A femtosecond Yb-doped fiber laser with generalized vector vortex beams output (Conference Presentation)

Science.gov (United States)

Huo, Tiancheng; Qi, Li; Zhang, Buyun; Chen, Zhongping

2017-03-01

Light carries both spin and orbital angular momentum (OAM) and the superpositions of these two dynamical properties have found many applications. Many techniques exist to create such light sources but none allow their creation at the femtosecond fiber laser. Here we report on a novel mode-locked Ytterbium-doped fiber laser that generates femtosecond pulses with generalized vector vortex states. The controlled generation of such pulses such as azimuthally and radially polarized light with definite orbital angular momentum modes are demonstrated. A unidirectional ring cavity constructed with the Yb-doped fiber placed at the end of the fiber section to reduces unnecessary nonlinear effects is employed for self-starting operation. Pairs of diffraction gratings are used for compensating the normal group velocity dispersion of the fiber and other elements. Mode-locked operation is achieved based on nonlinear polarization evolution, which is mainly implemented with the single mode fiber, the bulk wave plates and the variable spiral plates (q-plate with topological charge q=0.5). The conversion from spin angular momentum to the OAM and reverse inside the laser cavity are realized by means of a quarter-wave plate and a q-plate so that the polarization control was mapped to OAM mode control. The fiber laser is diode pumped by a wavelength-division multiplexing coupler, which leads to excellent stability and portability.

High-energy master oscillator power amplifier with near-diffraction-limited output based on ytterbium-doped PCF fiber

Science.gov (United States)

Li, Rao; Qiao, Zhi; Wang, Xiaochao; Fan, Wei; Lin, Zunqi

2017-10-01

With the development of fiber technologies, fiber lasers are able to deliver very high power beams and high energy pulses which can be used not only in scientific researches but industrial fields (laser marking, welding,…). The key of high power fiber laser is fiber amplifier. In this paper, we present a two-level master-oscillator power amplifier system at 1053 nm based on Yb-doped photonic crystal fibers. The system is used in the front-end of high power laser facility for the amplification of nano-second pulses to meet the high-level requirements. Thanks to the high gain of the system which is over 50 dB, the pulse of more than 0.89 mJ energy with the nearly diffraction-limited beam quality has been obtained.

Highly scalable, resonantly cladding-pumped, Er-doped fiber laser with record efficiency.

Science.gov (United States)

Dubinskii, M; Zhang, J; Ter-Mikirtychev, V

2009-05-15

We report the performance of a resonantly cladding-pumped, Yb-free, Er-doped fiber laser. We believe this is the first reported resonantly cladding-pumped fiber-Bragg-grating-based, Er-doped, large-mode-area (LMA) fiber laser. The laser, pumped by fiber-coupled InGaAsP/InP laser diode modules at 1,532.5 nm, delivers approximately 48 W of cw output at 1,590 nm. It is believed to be the highest power ever reported from a Yb-free Er-doped LMA fiber. This fully integrated laser also has the optical-to-optical efficiency of approximately 57%, to the best of our knowledge, the highest efficiency reported for cladding-pumped unidirectionally emitting Er-doped laser.

High efficiency fourth-harmonic generation from nanosecond fiber master oscillator power amplifier

Science.gov (United States)

Mu, Xiaodong; Steinvurzel, Paul; Rose, Todd S.; Lotshaw, William T.; Beck, Steven M.; Clemmons, James H.

2016-03-01

We demonstrate high power, deep ultraviolet (DUV) conversion to 266 nm through frequency quadrupling of a nanosecond pulse width 1064 nm fiber master oscillator power amplifier (MOPA). The MOPA system uses an Yb-doped double-clad polarization-maintaining large mode area tapered fiber as the final gain stage to generate 0.5-mJ, 10 W, 1.7- ns single mode pulses at a repetition rate of 20 kHz with measured spectral bandwidth of 10.6 GHz (40 pm), and beam qualities of Mx 2=1.07 and My 2=1.03, respectively. Using LBO and BBO crystals for the second-harmonic generation (SHG) and fourth-harmonic generation (FHG), we have achieved 375 μJ (7.5 W) and 92.5 μJ (1.85 W) at wavelengths of 532 nm and 266 nm, respectively. To the best of our knowledge these are the highest narrowband infrared, green and UV pulse energies obtained to date from a fully spliced fiber amplifier. We also demonstrate high efficiency SHG and FHG with walk-off compensated (WOC) crystal pairs and tightly focused pump beam. An SHG efficiency of 75%, FHG efficiency of 47%, and an overall efficiency of 35% from 1064 nm to 266 nm are obtained.

Preparation and spectroscopic properties of Yb-doped and Yb-Al-codoped high silica glasses

International Nuclear Information System (INIS)

Qiao Yanbo; Wen Lei; Wu Botao; Ren Jinjun; Chen Danping; Qiu Jianrong

2008-01-01

Yb-doped and Yb-Al-codoped high silica glasses have been prepared by sintering nanoporous glasses. The absorption, fluorescent spectra and fluorescent lifetimes have been measured and the emission cross-section and minimum pump intensities were calculated. Codoping aluminum ions enhanced the fluorescence intensity of Yb-doped high silica glass obviously. The emission cross-sections of Yb-doped and Yb-Al-codoped high silica glasses were 0.65 and 0.82 pm 2 , respectively. The results show that Yb-Al-codoped high silica glass has better spectroscopic properties for a laser material. The study of high silica glass doped with ytterbium is helpful for its application in Yb laser systems, especially for high-power and high-repetition lasers

Growth and characterization of Yb:Ho:YAG single crystal fiber

Science.gov (United States)

Yang, Yilun; Ye, Linhua; Bao, Renjie; Li, Shanming; Zhang, Peixiong; Xu, Min; Hang, Yin

2018-06-01

High quality Yb and Ho co-doped Y3Al5O12 single crystal fibers have been successfully grown by the laser heated pedestal growth method of up to 124 mm in length and 450 μm in diameter for the first time. The results of inductively coupled plasma-atomic emission spectrometry analysis, X-ray diffraction and Raman spectroscopy reveal that the lattice structure and doping concentrations of the SCF are the same as that of the bulk. Scanning electron microscopy microphotographs shows that the fibers only have minor diameter fluctuations within 0.5%.

5  W output power from a double-clad hybrid fiber with Yb-doped phosphate core and silicate cladding.

Science.gov (United States)

Wang, Longfei; He, Dongbing; Zhang, Lei; Yu, Chunlei; Feng, Suya; Wang, Meng; Chen, Danping; Hu, Lili

2017-08-01

For the first time, to the best of our knowledge, we report on the realization of a laser from a Yb-doped phosphate core/silicate cladding double-clad hybrid fiber. 5 W output power was extracted with 14.6% slope efficiency and a laser spectrum of a 1027 nm central wavelength from a 20 cm long single-mode fiber with a ∼10  μm core diameter in a 20%-4% laser cavity. The laser efficiency can be significantly enhanced by correspondingly adjusting and optimizing the laser oscillator.

Research of the mode instability threshold in high power double cladding Yb-doped fiber amplifiers

Energy Technology Data Exchange (ETDEWEB)

Wang, Yanshan; Ma, Yi; Sun, Yinhong; Peng, Wanjing; Tang, Chun [Institute of Applied Electronics, CAEP, Mianyang, Sichuan (China); The Key Laboratory of Science and Technology on High Energy Laser, CAEP, Mianyang, Sichuan (China); Liu, Qinyong; Ke, Weiwei [Institute of Applied Physics and Computational Mathematics, CAEP, Beijing (China); Wang, Xiaojun [Institute of Applied Physics and Computational Mathematics, CAEP, Beijing (China); Technical Institute of Physics and Chemistry, CAS, Beijing (China)

2017-08-15

We experimentally investigate the behavior of the mode instability (MI) threshold in the double cladding Yb-doped fiber amplifier when the amplifier is pumped by broad linewidth laser diodes and narrow linewidth laser diodes respectively. It is found that the MI threshold increases by 26% when the amplifier is pumped by the broad linewidth laser diodes. Experiment results show that the MI threshold is affected by the local heat load rather than the average or the total heat load. The calculation shows that the local heat deposit actually plays the key role to stimulate the MI behaviour. At the MI threshold position in the fiber, the local heat deposit also changes dramatically. The effect of the thermal conductivity on the MI threshold is also studied. Our investigation shows that the MI threshold increases from 1269 W to 1950 W when the thermal conductivity of the fiber amplifier is increased from 0.3 W/(m . K) to 5 W/(m . K). Through optimizing the pump linewidth and the cooling efficiency of the gain fiber, the MI threshold is doubled in our experiment. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Research of the mode instability threshold in high power double cladding Yb-doped fiber amplifiers

International Nuclear Information System (INIS)

Wang, Yanshan; Ma, Yi; Sun, Yinhong; Peng, Wanjing; Tang, Chun; Liu, Qinyong; Ke, Weiwei; Wang, Xiaojun

2017-01-01

We experimentally investigate the behavior of the mode instability (MI) threshold in the double cladding Yb-doped fiber amplifier when the amplifier is pumped by broad linewidth laser diodes and narrow linewidth laser diodes respectively. It is found that the MI threshold increases by 26% when the amplifier is pumped by the broad linewidth laser diodes. Experiment results show that the MI threshold is affected by the local heat load rather than the average or the total heat load. The calculation shows that the local heat deposit actually plays the key role to stimulate the MI behaviour. At the MI threshold position in the fiber, the local heat deposit also changes dramatically. The effect of the thermal conductivity on the MI threshold is also studied. Our investigation shows that the MI threshold increases from 1269 W to 1950 W when the thermal conductivity of the fiber amplifier is increased from 0.3 W/(m . K) to 5 W/(m . K). Through optimizing the pump linewidth and the cooling efficiency of the gain fiber, the MI threshold is doubled in our experiment. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Guiding and amplification properties of rod-type photonic crystal fibers with sectioned core doping

Science.gov (United States)

Selleri, S.; Poli, F.; Passaro, D.; Cucinotta, A.; Lægsgaard, J.; Broeng, J.

2009-05-01

Rod-type photonic crystal fibers are large mode area double-cladding fibers with an outer diameter of few millimeters which can provide important advantages for high-power lasers and amplifiers. Numerical studies have recently demonstrated the guidance of higher-order modes in these fibers, which can worsen the output beam quality of lasers and amplifiers. In the present analysis a sectioned core doping has been proposed for Ybdoped rod-type photonic crystal fibers, with the aim to improve the higher-order mode suppression. A full-vector modal solver based on the finite element method has been applied to properly design the low refractive index ring in the fiber core, which can provide an increase of the differential overlap between the fundamental and the higher-order mode. Then, the gain competition among the guided modes along the Yb-doped rod-type fibers has been investigated with a spatial and spectral amplifier model. Simulation results have shown the effectiveness of the sectioned core doping in worsening the higher-order mode overlap on the doped area, thus providing an effective single-mode behavior of the Yb-doped rod-type photonic crystal fibers.

Single-mode amplification in Yb-doped rod-type photonic crystal fibers for high brilliance lasers

DEFF Research Database (Denmark)

Poli, F.; Lægsgaard, Jesper; Passaro, D.

2009-01-01

This paper presents the effect of a low refractive index ring in the Yb-doped rod-type photonic crystal fibre core on the guided mode propagation and analyzed through a spatial and spectral amplifier model. The ring provides a higher differential overlap between the fundamental mode (FM...... to identify a proper ring characteristic that is width, position and refractive index. Then rod-type PCF designs have been optimized with a full-vector modal solver based on the finite-element method. Then, the amplification properties of the Yb-doped rod-type PCFs have been investigated by assuming a forward...

Multi-kW single fiber laser based on an extra large mode area fiber design

Science.gov (United States)

Langner, Andreas; Such, Mario; Schötz, Gerhard; Just, Florian; Leich, Martin; Schwuchow, Anka; Grimm, Stephan; Zimer, Hagen; Kozak, Marcin; Wedel, Björn; Rehmann, Georg; Bachert, Charley; Krause, Volker

2012-02-01

The quality of Yb-doped fused bulk silica produced by sintering of Yb-doped fused silica granulates has improved greatly in the past five years [1 - 4]. In particular, the refractive index and doping level homogeneity of such materials are excellent and we achieved excellent background fiber attenuation of the active core material down to about 20 dB/km at 1200 nm. The improvement of the Yb-doped fused bulk silica has enabled the development of multi-kW fiber laser systems based on a single extra large multimode laser fiber (XLMA fiber). When a single active fiber is used in combination with the XLMA multimode fiber of 1200 μm diameter simple and robust high power fiber laser setups without complex fiber coupling and fiber combiner systems become possible. In this papper, we will discuss in detail the development of the core material based on Yb-doped bulk silica and the characterization of Yb-doped fibers with different core compositions. We will also report on the excellent performance of a 4 kW fiber laser based on a single XLMA-fiber and show the first experimental welding results of steel sheets achieved with such a laser.

Atomic frequency reference at 1033 nm for ytterbium (Yb)-doped fiber lasers and applications exploiting a rubidium (Rb) 5S_1/2 to 4D_5/2 one-colour two-photon transition

Science.gov (United States)

Roy, Ritayan; Condylis, Paul C.; Johnathan, Yik Jinen; Hessmo, Björn

2017-04-01

We demonstrate a two-photon transition of rubidium (Rb) atoms from the ground state (5$S_{1/2}$) to the excited state (4$D_{5/2}$), using a home-built ytterbium (Yb)-doped fiber amplifier at 1033 nm. This is the first demonstration of an atomic frequency reference at 1033 nm as well as of a one-colour two-photon transition for the above energy levels. A simple optical setup is presented for the two-photon transition fluorescence spectroscopy, which is useful for frequency stabilization for a broad class of lasers. This spectroscopy has potential applications in the fiber laser industry as a frequency reference, particularly for the Yb-doped fiber lasers. This two-photon transition also has applications in atomic physics as a background- free high- resolution atom detection and for quantum communication, which is outlined in this article.

Thermo-optical effects in high-power Ytterbium-doped fiber amplifiers

DEFF Research Database (Denmark)

Hansen, Kristian Rymann; Alkeskjold, Thomas Tanggaard; Broeng, Jes

2011-01-01

We investigate the effect of temperature gradients in high-power Yb-doped fiber amplifiers by a numerical beam propagation model, which takes thermal effects into account in a self-consistent way. The thermally induced change in the refractive index of the fiber leads to a thermal lensing effect...

Ultraviolet photoluminescence in Gd-doped silica and phosphosilicate fibers

Directory of Open Access Journals (Sweden)

Y. Wang

2017-04-01

Full Text Available Optical fiber lasers operating in the near infrared and visible spectral regions have relied on the spectroscopic properties of rare earth ions such as Yb3+, Er3+, Tm3+, Nd3+, and Sm3+. Here, we investigate Gd3+ doping in phosphosilicate and pure silica fibers using solution doping and sol-gel techniques, respectively, for potential applications in the ultraviolet. Photoluminescence spectra for optical fiber bundles and fiber preforms were recorded and compared. Emissions at 312 nm (phosphosilicate and 314 nm (pure silica were observed when pumping to the Gd3+ 6DJ, 6IJ, and 6PJ = 5/2, 3/2 energy levels. Oxygen deficient center was observed in solution doping sample with a wide absorption band centered at around 248 nm not affecting pumping to 6IJ states.

Quantum sized Ag nanocluster assisted fluorescence enhancement in Tm3+-Yb3+ doped optical fiber beyond plasmonics

International Nuclear Information System (INIS)

Chattopadhyay, Rik; Haldar, Arindam; Paul, Mukul C.; Das, Shyamal; Bhadra, Shyamal K.

2015-01-01

We report a process for enhancing fluorescence emission from conventional rare earth ions in optical fiber by metal nanocluster (MNC) in nonresonant indirect pumping. The process is completely different from formal metal enhanced fluorescence phenomenon as the MNCs are too small in size to support localized surface plasmon and the excitation wavelength is far from plasmon resonance frequency. We used an established theory of two coupled oscillators to explain the simultaneous enhancement of Ytterbium (Yb 3+ ) and Thulium (Tm 3+ ) emission by silver (Ag) NCs under nonresonant pumping in optical fiber. The fiber is pumped with a 980 nm fiber pigtailed laser diode with input power of 20–100 mW to excite the Yb 3+ . Four times enhancement of Yb 3+ emission of 900–1100 nm and Tm 3+ upconversion emission around 474 nm, 650 nm, and 790 nm is observed in the fiber with Ag NCs

Erbium/ytterbium co-doped double clad fiber amplifier, its applications and effects in fiber optic communication systems

Science.gov (United States)

Dua, Puneit

Increased demand for larger bandwidth and longer inter-amplifiers distances translates to higher power budgets for fiber optic communication systems in order to overcome large splitting losses and achieve acceptable signal-to-noise ratios. Due to their unique design ytterbium sensitized erbium doped, double clad fiber amplifiers; offer significant increase in the output powers that can be obtained. In this thesis we investigate, a one-stage, high power erbium and ytterbium co-doped double clad fiber amplifier (DCFA) with output power of 1.4W, designed and built in our lab. Experimental demonstration and numerical simulation techniques have been used to systematically study the applications of such an amplifier and the effects of incorporating it in various fiber optic communication systems. Amplitude modulated subcarrier multiplexed (AM-SCM) CATV distribution experiment has been performed to verify the feasibility of using this amplifier in an analog/digital communication system. The applications of the amplifier as a Fabry-Perot and ring fiber laser with an all-fiber cavity, a broadband supercontinuum source and for generation of high power, short pulses at 5GHz have been experimentally demonstrated. A variety of observable nonlinear effects occur due to the high intensity of the optical powers confined in micron-sized cores of the fibers, this thesis explores in detail some of these effects caused by using the high power Er/Yb double clad fiber amplifier. A fiber optic based analog/digital CATV system experiences composite second order (CSO) distortion due to the interaction between the gain tilt---the variation of gain with wavelength, of the doped fiber amplifier and the wavelength chirp of the directly modulated semiconductor laser. Gain tilt of the Er/Yb co-doped fiber amplifier has been experimentally measured and its contribution to the CSO of the system calculated. Theoretical analysis of a wavelength division multiplexed system with closely spaced

Remote Water Temperature Measurements Based on Brillouin Scattering with a Frequency Doubled Pulsed Yb:doped Fiber Amplifier

Directory of Open Access Journals (Sweden)

Thomas Walther

2008-09-01

Full Text Available Temperature profiles of the ocean are of interest for weather forecasts, climate studies and oceanography in general. Currently, mostly in situ techniques such as fixed buoys or bathythermographs deliver oceanic temperature profiles. A LIDAR method based on Brillouin scattering is an attractive alternative for remote sensing of such water temperature profiles. It makes it possible to deliver cost-effective on-line data covering an extended region of the ocean. The temperature measurement is based on spontaneous Brillouin scattering in water. In this contribution, we present the first water temperature measurements using a Yb:doped pulsed fiber amplifier. The fiber amplifier is a custom designed device which can be operated in a vibrational environment while emitting narrow bandwidth laser pulses. The device shows promising performance and demonstrates the feasibility of this approach. Furthermore, the current status of the receiver is briefly discussed; it is based on an excited state Faraday anomalous dispersion optical filter.

Tm-Yb Doped Optical Fiber Performance with Variation of Host-Glass Composition

Directory of Open Access Journals (Sweden)

Anirban Dhar

2014-01-01

Full Text Available The fabrication process of Thulium-Ytterbium doped optical fiber comprising different host glass through the Modified Chemical Vapor Deposition (MCVD coupled with solution doping technique is presented. The material and optical performance of different fibers are compared with special emphasis on their lasing efficiency for 2 µm application.

Mass fabrication of homogeneously Yb-doped silica nanoparticles and their spectroscopic properties

International Nuclear Information System (INIS)

Xiong Liangming; Sekiya, Edson H; Saito, Kazuya

2009-01-01

A large number of homogeneously Yb-doped silica nanoparticles were continually fabricated in a vapor synthesis route, in which the Yb doping level can be well controlled by varying either the heating temperature or the carrier gas flow rate of the Yb precursor. The sizes, shapes, and morphologies of the nanoparticles were examined, and no crystallites and no Yb 2 O 3 clusters were observed in the nanoparticles. These nanoparticles exhibit a clear Yb 3+ -derived absorption at around 973-975 nm and a dependence of the emission intensity and decay time on the doping level, much different from that of sintered pellets.

