fiber delay line.

    Science.gov (United States)

    Dong, Jing; Hu, Yongqi; Huang, Junchao; Ye, Meifeng; Qu, Qiuzhi; Li, Tang; Liu, Liang

    2015-02-10

    An ultralow-noise, subhertz 1.55 μm erbium-doped fiber laser that is locked on an all-fiber-based Michelson interferometer is presented in this paper. The interferometer uses 500 m SMF-28 optical fiber and an acousto-optic modulator to allow heterodyne detection. By comparing two identical laser systems, a 0.67 (0.21) Hz linewidth beat-note signal is achieved and we obtain fractional frequency instability of 7×10(-15) at short timescales (0.1-1 s). The frequency noise power spectral density of two identical lasers is below -1  dB Hz(2)/Hz at 1 Hz and it reaches -18  dB Hz(2)/Hz from 200 Hz to 1 kHz.

  9. A high-efficiency Brillouin fiber ring laser

    Institute of Scientific and Technical Information of China (English)

    Pingping Zhang; Shuling Hu; Shuying Chen; Yuanhong Yang; Chunxi Zhang

    2009-01-01

    A high-efficiency Brillouin fiber ring laser is demonstrated using the standard single-mode fiber.The laser exhibits a 3.6-mW threshold.The output power is 22 mW with 40-nlW pump power,and the maximum optical-to-optical efficiency is 55%. The output is single wavelength with a 3-dB linewidth of 5 MHz,and the interval of center frequency between the laser and the pump light is 11 GHz (0.088 nm).It is shown that the stimulated Brillouin scattering threshold of ring resonator is lower and the energy transfer efficiency is higher than those in fiber.

  10. Optical Fiber Sensor Based on Localized Surface Plasmon Resonance Using Silver Nanoparticles Photodeposited on the Optical Fiber End

    Science.gov (United States)

    Ortega-Mendoza, J. Gabriel; Padilla-Vivanco, Alfonso; Toxqui-Quitl, Carina; Zaca-Morán, Placido; Villegas-Hernández, David; Chávez, Fernando

    2014-01-01

    This paper reports the implementation of an optical fiber sensor to measure the refractive index in aqueous media based on localized surface plasmon resonance (LSPR). We have used a novel technique known as photodeposition to immobilize silver nanoparticles on the optical fiber end. This technique has a simple instrumentation, involves laser light via an optical fiber and silver nanoparticles suspended in an aqueous medium. The optical sensor was assembled using a tungsten lamp as white light, a spectrometer, and an optical fiber with silver nanoparticles. The response of this sensor is such that the LSPR peak wavelength is linearly shifted to longer wavelengths as the refractive index is increased, showing a sensitivity of 67.6 nm/RIU. Experimental results are presented. PMID:25302813

  11. Optical fiber sensor based on localized surface plasmon resonance using silver nanoparticles photodeposited on the optical fiber end.

    Science.gov (United States)

    Ortega-Mendoza, J Gabriel; Padilla-Vivanco, Alfonso; Toxqui-Quitl, Carina; Zaca-Morán, Placido; Villegas-Hernández, David; Chávez, Fernando

    2014-10-09

    This paper reports the implementation of an optical fiber sensor to measure the refractive index in aqueous media based on localized surface plasmon resonance (LSPR). We have used a novel technique known as photodeposition to immobilize silver nanoparticles on the optical fiber end. This technique has a simple instrumentation, involves laser light via an optical fiber and silver nanoparticles suspended in an aqueous medium. The optical sensor was assembled using a tungsten lamp as white light, a spectrometer, and an optical fiber with silver nanoparticles. The response of this sensor is such that the LSPR peak wavelength is linearly shifted to longer wavelengths as the refractive index is increased, showing a sensitivity of 67.6 nm/RIU. Experimental results are presented.

  12. Optical Fiber Sensor Based on Localized Surface Plasmon Resonance Using Silver Nanoparticles Photodeposited on the Optical Fiber End

    Directory of Open Access Journals (Sweden)

    J. Gabriel Ortega-Mendoza

    2014-10-01

    Full Text Available This paper reports the implementation of an optical fiber sensor to measure the refractive index in aqueous media based on localized surface plasmon resonance (LSPR. We have used a novel technique known as photodeposition to immobilize silver nanoparticles on the optical fiber end. This technique has a simple instrumentation, involves laser light via an optical fiber and silver nanoparticles suspended in an aqueous medium. The optical sensor was assembled using a tungsten lamp as white light, a spectrometer, and an optical fiber with silver nanoparticles. The response of this sensor is such that the LSPR peak wavelength is linearly shifted to longer wavelengths as the refractive index is increased, showing a sensitivity of 67.6 nm/RIU. Experimental results are presented.

  13. Monolithic, High-Speed Fiber-Optic Switching Array for Lidar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA SBIR Phase II effort will develop a 1 x 10 prototype non-mechanical fiber optic switch for use with high power lasers. The proposed optical device is a...