Monolithic Highly Stable Yb-Doped Femtosecond Fiber Lasers for Applications in Practical Biophotonics

DEFF Research Database (Denmark)

Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

2012-01-01

in the development of all-fiber nonlinear-optical laser control schemes, which resulted in the demonstration of highly stable monolithic, i.e., not containing any free-space elements, lasers with direct fiber-end delivery of femtosecond pulses. This paper provides an overview of the progress in the development...... of such all-fiber mode-locked lasers based on Yb-fiber as gain medium, operating at the wavelength around 1 $\\mu$m, and delivering femtosecond pulses reaching tens of nanojoules of energy.......Operational and environmental stability of ultrafast laser systems is critical for their applications in practical biophotonics. Mode-locked fiber lasers show great promise in applications such as supercontinuum sources or multiphoton microscopy systems. Recently, substantial progress has been made...

Diode-pumped laser with Yb:YAG single-crystal fiber grown by the micro-pulling down technique

Science.gov (United States)

Sangla, D.; Aubry, N.; Didierjean, J.; Perrodin, D.; Balembois, F.; Lebbou, K.; Brenier, A.; Georges, P.; Tillement, O.; Fourmigué, J.-M.

2009-02-01

Laser emission obtained from an Yb:YAG single-crystal fiber directly grown by the micro-pulling down technique is demonstrated for the first time. We achieved 11.2 W of continuous wave (CW) output power at 1031 nm for 55 W of incident pump power at 940 nm. In the Q-switched regime, we obtained pulses as short as 17 ns, for an average power of 2.3 W at 2 kHz corresponding to an energy of 1.15 mJ. In both cases, the M 2 factor was 2.5. This single-crystal fiber showed performance similar to a standard rod elaborated by the Czochralski method. The potential of Yb3+-doped single-crystal fibers is presented for scalable high-average and high-peak-power laser systems.

Monolithic Yb-fiber femtosecond laser with intracavity all-solid PBG fiber and ex-cavity HC-PCF

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Liu, Xiaomin; Lægsgaard, Jesper

2010-01-01

(PM) photonic bandgap fiber (PBG) is used in the cavity of the master oscillator for dispersion compensation and stabilization of modelocking. The final compression of an chirped-pulse-amplified laser signal is performed in a hollow PM PCF, yielding final fiber-delivered pulse energy of around 7 n......J, and pulse duration of around 297 fs. The self-stabilization mechanism of the oscillator, based on the optical nonlinearities in an AS PCF, results in excellent environmental and operational stability of our laser. Stable self-starting fundamental modelocking is maintained for at least 4 days of operation......We demonstrate an all-fiber femtosecond master oscillator / power amplifier operating at the central wavelength of 1033 nm, based on Yb-doped fiber as gain medium, and two different kinds of photonic crystal fibers for dispersion control and stabilization. An all-solid (AS) polarization maintaining...

Comparison on different repetition rate locking methods in Er-doped fiber laser

Science.gov (United States)

Yang, Kangwen; Zhao, Peng; Luo, Jiang; Huang, Kun; Hao, Qiang; Zeng, Heping

2018-05-01

We demonstrate a systematic comparative research on the all-optical, mechanical and opto-mechanical repetition rate control methods in an Er-doped fiber laser. A piece of Yb-doped fiber, a piezoelectric transducer and an electronic polarization controller are simultaneously added in the laser cavity as different cavity length modulators. By measuring the cavity length tuning ranges, the output power fluctuations, the temporal and frequency repetition rate stability, we show that all-optical method introduces the minimal disturbances under current experimental condition.

Quantum sized Ag nanocluster assisted fluorescence enhancement in Tm{sup 3+}-Yb{sup 3+} doped optical fiber beyond plasmonics

Energy Technology Data Exchange (ETDEWEB)

Chattopadhyay, Rik; Haldar, Arindam; Paul, Mukul C.; Das, Shyamal; Bhadra, Shyamal K., E-mail: skbhadra@cgcri.res.in [Fiber Optics and Photonics Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata 700032 (India)

2015-12-07

We report a process for enhancing fluorescence emission from conventional rare earth ions in optical fiber by metal nanocluster (MNC) in nonresonant indirect pumping. The process is completely different from formal metal enhanced fluorescence phenomenon as the MNCs are too small in size to support localized surface plasmon and the excitation wavelength is far from plasmon resonance frequency. We used an established theory of two coupled oscillators to explain the simultaneous enhancement of Ytterbium (Yb{sup 3+}) and Thulium (Tm{sup 3+}) emission by silver (Ag) NCs under nonresonant pumping in optical fiber. The fiber is pumped with a 980 nm fiber pigtailed laser diode with input power of 20–100 mW to excite the Yb{sup 3+}. Four times enhancement of Yb{sup 3+} emission of 900–1100 nm and Tm{sup 3+} upconversion emission around 474 nm, 650 nm, and 790 nm is observed in the fiber with Ag NCs.

Monolithic Yb-fiber femtosecond laser using photonic crystal fiber

DEFF Research Database (Denmark)

Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

2008-01-01

We demonstrate, both experimentally and theoretically, an environmentally stable monolithic all-PM modelocked femtosecond Yb-fiber laser, with laser output pulse compressed in a spliced-on low-loss hollow-core photonic crystal fiber. Our laser provides direct fiber-end delivery of 4 nJ pulses...

3 kW single stage all-fiber Yb-doped single-mode fiber laser for highly reflective and highly thermal conductive materials processing

Science.gov (United States)

Ikoma, S.; Nguyen, H. K.; Kashiwagi, M.; Uchiyama, K.; Shima, K.; Tanaka, D.

2017-02-01

A 3 kW single stage all-fiber Yb-doped single-mode fiber laser with bi-directional pumping configuration has been demonstrated. Our newly developed high-power LD modules are employed for a high available pump power of 4.9 kW. The length of the delivery fiber is 20 m which is long enough to be used in most of laser processing machines. An output power of 3 kW was achieved at a pump power of 4.23 kW. The slope efficiency was 70%. SRS was able to be suppressed at the same output power by increasing ratio of backward pump power. The SRS level was improved by 5dB when 57% backward pump ratio was adopted compared with the case of 50%. SRS was 35dB below the laser power at the output power of 3 kW even with a 20-m delivery fiber. The M-squared factor was 1.3. Single-mode beam quality was obtained. To evaluate practical utility of the 3 kW single-mode fiber laser, a Bead-on-Plate (BoP) test onto a pure copper plate was executed. The BoP test onto a copper plate was made without stopping or damaging the laser system. That indicates our high power single-mode fiber lasers can be used practically in processing of materials with high reflectivity and high thermal conductivity.

White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+-Na+ ion-exchanged aluminum germanate glass channel waveguide

Science.gov (United States)

Liu, Xiao; Chen, Baojie; Pun, Edwin Yue Bun; Lin, Hai

2013-01-01

Rare-earth ions doped K+-Na+ ion-exchanged aluminum germanate (NMAG) glass channel waveguides have been designed and fabricated. Under 980 nm laser pumping, an intense upconversion white light transmission trace was observed in Tm3+/Ho3+/Yb3+ triply doped NMAG glass channel waveguide and a high-brightness light spot was achieved from the output end of the fiber connected to the waveguide channel. The fluorescent colors were diverse and located within or near the white region in CIE chromaticity diagram under various pumping powers. These admirable results indicate that Tm3+/Ho3+/Yb3+ triply doped NMAG channel waveguide is a promising light source for medical and high-precision processing illumination.

Guiding and amplification properties of rod-type photonic crystal fibers with sectioned core doping

DEFF Research Database (Denmark)

Selleri, Stefano; Poli, Federica; Passaro, Davide

2009-01-01

Rod-type photonic crystal fibers are large mode area double-cladding fibers with an outer diameter of few millimeters which can provide important advantages for high-power lasers and amplifiers. Numerical studies have recently demonstrated the guidance of higher-order modes in these fibers, which...... can worsen the output beam quality of lasers and amplifiers. In the present analysis a sectioned core doping has been proposed for Yb-doped rod-type photonic crystal fibers, with the aim to improve the higher-order mode suppression. A full-vector modal solver based on the finite element method has...

Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO₂.

Science.gov (United States)

Wang, Ling; Zeng, Huidan; Yang, Bin; Ye, Feng; Chen, Jianding; Chen, Guorong; Smith, Andew T; Sun, Luyi

2017-02-28

Yb 3+ -doped phosphate glasses containing different amounts of SiO₂ were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO₂ on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO₂ possessed the longest fluorescence lifetime (1.51 ms), the highest gain coefficient (1.10 ms·pm²), the maximum Stark splitting manifold of ²F 7/2 level (781 cm -1 ), and the largest scalar crystal-field N J and Yb 3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO₂ promoted the formation of P=O linkages, but broke the P=O linkages when the SiO₂ content was greater than 26.7 mol %. Based on the previous 29 Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO₆] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb 3+ -doped gain medium for solid-state lasers and optical fiber amplifiers.

Cladding-pumped Yb-doped fiber laser with vortex output beam

OpenAIRE

Lin, Di; Clarkson, William

2015-01-01

A simple technique for selectively generating a donut-shaped LP11 mode with vortex phase front in a cladding-pumped ytterbium-doped fiber laser is reported. The laser yielded 36W of output with a slope efficiency of 74%.

Thermal effects on light emission in Yb3+ -sensitized rare-earth doped optical glasses

International Nuclear Information System (INIS)

Gouveia, E.A.; Araujo, M.T. de; Gouveia-Neto, A.S.

2001-01-01

The temperature effect upon infrared-to-visible frequency upconversion fluorescence emission in off-resonance infrared excited Yb 3+ -sensitized rare-earth doped optical glasses is theoretically and experimentally investigated. We have examined samples of Er3+/Yb 3+ -codoped Ga 2 S 3 :La 2 O 3 chalcogenide glasses and germanosilicate optical fibers, and Ga2O3:La 2 O 3 chalcogenide and fluoroindate glasses codoped with Pr 3+ /Yb 3+ , excited off-resonance at 1.064μm. The experimental results revealed thermal induced enhancement in the visible upconversion emission intensity as the samples temperatures were increased within the range of 20 deg C to 260 deg C. The fluorescence emission enhancement is attributed to the temperature dependent multiphonon-assisted anti-Stokes excitation process of the ytterbium-sensitizer. A theoretical approach that takes into account a sensitizer temperature dependent effective absorption cross section, which depends upon the phonon occupation number in the host matrices, has proven to agree very well with the experimental data. As beneficial applications of the thermal enhancement, a temperature tunable amplifier and a fiber laser with improved power performance are presented. (author)

Assessment of effect of Yb3+ ion pairs on a highly Yb-doped double-clad fibre laser

Science.gov (United States)

Vallés, J. A.; Martín, J. C.; Berdejo, V.; Cases, R.; Álvarez, J. M.; Rebolledo, M. Á.

2018-03-01

Using a previously validated characterization method based on the careful measurement of the characteristic parameters and fluorescence emission spectra of a highly Yb-doped double-clad fibre, we evaluate the contribution of ion pair induced processes to the output power of a double-clad Yb-doped fibre ring laser. This contribution is proved to be insignificant, contrary to analysis by other authors, who overestimate the role of ion pairs.

Evaluation of material dispersion using a nanosecond optical pulse radiator.

Science.gov (United States)

Horiguchi, M; Ohmori, Y; Miya, T

1979-07-01

To study the material dispersion effects on graded-index fibers, a method for measuring the material dispersion in optical glass fibers has been developed. Nanosecond pulses in the 0.5-1.7-microm region are generated by a nanosecond optical pulse radiator and grating monochromator. These pulses are injected into a GeO(2)-P(2)0(5)-doped silica graded-index fiber. Relative time delay changes between different wavelengths are used to determine material dispersion, core glass refractive index, material group index, and optimum profile parameter of the graded-index fiber. From the measured data, the optimum profile parameter on the GeO(2)-P(2)O(5)-doped silica graded-index fiber could be estimated to be 1.88 at 1.27 microm of the material dispersion free wavelength region and 1.82 at 1.55 microm of the lowest-loss wavelength region in silica-based optical fiber waveguides.

High-efficiency 2 μm Tm-doped fiber laser

International Nuclear Information System (INIS)

Dvornikov, D.

2013-01-01

Full text: Tm doped fiber laser operating in so called 'eye safe' wavelength region and designed in a MOPA configuration has been demonstrated. Large-mode-area fiber design and availability of high-brightness, high-power pump diodes at 795 nm made possible maximum output power of 25 W achieved at incident pump power of 72 W resulting in optical conversion efficiency about 35%. An important factor that led to an interest in 2 μm Tm-doped lasers is significantly broader spectral tunability of Tm-doped fibers compared to Yb-doped fibers, spanning wavelengths from below 1850 nm to beyond 2100 nm, corresponding to more than 200 nm of available bandwidth. This wavelength region covers the water absorption peaks around 1940 nm, making these lasers a valuable tool for precise medical procedures including noninvasive surgery, as well as several atmospheric transmission windows that are useful for remote sensing, laser radar and range-finding. This work was carried out as part of the EU funded Joint Operational Programme 'Black Sea Basin 2007-2013' and project 2.2.1.74459.339, MIS-ETC 1443 'Research networking for the environmental monitoring and mitigation of adverse ecological effects in the Black Sea Basin (BSB Net-Eco)'.

Monolithic femtosecond Yb-fiber laser with photonic crystal fibers

DEFF Research Database (Denmark)

Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

We demonstrate a monolithic stable SESAM-modelocked self-starting Yb-fiber laser. A novel PM all-solid photonic bandgap fiber is used for intra-cavity of dispersion management. The ex-cavity final pulse compression is performed in a spliced-on PM hollow-core photonic crystal fiber. The laser...... directly delivers 9 nJ pulses of 275 fs duration with pulse repetition of 26.7MHz....

Dielectric relaxation in Yb-doped SrZrO3

International Nuclear Information System (INIS)

Kamishima, O; Abe, Y; Ishii, T; Kawamura, J; Hattori, T

2004-01-01

The dielectric constant of the proton conductor SrZr 1-x Yb x O 3 (x 0-0.1) was measured as a function of temperature and frequency. Two well-defined relaxation peaks were observed in SrZrO 3 doped with more than 1 mol% of Yb. The assignment of the two dielectric relaxations is discussed in terms of IR spectra and by free energy calculation for a miscibility of dopant Yb ions. The Yb concentration dependence of the relaxation strength of the two dielectric relaxations is in agreement with the results calculated from the free energy. The two relaxations can be assigned to a reorientation of a single Yb-OH dipole and of Yb-OH dipoles associated with Yb-clusters. The attractive energy for Yb-clustering in SrZrO 3 is evaluated at about -85 meV

Q-switched Erbium-doped fiber laser at 1600 nm for photoacoustic imaging application

Energy Technology Data Exchange (ETDEWEB)

Piao, Zhonglie [Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, California 92612 (United States); Zeng, Lvming; Chen, Zhongping, E-mail: z2chen@uci.edu, E-mail: ckim@pusan.ac.kr [Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, California 92612 (United States); Kim, Chang-Seok, E-mail: z2chen@uci.edu, E-mail: ckim@pusan.ac.kr [Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

2016-04-04

We present a nanosecond Q-switched Erbium-doped fiber (EDF) laser system operating at 1600 nm with a tunable repetition rate from 100 kHz to 1 MHz. A compact fiber coupled, acousto-optic modulator-based EDF ring cavity was used to generate a nanosecond seed laser at 1600 nm, and a double-cladding EDF based power amplifier was applied to achieve the maximum average power of 250 mW. In addition, 12 ns laser pulses with the maximum pulse energy of 2.4 μJ were obtained at 100 kHz. Furthermore, the Stokes shift by Raman scattering over a 25 km long fiber was measured, indicating that the laser can be potentially used to generate the high repetition rate pulses at the 1.7 μm region. Finally, we detected the photoacoustic signal from a human hair at 200 kHz repetition rate with a pulse energy of 1.2 μJ, which demonstrates that a Q-switched Er-doped fiber laser can be a promising light source for the high speed functional photoacoustic imaging.

Growth and laser action of Yb: YVO4 crystals with low Yb doping concentration

Science.gov (United States)

Zhong, Degao; Teng, Bing; Li, Jianhong; Zhang, Shiming; Zhang, Bingtao; Wang, Chao; Tian, Xueping; Liu, Junhai

2012-11-01

Yb: YVO4 single crystals with low doping concentrations of Yb3+ less than 0.3 at% were grown using the Czochralski method. The polarized absorption spectra were measured at room temperature. Strong anisotropy exists in the absorption spectra, resulting in almost entirely different features for π-polarization and σ-polarization. The laser emission spectrum and relationship curve between the output power and absorbed pump power (Pabs) were measured. The continuous-wave laser action of Yb: YVO4 single crystal in a range of 1020.4-1026.3 nm was realized by using a high-power diode laser as the pump source.

Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO2

Directory of Open Access Journals (Sweden)

Ling Wang

2017-02-01

Full Text Available Yb3+-doped phosphate glasses containing different amounts of SiO2 were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO2 on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO2 possessed the longest fluorescence lifetime (1.51 ms, the highest gain coefficient (1.10 ms·pm2, the maximum Stark splitting manifold of 2F7/2 level (781 cm−1, and the largest scalar crystal-field NJ and Yb3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO2 promoted the formation of P=O linkages, but broke the P=O linkages when the SiO2 content was greater than 26.7 mol %. Based on the previous 29Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO6] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb3+-doped gain medium for solid-state lasers and optical fiber amplifiers.

Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO2

Science.gov (United States)

Wang, Ling; Zeng, Huidan; Yang, Bin; Ye, Feng; Chen, Jianding; Chen, Guorong; Smith, Andew T.; Sun, Luyi

2017-01-01

Yb3+-doped phosphate glasses containing different amounts of SiO2 were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO2 on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO2 possessed the longest fluorescence lifetime (1.51 ms), the highest gain coefficient (1.10 ms·pm2), the maximum Stark splitting manifold of 2F7/2 level (781 cm−1), and the largest scalar crystal-field NJ and Yb3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO2 promoted the formation of P=O linkages, but broke the P=O linkages when the SiO2 content was greater than 26.7 mol %. Based on the previous 29Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO6] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb3+-doped gain medium for solid-state lasers and optical fiber amplifiers. PMID:28772601

Radiation hardening of optical fibers and fiber sensors for space applications: recent advances

Science.gov (United States)

Girard, S.; Ouerdane, Y.; Pinsard, E.; Laurent, A.; Ladaci, A.; Robin, T.; Cadier, B.; Mescia, L.; Boukenter, A.

2017-11-01

In these ICSO proceedings, we review recent advances from our group concerning the radiation hardening of optical fiber and fiber-based sensors for space applications and compare their benefits to state-of-the-art results. We focus on the various approaches we developed to enhance the radiation tolerance of two classes of optical fibers doped with rare-earths: the erbium (Er)-doped ones and the ytterbium/erbium (Er/Yb)-doped ones. As a first approach, we work at the component level, optimizing the fiber structure and composition to reduce their intrinsically high radiation sensitivities. For the Erbium-doped fibers, this has been achieved using a new structure for the fiber that is called Hole-Assisted Carbon Coated (HACC) optical fibers whereas for the Er/Ybdoped optical fibers, their hardening was successfully achieved adding to the fiber, the Cerium element, that prevents the formation of the radiation-induced point defects responsible for the radiation induced attenuation in the infrared part of the spectrum. These fibers are used as part of more complex systems like amplifiers (Erbium-doped Fiber Amplifier, EDFA or Yb-EDFA) or source (Erbium-doped Fiber Source, EDFS or Yb- EDFS), we discuss the impact of using radiation-hardened fibers on the system radiation vulnerability and demonstrate the resistance of these systems to radiation constraints associated with today and future space missions. Finally, we will discuss another radiation hardening approach build in our group and based on a hardening-by-system strategy in which the amplifier is optimized during its elaboration for its future mission considering the radiation effects and not in-lab.

Thermodynamic properties of multiferroic Mg doped YbMnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Sattibabu, Bhumireddi, E-mail: bsb.satti@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Bhatnagar, A.K., E-mail: anilb42@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); School of Physics, University of Hyderabad, Hyderabad 500046 (India); Samatham, S. Shanmukharao; Singh, D. [Low Temperature Laboratory, UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001, M.P. (India); Rayaprol, S. [UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC Campus, Mumbai 400085 (India); Das, D. [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Siruguri, V. [UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC Campus, Mumbai 400085 (India); Ganesan, V. [Low Temperature Laboratory, UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001, M.P. (India)

2015-09-25

Highlights: • Specific heat data shows that T{sub N} increases for Mg doped YbMnO{sub 3} from 83 K to 86 K. • Yb{sub 1−x}Mg{sub x}MnO{sub 3} (x = 0.0 and 0.05) shows multiple magnetic transitions. • RCP are found to be 26.1 J/mol and 27.2 J/mol for YbMnO{sub 3} and Yb{sub 0.95}Mg{sub 0.05}MnO{sub 3}. - Abstract: Calorimetric studies of polycrystalline samples Yb{sub 1−x}Mg{sub x}MnO{sub 3} with x = 0.0 and 0.05 are reported. It is revealed that the Mg doping raises the antiferromagnetic ordering temperature, T{sub N,} from 83 K for x = 0.0 to 86 K for x = 0.05. A ferromagnetic ordering is also observed around 3 K. The broad feature in the specific heat data just above ferromagnetic ordering, is attributed to the Schottky anomaly. The estimated effective molecular fields from the Schottky analysis are H{sub mf} = 3.0 and 3.5 T for YbMnO{sub 3} and Yb{sub 0.95}Mg{sub 0.05}MnO{sub 3}, respectively. High temperature shift of Schottky anomaly with Mg doping indicates increase in effective molecular field of Mn at the Yb 4b site. The data supports that the idea that although molecular field is mainly responsible for the Schottky anomaly in Yb{sub 1−x}Mg{sub x}MnO{sub 3} and Mn{sup 3+} spin ordering also affects it. Magnetic part of the specific heat is obtained by subtracting the lattice contribution estimated using two Debye temperatures. The magnetic entropy change (ΔS{sub mag}) for pure and doped samples are 2.0 J mol{sup −1} K{sup −1} and 2.1 J mol{sup −1} K{sup −1} respectively, while the relative cooling power (RCP) calculate 26.1 J/mol, 27.2 J/mol for a field change of 10 T.

Growth and luminescent properties of Yb3+--doped oxide single crystals for scintillator application

International Nuclear Information System (INIS)

Yoshikawa, A.; Ogino, H.; Shim, J.B.; Nikl, M.; Solovieva, N.; Fukuda, T.

2004-01-01

Rod-shaped (Lu 1-x Yb x ) 3 Al 5 O 12 with x=0.05, 0.15, 0.30 and (Y 1-x Yb x )AlO 3 with x=0.05, 0.10, 0.30 single crystals were grown by the micro-pulling-down method. Edge-defined film-fed growth method was used to prepare (Y 0.9 Yb 0.1 )VO 4 crystal, while Ca 8 (La 1.98 Yb 0.02 )(PO 4 ) 6 O 2 crystal was grown by the Czochralski method. Luminescence of these crystals was studied with main attention paid to the charge transfer emission of Yb 3+ . Temperature tuned decay times in the time scale of units--tens of nanosecond was measured as a feature possibly interesting for an application in scintillation detectors in positron emission tomography

High-efficiency cavity-dumped micro-chip Yb:YAG laser

Science.gov (United States)

Nishio, M.; Maruko, A.; Inoue, M.; Takama, M.; Matsubara, S.; Okunishi, H.; Kato, K.; Kyomoto, K.; Yoshida, T.; Shimabayashi, K.; Morioka, M.; Inayoshi, S.; Yamagata, S.; Kawato, S.

2014-09-01

High-efficiency cavity-dumped ytterbium-doped yttrium aluminum garnet (Yb:YAG) laser was developed. Although the high quantum efficiency of ytterbium-doped laser materials is appropriate for high-efficiency laser oscillation, the efficiency is decreased by their quasi-three/four laser natures. High gain operation by high intensity pumping is suitable for high efficiency oscillation on the quasi-three/four lasers without extremely low temperature cooling. In our group, highest efficiency oscillations for continuous wave, nanosecond to picosecond pulse lasers were achieved at room temperature by the high gain operation in which pump intensities were beyond 100 kW/cm2.

Multimodal emissions from Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate glass: Upconversion, downshifting and quantum cutting

Energy Technology Data Exchange (ETDEWEB)

Bahadur, A.; Yadav, R.S.; Yadav, R.V.; Rai, S.B., E-mail: sbrai49@yahoo.co.in

2017-02-15

This paper reports the optical properties of Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate (LB) glass prepared by melt quench method. The absorption spectrum of the Yb{sup 3+} doped LB glass contains intense NIR band centered at 976 nm due to {sup 2}F{sub 7/2}→{sup 2}F{sub 5/2} transition. The emission spectra of the prepared glasses have been monitored on excitation with 266, 355 and 976 nm. The Yb{sup 3+} doped glass emits a broad NIR band centered at 976 nm whereas the Tb{sup 3+} doped glass gives off visible bands on excitations with 266 and 355 nm. When the Tb{sup 3+} and Yb{sup 3+} ions are co-doped together, the emission intensity in the visible region decreases whereas it increases in the NIR region significantly. The increase in the emission intensity in the NIR region is due to efficient cooperative energy transfer (CET) from Tb{sup 3+} to Yb{sup 3+} ions. The quantum cutting efficiency for Tb{sup 3+}/Yb{sup 3+} co-doped glass has been calculated and compared for 266 and 355 nm excitations. The quantum cutting efficiency is larger for 355 nm excitation (137%). The Tb{sup 3+}/Yb{sup 3+} co-doped LB glass also emits upconverted visible bands on excitation with 976 nm. The mechanisms involved in the energy transfer have been discussed using schematic energy level diagram. The Tb{sup 3+}/Yb{sup 3+} co-doped LB glass may be used in the optical devices and in solar cell for solar spectral conversion and behaves as a multi-modal photo-luminescent material. - Graphical abstract: The Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate (LB) glass prepared by melt quench method emits upconverted visible emissions through upconversion CET from Yb{sup 3+} to Tb{sup 3+} ions and quantum cutting emissions through downconversion CET from Tb{sup 3+} to Yb{sup 3+} ions. Therefore, the Tb{sup 3+}/Yb{sup 3+} co-doped LB glass may find applications in optical devices and solar cell and behaves as a multi-modal photo-luminescent material. - Highlights: • The Tb{sup 3+}/Yb{sup 3

Downconversion in Pr3+–Yb3+ co-doped ZBLA fluoride glasses

International Nuclear Information System (INIS)

Maalej, O.; Boulard, B.; Dieudonné, B.; Ferrari, M.; Dammak, M.; Dammak, M.

2015-01-01

Fluorozirconate ZBLA glasses with molar composition 57ZrF 4 –34BaF 2 –5LaF 3 –4AlF 3 –0.5PrF 3 –xYbF 3 (from x=0 to 10) were synthesized to evaluate the rate of the conversion of visible photons into infrared photons. The emission spectra in the near infrared (NIR) at 950–1100 nm and the luminescence decays in the visible and NIR indicate an energy transfer from Pr 3+ to Yb 3+ upon blue excitation of Pr 3+ at 440 nm. The energy transfer efficiency increases with Yb 3+ concentration to reach 86% with 0.5Pr 3+ –10Yb 3+ co-doping (in mol%). However, the quenching of the Yb 3+ emission strongly reduces the efficiency of the downconversion process: the decay time values decrease from 600 µs (x=0.5 mol%) to 85 µs (x=10 mol%). - Highlights: • We synthesized 0.5Pr 3+ –xYb 3+ co-doped ZBLA glasses (from x=0 to 10 mol %). • Photoluminescence of Yb 3+ was observed at 980 nm under blue excitation. • Time resolved measurements have been performed in the visible and near infrared. • Energy transfer efficiency from Pr 3+ to Yb 3+ reaches 86% in 0.5 Pr 3+ –10Yb 3+ glass

Photoluminescence study of Sm{sup 3+}–Yb{sup 3+}co-doped tellurite glass embedding silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Reza Dousti, M., E-mail: mrdousti@ifsc.usp.br [Laboratório de Espectroscopia de Materiais Funcionais (LEMAF), Instituto de Fisica de São Carlos, Universidade de São Paulo, Av. Trabalhador So-carlense 400, São Carlos, SP 13566-590 (Brazil); Department of Physics, Tehran-North Branch, Islamic Azad University Tehran (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Amjad, R.J. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Hosseinian S, R.; Salehi, M.; Sahar, M.R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia)

2015-03-15

We report on the upconversion emission of Sm{sup 3+} ions doped tellurite glass in the presence of Yb{sup 3+} ions and silver nanoparticles. The enhancement of infrared-to-visible upconversion emissions is achieved under 980 nm excitation wavelength and attributed to the high absorption cross section of Yb{sup 3+} ions and an efficient energy transfer to Sm{sup 3+} ions. Further enhancements are attributed to the plasmonic effect via metallic nanoparticles resulting in the large localized field around rare earth ions. However, under excitation at 406 nm, the addition of Yb{sup 3+} content and heat-treated silver nanoparticles quench the luminescence of Sm{sup 3+} ions likely due to quantum cutting and plasmonic diluent effects, respectively. - Highlights: • Sm{sup 3+} tellurite glasses co-doped with Yb{sup 3+} ions and tri-doped with Yb{sup 3+}:Ag NPs were prepared. • In first step, Yb{sup 3+} ions enhanced the upconversion emissions of Sm{sup 3+} doped samples. • In second step, Ag NPs further enhanced the upconversion emissions in tri-doped glasses. • Finally, the quench in luminescence under 406 nm excitation is observed and discussed.

A 98 W 1178 nm Yb-doped solid-core photonic bandgap fiber oscillator

International Nuclear Information System (INIS)

Fan, Xinyan; Chen, Mingchen; Shirakawa, Akira; Ueda, Ken-ichi; Olausson, Christina B; Broeng, Jes

2013-01-01

A high-power ytterbium-doped solid-core photonic bandgap fiber laser directly oscillating at 1178 nm is reported. The sharp-cut bandpass distributed filtering effect of photonic bandgap fiber can suppress amplified spontaneous emission (ASE) in the conventional high-gain spectral region. The oscillator is composed of a high reflection fiber Bragg grating spliced with a 39 m gain fiber and a Fresnel fiber end surface. A model based on rate equations is investigated numerically. A record output power of 98 W is achieved with a slope efficiency of 54%. The laser linewidth is 0.5 nm. The spectrum at 98 W indicates that ASE and parasitic lasing are suppressed effectively. (letter)

Spectroscopy of Yb-doped tungsten-tellurite glass and assessment of its lasing properties

Science.gov (United States)

Merzliakov, M. A.; Kouhar, V. V.; Malashkevich, G. E.; Pestryakov, E. V.

2018-01-01

Glasses of the TeO2-WO3-Yb2O3 system are synthesized for wide range of Yb3+ concentrations of up to 6.0 × 1021 ions/cm3. The spectral-luminescent properties of lightly doped samples are investigated at room temperature and at the boiling point of liquid nitrogen. The energies of the Stark levels of the ground and excited states of Yb3+ ions incorporated into tungsten-tellurite glass are determined by analyzing the low-temperature spectra. The absorption, emission, and gain cross section spectra are obtained. The excess of the measured fluorescence decay time over the radiative lifetime ∼0.3 ms derived from the absorption spectra is attributed to the reabsorption effect in bulk samples. Measurements of lightly doped glass powder in the immersion liquid are made to reduce the effect of reabsorption. The fluorescence decay time of the powder is very close to the calculated radiative lifetime. Compared with phosphate, silicate, and other Yb3+-doped glasses, the tungsten-tellurite glass has a promising potential as a gain medium for lasers and amplifiers.

100J-level nanosecond pulsed Yb:YAG cryo-cooled DPSSL amplifier

Science.gov (United States)

Smith, J. M.; Butcher, T. J.; Mason, P. D.; Ertel, K.; Phillips, P. J.; Banerjee, S.; De Vido, M.; Chekhlov, O.; Divoky, M.; Pilar, J.; Shaikh, W.; Hooker, C.; Lucianetti, A.; Hernandez Gomez, C.; Mocek, T.; Edwards, C.; Collier, J. L.

2018-02-01

We report on the successful demonstration of the world's first kW average power, 100 Joule-class, high-energy, nanosecond pulsed diode-pumped solid-state laser (DPSSL), DiPOLE100. Results from the first long-term test for amplification will be presented; the system was operated for 1 hour with 10 ns duration pulses at 10 Hz pulse repetition rate and an average output energy of 105 J and RMS energy stability of approximately 1%. The laser system is based on scalable cryogenic gas-cooled multi-slab ceramic Yb:YAG amplifier technology. The DiPOLE100 system comprises three major sub-systems, a spatially and temporally shaped front end, a 10 J cryo-amplifier and a 100 J cryo-amplifier. The 10 J cryo-amplifier contain four Yb:YAG ceramic gain media slabs, which are diode pumped from both sides, while a multi-pass architecture configured for seven passes enables 10 J of energy to be extracted at 10 Hz. This seeds the 100 J cryo-amplifier, which contains six Yb:YAG ceramic gain media slabs with the multi-pass configured for four passes. Our future development plans for this architecture will be introduced including closed-loop pulse shaping, increased energy, higher repetition rates and picosecond operation. This laser architecture unlocks the potential for practical applications including new sources for industrial materials processing and high intensity laser matter studies as envisioned for ELI [1], HiLASE [2], and the European XFEL [3]. Alternatively, it can be used as a pump source for higher repetition rate PW-class amplifiers, which can themselves generate high-brightness secondary radiation and ion sources leading to new remote imaging and medical applications.

All-fiber nonlinearity- and dispersion-managed dissipative soliton nanotube mode-locked laser

Energy Technology Data Exchange (ETDEWEB)

Zhang, Z. [Department of Physics, Bilkent University, 06800 Ankara (Turkey); Nanjing University of Posts and Communications, Nanjing 210003 (China); Popa, D., E-mail: dp387@cam.ac.uk; Wittwer, V. J.; Milana, S.; Hasan, T.; Jiang, Z.; Ferrari, A. C. [Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Ilday, F. Ö. [Department of Physics, Bilkent University, 06800 Ankara (Turkey); Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey)

2015-12-14

We report dissipative soliton generation from an Yb-doped all-fiber nonlinearity- and dispersion-managed nanotube mode-locked laser. A simple all-fiber ring cavity exploits a photonic crystal fiber for both nonlinearity enhancement and dispersion compensation. The laser generates stable dissipative solitons with large linear chirp in the net normal dispersion regime. Pulses that are 8.7 ps long are externally compressed to 118 fs, outperforming current nanotube-based Yb-doped fiber laser designs.

75 W 40% efficiency single-mode all-fiber erbium-doped laser cladding pumped at 976 nm.

Science.gov (United States)

Kotov, L V; Likhachev, M E; Bubnov, M M; Medvedkov, O I; Yashkov, M V; Guryanov, A N; Lhermite, J; Février, S; Cormier, E

2013-07-01

Optimization of Yb-free Er-doped fiber for lasers and amplifiers cladding pumped at 976 nm was performed in this Letter. The single-mode fiber design includes an increased core diameter of 34 μm and properly chosen erbium and co-dopant concentrations. We demonstrate an all-fiber high power laser and power amplifier based on this fiber with the record slope efficiency of 40%. To the best of our knowledge, the achieved output power of 75 W is the highest power reported for such lasers.

Absorption Spectra Of Rbcl:Yb Rbbr:Yb And Rbi:Yb Crystals ...

African Journals Online (AJOL)

Single crystals of rubidium chloride, bromide and iodide were doped with substitutional divalent ytterbium, Yb ions, by heating them in ytterbium atmosphere. The absorption spectra of the Yb doped crystals were measured at room and liquid nitrogen temperatures. The spectra were found to consist of intense broad ...

Synthesis and thermoelectric properties of rare earth Yb-doped Ba8−xYbxSi30Ga16 clathrates

International Nuclear Information System (INIS)

Liu, Lihua; Li, Feng; Wei, Yuping; Chen, Ning; Bi, Shanli; Qiu, Hongmei; Cao, Guohui; Li, Yang

2014-01-01

Highlights: • Samples with the chemical formula Ba8− x Yb x Si 30 Ga 16 (x = 0, 0.5, 0.7, 1 and 1.5) were prepared. • Some Yb atoms enter the clathrate lattice to replace Ba, while other Yb atoms are oxidized as Yb 2 O 3 . • The thermal conductivity decreases with Yb-doping. • Thermoelectric figure of merit ZT significantly increased. -- Abstract: The potential thermoelectric and magnetic application of clathrate materials with rare-earth doping is the focus of much of the recent research activity in the synthetic material physics and chemistry. A series of clathrate samples with the chemical formula Ba 8−x Yb x Si 30 Ga 16 (x = 0, 0.5, 0.7, 1 and 1.5) were prepared by combining arc melting, ball milling and spark plasma sintering (SPS) techniques. X-ray diffraction and scanning electronic microscopy combined with energy-dispersive X-ray spectroscopy (EDS) analysis showed the dominant phase to be the type-I clathrate. Whereas, X-ray structural refinement and EDS analysis indicated that some Yb atoms enter the clathrate lattice to replace Ba at 2a sites, while other Yb atoms are oxidized as Yb 2 O 3 precipitated around grain boundaries. The solid solubility of Yb into clathrate lattice yielded x ∼ 0.3. Comparative analysis between Yb-doped and Yb-free clathrates showed that the thermal conductivity decreases with Yb-doping. Consequently, thermoelectric figure of merit ZT significantly increased

Magnetocaloric effect in In doped YbMnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Sattibabu, Bhumireddi, E-mail: bsb.satti@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Department of Electronics and Physics, Institute of Science, GITAM University, Visakhapatnam 530045 (India); Bhatnagar, A.K., E-mail: anilb42@gmail.com [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Vinod, K.; Mani, Awadhesh [Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

2017-06-01

Magnetic and magnetocaloric (MCE) properties of Yb{sub 0.9}In{sub 0.1}MnO{sub 3} and Yb{sub 0.8}In{sub 0.2}MnO{sub 3} polycrystalline samples are presented in this paper. Isothermal magnetization measurements reveal a field induced magnetic transition. Magnetic entropy change of 2.34±0.35 J/mole-K for Yb{sub 0.9}In{sub 0.1}MnO{sub 3} and 2.64±0.38 J/mole-K for Yb{sub 0.8}In{sub 0.2}MnO{sub 3} field change ΔH =10 KOe is observed around the ferromagnetic ordering temperature of Yb{sup 3+}. Values of relative cooling power for the same field change are found to be 38.03±9 J /mol, and 40.90±10 J/mol for Yb{sub 0.9}In{sub 0.1}MnO{sub 3} and Yb{sub 0.8}In{sub 0.2}MnO{sub 3}, respectively. These values suggest In doped YbMnO{sub 3} may be a potential candidate for magnetic refrigerant at low temperatures.

Influence of interfacial reactions on the fiber push-out behavior in sapphire fiber-reinforced-NiAl(Yb) composites

International Nuclear Information System (INIS)

Tewari, S.N.; Asthana, R.; Tiwari, R.; Bowman, R.R.

1993-01-01

The influence of microstructure of the fiber-matrix interface on the fiber push-out behavior has been examined in sapphire fiber-reinforced NiAl and NiAl(Yb) matrix composites synthesized using powder metallurgy techniques combined with zone directional solidification (DS). The push-out stress-displacement curves were observed to consist of an initial 'pseudoelastic' region, wherein the stress increased linearly with displacement, followed by an 'inelastic' region, where the slope of the stress-displacement plot decreased until a maximum stress was reached, and the subsequent stress drop to a constant 'frictional' stress. Chemical reaction between the fiber and the matrix resulted in higher interfacial shear strength in powder cloth processed sapphire-NiAl(Yb) composites as compared to the sapphire-NiAl composites. Grain boundaries in contact with the fibers on the back face of the push-out samples were the preferred sites for crack nucleation in PM composites. The frictional stress was independent of the microstructure and processing variables for NiAl composites, but showed strong dependence on these variables for the NiAl(Yb) composites. The DS processing enhanced the fiber-matrix interfacial shear strength of feedstock PM-NiAl/sapphire composites. However, it reduced the interfacial shear strength of PM-NiAl(Yb)-sapphire composites

Synthesis and characterization of Nd3+: Yb3+ co-doped near infrared sensitive fluorapatite nanoparticles as a bioimaging probe

Science.gov (United States)

Karthi, S.; Kumar, G. A.; Sardar, D. K.; Santhosh, C.; Girija, E. K.