  14. Biosensing with optical fiber gratings

    Directory of Open Access Journals (Sweden)

    Chiavaioli Francesco

    2017-06-01

    Full Text Available Optical fiber gratings (OFGs, especially long-period gratings (LPGs and etched or tilted fiber Bragg gratings (FBGs, are playing an increasing role in the chemical and biochemical sensing based on the measurement of a surface refractive index (RI change through a label-free configuration. In these devices, the electric field evanescent wave at the fiber/surrounding medium interface changes its optical properties (i.e. intensity and wavelength as a result of the RI variation due to the interaction between a biological recognition layer deposited over the fiber and the analyte under investigation. The use of OFG-based technology platforms takes the advantages of optical fiber peculiarities, which are hardly offered by the other sensing systems, such as compactness, lightness, high compatibility with optoelectronic devices (both sources and detectors, and multiplexing and remote measurement capability as the signal is spectrally modulated. During the last decade, the growing request in practical applications pushed the technology behind the OFG-based sensors over its limits by means of the deposition of thin film overlays, nanocoatings, and nanostructures, in general. Here, we review efforts toward utilizing these nanomaterials as coatings for high-performance and low-detection limit devices. Moreover, we review the recent development in OFG-based biosensing and identify some of the key challenges for practical applications. While high-performance metrics are starting to be achieved experimentally, there are still open questions pertaining to an effective and reliable detection of small molecules, possibly up to single molecule, sensing in vivo and multi-target detection using OFG-based technology platforms.

  15. "Reliability Of Fiber Optic Lans"

    Science.gov (United States)

    Code n, Michael; Scholl, Frederick; Hatfield, W. Bryan

    1987-02-01

    Fiber optic Local Area Network Systems are being used to interconnect increasing numbers of nodes. These nodes may include office computer peripherals and terminals, PBX switches, process control equipment and sensors, automated machine tools and robots, and military telemetry and communications equipment. The extensive shared base of capital resources in each system requires that the fiber optic LAN meet stringent reliability and maintainability requirements. These requirements are met by proper system design and by suitable manufacturing and quality procedures at all levels of a vertically integrated manufacturing operation. We will describe the reliability and maintainability of Codenoll's passive star based systems. These include LAN systems compatible with Ethernet (IEEE 802.3) and MAP (IEEE 802.4), and software compatible with IBM Token Ring (IEEE 802.5). No single point of failure exists in this system architecture.

  16. A compact optical fiber positioner

    Science.gov (United States)

    Hu, Hongzhuan; Wang, Jianping; Liu, Zhigang; Zhou, Zengxiang; Zhai, Chao; Chu, Jiaru

    2016-07-01

    In this paper, a compact optical fiber positioner is proposed, which is especially suitable for small scale and high density optical fiber positioning. Based on the positioning principle of double rotation, positioner's center shaft depends on planetary gear drive principle, meshing with the fixed annular gear central motor gear driving device to rotate, and the eccentric shaft rotated driving by a coaxial eccentric motor, both center and the eccentric shaft are supported by a rolling bearings; center and eccentric shaft are both designed with electrical zero as a reference point, and both of them have position-limiting capability to ensure the safety of fiber positioning; both eccentric and center shaft are designed to eliminating clearance with spring structure, and can eliminate the influence of gear gap; both eccentric and center motor and their driving circuit can be installed in the positioner's body, and a favorable heat sink have designed, the heat bring by positioning operation can be effectively transmit to design a focal plane unit through the aluminum component, on sleeve cooling spiral airway have designed, when positioning, the cooling air flow is inlet into install hole on the focal plate, the cooling air flow can effectively take away the positioning's heat, to eliminate the impact of the focus seeing. By measuring position device's sample results show that: the unit accuracy reached 0.01mm, can meet the needs of fiber positioning.

  17. Fiber optics physics and technology

    CERN Document Server

    Mitschke, Fedor

    2016-01-01

    This book tells you all you want to know about optical fibers: Their structure, their light-guiding mechanism, their material and manufacture, their use. It began with telephone, then came telefax and email. Today we use search engines, music downloads and internet videos, all of which require shuffling of bits and bytes by the zillions. The key to all this is the conduit: the line which is designed to carry massive amounts of data at breakneck speed. In their data carrying capacity optical fiber lines beat all other technologies (copper cable, microwave beacons, satellite links) hands down, at least in the long haul; wireless devices rely on fibers, too. Several effects tend to degrade the signal as it travels down the fiber: they are spelled out in detail. Nonlinear processes are given due consideration for a twofold reason: On the one hand they are fundamentally different from the more familiar processes in electrical cable. On the other hand, they form the basis of particularly interesting and innovative ...

  18. Fiber-optic communication systems

    CERN Document Server

    Agrawal, Govind P

    2010-01-01

    This book provides a comprehensive account of fiber-optic communication systems. The 3rd edition of this book is used worldwide as a textbook in many universities. This 4th edition incorporates recent advances that have occurred, in particular two new chapters. One deals with the advanced modulation formats (such as DPSK, QPSK, and QAM) that are increasingly being used for improving spectral efficiency of WDM lightwave systems. The second chapter focuses on new techniques such as all-optical regeneration that are under development and likely to be used in future communication systems. All othe

  19. Fiber Optic Geophysics Sensor Array

    Science.gov (United States)

    Grochowski, Lucjan

    1989-01-01

    The distributed optical sensor arrays are analysed in view of specific needs of 3-D seismic explorations methods. There are compared advantages and disadventages of arrays supported by the sensors which are modulated in intensity and phase. In these systems all-fiber optic structures and their compabilities with digital geophysic formats are discussed. It was shown that the arrays based on TDM systems with the intensity modulated sensors are economically and technically the best matched for geophysic systems supported by a large number of the sensors.

  20. MX optical fiber communication system

    Science.gov (United States)

    Keiser, G.

    The fiber optic (FO) network for the proposed MX mobile basing scheme is described. C3 operations would be implemented through 15,000 km of FO links between 4800 sites. Burying the cables would ensure continued C3 operations in a hostile environment, although protection would be needed from burrowing rodents. Technology development criteria, such as optical sources and photodetectors for the 1300-1600 nm long wavelength region, are noted, together with construction of a test site at an Air Force base in California.