2018-03-01

Trivalent Nd and Yb co-doped rod shaped hexagonal phase fluorapatite (FAP) nanoparticles of length and width about 32 and 13 nm, respectively were prepared by hydrothermal method and investigated the ability for 980 nm emission via Nd3+ → Yb3+ energy transfer with the objective of utilizing them in biomedical imaging. Nd3+ → Yb3+ energy transfer in FAP was studied as a function of both Nd3+ and Yb3+ concentrations and found that when Yb3+ concentration was 10 mol% the FAP phase has partially turned in to YbPO4 phase. The Yb3+ emission intensity at 980 nm significantly increased up to 5 mol% Yb3+ doping and then reduced drastically for further increase in its concentration. Nd3+ →Yb3+ energy transfer rates were evaluated from the decay curves and found that a transfer rate of 71% for 2 mol% Nd3+ co-doped with 5 mol% Yb3+. The cytocompatibility test with fibroblast like cells using MTT assay revealed that the nanoparticles are compatible with the cells.

Characterizations of Pr-doped Yb3Al5O12 single crystals for scintillator applications

Science.gov (United States)

Yoshida, Yasuki; Shinozaki, Kenji; Igashira, Takuya; Kawano, Naoki; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

2018-04-01

Yb3Al5O12 (YbAG) single crystals doped with different concentrations of Pr were synthesized by the Floating Zone (FZ) method. Then, we evaluated their basic optical and scintillation properties. All the samples showed photoluminescence (PL) with two emission bands appeared approximately 300-500 nm and 550-600 nm due to the charge transfer luminescence of Yb3+ and intrinsic luminescence of the garnet structure, respectively. A PL decay profile of each sample was approximated by a sum of two exponential decay functions, and the obtained decay times were 1 ns and 3-4 ns. In the scintillation spectra, we observed emission peaks in the ranges from 300 to 400 nm and from 450 to 550 nm for all the samples. The origins of these emissions were attributed to charge transfer luminescence of Yb3+ and intrinsic luminescence of the garnet structure, respectively. The scintillation decay times became longer with increasing the Pr concentrations. Among the present samples, the 0.1% Pr-doped sample showed the lowest scintillation afterglow level. In addition, pulse height spectrum of 5.5 MeV α-rays was demonstrated using the Pr-doped YbAG, and we confirmed that all the samples showed a full energy deposited peak. Above all, the 0.1% Pr-doped sample showed the highest light yield with a value of 14 ph/MeV under α-rays excitation.

Color tunable emission through energy transfer from Yb3+ co-doped SrSnO3: Ho3+ perovskite nano-phosphor

Science.gov (United States)

Jain, Neha; Singh, Rajan Kr.; Sinha, Shriya; Singh, R. A.; Singh, Jai

2018-04-01

First time color tunable lighting observed from Ho3+ and Yb3+ co-doped SrSnO3 perovskite. Down-conversion and up-conversion (UC) photoluminescence emission spectra were recorded to understand the whole mechanism of energy migration between Ho3+ and Yb3+ ions. The intensity of green and red emission varies with Yb3+ doping which causes multicolour emissions from nano-phosphor. The intensity of UC red emission (654 nm) obtained from 1 at.% Ho3+ and 3 at.% Yb3+ co-doped nano-phosphor is nine times higher than from 1 at.% Ho3+ doped SrSnO3 nano-phosphor. Enhanced brightness of 654 nm in UC process belongs in biological transparency window so that it might be a promising phosphor in the bio-medical field. Moreover, for the other Yb3+ co-doped nano-phosphor, Commission Internationale de l'Éclairage chromaticity co-ordinates were found near the white region and their CCT values lie in the range 4900-5100 K indicating cool white. Decay time was measured for 545 nm emission of Ho3+ ion found in 7.652 and 8.734 µs at 355 nm excitation. The variation in lifetime was observed in ascending order with increasing Yb3+ concentration which supports PL emission spectra observation that with increasing Yb3+ concentration, rate of transition has changed. These studies reveal that Ho3+ and Yb3+ co-doped phosphor is useful for fabrication of white LEDs.

Spectroscopic properties of Er3+ and Yb3+ co-doped glass ceramics containing SrF2 nanocrystals

International Nuclear Information System (INIS)

Qiao Xvsheng; Fan Xianping; Wang Minquan; Zhang Xianghua

2009-01-01

The spectroscopic properties of Er 3+ /Yb 3+ co-doped 50SiO 2 -10Al 2 O 3 -20ZnF 2 -20SrF 2 glass and glass ceramic containing SrF 2 nanocrystals were investigated. The formation of SrF 2 nanocrystals in the glass ceramic was confirmed by XRD. The oscillator strengths for several transitions of the Er 3+ ions in the glass ceramic have been obtained and the Judd-Ofelt parameters were then determined. The XRD result and Judd-Ofelt parameters suggested that Er 3+ and Yb 3+ ions had efficiently enriched in the SrF 2 nanocrystals in the glass ceramic. The lifetime of excited states has been used to reveal the surroundings of luminescent Er 3+ and Yb 3+ and energy transfer (ET) mechanism between Er 3+ and Yb 3+ . Much stronger upconversion luminescence and longer lifetime of the Er 3+ /Yb 3+ co-doped glass ceramic were observed in comparison with the Er 3+ /Yb 3+ co-doped glass, which could be ascribed to more efficient ET from Yb 3+ to Er 3+ due to the enrichment of Yb 3+ and Er 3+ and the shortening of the distance between lanthanide ions in the precipitated SrF 2 nanocrystals.

Monolithic stabilized Yb-fiber All-PM laser directly delivering nJ-level femtosecond pulses

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Liu, Xiaomin; Lægsgaard, Jesper

2008-01-01

We present a monolithic, self-starting, all-PM, stabilized Yb-fiber laser, pulse-compressed in a hollow-core PM photonic crystal fiber, providing the 370 fs pulses of 4 nJ energy with high mode quality.......We present a monolithic, self-starting, all-PM, stabilized Yb-fiber laser, pulse-compressed in a hollow-core PM photonic crystal fiber, providing the 370 fs pulses of 4 nJ energy with high mode quality....

Sub-100 fs pulses from an all-polarization maintaining Yb-fiber oscillator with an anomalous dispersion higher-order-mode fiber

DEFF Research Database (Denmark)

Verhoef, A. J.; Zhu, L.; Israelsen, Stine Møller

2015-01-01

, was investigated for different settings of the intracavity dispersion. When the cavity is operated with close to zero net dispersion, highly stable 0.5-nJ pulses externally compressed to sub-100-fs are generated. These are to our knowledge the shortest pulses generated from an all-polarization-maintaining Yb-fiber......We present an Yb-fiber oscillator with an all-polarizationmaintaining cavity with a higher-order-mode fiber for dispersion compensation. The polarization maintaining higher order mode fiber introduces not only negative second order dispersion but also negative third order dispersion in the cavity......, in contrast to dispersion compensation schemes used in previous demonstrations of all-polarization maintaining Yb-fiber oscillators. The performance of the saturable absorber mirror modelocked oscillator, that employs a free space scheme for coupling onto the saturable absorber mirror and output coupling...

Sub-100 fs pulses from an all-polarization maintaining Yb-fiber oscillator with an anomalous dispersion higher-order-mode fiber

DEFF Research Database (Denmark)

Verhoef, A.J.; Zhu, L.; Israelsen, Stine Møller

2015-01-01

, was investigated for different settings of the intracavity dispersion. When the cavity is operated with close to zero net dispersion, highly stable 0.5-nJ pulses externally compressed to sub-100-fs are generated. These are to our knowledge the shortest pulses generated from an all-polarization-maintaining Yb-fiber......We present an Yb-fiber oscillator with an all-polarization-maintaining cavity with a higher-order-mode fiber for dispersion compensation. The polarization maintaining higher order mode fiber introduces not only negative second order dispersion but also negative third order dispersion in the cavity......, in contrast to dispersion compensation schemes used in previous demonstrations of all-polarization maintaining Yb-fiber oscillators. The performance of the saturable absorber mirror modelocked oscillator, that employs a free space scheme for coupling onto the saturable absorber mirror and output coupling...

Nanocrystal in Er3+-doped SiO2-ZrO2 Planar Waveguide with Yb3+ Sensitizer

International Nuclear Information System (INIS)

Razaki, N. Iznie; Jais, U. Sarah; Abd-Rahman, M. Kamil; Bhaktha, S. N. B.; Chiasera, A.; Ferrari, M.

2010-01-01

Higher doping of Er 3+ in glass ceramic waveguides would cause concentration and pair-induced quenching which lead to inhomogeneous line-width of luminescence spectrum thus reduce output intensity. Concentration quenching can be overcome by introducing ZrO 2 in the glass matrix while co-doping with Yb 3+ which acts as sensitizer would improve the excitation efficiency of Er 3+ . In this study, SiO 2 -ZrO 2 planar waveguides having composition in mol percent of 70SiO 2 -30ZrO 2 doped with Er 3+ and co-doped with Yb 3+ , were prepared via sol-gel route. Narrower and shaper peaks of PL and XRD shows the formation of nanocrystals. Intensity is increase with addition amount of Yb 3+ shows sensitizing effect on Er 3+ .

Down-conversion luminescence from (Ce, Yb) co-doped oxygen-rich silicon oxides

International Nuclear Information System (INIS)

Heng, C. L.; Wang, T.; Su, W. Y.; Wu, H. C.; Yin, P. G.; Finstad, T. G.

2016-01-01

We have studied down-conversion photoluminescence (PL) from (Ce, Yb) co-doped “oxygen rich” silicon oxide films prepared by sputtering and annealing. The Ce"3"+ ∼510 nm PL is sensitive to the Ce concentration of the films and is much stronger for 3 at. % Ce than for 2 at. % Ce after annealing at 1200 °C. The PL emission and excitation spectroscopy results indicate that the excitation of Yb"3"+ is mainly through an energy transfer from Ce"3"+ to Yb"3"+, oxide defects also play a role in the excitation of Yb"3"+ after lower temperature (∼800 °C) annealing. The Ce"3"+ 510 nm photon excites mostly only one Yb"3"+ 980 nm photon. Temperature-dependent PL measurements suggest that the energy transfer from Ce"3"+ to Yb"3"+ is partly thermally activated.

Density-functional study on the robust ferromagnetism in rare-earth element Yb-doped SnO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kai-Cheng, E-mail: kczhang@yeah.net [College of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Li, Yong-Feng [Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal ResourcesInner Mongolia University of Science and Technology, Baotou 014010 (China); School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Liu, Yong [State Key Laboratory of Metastable Materials Science and Technology and College of Science, Yanshan University, Qinhuangdao, Hebei 066004 (China); Chi, Feng [College of Engineering, Bohai University, Jinzhou 121013 (China)

2014-06-01

So far, little has been known about the ferromagnetism induced by p–f hybridization. We investigate the magnetic properties of Yb-doped SnO{sub 2} by first-principles calculations. We find that the doped system favors the ferromagnetic state and a room-temperature ferromagnetism can be expected in it. The origin of ferromagnetism can be attributed to the p–f hybridization between Yb impurity and its surrounding oxygen atoms. The formation energy of defect complex is calculated and the magnetic mediation of intrinsic vacancies is studied. Our results reveal that the formation energy of the defect complex with Sn vacancy is about 7.3 eV lower in energy than that with oxygen vacancy. This means Sn vacancy is much easier to form than oxygen vacancy in the presence of Yb substitution. The ferromagnetism of the doped system is greatly enhanced in the presence of Sn vacancies. - Highlights: • Room-temperature ferromagnetism can be expected in Yb-doped SnO{sub 2}. • The origin of ferromagnetism can be attributed to the p–f hybridization between Yb and O atoms. • Oxygen vacancies are much hard to form and contribute little to the ferromagnetism. • Sn vacancies are easy to form under oxygen-rich condition and stabilize the ferromagnetism effectively.

Filament-induced luminescence and supercontinuum generation in undoped, Yb-doped, and Nd-doped YAG crystals

Science.gov (United States)

Kudarauskas, D.; Tamošauskas, G.; Vengris, M.; Dubietis, A.

2018-01-01

We present a comparative spectral study of filament-induced luminescence and supercontinuum generation in undoped, Yb-doped, and Nd-doped YAG crystals. We show that supercontinuum spectra generated by femtosecond filamentation in undoped and doped YAG crystals are essentially identical in terms of spectral extent. On the other hand, undoped and doped YAG crystals exhibit remarkably different filament-induced luminescence spectra whose qualitative features are independent of the excitation wavelength and provide information on the energy deposition to embedded dopants, impurities, and the crystal lattice itself. Our findings suggest that filament-induced luminescence may serve as a simple and non-destructive tool for spectroscopic studies in various transparent dielectric media.

Backward pumping kilowatt Yb3+-doped double-clad fiber laser

Science.gov (United States)

Han, Z. H.; Lin, X. C.; Hou, W.; Yu, H. J.; Zhou, S. Z.; Li, J. M.

2011-09-01

A ytterbium-doped double-clad fiber laser generating up to 1026 W of continuous-wave output power at 1085 nm with a slope efficiency of 74% by single-ended backward pumping configuration is reported. The core diameter was 20 μm with a low numerical aperture of 0.06, and a good beam quality (BPP < 1.8 mm mrad) is achieved without special mode selection methods. No undesirable roll-over was observed in output power with increasing pump power, and the maximum output power was limited by the available pump power. The instability of maximum output power was better than ±0.6%. Different pumping configurations were also compared in experiment, which shows good agreements with theoretical analyses.

Crystal growth, optical properties, and laser operation of Yb3+-doped NYW single crystal

Science.gov (United States)

Cheng, Y.; Xu, X. D.; Yang, X. B.; Xin, Z.; Cao, D. H.; Xu, J.

2009-11-01

Laser crystal Yb3+-doped NaY(WO4)2 (Yb:NYW) with excellent quality has been grown by Czochralski technique. The rocking curves from (400) plane of as-grown Yb:NYW crystal was measured and the full-width value at half-maximum was 19.92″. The effective segregation coefficients were measured by the X-ray fluorescence method. The polarized absorption spectra and the fluorescence spectra of Yb:NYW crystal were measured at room temperature. The fluorescence decay lifetime of Yb3+ ion in NYW crystal has been investigated. The spectroscopic parameters of Yb:NYW crystal are calculated and compared with those of Yb:YAG crystal. A continuous wave output power of 3.06 W at 1031 nm was obtained with a slope efficiency of 42% by use of diode pumping.

Upconversion dynamics in Yb3+-Ho3+-doped fluoroindate glasses

International Nuclear Information System (INIS)

Martin, I.R.; Rodriguez, V.D.; Lavin, V.; Rodriguez-Mendoza, U.R.

1998-01-01

The mechanisms and dynamics of the upconversion emissions in Yb 3+ -Ho 3+ -doped fluoroindate glasses by exciting at 975 nm have been analysed. The upconversion efficiencies have been measured as a function of temperature in the range from 12 to 295 K. The temporal evolution of the 545- and 650-nm upconversion emissions obtained under flash excitation at 975 nm in codoped samples with 2.25 mol.% of Yb 3+ and 0.75 mol.% of Ho 3+ cannot be described using the energy migration model. This indicates that at this concentration of Yb 3+ the rapid migration regimen between these ions has not been reached. A model is proposed in order to explain the temporal evolution of these emissions taking into account energy migration between donors and backtransfer processes. (orig.)

Fiber Coupled Pulse Shaper for Sub-Nanosecond Pulse Lidar, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This Small Business Innovation Research Phase II effort will develop an all-diode laser and fiber optic based, single frequency, sub-nanosecond pulsed laser source...

Characteristics and Laser Performance of Yb3+-Doped Silica Large Mode Area Fibers Prepared by Sol–Gel Method

Directory of Open Access Journals (Sweden)

Shikai Wang

2013-12-01

Full Text Available Large-size 0.1 Yb2O3–1.0 Al2O3–98.9 SiO2 (mol% core glass was prepared by the sol–gel method. Its optical properties were evaluated. Both large mode area double cladding fiber (LMA DCF with core diameter of 48 µm and large mode area photonic crystal fiber (LMA PCF with core diameter of 90 µm were prepared from this core glass. Transmission loss at 1200 nm is 0.41 dB/m. Refractive index fluctuation is less than 2 × 10−4. Pumped by 976 nm laser diode LD pigtailed with silica fiber (NA 0.22, the slope efficiency of 54% and “light-to-light” conversion efficiency of 51% were realized in large mode area double cladding fiber, and 81 W laser power with a slope efficiency of 70.8% was achieved in the corresponding large mode area photonic crystal fiber.

Photonic Crystal Fibers

National Research Council Canada - National Science Library

Kristiansen, Rene E

2005-01-01

This report results from a contract tasking Crystal Fibre A/S as follows: Crystal Fibre will conduct research and development of large mode area, dual clad multi-core Yb-doped photonic crystal fiber...

Co-operative energy transfer in Yb3+-Er3+ co-doped SrGdxOy upconverting phosphor

Science.gov (United States)

Kumar, Ashwini; Pathak, Trilok K.; Dhoble, S. J.; . Terblans, J. J.; Swart, H. C.

2018-04-01

Upconversion nanoparticles (UCNPs) have shown considerable interest in many fields; however, low upconversion efficiency of UCNPs is still the most severe limitation of their applications. Yb3+ and Er3+ co-doped SrGd4O7/Gd2O3(SGO) upconversion (UC) phosphors were synthesized by a modified co-precipitation process. The UC properties were investigated by direct excitation with a 980 nm laser. It was observed that the as prepared materials showed relatively strong green emission, while upon the incorporation of the Er3+ ion, there was an increase in the upconversion luminescence intensity for the red component. The effect of different doping concentration of Er3+on the emission spectra and X-ray diffraction patterns of the UC materials have also been studied. The luminescence lifetimes and Commission Internationale de L'Eclairage coordinates for these as prepared samples were determined to understand the energy transfer (ET) mechanisms occurring between Yb3+ and Er3+ in the SGO host matrix. The UC luminescence intensity as a function of laser pump power was monitored and it was confirmed that the UC process in SGO:Yb3+/Er3+is a two-photon absorption process. The findings reported here are expected to provide a better approach for understanding of the ET mechanisms in the oxide based Yb3+/Er3+ co-doped UC phosphors. This study might be helpful in precisely defined applications where optical transitions are essential criterion and this can be easily achieved by smart tuning of the emission properties of Yb3+/Er3+ co-doped UC phosphors.

Analysis of structure origin and luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glass.

Science.gov (United States)

Chen, Fangze; Jing, Xufeng; Wei, Tao; Wang, Fengchao; Tian, Ying; Xu, Shiqing

2014-08-14

The near infrared luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glasses have been investigated. The various effects on structure and 1.53 μm emission were analyzed as a function of Yb(3+) concentration. The energy transfer mechanism was proposed. High measured lifetime (10.75 ms), large effective full widths at half maximum (73.71 nm) and large gain per unit length (62.8 × 10(-)(24)cm(2)s) have been achieved in prepared glass. The present glass co-doped with 6mol% YbF3 and 2 mol% ErF3 showed magnificent luminescence properties for telecommunication application. Copyright © 2014 Elsevier B.V. All rights reserved.

Design of an amplifier model accounting for thermal effect in fully aperiodic large pitch fibers

Science.gov (United States)

Tragni, K.; Molardi, C.; Poli, F.; Dauliat, R.; Leconte, B.; Darwich, D.; du Jeu, R.; Malleville, M. A.; Jamier, R.; Selleri, S.; Roy, P.; Cucinotta, A.

2018-02-01

Yb-doped Photonic Crystal Fibers (PCFs) have triggered a significant power scaling into fiber-based lasers. However thermally-induced effects, like mode instability, can compromise the output beam quality. PCF design with improved Higher Order Mode (HOM) delocalization and effective thermal resilience can contain the problem. In particular, Fully- Aperiodic Large-Pitch Fibers (FA-LPFs) have shown interesting properties in terms of resilience to thermal effects. In this paper the performances of a Yb-doped FA-LPF amplifier are experimentally and numerically investigated. Modal properties and gain competition between Fundamental Mode (FM) and first HOM have been calculated, in presence of thermal effects. The main doped fiber characteristics have been derived by comparison between experimental and numerical results.

Fiber fuse behavior in kW-level continuous-wave double-clad field laser

International Nuclear Information System (INIS)

Sun Jun-Yi; Xiao Qi-Rong; Li Dan; Wang Xue-Jiao; Zhang Hai-Tao; Gong Ma-Li; Yan Ping

2016-01-01

In this study, original experimental data for fiber fuse in kW-level continuous-wave (CW) high power double-clad fiber (DCF) laser are reported. The propagating velocity of the fuse is 9.68 m/s in a 3.1-kW Yb-doped DCF laser. Three other cases in Yb-doped DCF are also observed. We think that the ignition of fiber fuse is caused by thermal mechanism, and the formation of bullet-shaped tracks is attributed to the optical discharge and temperature gradient. The inducements of initial fuse and formation of bullet-shaped voids are analyzed. This investigation of fiber fuse helps better understand the fiber fuse behavior, in order to avoid the catastrophic destruction caused by fiber fuse in high power fiber laser. (paper)

Modeling of Yb3+-sensitized Er3+-doped silica waveguide amplifiers

DEFF Research Database (Denmark)

Lester, Christian; Bjarklev, Anders Overgaard; Rasmussen, Thomas

1995-01-01

A model for Yb3+-sensitized Er3+-doped silica waveguide amplifiers is described and numerically investigated in the small-signal regime. The amplified spontaneous emission in the ytterbium-band and the quenching process between excited erbium ions are included in the model. For pump wavelengths...

Femtosecond all-polarization-maintaining fiber laser operating at 1028 nm

DEFF Research Database (Denmark)

Olsson, R.K.; Andersen, T.V.; Leick, Lasse

2008-01-01

We present an effective solution for an all-polarization-maintaining modelocked femtosecond fiber laser operating at the central wavelength of 1028 nm. The laser is based on an Yb-doped active fiber. Modelocking is enabled by a semiconductor saturable absorber mirror, and the central wavelength i...... is enforced by a fiber Bragg grating. The laser is self-starting and demonstrates excellent stability gainst Q-switching. Pulse energies reach 13 nJ at 34 MHz repetition rate. External compression leads to near transform-limited pulses of 140 fs.......We present an effective solution for an all-polarization-maintaining modelocked femtosecond fiber laser operating at the central wavelength of 1028 nm. The laser is based on an Yb-doped active fiber. Modelocking is enabled by a semiconductor saturable absorber mirror, and the central wavelength...

Evolution of magnetic properties and exchange interactions in Ru doped YbCrO3

International Nuclear Information System (INIS)

Dalal, Biswajit; Sarkar, Babusona; De, S K; Dev Ashok, Vishal

2016-01-01

Magnetic properties of YbCr 1−x Ru x O 3 as a function of temperature and magnetic field have been investigated to explore the intriguing magnetic phenomena in rare-earth orthochromites. A quantitative analysis of x-ray photoelectron spectroscopy confirms the mixed valence state (Yb 3+  and Yb 2+ ) of Yb ions for the highest doped sample. Field-cooled magnetization reveals a broad peak around 75 K and then becomes zero at about 20–24 K, due to the antiparallel coupling between Cr 3+ and Yb 3+ moments. An increase of the Ru 4+ ion concentration leads to a slight increase of compensation temperature T comp from 20 to 24 K, but the Néel temperature remains constant. A larger value of the magnetic moment of Yb ions gives rise to negative magnetization at low temperature. An external magnetic field significantly modifies the temperature dependent magnetization. Simulation of temperature dependent magnetization data, below T N , based on the three (two) magnetic sub-lattice model predicts stronger intra-sublattice exchange interaction than that of inter-sublattice. Thermal hysteresis and Arrot plots suggest first order magnetic phase transition. Random substitution of Ru 4+ ion reduces the magnetic relaxation time. Weak ferromagnetic component in canted antiferromagnetic system and negative internal magnetic field cause zero-field-cooled exchange bias effect. Large magnetocrystalline anisotropy associated with Ru creates high coercivity in the Ru doped sample. A maximum value of magnetocaloric effect is found around the antiferromagnetic ordering of Yb 3+ ions. Antiferromagnetic transition at about 120 K and temperature induced magnetization reversal lead to normal and inverse magnetocaloric effects in the same material. (paper)

Tunable multicolor and white-light upconversion luminescence in Yb3+/Tm3+/Ho3+ tri-doped NaYF4 micro-crystals.

Science.gov (United States)

Lin, Hao; Xu, Dekang; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

2015-09-01

NaYF4 micro-crystals with various concentrations of Yb(3+) /Tm(3+) /Ho(3+) were prepared successfully via a simple and reproducible hydrothermal route using EDTA as the chelating agent. Their phase structure and surface morphology were studied using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD patterns revealed that all the samples were pure hexagonal phase NaYF4. SEM images showed that Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 were hexagonal micro-prisms. Upconversion photoluminescence spectra of Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 micro-crystals with various dopant concentrations under 980 nm excitation with a 665 mW pump power were studied. Tunable multicolor (purple, purplish blue, yellowish green, green) and white light were achieved by simply adjusting the Ho(3+) concentration in 20%Yb(3+)/1%Tm(3+)/xHo(3+) tri-doped NaYF4 micro-crystals. Furthermore, white-light emissions could be obtained using different pump powers in 20%Yb(3+)/1%Tm(3+)/1%Ho(3+) tri-doped NaYF4 micro-crystals at 980 nm excitation. The pump power-dependent intensity relationship was studied and relevant energy transfer processes were discussed in detail. The results suggest that Yb(3+)/Tm(3+) Ho(3+) tri-doped NaYF4 micro-crystals have potential applications in optoelectronic devices such as photovoltaic, plasma display panel and white-light-emitting diodes. Copyright © 2014 John Wiley & Sons, Ltd.

High-power Yb-doped continuous-wave and pulsed fibre lasers

Indian Academy of Sciences (India)

2014-01-05

Jan 5, 2014 ... In this article, a review of Yb-doped CW and pulsed fibre lasers along with our study on self-pulsing dynamics in CW fibre lasers to find its role in high-power fibre laser development and the physical ... Solid State Laser Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, India ...

Luminescence properties of Y2O3:Bi3+, Yb3+ co-doped phosphor for application in solar cells

Science.gov (United States)

Lee, E.; Kroon, R. E.; Terblans, J. J.; Swart, H. C.

2018-04-01

Bismuth (Bi3+) and ytterbium (Yb3+) co-doped yttrium oxide (Y2O3) phosphor powder was successfully synthesised using the co-precipitation technique. The X-ray diffraction (XRD) patterns confirmed that a single phase cubic structure with a Ia-3 space group was formed. The visible emission confirmed the two symmetry sites, C2 and S6, found in the Y2O3 host material and revealed that Bi3+ ions preferred the S6 site as seen the stronger emission intensity. The near-infrared (NIR) emission of Yb3+ increased significantly by the presence of the Bi3+ ions when compared to the singly doped Y2O3:Yb3+ phosphor with the same Yb3+ concentration. An increase in the NIR emission intensity was also observed by simply increasing the Yb3+ concentration in the Y2O3:Bi3+, Yb3+ phosphor material where the intensity increased up to x = 5.0 mol% of Yb3+ before decreasing due to concentration quenching.

Ytterbium-Phosphate Glass for Microstructured Fiber Laser

Directory of Open Access Journals (Sweden)

Ryszard Stępień

2014-06-01

Full Text Available In the paper, we report on the development of a synthesis and melting method of phosphate glasses designed for active microstructured fiber manufacturing. Non-doped glass synthesized in a P2O5-Al2O3-BaO-ZnO-MgO-Na2O oxide system served as the matrix material; meanwhile, the glass was doped with 6 mol% (18 wt% of Yb2O3, as fiber core. The glasses were well-fitted in relation to optical (refractive index and thermal proprieties (thermal expansion coefficient, rheology. The fiber with the Yb3+-doped core, with a wide internal photonic microstructure for a laser pump, as well as with a high relative hole size in the photonic outer air-cladding, was produced. The laser built on the basis of this fiber enabled achieving 8.07 W of output power with 20.5% slope efficiency against the launched pump power, in single-mode operation M2 = 1.59, from a 53 cm-long cavity.

Near-infrared quantum cutting in Yb3+ ion doped strontium vanadate

Science.gov (United States)

Sawala, N. S.; Bajaj, N. S.; Omanwar, S. K.

2016-05-01

The materials Sr3-x(VO4)2:xYb were successfully synthesized by co-precipitation method varying the concentration of Yb3+ ions from 0 to 0.06 mol. It was characterize by powder X-ray powder diffraction (XRD) and surface morphology was studied by scanning electronic microscope (SEM). The photoluminescence (PL) properties were studied by spectrophotometers in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Yb3+ ion doped tristrontium vanadate (Sr3(VO4)2) phosphors that can convert a photon of UV region (349 nm) into photons of NIR region (978, 996 and 1026 nm). Hence this phosphor could be used as a quantum cutting (QC) luminescent convertor in front of crystalline silicon solar cell (c-Si) panels to reduce thermalization loss due to spectral mismatch of the solar cells. The theoretical value of quantum efficiency (QE) was calculated from steady time decay measurement and the maximum efficiency approached up to 144.43%. The Sr(3-x) (VO4)2:xYb can be potentiality used for betterment of photovoltaic (PV) technology.

Up-conversion mechanisms in Er{sup 3+} doped YbAG crystals

Energy Technology Data Exchange (ETDEWEB)

Kaczkan, Marcin; Borowska, Maja [Institute of Microelectronics and Optoelectronics PW, Warsaw (Poland); Malinowski, Michal [Institute of Microelectronics and Optoelectronics PW, Warsaw (Poland); Institute of Electronic Materials Technology, Warsaw (Poland); Lukasiewicz, Tadeusz; Kolodziejak, Katarzyna [Institute of Electronic Materials Technology, Warsaw (Poland)

2009-07-15

Up-conversion phenomena leading to the red, green and violet emissions in erbium doped ytterbium-aluminum garnet (YbAG) are investigated. Absorption and emission spectra and luminescence dynamics from various excited states of YbAG:Er{sup 3+} were registered. The low temperature absorption spectra were used to determine Stark levels energies of Er{sup 3+} ion in the investigated host. Emissions from the high lying excited states {sup 2}G{sub 9/2}, {sup 4}S{sub 3/2} and {sup 4}F{sub 9/2} of Er{sup 3+} were characterized under pulsed multi-photon IR excitation in the region of wavelength corresponding to the strong {sup 2}F{sub 7/2} {yields} {sup 2}F{sub 5/2} absorption transition of Yb{sup 3+} ions. Using the rate equations formalism the dynamics of the observed emissions were modeled. From the comparison of the measured and calculated decays the energy transfer rates between Yb{sup 3+} and Er{sup 3+} ions were evaluated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

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....

Effect of Structural Stress on the Laser Quality of Highly Doped Yb:KY(WO4)2/KY(WO4)2 and Yb:KLu(WO4)2/KLu(WO4)2 Epitaxial Structures

International Nuclear Information System (INIS)

Carvajal, J.; Raghothamachar, B.; Silvestre, O.; Chen, H.; Pujol, M.; Petrov, V.; Dudley, M.; Aguilo, M.; Diaz, F.

2009-01-01

In this communication we demonstrate how the difference in laser performance of two highly doped (20 at %) epitaxial layers of Yb-doped KY(WO4)2 (KYW) grown on a KYW substrate and Yb-doped KLu(WO4)2 (KLuW) grown on a KLuW substrate, respectively, is related to the presence of structural stress in the epilayers, investigated by synchrotron white beam X-ray topography. From the results obtained, it is clear that the samples that show a larger amount of structural stress, Yb:KYW/KYW epitaxies, lead to lower efficiency in laser operation, giving a direct correlation between the existence and magnitude of such structural stress and the loss in efficiency of laser performance in such epitaxial layers which, from a spectroscopical point of view, are otherwise equivalent.

White phosphor using Yb3+-sensitized Er3+-and Tm3+-doped sol-gel derived lead-fluorosilicate transparent glass ceramic excited at 980 nm

Science.gov (United States)

Tavares, M. C. P.; da Costa, E. B.; Bueno, L. A.; Gouveia-Neto, A. S.

2018-01-01

Generation of primary colors and white light through frequency upconversion using sol-gel derived 80SiO2:20PbF2 vitroceramic phosphors doped with Er3+, Er3+/Yb3+, Tm3+/Yb3+, and Er3+/Tm3+/Yb3+ excited at 980 nm is demonstrated. For Er3+ and Er3+/Yb3+ doped samples emissions were obtained in the blue (410 nm), green (530, and 550 nm) and red (670 nm) regions, corresponding to the 2H9/2 → 4I15/2,2H11/2 → 4I15/2, 4S3/2 → 4I152 and 4F9/2 → 4I15/2 transitions of Er3+, respectively. The codoping with Yb3+ ions altered the spectral profile of most of the emissions compared to the single doped samples, resulting in changes in the emitted color, in addition to a significant increase in the emission intensity. In Tm3+/Yb3+ co-doped samples visible emissions in the blue (480 nm), and red (650 nm), corresponding to transitions 1G4 → 3H6 and 1G4 → 3F4 of Tm3+, respectively, were obtained. The emission intensity around 480 nm overcome the red emission, and luminescence showed a predominantly blue tone. White light with CIE-1931 coordinates (0.36; 0.34) was produced by homogeneously mixing up powders of heat treated at 400 °C co-doped samples 5.0Er3+/5.0Yb3+ and 0.5Tm3+/2.5Yb3+ in the mass ratio of 13%, and 87%, respectively. The measured emission spectrum for a sample resulting from the mixture showed a profile with very good agreement with the spectrum found from the superimposition of the spectra of the co-doped samples.

Controllable synthesis and crystal structure determined upconversion luminescence properties of Tm{sup 3+} (Er{sup 3+}) ions doped YbF{sub 3} and NaYbF{sub 4} crystals

Energy Technology Data Exchange (ETDEWEB)

Jiang, Tao [Institute of Photonics, Faculty of Science, Ningbo University, Ningbo 315211 (China); Qin, Weiping, E-mail: wpqin@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Zhou, Jun [Institute of Photonics, Faculty of Science, Ningbo University, Ningbo 315211 (China)

2014-04-01

Graphical abstract: - Highlights: • The synthesis of YbF{sub 3} and NaYbF{sub 4} crystals was successfully fulfilled by hydrothermal method. • The phase and morphology of products were adjusted by changing the hydrothermal conditions. • Relatively enhanced ultraviolet upconversion emissions were observed in YbF{sub 3} nanocrystals. • The crystalline phase impact on the upconversion luminescence was systematically studied. - Abstract: The synthesis of YbF{sub 3} and NaYbF{sub 4} crystals was successfully fulfilled by a facial hydrothermal method. The phase and morphology of the products were adjusted by changing the surfactant additive and fluorine source and tuning the pH value of the initial solution. The products with various morphologies range from octahedral nanoparticles, corn-like nanobundles, nanospheres, microrods, and hollow microprisms were prepared at different conditions. The growth mechanism of these products has been systematically studied. Impressively, relatively enhanced high order ultraviolet (UV) upconversion (UC) luminescence was observed in Tm{sup 3+} (Er{sup 3+}) ions doped YbF{sub 3} nanocrystals (NCs) compared with NaYbF{sub 4} microcrystals under the excitation of 980 nm infrared laser. The investigation results reveal that the crystal symmetry of matrix has significant effect on the spectra and lifetimes of the doping lanthanide ions. The simply synthesized water soluble YbF{sub 3} NCs with efficient UV UC luminescence may find potential application in biochemistry.

Status of fiber lasers study of on ytterbium doped fiber laser and laser spectroscopy of doped fibers

International Nuclear Information System (INIS)

Magne, S.

1994-07-01

This work shows all the advantages and drawbacks of the rare-earth-doped fiber lasers and fiber optical amplifiers, pointing out their potential use for instrumentation and optical fiber sensor technology. The theory of light propagation in optical fibers is presented in order to understand the manufacturing methods. A comparative study of preform surface and concentration analysis is performed. The gain behaviour is also thoroughly examined. A synthesis of all technological parameters of the fiber laser is then established and all technologies of the constituting integrated components are reviewed and compared. The experimental techniques mainly involve: site selective excitation tunability, cooperative luminescence, oxidation state changes induced by gamma irradiation, ytterbium-doped mono-mode continuous wave tunable three-level fiber laser. (TEC). 622 refs., 176 figs

Multifunctional hydroxyapatite/Na(Y/Gd)F4:Yb3+,Er3+ composite fibers for drug delivery and dual modal imaging.

Science.gov (United States)

Liu, Min; Liu, Hui; Sun, Shufen; Li, Xuejiao; Zhou, Yanmin; Hou, Zhiyao; Lin, Jun

2014-02-04

Porous hydroxyapatite (HAp) composite fibers functionalized with up-conversion (UC) luminescent and magnetic Na(Y/Gd)F4:Yb(3+),Er(3+) nanocrystals (NCs) have been fabricated via electrospinning. After transferring hydrophobic oleic acid-capped Na(Y/Gd)F4:Yb(3+),Er(3+) NCs into aqueous solution, these water-dispersible NCs were dispersed into precursor electrospun solution containing CTAB. Na(Y/Gd)F4:Yb(3+),Er(3+)@HAp composite fibers were fabricated by the high temperature treatment of the electrospun Na(Y/Gd)F4:Yb(3+),Er(3+) NCs decorated precursor fibers. The biocompatibility test on MC 3T3-E1 cells using MTT assay shows that the HAp composite fibers have negligible cytotoxity, which reveals the HAp composite fibers could be a drug carrier for drug delivery. Because the contrast brightening is enhanced at increased concentrations of Gd(3+), the HAp composite fibers can serve as T1 magnetic resonance imaging contrast agents. In addition, the composites uptaken by MC 3T3-E1 cells present the UC luminescent emission of Er(3+) under the excitation of a 980 nm near-infrared laser. The above findings reveal Na(Y/Gd)F4:Yb(3+),Er(3+)@HAp composite fibers have potential applications in drug storage/release and magnetic resonance/UC luminescence imaging.

Enhancing photovoltaic performance of dye-sensitized solar cell by rare-earth doped oxide of Lu2O3:(Tm3+, Yb3+)

International Nuclear Information System (INIS)

Li Qingbei; Lin Jianming; Wu Jihuai; Lan Zhang; Wang Yue; Peng Fuguo; Huang Miaoliang

2011-01-01

Highlights: → Tm 3+ /Yb 3+ codoped oxide is introduced into the TiO 2 film in dye-sensitized solar cell. → The RE improves light harvest via conversion luminescence and increases photocurrent. → The RE elevates the oxide film energy level and increases the cell photovoltage. → The cell efficiency is increased by 11.1% compared to the cell lacking of RE doping. - Abstract: In order to increase of the photocurrent, photovoltage and energy conversion efficiency of dye-sensitized solar cell (DSSC), rare-earth doped oxide of Lu 2 O 3 :(Tm 3+ , Yb 3+ ) is prepared and introduced into the TiO 2 film in the DSSC. As a luminescence medium, Lu 2 O 3 :(Tm 3+ , Yb 3+ ) improves incident light harvest via a conversion luminescence process and increases photocurrent; as a p-type dopant, the rare-earth ions elevate the energy level of the oxide film and increase the photovoltage. Under a simulated solar light irradiation of 100 mW cm -2 , the light-to-electric energy conversion efficiency of the DSSC with Lu 2 O 3 :(Tm 3+ , Yb 3+ ) doping reaches 6.63%, which is increased by 11.1% compared to the DSSC without Lu 2 O 3 :(Tm 3+ , Yb 3+ ) doping.

Bismuth silicate glass: A new choice for 2 μm fiber lasers

Science.gov (United States)

Ding, Jia; Zhao, Guoying; Tian, Ying; Chen, Wei; Hu, Lili

2012-11-01

We report on a new Yb3+/Tm3+/Ho3+ co-doped bismuth silicate glass: SiO2-Bi2O3-R2O (R = Li, Na, K) for 2 μm fiber lasers. Bi2O3 was introduced into alkali silicate glass to optimize 2 μm emission properties. Physical, chemical and spectroscopic properties of Yb3+/Tm3+/Ho3+ co-doped SiO2-Bi2O3-R2O (SBR) glass were presented. The Yb3+/Tm3+/Ho3+ co-doped SBR glass shows excellent thermal stability (ΔT = 162 °C), an intense 2.0 μm emission pumped by 980 nm LD with a lifetime of 1.33 ms and width of 168 nm, large maximum emission cross section of Ho3+ (5.3 × 10-21 cm2), thus large σemτ product (7.049 × 10-24 cm2 s), which suggest its application in 2 μm fiber lasers.

Theoretical modelling of dual-wavelength pumped Yb3+–Tm3+ co-doped silica fibre laser

International Nuclear Information System (INIS)

Fu, Yuqing; Chen, Jianguo

2010-01-01

Numerical simulations have, for the first time to our knowledge, been carried out to characterize the Yb 3+ –Tm 3+ co-doped silica fibre laser (YTFL), defined by a fibre grating and an end mirror, by using the rate equations, which take into consideration both the energy transfer processes from Yb 3+ to Tm 3+ ions and the cross-relaxation processes among different Tm 3+ ions. A dual-wavelength pumping scheme with one at 805 nm and the other at 975 nm is used to pump the YTFL. We have investigated the wavelength-dependent output power of the YTFL, from 1750 to 2200 nm, which takes its maximum output power at ∼ 1800 nm. The effect of the cross-relaxation processes in the Tm 3+ -doped silica fibre laser has been studied. The results indicate that these processes are beneficial to the laser and should be considered in the theoretical modelling. The influence of the Yb 3+ concentration on the characteristics of the YTFL has also been analysed and the results show that Yb 3+ dopants can improve the output power and slope efficiency of the laser

Enhanced frequency upconversion study in Er3+/Yb3+ doped/codoped TWTi glasses

Science.gov (United States)

Azam, Mohd; Rai, Vineet Kumar

2018-04-01

Er3+/Yb3+ doped/codoped TeO2-WO3-TiO2 (TWTi) glasses have been prepared by using the melt-quenching technique. The upconversion (UC) emission spectra of the developed glasses have been recorded upon 980 nm laser excitation. Three intense UC emission bands have been observed within the green and red region centered at ˜532 nm, ˜553 nm and ˜669 nm corresponding to the 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions respectively in the singly Er3+ doped glass. On introducing Yb3+ ions in the singly Er3+ doped glass, an enhancement of about ˜ 12 times and ˜50 times in the green and red bands respectively have been observed even at low pump power ˜ 364 mW followed by two photon absorption process. Colour tunability from yellowish green to pure green colour region has been observed on varying the pump power. The prepared glass can be used to produce NIR to green upconverter and colour tunable display devices.

Efficient pump module coupling >1kW from a compact detachable fiber

Science.gov (United States)

Dogan, M.; Chin, R. H.; Fulghum, S.; Jacob, J. H.; Chin, A. K.

2018-02-01

In the most developed fiber amplifiers, optical pump power is introduced into the 400μm-diameter, 0.46NA first cladding of the double-clad, Yb-doped, gain fiber, using a (6+1):1 multi-mode fiber combiner. For this configuration, the core diameter and numerical aperture of the pump delivery fibers have maximum values of 225μm and 0.22, respectively. This paper presents the first fiber-coupled laser-diode pump module emitting more than 1kW of claddingmode- stripped power from a detachable 225μm, 0.22NA delivery fiber at 976nm. The electrical-to-optical power conversion efficiency at 1kW is 50%. The FWHM spectral width at 1kW output is 4nm and has an excellent overlap with the narrow absorption spectrum of ytterbium in glass. Six of these pump modules attached to a (6+1):1 multimode combiner enable a 5-6kW, single-mode, Yb-doped fiber amplifier.

Synthesis and characterization of (Ba,Yb doped ceria nanopowders

Directory of Open Access Journals (Sweden)

Branko Matović

2011-06-01

Full Text Available Nanometric size (Ba, Yb doped ceria powders with fluorite-type structure were obtained by applying selfpropagating room temperature methods. Tailored composition was: Ce0.95−xBa0.05YbxO2−δ with fixed amount of Ba − 0.05 and varying Yb content “x” from 0.05 to 0.2. Powder properties such as crystallite and particle size and lattice parameters have been studied. Röntgen diffraction analyses (XRD were used to characterize the samples at room temperature. Also, high temperature treatment (up to 1550°C was used to follow stability of solid solutions. The mean diameters of the nanocrystals are determined from the full width at half maxima (FWHM of the XRD peaks. It was found that average diameter of crystallites is less than 3 nm. WilliamsonHall plots were used to separate the effect of the size and strain in the nanocrystals.

Upconversion improvement in KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} nanoparticles by doping Al{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Zhou, Haifang [Fuzhou University, School of Physics and Information Engineering, and Institute of Micro-Nano Devices and Solar Cells, Fuzhou (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou, Jiangsu (China); Wang, Xiechun; Lai, Yunfeng; Cheng, Shuying; Zheng, Qiao; Yu, Jinlin [Fuzhou University, School of Physics and Information Engineering, and Institute of Micro-Nano Devices and Solar Cells, Fuzhou (China)

2017-10-15

Rare-earth ion-doped upconversion (UC) materials show great potential applications in optical and optoelectronic devices due to their novel optical properties. In this work, hexagonal KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} nanoparticles (NPs) were successfully synthesized by a hydrothermal method, and remarkably enhanced upconversion luminescence in green and red emission bands in KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} NPs has been achieved by doping Al{sup 3+} ions under 980 nm excitation. Compared to the aluminum-free KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} NPs sample, the UC fluorescence intensities of the green and red emissions of NPs doped with 10 at.% Al{sup 3+} ions were significantly enhanced by 5.9 and 7.3 times, respectively. Longer lifetimes of the doped samples were observed for the {sup 4}S{sub 3/2} state and {sup 4}F{sub 9/2} state. The underlying reason for the UC enhancement by doping Al{sup 3+} ions was mainly ascribed to distortion of the local symmetry around Er{sup 3+} ions and adsorption reduction of organic ligands on the surface of NPs. In addition, the influence of doping Al{sup 3+} ions on the structure and morphology of the NPs samples was also discussed. (orig.)

Fluorescence properties of Yb3+-Er3+ co-doped phosphate glasses containing silver nanoparticles

Science.gov (United States)

Martínez Gámez, Ma A.; Vallejo H, Miguel A.; Kiryanov, A. V.; Licea-Jiménez, L.; Lucio M, J. L.; Pérez-García, S. A.

2018-04-01

Er3+-Yb3+ co-doped phosphate glasses containing silver nitrate (SN), were fabricated. Transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) analyses were used to evidence the nucleation and presence of silver nanoparticles (SNP). The basic parameters of the glasses were inspected by means of absorption and fluorescence spectra, and fluorescence lifetimes under excitation at 916 nm (in-band of Yb3+), and at 406 nm (in-band of surface plasmon resonance given by the presence of SNP). The spectra as well as estimates for the basic parameters defining the lasing/amplifying potential of the glasses were studied as a function of SN concentration. The experimental results indicate that by increasing the SN content an enhancement of Er3+/Yb3+ fluorescence takes place.

Spectroscopic investigation of zinc tellurite glasses doped with Yb3 + and Er3 + ions

Science.gov (United States)

Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

2016-08-01

This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80 - x - y) TeO2 + (0.20) ZnO + xEr2O3 + yYb2O3 (x = 0, y = 0; x = 0.004, y = 0; x = 0, y = 0.05 and x = 0.004, y = 0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er3 + glasses as erbium doped fiber amplifiers at 1.55 μm in infrared emission region.

Microwave hydrothermal synthesis and upconversion properties of Yb3+/Er3+ doped YVO4 nanoparticles.

Science.gov (United States)

Kshetri, Yuwaraj K; Regmi, Chhabilal; Kim, Hak-Soo; Lee, Soo Wohn; Kim, Tae-Ho

2018-05-18

Yb 3+ and Er 3+ doped YVO 4 (Yb 3+ /Er 3+ :YVO 4 ) nanoparticles with highly efficient near-infrared to visible upconversion properties have been synthesized by microwave hydrothermal process. Uniform-sized Yb 3+ /Er 3+ :YVO 4 nanoparticles were synthesized within 1 h at 140 °C which is relatively faster than the conventional hydrothermal process. Under 980 nm laser excitation, strong green and less strong red emissions are observed which are attributed to 2 H 11/2 , 4 S 3/2 to 4 I 15/2 and 4 F 9/2 to 4 I 15/2 transitions of Er 3+ respectively. The emission intensity is found to depend strongly on the concentration of Yb 3+ . The quadratic dependence of upconversion intensity on the excitation power indicates that the upconversion process is governed by two-photon absorption process.

Microwave hydrothermal synthesis and upconversion properties of Yb3+/Er3+ doped YVO4 nanoparticles

Science.gov (United States)

Kshetri, Yuwaraj K.; Regmi, Chhabilal; Kim, Hak-Soo; Wohn Lee, Soo; Kim, Tae-Ho

2018-05-01

Yb3+ and Er3+ doped YVO4 (Yb3+/Er3+:YVO4) nanoparticles with highly efficient near-infrared to visible upconversion properties have been synthesized by microwave hydrothermal process. Uniform-sized Yb3+/Er3+:YVO4 nanoparticles were synthesized within 1 h at 140 °C which is relatively faster than the conventional hydrothermal process. Under 980 nm laser excitation, strong green and less strong red emissions are observed which are attributed to 2H11/2, 4S3/2 to 4I15/2 and 4F9/2 to 4I15/2 transitions of Er3+ respectively. The emission intensity is found to depend strongly on the concentration of Yb3+. The quadratic dependence of upconversion intensity on the excitation power indicates that the upconversion process is governed by two-photon absorption process.

Ytterbium doped silicon clusters YbSi{sub n} (n = 4–10) and their anions: Structures, thermochemistry, and electron affinities

Energy Technology Data Exchange (ETDEWEB)

Xie, Xiaohong [School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot 010051 (China); Hao, Dongsheng [School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot 010051 (China); School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051 (China); Yang, Jucai, E-mail: yangjc@imut.edu.cn [School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot 010051 (China); School of Energy and Power Engineering, Inner Mongolia University of Technology, Hohhot 010051 (China)

2015-11-05

Highlights: • The ground-state structure of YbSi{sub n} and its anion is substitutional structure. • The four DFT AEAs are in excellent agreement with the experimental data. • Theoretical AEA of 2.33 eV of YbSi{sub 9} is more reasonable than the experimental 2.60 eV. • Hardness analysis reveals that doping Yb to Si{sub n} raises photochemical sensitivity. • Relative stabilities of YbSi{sub n} and their anions are examined. - Abstract: The structures, electron affinities, dissociation energies, hardness, and dipole moments of YbSi{sub n} (n = 4–10) and their anions were examined using B3LYP, TPSSh, PBE and wB97X methods. The lowest-energy structures can be regarded as replacing a Si of the ground-state structure of Si{sub n+1} with a Yb atom. The theoretical adiabatic electron affinities (AEAs) of YbSi{sub n} are in excellent agreement with experimental data. The average absolute errors from experiment are by 0.08, 0.07, 0.05 and 0.08 eV at the B3LYP, the TPSSh, the PBE and the wB97X levels, respectively. Theoretical AEAs of 2.33 ± 0.05 eV for YbSi{sub 9} are more reliable than the experimental value of 2.60 ± 0.05 eV. The hardness analysis reveals that doping Yb atom to Si{sub n} (n = 4–10) clusters raises the photochemical sensitivity. The dissociation energies of Yb atom from YbSi{sub n} and their anions were calculated to examine relative stabilities.

Oxygen plasma effects on zero resistance behavior of Yb,Er-doped YBCO (123) based superconductors

Energy Technology Data Exchange (ETDEWEB)

Schaefer, Helmut; Rathmann, Dirk [Department of Physics, Biophysics, and Photosynthesis, Freie Universitaet Berlin (Germany); Banko, Franziska; Steinhart, Martin [Physical Chemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany); Nordmann, Joerg; Voss, Benjamin [Inorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany); Walder, Lorenz [Organic Chemistry, Molecular Electrochemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany)

2014-08-15

Rare-earth doped YBa{sub 2}Cu{sub 3}O{sub 7-δ} samples were synthesized starting from the corresponding oxides Y{sub 2}O{sub 3}, Yb{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, CuO as well as Ba(OH){sub 2} by heating to 950 C under air. The doping concentrations were adjusted to 15 % Yb, 7 % Er and 20 % Yb, 15 % Er, respectively, with respect to the yttrium content. The orthogonal phased (123) YBCO ceramics were exposed to an oxygen plasma for 140 and 380 min. Zero resistance temperature (T{sub c,0}) was determined by measuring the resistivity-temperature dependence using a classical four point measurement approach. Under optimal conditions with respect to the material composition and the oxygen treatment an unusual high zero resistance temperature of 97.5 K (T{sub c,onset} ∼ 101 K) was achieved. This represents an increase of T{sub c,0} by 7.5 K. The oxygen treatment could not be monitored by IR spectroscopy, X-ray fluorescence spectroscopy, and X-ray powder diffraction. The results showed good reproducibility. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Effects of adding metals to MoS2 in a ytterbium doped Q-switched fiber laser

Science.gov (United States)

Khaleque, Abdul; Liu, Liming

2018-03-01

Molybdenum disulfide (MoS2) is widely used in lubricants, metallic alloys and in electronic and optical components. It is also used as saturable absorbers (SAs) in lasers (e.g. fiber lasers): a simple deposition of MoS2 on the fiber end can create a saturable absorber without the necessity of extensive alignment of the optical beam. In this article, we study the effects of adding different metals (Cr, Au, and Al) to MoS2 in a ytterbium (Yb)-doped Q-switched fiber laser. Experimental results show that the addition of a thin layer of gold and aluminium can reduce pulse durations to about 5.8 μs and 8.5 μs, respectively, compared with pure MoS2 with pulse duration of 12 μs. Experimental analysis of the combined metal and MoS2 based composite SAs can be useful in fiber laser applications where it may also find applications in medical, three dimensional (3D) active imaging and dental applications.

Long distance transmission through distributed erbium-doped fibers

DEFF Research Database (Denmark)

Rottwitt, Karsten; Povlsen, Jørn Hedegaard; Bjarklev, Anders Overgaard

1993-01-01

High bit rate, all-optical long-distance transmission could be created through the combined use of loss-compensating gain in erbium-doped fibers and solitons. A detailed analysis of the distributed erbium-doped fiber, including the spectral-gain dependency, is combined with an optimum design...... of the transmission fiber and general bit-error-rate calculations. Changes in wavenumber, group velocity, and fiber dispersion due to erbium doping in a single-mode fiber are evaluated, and a reduction in bit-error rates due to the erbium spectral-gain profile is shown. Transmission through distributed erbium......-doped fiber with 100-km separation between each pump-power station is shown, with a total bit-rate distance product of 55 Gb/s · Mm...

Mo0.5W0.5S2 for Q-switched pulse generation in ytterbium-doped fiber laser

Science.gov (United States)

Wang, Junli; Chen, Lei; Dou, Chenxi; Yan, Haiting; Meng, Lingjie; Wei, Zhiyi

2018-06-01

In this work, we fabricate the Mo0.5W0.5S2 by microwave-assisted solvothermal method, and report the Q-switched Yb-doped fiber lasers (YDFL) using Mo0.5W0.5S2 polymer film and tapered fiber as the saturable absorbers (SAs). The modulation depth and saturable intensity of the film SA are 5.63% and 6.82 MW cm‑2. The shortest pulse duration and the maximum single pulse energy are 1.22 μs and 148.8 nJ for the film SA, 1.46 μs and 339 nJ for the fiber-taper SA. To the best of our knowledge, this is the first report on the Q-switched YDFL using Mo0.5W0.5S2 SAs.

Over 19 W Single-Mode 1545 nm Er,Yb Codoped All-Fiber Laser

Directory of Open Access Journals (Sweden)

Jiadong Wu

2017-01-01

Full Text Available We report a high-power cladding-pumped Er,Yb codoped all-fiber laser with truly single transverse mode output. The fiber laser is designed to operate at 1545 nm by the use of a pair of fiber Bragg gratings (FBGs to lock and narrow the output spectrum, which can be very useful in generating the eye-safe ~1650 nm laser emission through the Stimulated Raman Scattering (SRS in silica fibers that is of interest in many applications. Two pieces of standard single-mode fibers are inserted into the laser cavity and output port to guarantee the truly single-mode output as well as good compatibility with other standard fiber components. We have obtained a maximum output power of 19.2 W at 1544.68 nm with a FWHM spectral width of 0.08 nm, corresponding to an average overall slope efficiency of 31.9% with respect to the launched pump power. This is, to the best of our knowledge, the highest output power reported from simple all-fiber single-mode Er,Yb codoped laser oscillator architecture.

Rare-earth-doped fluorozirconate fiber lasers

International Nuclear Information System (INIS)

Brierly, M.C.; France, P.W.; Moore, M.W.; Davey, S.T.

1988-01-01

Rare-earth-doped fiber lasers fabricated using silica-based fibers are rapidly becoming an established technology. Simultaneously, in the search for lower losses to achieve longer repeaterless communications links, another fiber technology based on fluorozirconate glasses is emerging. Fluorozirconate glass systems are known to be suitable laser hosts, and the authors have already reported Nd-doped fiber lasers using this technology. Recently the authors have used a 0.5-m length of 44-μm core fluorozirconate fiber doped with 1000 ppm of Nd 3+ ions in a longitudinally pumped Fabry-Perot cavity with a 90% output coupler. They observed lasing at 1.05 μm with a threshold of 33-mW launched power at 514 nm and a slope efficiency of 16.8%. The authors attribute this improvement to the higher dopant concentration, better fiber to mirror coupling, and more optimum output coupler reflectivity. In addition the same fiber used with two high-reflector mirrors at 1.35μm produced lasing at 1.35μm with a threshold of 60-mW launched power

New configurations for short-pulses high power solid-state lasers: conception and realization of highly doped waveguide amplifiers/lasers grown by liquid phase epitaxy and demonstration of Y2SiO5: Yb and Lu2SiO5: Yb femtosecond lasers

International Nuclear Information System (INIS)

Thibault, F.

2006-04-01

Yb-doped yttrium and lutetium ortho-silicates, Y 2 SiO 5 :Yb and Lu 2 SiO 5 :Yb respectively, exhibit spectroscopic properties favorable to an efficient laser operation in both high power cw and femtosecond regime. Their first diode-pumped femtosecond operation demonstration lead to exceptional performances in terms of output power and efficiency. In order to realize compact and efficient solid-state laser devices using those materials, we chose a configuration with an Yb-doped medium planar waveguide geometry, grown by liquid phase epitaxy, face-pumped by a single laser diode bar. The growth of highly doped Y 2 SiO 5 :Yb layers, within a large range of compositions and thicknesses, was demonstrated. The refractive index increase due to the substitution of the various dopants is analyzed. The layers spectroscopic properties are similar to the bulk ones, with an noticeably higher crystalline quality. The Yb ion lifetime evolution with respect to its doping shows up a particularly low decrease, proof of a low concentration of extrinsic quenching centers. The covered YSO:24%Yb waveguides exhibit lower than 0.3 dB/cm propagation losses, and provided up to 2.9 dB/cm net amplification at 1082 nm with a single mode output. The realization of the first diode-pumped monolithic cw waveguide lasers was also demonstrated. For a 4% output coupler, they provided up to 340 mW at 1082 nm with a 14% slope efficiency. (author)

Synthesis of Er and Er : Yb doped sol–gel derived silica glass and ...

Indian Academy of Sciences (India)

Unknown

Materials Science Centre, †Central Research Facility, Optical Fibre Unit, Indian Institute of Technology,. Kharagpur 721 302, India. MS received 1 March 2004; revised 4 July 2004. Abstract. Er3+ and Er3+ : Yb3+ doped optical quality, crack and bubble free glasses for possible use in mak- ing laser material have been ...

Direct comparison of Yb3+-doped LiYF4 and LiLuF4 as laser media at room-temperature

International Nuclear Information System (INIS)

Yin, J G; Hang, Y; He, X M; Zhang, L H; Zhao, C C; Gong, J; Zhang, P X

2012-01-01

We present an extensive comparative analysis on the growth, the spectroscopic features, and the laser performances of room temperature Yb(5%):LiYF 4 (YLF) and Yb(5%):LiLuF 4 (LLF) crystals in the same conditions. The gain cross section, fluorescence lifetimes, laser thresholds and laser slope efficiencies are compared for the first time. It appears that Yb 3+ -doped LLF crystal might be more promising for diode-pumped high power laser operation

Tunable Single Frequency 1.55 Micron Fiber Laser, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a widely tunable, narrow linewidth, single frequency fiber laser by developing an innovative Er/Yb-co-doped...

Highly-stable monolithic femtosecond Yb-fiber laser system based on photonic crystal fibers

DEFF Research Database (Denmark)

Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

2010-01-01

in the oscillator cavity for dispersion balancing and nonlinear optical limiting, and another one is used for low nonlinearity final pulse recompression. The chirped-pulse amplification and recompression of the 232-fs, 45-pJ/pulse oscillator output yields a final direct fiber-end delivery of 7.3-nJ energy pulses......A self-starting, passively stabilized, monolithic all polarizationmaintaining femtosecond Yb-fiber master oscillator / power amplifier with very high operational and environmental stability is demonstrated. The system is based on the use of two different photonic crystal fibers. One is used...... of around 297 fs duration. Our laser shows exceptional stability. No Q-switched modelocking events were detected during 4-days long observation. An average fluctuation of only 7.85 · 10−4 over the mean output power was determined as a result of more than 6-hours long measurement. The laser is stable towards...

Spectroscopic investigations of OH- influence on near-infrared fluorescence quenching of Yb3+/Tm3+ co-doped sodium-metaphosphate glasses

International Nuclear Information System (INIS)

Terra, I.A.A.; Camargo, A.S.S. de; Terrile, M.C.; Nunes, L.A.O.

2008-01-01

Energy transfer processes were studied in two sets of Yb 3+ and Tm 3+ co-doped sodium-metaphosphate glasses, prepared in air and nitrogen atmospheres. Using Foerster, Dexter, and Miyakawa theoretical models, the energy transfer parameters were calculated. The main ion-ion energy transfer processes analyzed were energy migration among Yb 3+ ions, cross-relaxations between Yb 3+ and Tm 3+ ions, and interactions with OH - radicals. The results indicated that Yb→Tm energy transfer favors 1.8 μm emissions, and there is no evidence of concentration quenching up to 2% Tm 2 O 3 doping. As expected, samples prepared in nitrogen atmosphere present higher fluorescence quantum efficiency than those prepared in air, and this feature is specially noted in the near-infrared region, where the interaction with the OH - radicals is more pronounced

Energy transfer and downconversion near-infrared material of Tb{sup 3+} and Yb{sup 3+} doped Ca{sub 5}(BO{sub 3}){sub 3}F

Energy Technology Data Exchange (ETDEWEB)

Hou, Dejian; Li, Jin-Yan [School of Metallurgy and Chemistry Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China); Lin, Huihong, E-mail: linhh@hstc.edu.cn [School of Chemical and Environmental Engineering, Hanshan Normal University, Chaozhou 521041, Guangdong (China); Zhang, Jingxiang [School of Chemical and Environmental Engineering, Hanshan Normal University, Chaozhou 521041, Guangdong (China)

2016-11-01

Yb{sup 3+} and Tb{sup 3+} singly doped and Tb{sup 3+}–Yb{sup 3+} co-doped Ca{sub 5}(BO{sub 3}){sub 3}F phosphors were prepared by a solid state reaction method. The luminescence emission and excitation spectra as well as the luminescence decay curves were investigated. The emission bands of Yb{sup 3+} ion are located around 1000 nm, matching well with the optimal response of Si-based solar cells. Tb{sup 3+} can be a sensitizer for Yb{sup 3+} in the host. The energy transfer from Tb{sup 3+} to Yb{sup 3+} was investigated, the energy transfer mechanism was proposed as cooperative energy transfer. Tb{sup 3+} concentration dependent quantum efficiency was calculated and the maximum efficiency approached 115.5%.

Near-infrared optical properties of Yb3+-doped silicate glass waveguides prepared by double-energy proton implantation

Science.gov (United States)

Shen, Xiao-Liang; Zhu, Qi-Feng; Zheng, Rui-Lin; Lv, Peng; Guo, Hai-Tao; Liu, Chun-Xiao

2018-03-01

We report on the preparation and properties of an optical planar waveguide structure operating at 1539 nm in the Yb3+-doped silicate glass. The waveguide was formed by using (470 + 500) keV proton implantation at fluences of (1.0 + 2.0) × 1016 ions/cm2. The waveguiding characteristics including the guided-mode spectrum and the near-field image were investigated by the m-line technique and the finite-difference beam propagation method. The energy distribution for implanted protons and the refractive index profile for the proton-implanted waveguide were simulated by the stopping and range of ions in matter and the reflectivity calculation method. The proton-implanted Yb3+-doped silicate glass waveguide is a candidate for optoelectronic elements in the near-infrared region.

Spectroscopic investigation of zinc tellurite glasses doped with Yb(3+) and Er(3+) ions.

Science.gov (United States)

Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

2016-08-05

This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80-x-y) TeO2+(0.20) ZnO+xEr2O3+yYb2O3 (x=0, y=0; x=0.004, y=0; x=0, y=0.05 and x=0.004, y=0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er(3+) glasses as erbium doped fiber amplifiers at 1.55μm in infrared emission region. Copyright © 2016 Elsevier B.V. All rights reserved.

Yb and Er co-doped Y2Ce2O7 nanoparticles: synthesis and ...

Indian Academy of Sciences (India)

much attention due to their potential applications in display .... Figure 1. XRD patterns of Yb3+ and Er3+ co-doped Y2Ce2O7 nanoparticles prepared for 4 h at different sintering .... vels relax to the ground 4I15/2 level (You et al 2012). For.

2 µm high-power dissipative soliton resonance in a compact σ-shaped Tm-doped double-clad fiber laser

Science.gov (United States)

Du, Tuanjie; Li, Weiwei; Ruan, Qiujun; Wang, Kaijie; Chen, Nan; Luo, Zhengqian

2018-05-01

We report direct generation of a high-power, large-energy dissipative soliton resonance (DSR) in a 2 µm Tm-doped double-clad fiber laser. A compact σ-shaped cavity is formed by a fiber Bragg grating and a 10/90 fiber loop mirror (FLM). The 10/90 FLM is not only used as an output mirror, but also acts as a nonlinear optical loop mirror for initiating mode locking. The mode-locked laser can deliver high-power, nanosecond DSR pulses at 2005.9 nm. We further perform a comparison study of the effect of the FLM’s loop length on the mode-locking threshold, peak power, pulse energy, and optical spectrum of the DSR pulses. We achieve a maximum average output power as high as 1.4 W, a maximum pulse energy of 353 nJ, and a maximum peak power of 84 W. This is, to the best of our knowledge, the highest power for 2 µm DSR pulses obtained in a mode-locked fiber laser.

Modifying the size and uniformity of upconversion Yb/Er:NaGdF4 nanocrystals through alkaline-earth doping.

Science.gov (United States)

Lei, Lei; Chen, Daqin; Huang, Ping; Xu, Ju; Zhang, Rui; Wang, Yuansheng

2013-11-21

NaGdF4 is regarded as an ideal upconversion (UC) host material for lanthanide (Ln(3+)) activators because of its unique crystal structure, high Ln(3+) solubility, low phonon energy and high photochemical stability, and Ln(3+)-doped NaGdF4 UC nanocrystals (NCs) have been widely investigated as bio-imaging and magnetic resonance imaging agents recently. To realize their practical applications, controlling the size and uniformity of the monodisperse Ln(3+)-doped NaGdF4 UC NCs is highly desired. Unlike the routine routes by finely adjusting the multiple experimental parameters, herein we provide a facile and straightforward strategy to modify the size and uniformity of NaGdF4 NCs via alkaline-earth doping for the first time. With the increase of alkaline-earth doping content, the size of NaGdF4 NCs increases gradually, while the size-uniformity is still retained. We attribute this "focusing" of size distribution to the diffusion controlled growth of NaGdF4 NCs induced by alkaline-earth doping. Importantly, adopting the Ca(2+)-doped Yb/Er:NaGdF4 NCs as cores, the complete Ca/Yb/Er:NaGdF4@NaYF4 core-shell particles with excellent size-uniformity can be easily achieved. However, when taking the Yb/Er:NaGdF4 NCs without Ca(2+) doping as cores, they could not be perfectly covered by NaYF4 shells, and the obtained products are non-uniform in size. As a result, the UC emission intensity of the complete core-shell NCs increases by about 30 times in comparison with that of the cores, owing to the effective surface passivation of the Ca(2+)-doped cores and therefore protection of Er(3+) in the cores from the non-radiative decay caused by surface defects, whereas the UC intensity of the incomplete core-shell NCs is enhanced by only 3 times.

Improved terbium-doped, lithium-loaded glass scintillator fibers

International Nuclear Information System (INIS)

Spector, G.B.; McCollum, T.; Spowart, A.R.

1993-01-01

An improved terbium-doped, 6 Li-loaded glass scintillator has been drawn into fibers. Tests indicate that the neutron detection response of the fibers is superior to the response with fibers drawn from the original terbium-doped glass. The new fibers offer less attenuation (1/e length of ∝40 cm) and improved gamma ray/neutron discrimination. The improved fibers will be incorporated in a scintillator fiber optic long counter for neutron detection. (orig.)

Upconversion and pump saturation mechanisms in Er3+/Yb3+ co-doped Y2Ti2O7 nanocrystals

International Nuclear Information System (INIS)

Wang, Fengxiao; Song, Feng; Zhang, Gong; Han, Yingdong; Li, Qiong; Tian, Jianguo; Ming, Chengguo

2014-01-01

The Er 3+ /Yb 3+ co-doped Y 2 Ti 2 O 7 nanocrystals were synthesized by the sol–gel method. X-ray diffraction, transmission electronic microscopy, and photoluminescence spectra were measured to verify the Y 2 Ti 2 O 7 nanocrystalline produced in the sample annealed at 800 °C. The anomalous slopes of the fitted line in the log-log plots for upconversion emissions and the pump-saturation effect of near-infrared emission were observed in the nanocrystalline samples. A theoretical model of practical Er 3+ /Yb 3+ co-doped system based on the rate equations were put forward and explained the experimental phenomena well

Tm3+/Yb3+ co-doped tellurite glass with silver nanoparticles for 1.85 μm band laser material

Science.gov (United States)

Huang, Bo; Zhou, Yaxun; Cheng, Pan; Zhou, Zizhong; Li, Jun; Jin, Wei

2016-10-01

Tm3+/Yb3+ co-doped tellurite glasses with different silver nanoparticles (Ag NPs) concentrations were prepared using the conventional melt-quenching technique and characterized by the UV/Vis/NIR absorption spectra, 1.85 μm band fluorescence emission spectra, transmission electron microscopy (TEM) images, differential scanning calorimeter (DSC) curves and X-ray diffraction (XRD) patterns to investigate the effects of Ag NPs on the 1.85 μm band spectroscopic properties of Tm3+ ions, thermal stability and structural nature of glass hosts. Under the excitation of 980 nm laser diode (LD), the 1.85 μm band fluorescence emission of Tm3+ ions enhances significantly in the presence of Ag NPs with average diameter of ∼8 nm and local surface Plasmon resonance (LSPR) band of ∼590 nm, which is mainly attributed to the increased local electric field induced by Ag NPs at the proximity of doped rare-earth ions on the basis of energy transfer from Yb3+ to Tm3+ ions. An improvement by about 110% of fluorescence intensity is observed in the Tm3+/Yb3+ co-doped tellurite glass containing 0.5 mol% amount of AgNO3 while the prepared glass samples possess good thermal stability and amorphous structural nature. Meanwhile, the Judd-Ofelt intensity parameters Ωt (t = 2,4,6), spontaneous radiative transition probabilities, fluorescence branching ratios and radiative lifetimes of relevant excited levels of Tm3+ ions were determined based on the Judd-Ofelt theory to reveal the enhanced effects of Ag NPs on the 1.85 μm band spectroscopic properties, and the energy transfer micro-parameters and phonon contribution ratios were calculated based on the non-resonant energy transfer theory to elucidate the energy transfer mechanism between Yb3+ and Tm3+ ions. The present results indicate that the prepared Tm3+/Yb3+ co-doped tellurite glass with an appropriate amount of Ag NPs is a promising lasing media applied for 1.85 μm band solid-state lasers and amplifiers.

Double nanosecond pulses generation in ytterbium fiber laser

Energy Technology Data Exchange (ETDEWEB)

Veiko, V. P.; Samokhvalov, A. A., E-mail: samokhvalov.itmo@gmail.com; Yakovlev, E. B.; Zhitenev, I. Yu.; Kliushin, A. N. [Saint-Petersburg State University of Information Technologies, Mechanics and Optics, Kronverksky Pr. 49, Saint Petersburg (Russian Federation); Lednev, V. N. [Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str., 38, Moscow (Russian Federation); National University of Science and Technology MISiS, Leninskyave., 4, Moscow (Russian Federation); Pershin, S. M. [Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str., 38, Moscow (Russian Federation)

2016-06-15

Double pulse generation mode for nanosecond ytterbium fiber laser was developed. Two sequential 60-200 ns laser pulses with variable delay between them were generated by acousto-optic modulator opening with continuous diode pumping. A custom radio frequency generator was developed to produce two sequential “opening” radio pulses with a delay of 0.2–1 μs. It was demonstrated that double pulse generation did not decrease the average laser power while providing the control over the laser pulse power profile. Surprisingly, a greater peak power in the double pulse mode was observed for the second laser pulse. Laser crater studies and plasma emission measurements revealed an improved efficiency of laser ablation in the double pulse mode.

Lattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin films

KAUST Repository

Sarath Kumar, S. R.; Cha, Dong Kyu; Alshareef, Husam N.

2011-01-01

Lattice dynamics, low-temperature electrical transport, and high-temperature thermoelectric properties of (In, Yb)-doped CoSb3thin films on different substrates are reported. Pulsed laser deposition under optimized conditions yielded single

Switchable Q-switched and modelocked operation in ytterbium doped fiber laser under all-normal-dispersion configuration

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, Pranb K., E-mail: pkm@rrcat.gov.in; Gupta, Pradeep K.; Singh, Chandra Pal; Singh, Amarjeet; Sharma, Sunil K.; Bindra, Kushvinder S.; Oak, Shrikant M. [Solid State Laser Division, Raja Ramanna Center for Advanced Technology, Indore, M.P. 452013 (India)

2015-03-15

We have constructed an Yb-doped fiber laser in all-normal-dispersion configuration which can be independently operated in Q-switched or modelocked configuration with the help of a simple fiber optic ring resonator (FORR). In the presence of FORR, the laser operates in Q-switched mode producing stable pulses in the range of 1 μs-200 ns with repetition rate in the range of 45 kHz-82 kHz. On the other hand, the laser can be easily switched to mode-locked operation by disjoining the FORR loop producing train of ultrashort pulses of ∼5 ps duration (compressible to ∼150 fs) at ∼38 MHz repetition rate. The transmission characteristics of FORR in combination with the nonlinear polarization rotation for passive Q-switching operation is numerically investigated and experimentally verified. The laser can serve as a versatile seed source for power amplifier which can be easily configured for application in the fields that require different pulsed fiber lasers.

The effect of intentional potassium co-doping on the luminescent properties of Yb3+ and Tm3+ doped α-NaYF4 core and core–shell nanoparticles

International Nuclear Information System (INIS)

Misiak, Małgorzata; Stręk, Wiesław; Arabasz, Sebastian; Bednarkiewicz, Artur

2016-01-01

Simple and effective ways to circumvent limited luminescence efficiency of up-converting nanoparticles (UCNPs) are sought. One of the methods relays on distorting the crystallographic structure of host material by co-doping the nanocrystals with optically inactive co-dopants. Here we study the influence of K + doping and surface passivation on the up-converting properties of the α-NaYF 4 nanocrystals co-doped with 20% Yb 3+ and 0.1 or 2% Tm 3+ . The intentionally chosen concentrations of K + ions, which were meant to replaced sodium ions were fixed to 0, 5, 10, 20 to 30%. Potassium ions modified the spectroscopic properties of both core and core–shell NPs, but the differences were noticed between samples doped with 0.1% Tm 3+ and 2% Tm 3+ ions. Replacement of sodium by potassium ions decreased up-conversion luminescence intensity as well as shortened thulium excited states lifetimes in the samples doped with 0.1% Tm 3+ , while the opposite behavior was found in the samples co-doped with higher 2% thulium concentration. - Highlights: • We studied the influence of K + doping on luminescent properties of α-NaYF 4 :YbTm. • The 0.1 and 2% Tm doped core and core–shell samples were investigated. • K + -doping influence on UC properties was different in low and highly Tm doped NPs. • The explanations of the observed variations were proposed.

NIR to visible upconversion in Er3+/Yb3+ co-doped CaYAl3O7 phosphor obtained by solution combustion process

International Nuclear Information System (INIS)

Singh, Vijay; Rai, Vineet Kumar; Al-Shamery, Katharina; Nordmann, Joerg; Haase, Markus

2011-01-01

Using the combustion synthesis, CaYAl 3 O 7 :Er 3+ phosphor powders co-doped with Yb 3+ have been prepared at low temperatures (550 o C) in a few minutes. Formation of the compound was confirmed by X-ray powder diffraction. Near-infrared to visible upconversion fluorescence emission in the Er 3+ doped CaYAl 3 O 7 phosphor powder has been observed. The effect of co-doping with triply ionized ytterbium in the CaYAl 3 O 7 :Er 3+ phosphor has been studied and the process involved is discussed. - Highlights: → The green emitting up-conversion CaYAl 3 O 7 :Er 3+ phosphor powders co-doped with Yb 3+ have been prepared by easy combustion method. → The combustion method is a simple, energy saving, fast and economical viable process. → The luminescence intensity in the co-doped phosphor is enhanced by several times compared to that of the singly (Er 3+ ) doped phosphor.

Cerium-doped scintillating fused-silica fibers

Science.gov (United States)

Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P.; Faulkner, J.; Kunori, S.

2018-04-01

We report on a set of measurements made on (scintillating) cerium-doped fused-silica fibers using high-energy particle beams. These fibers were uniformly embedded in a copper absorber in order to utilize electromagnetic showers as a source of charged particles for generating signals. This new type of cerium-doped fiber potentially offers myriad new applications in calorimeters in high-energy physics, tracking systems, and beam monitoring detectors for future applications. The light yield, pulse shape, attenuation length, and light propagation speeds are given and discussed. Possible future applications are also explored.

Electrical and microstructural properties of Yb-doped CeO2

Directory of Open Access Journals (Sweden)

B. Matović

2014-06-01

Full Text Available Nanopowdered Ce1−xYbxO2−δ solid solutions (0 ≤ x ≤ 0.2 were synthesized by a self-propagating room temperature synthesis. XRD and SEM were used to study the properties of these materials as well as the Yb solubility in CeO2 lattice. Results showed that all the obtained powders were solid solutions with a fluorite-type crystal structure and with nanometric particle size. The average size of Ce1−xYbxO2−δ particles was approximately 3 nm. Electrochemical impedance spectroscopy for the sintered pellets depicted that it was possible to separate Rbulk and Rgb in the temperature interval of 550–800 °C. The activation energy for the bulk conduction was 1.03 eV and for grain boundary conduction was 1.14 eV. Grain boundary resistivity dominates over the other resistivities. These measurements confirmed that Yb3+-doped CeO2 material had a potential as electrolyte for intermediate-temperature solid oxide fuel cell applications.

Investigations on luminescence behavior of Er3+/Yb3+ co-doped boro-tellurite glasses

Science.gov (United States)

Maheshvaran, K.; Arunkumar, S.; Venkata Krishnaiah, K.; Marimuthu, K.

2015-01-01

Er3+/Yb3+ co-doped boro-tellurite glasses with the chemical composition 30TeO2+(24 - x)B2O3 + 15SrO + 10BaO + 10Li2O + 10LiF + 1Er2O3 + xYb2O3 (where x = 0, 0.1, 0.5, 1 and 2 in wt%) have been prepared and their luminescence behavior were studied and reported. Absorption spectral measurements have been used to derive the Judd-Ofelt (JO) intensity parameters from the experimental and calculated oscillator strength values following the JO theory. The various lasing parameters such as stimulated emission cross-section (σEp), experimental and calculated branching ratios (βR) and radiative lifetime (τcal) for the 2H9/2 → 4I15/2, 4S3/2 → 4I15/2 and 4I13/2 → 4I15/2 emission transitions were determined using the JO intensity parameters. The absorption and emission cross-section values for the 4I13/2 → 4I15/2 emission band have been calculated using McCumbar theory and the Gain cross-section for the 4I13/2 → 4I15/2 emission transition also obtained. The upconversion emission mechanism have been studied through various energy transfer processes and the intensity of the upconversion emission transitions are found to increase with the increase in Yb3+ ion concentration. The luminescence decay curves corresponding to the 4I13/2 → 4I15/2 transition of the Er3+/Yb3+ co-doped boro-tellurite glasses under 980 nm excitation wavelength have also been studied and reported in the present work.

Enhanced infrared-to-visible up-conversion emission and temperature sensitivity in (Er3+,Yb3+, and W6+) tri-doped Bi4Ti3O12 ferroelectric oxide

Science.gov (United States)

Bokolia, Renuka; Mondal, Manisha; Rai, V. K.; Sreenivas, K.

2017-02-01

Strong up conversion (UC) luminescence at 527, 550, and 662 nm is compared under an excitation of 980 nm in single doped (Er3+), co-doped (Er3+/Yb3+), and (Er3+/Yb3+/W6+) tri-doped bismuth titanate (Bi4Ti3O12). For the co-doped system, the frequency (UC) emission intensity due to Er3+ ions is enhanced significantly in the green bands due to the efficient energy transfer from Yb3+ to Er3+ ions. Further increase in the emission intensity is seen with non-luminescent W6+ ions in the tri-doped system due to the modification in the local crystal field around the Er3+ ions, and is evidenced through a gradual change in the crystal structure of the host lattice with increasing W6+ content. The observed changes in the fluorescence lifetime and the associated energy transfer mechanisms are discussed. A progressive reduction of the lifetime of the 4S3/2 levels of Er3+ ions from 72 to 58.7 μs with the introduction of Yb3+ and W6+ dopant increases the transition probability and enhances the UC emission intensity. The efficiency of the energy transfer process ( η ) in the co-doped and tri-doped systems is found to be 9.4% and 18.6%, respectively, in comparison to the single doped system. Temperature sensing based on the fluorescence intensity ratio (FR) technique shows high sensitivity (0.0123 K-1) in the high temperature range (293 to 523 K) for an optimum content of Er3+, Yb3+, and W6+ with x = 0.03, y = 0.18, and z = 0.06 at. % in the tri-doped Bi4-x-yErxYbyTi3-zWzO12 ferroelectric composition, and is found useful for potential applications in optical thermometry.

Two-wavelength, passive self-injection-controlled operation of diode-pumped cw Yb-doped crystal lasers.

Science.gov (United States)

Louyer, Yann; Wallerand, Jean-Pierre; Himbert, Marc; Deneva, Margarita; Nenchev, Marin

2003-09-20

We demonstrate and investigate a peculiar mode of cw Yb3+-doped crystal laser operation when two emissions, at two independently tunable wavelengths, are simultaneously produced. Both emissions are generated from a single pumped volume and take place in either a single beam or spatially separated beams. The laser employs original two-channel cavities that use a passive self-injection-locking (PSIL) control to reduce intracavity loss. The advantages of the application of the PSIL technique and some limitations are shown. The conditions for two-wavelength multimode operation of the cw quasi-three-level diode-pumped Yb3+ lasers and the peculiarity of such an operation are carried out both theoretically and experimentally. The results reported are based on the example of a Yb3+:GGG laser but similar results are also obtained with a Yb3+:YAG laser. The laser operates in the 1023-1033-nm (1030-1040-nm) range with a total output power of 0.4 W. A two-wavelength, single longitudinal mode generation is also obtained.

Continuous wave and tunable laser operation of Yb3+ in disordered NaLa(MoO4)2

Science.gov (United States)

Rico, M.; Liu, J.; Cano-Torres, J. M.; García-Cortés, A.; Cascales, C.; Zaldo, C.; Griebner, U.; Petrov, V.

2005-09-01

Continuous-wave Yb3+ laser operation is studied in single crystals of disordered NaLa(MoO4)2 at room temperature. The sample used was grown by the Czochralski technique and incorporates an Yb ion density of 3.1×1020 cm-3. The effect of the Yb concentration on some of the crystal properties is described as well as the spectroscopic Yb3+ properties at 5 K. Maximum slope efficiencies of about 40% for π and 38% for σ polarization were obtained under Ti:sapphire laser pumping near 976 nm, respectively. The maximum output power for the π polarization was 400 mW at 1039.5 nm, the threshold in this case amounted to 240 mW (absorbed pump power). The laser emission was tunable between 1016 and 1064 nm with a Lyot filter. Lasing was also realized by pumping with a fiber-coupled diode laser module. Maximum output power of 900 mW at 1035 nm was achieved in this case for the π polarization and the threshold was 280 mW. The results, in terms of output power and tunability, are superior in comparison to all previous reports on Yb-doped disordered double tungstate or molybdate crystals and represent a significant improvement in comparison to earlier experiments with low-doped Yb:NaLa(MoO4)2.

High energy single frequency Yb:YAG crystalline fiber waveguide master oscillator power amplifier, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The overall objective is to demonstrate the concept of Yb:YAG crystalline fiber MOPA laser and investigation the technical feasibility toward 50 mJ single frequency...

Spectroscopic investigations of OH{sup -} influence on near-infrared fluorescence quenching of Yb{sup 3+}/Tm{sup 3+} co-doped sodium-metaphosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Terra, I.A.A. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Saocarlense 400, CEP 13566-590, USP-Sao Carlos, SP (Brazil)], E-mail: idelma@ifsc.usp.br; Camargo, A.S.S. de; Terrile, M.C.; Nunes, L.A.O. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Saocarlense 400, CEP 13566-590, USP-Sao Carlos, SP (Brazil)

2008-05-15

Energy transfer processes were studied in two sets of Yb{sup 3+} and Tm{sup 3+} co-doped sodium-metaphosphate glasses, prepared in air and nitrogen atmospheres. Using Foerster, Dexter, and Miyakawa theoretical models, the energy transfer parameters were calculated. The main ion-ion energy transfer processes analyzed were energy migration among Yb{sup 3+} ions, cross-relaxations between Yb{sup 3+} and Tm{sup 3+} ions, and interactions with OH{sup -} radicals. The results indicated that Yb{yields}Tm energy transfer favors 1.8 {mu}m emissions, and there is no evidence of concentration quenching up to 2% Tm{sub 2}O{sub 3} doping. As expected, samples prepared in nitrogen atmosphere present higher fluorescence quantum efficiency than those prepared in air, and this feature is specially noted in the near-infrared region, where the interaction with the OH{sup -} radicals is more pronounced.

Growth, characterization, and waveguide lasing of Yb3+, Lu3+, Gd3+ co-doped KY(WO4)2 thin layers

NARCIS (Netherlands)

Aravazhi, S.; Geskus, D.; Günther, D.; Worhoff, Kerstin; Pollnau, Markus

2009-01-01

Monoclinic crystals of KY(WO4)2 (KYW) doped with different rare-earth ions are among the highly promising materials for building compact solid-state lasers. We report the liquid phase epitaxy (LPE) growth of 3-5 µm thick KYW:Gd3+, Lu3+, Yb3+ layers for Yb3+ concentrations of 1.2, 1.7, and 2.4 mol%

1.8 μm luminescent properties and energy transfer of Yb{sup 3+}/Tm{sup 3+} co-doped α-NaYF{sub 4} single crystals

Energy Technology Data Exchange (ETDEWEB)

Feng, Zhigang [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Xia, Haiping, E-mail: hpxcm@nbu.edu.cn [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Wang, Cheng; Zhang, Zhixiong; Jiang, Dongsheng; Zhang, Jian; He, Shinan; Tang, Qingyang; Sheng, Qiguo; Gu, Xuemei; Zhang, Yuepin [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Chen, Baojiu [Department of Physics, Dalian Maritime University, Dalian, Liaoning Province, 116026 (China); Jiang, Haochuan, E-mail: jianghaochuan@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, The Chinese Academy of Sciences, Ningbo, Zhejiang, 315211 (China)

2016-09-25

This paper reports on successful preparation of α-NaYF{sub 4} single crystals co-doped with ∼1.9 mol% Tm{sup 3+} and various concentrations (3.85 mol%, 7.69 mol%, 11.54 mol%, 15.38 mol%) of Yb{sup 3+} by using a flux-Bridgman method. The fluorescence decay curve was measured to investigate the luminescent properties of the Yb{sup 3+}/Tm{sup 3+} co-doped α-NaYF{sub 4}, and the energy transfer process from Yb{sup 3+} to Tm{sup 3+}; the J-O intensity parameters of Tm{sup 3+} were further calculated and analyzed according to the absorption spectra. Results show that, an intense 1.8 μm emission was achieved with Yb{sup 3+} as sensitizer for Tm{sup 3+} in the α-NaYF{sub 4} single crystal under the excitation of 980 nm LD (Laser Diode) because of the strong energy transfer from Yb{sup 3+} to Tm{sup 3+}. The maximum emission intensity at 1.8 μm is obtained at about 15.38 mol% doping concentration of Yb{sup 3+} when the concentration of Tm{sup 3+} ions is fixed at ∼1.90 mol% in the current research. Moreover, the calculated maximum value of emission cross section at 1.8 μm is 1.63 × 10{sup −20} cm{sup 2} for 3.85 mol% Yb{sup 3+}/1.9 mol% Tm{sup 3+} sample, and the obtained energy transfer rate (W{sub ET}) and energy transfer efficiency (η) are 1543 s{sup −1} and 83.8%, respectively. Our analysis of the fluorescence dynamics indicates that electric dipole-dipole interaction is dominant for the energy transfer from Yb{sup 3+} ions to Tm{sup 3+} ions by using Inokuti-Hirayama’s model. - Highlights: • The Tm{sup 3+}/Yb{sup 3+} co-doped α-NaYF{sub 4} single crystals were grown by Bridgman method. • The 1.8 μm emission intensity is obtained at 15.38 mol% Yb{sup 3+}/1.90 mol% Tm{sup 3+} sample. • The maximum value of emission cross section at 1.8 μm is 1.63 × 10{sup −20} cm{sup 2}. • The energy transfer rate is 1543 s{sup −1} and energy transfer efficiency is 83.8%. • The physical mechanism for energy transfer from Yb{sup 3+} to Tm{sup 3+} ions

Upconversion properties of Er3+/Yb3+ co-doped TeO2-TiO2-K2O glasses.

Science.gov (United States)

Su, Fangning; Deng, Zaide

2006-01-01

The Er3+/Yb3+ co-doped TeO2-TiO2-K2O glasses were prepared by conventional melting procedures, and their upconversion spectra were performed. The dependence of luminescence intensity on the ratio of Yb3+/Er3+ was studied, and the relationship between green upconversion luminescence intensity and Er3+ concentration is discussed in detail. The 546 nm green upconversion luminescence intensity is optimised in the studied glasses either when the Yb3+/Er3+ ratio is 25/1 and Er3+ concentration is 0.1 mol%, or when the Yb3+/Er3+ ratio is 10/1 and Er3+ concentration is 0.15 mol%. These glasses could be one of the potential candidates for LD pumping microchip solid-state lasers.

Monolithic all-PM femtosecond Yb-fiber laser stabilized with a narrow-band fiber Bragg grating and pulse-compressed in a hollow-core photonic crystal fiber

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Liu, Xiaomin; Lægsgaard, Jesper

2008-01-01

. The laser output is compressed in a spliced-on hollow-core PM photonic crystal fiber, thus providing direct end-of-the-fiber delivery of pulses of around 370 fs duration and 4 nJ energy with high mode quality. Tuning the pump power of the end amplifier of the laser allows for the control of output pulse......We report on an environmentally stable self-starting monolithic (i.e. without any free-space coupling) all-polarization-maintaining (PM) femtosecond Yb-fiber laser, stabilized against Q-switching by a narrow-band fiber Bragg grating and modelocked using a semiconductor saturable absorber mirror...

Enhanced Power Conversion Efficiency of Perovskite Solar Cells with an Up-Conversion Material of Er3+-Yb3+-Li+ Tri-doped TiO2.

Science.gov (United States)

Zhang, Zhenlong; Qin, Jianqiang; Shi, Wenjia; Liu, Yanyan; Zhang, Yan; Liu, Yuefeng; Gao, Huiping; Mao, Yanli

2018-05-11

In this paper, Er 3+ -Yb 3+ -Li + tri-doped TiO 2 (UC-TiO 2 ) was prepared by an addition of Li + to Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 presented an enhanced up-conversion emission compared with Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 was applied to the perovskite solar cells. The power conversion efficiency (PCE) of the solar cells without UC-TiO 2 was 14.0%, while the PCE of the solar cells with UC-TiO 2 was increased to 16.5%, which presented an increase of 19%. The results suggested that UC-TiO 2 is an effective up-conversion material. And this study provided a route to expand the spectral absorption of perovskite solar cells from visible light to near-infrared using up-conversion materials.

Magnetically sensitive nanodiamond-doped tellurite glass fibers.

Science.gov (United States)

Ruan, Yinlan; Simpson, David A; Jeske, Jan; Ebendorff-Heidepriem, Heike; Lau, Desmond W M; Ji, Hong; Johnson, Brett C; Ohshima, Takeshi; Afshar V, Shahraam; Hollenberg, Lloyd; Greentree, Andrew D; Monro, Tanya M; Gibson, Brant C

2018-01-19

Traditional optical fibers are insensitive to magnetic fields, however many applications would benefit from fiber-based magnetometry devices. In this work, we demonstrate a magnetically sensitive optical fiber by doping nanodiamonds containing nitrogen vacancy centers into tellurite glass fibers. The fabrication process provides a robust and isolated sensing platform as the magnetic sensors are fixed in the tellurite glass matrix. Using optically detected magnetic resonance from the doped nanodiamonds, we demonstrate detection of local magnetic fields via side excitation and longitudinal collection. This is a first step towards intrinsically magneto-sensitive fiber devices with future applications in medical magneto-endoscopy and remote mineral exploration sensing.

Polarized spectra calculation and continuous wave laser operation of Yb-doped disordered Ca3La2(BO3)4 crystal

Science.gov (United States)

Wang, Yeqing; Chen, Aixi; You, Zhenyu; Tu, Chaoyang

2015-12-01

A notable disorder crystal Yb:Ca3La2(BO3)4 crystal with Yb3+ ion doping concentration of 10 at.% was grown by the Czochralski method. The polarized absorption, polarized emission, and polarized gain cross sections were systematically calculated. The laser operations were investigated with Yb:Ca3La2(BO3)4 crystals cut along the a, b, and c crystallographic axes. The highest output power of 3.88 W was obtained by using the b-cut Yb:Ca3La2(BO3)4 crystal, with a slope efficiency of 62%. Additionally, it was confirmed that the output laser spectra were largely dependent on the output coupler.

Polarized spectra calculation and continuous wave laser operation of Yb-doped disordered Ca3La2(BO3)4 crystal

International Nuclear Information System (INIS)

Wang, Yeqing; Chen, Aixi; You, Zhenyu; Tu, Chaoyang

2015-01-01

A notable disorder crystal Yb:Ca 3 La 2 (BO 3 ) 4 crystal with Yb 3+ ion doping concentration of 10 at.% was grown by the Czochralski method. The polarized absorption, polarized emission, and polarized gain cross sections were systematically calculated. The laser operations were investigated with Yb:Ca 3 La 2 (BO 3 ) 4 crystals cut along the a, b, and c crystallographic axes. The highest output power of 3.88 W was obtained by using the b-cut Yb:Ca 3 La 2 (BO 3 ) 4 crystal, with a slope efficiency of 62%. Additionally, it was confirmed that the output laser spectra were largely dependent on the output coupler. (paper)

Ho3+/Yb3+ co-doped TeO2-BaF2-Y2O3 glasses for ∼1.2 μm laser applications

Science.gov (United States)

Wang, Shunbin; Li, Chengzhi; Yao, Chuanfei; Jia, Shijie; Jia, Zhixu; Qin, Guanshi; Qin, Weiping

2017-02-01

Intense ∼1.2 μm fluorescence is observed in Ho3+/Yb3+ co-doped TeO2-BaF2-Y2O3 glasses under 915 nm laser diode excitation. The 1.2 μm emission can be ascribed to the transition 5I6→5I8 of Ho3+. With the introducing of BaF2, the content of OH in the glasses drops markedly, and the 1.2 μm emission intensity increases gradually as increasing the concentration percentage of BaF2. Furthermore, microstructured fibers based on the TeO2-BaF2-Y2O3 glasses are fabricated by using a rod-in-tube method, and a relative positive gain of ∼9.42 dB at 1175.3 nm is obtained in a 5 cm long fiber.

40 W picosecond fiber amplifier with the large mode-area polarized crystal fiber

International Nuclear Information System (INIS)

Yu, H; Zhou, J; Wushouer, X; Yan, P; Wang, D; Gong, M

2009-01-01

We reported the 5W picosecond laser with pulse width of 30 ps and the repetition rate of 100 MHz, which was amplified to 40.2 W with the linear polarized Yb-doped photonic crystal fiber (PCF), with the slope efficiency of about 58%. As much as 17.3 W second-harmonic power was achieved corresponding to the conversion efficiency of 43%

Femtosecond Mode-locked Fiber Laser at 1 μm Via Optical Microfiber Dispersion Management.

Science.gov (United States)

Wang, Lizhen; Xu, Peizhen; Li, Yuhang; Han, Jize; Guo, Xin; Cui, Yudong; Liu, Xueming; Tong, Limin

2018-03-16

Mode-locked Yb-doped fiber lasers around 1 μm are attractive for high power applications and low noise pulse train generation. Mode-locked fiber lasers working in soliton and stretched-pulse regime outperform others in terms of the laser noise characteristics, mechanical stability and easy maintenance. However, conventional optical fibers always show a normal group velocity dispersion around 1 μm, leading to the inconvenience for necessary dispersion management. Here we show that optical microfibers having a large anomalous dispersion around 1 μm can be integrated into mode-locked Yb-doped fiber lasers with ultralow insertion loss down to -0.06 dB, enabling convenient dispersion management of the laser cavity. Besides, optical microfibers could also be adopted to spectrally broaden and to dechirp the ultrashort pulses outside the laser cavity, giving rise to a pulse duration of about 110 fs. We believe that this demonstration may facilitate all-fiber format high-performance ultrashort pulse generation at 1 μm and may find applications in precision measurements, large-scale facility synchronization and evanescent-field-based optical sensing.

Dependence of upconversion emission intensity on Yb3+ concentration in Er3+/Yb3+ co-doped flake shaped Y2(MoO4)3 phosphors

International Nuclear Information System (INIS)

Lu Weili; Cheng Lihong; Zhong Haiyang; Sun Jiashi; Wan Jing; Tian Yue; Chen Baojiu

2010-01-01

Yttrium molybdate phosphors with fixed Er 3+ and various Yb 3+ concentrations were synthesized via a co-precipitation method. The crystal structure and the morphology of the phosphor were characterized by means of x-ray diffraction and field-emission scanning electron microscopy. Under 980 nm excitation, red and green upconversion emissions centred at 660, 553 and 530 nm were observed. Quantitative analyses on the dependence of upconversion emission intensity on the working current of a laser diode (LD) indicated that two-photon processes are responsible for both red and green upconversion emissions in both cases of low and high Yb 3+ concentrations. The relationship between the emission intensity ratio of 2 H 11/2 → 4 I 15/2 to 4 S 3/2 → 4 I 15/2 and the working current of the LD was studied for the samples doped with low and high Yb 3+ concentrations. Finally, a set of rate equations was established based on the possible upconversion mechanism, and an empirical formula was proposed to describe the Yb 3+ concentration dependence of upconversion emission intensity; the empirical formula fits well with the experimental data.

A cladding-pumped, tunable holmium doped fiber laser.

Science.gov (United States)

Simakov, Nikita; Hemming, Alexander; Clarkson, W Andrew; Haub, John; Carter, Adrian

2013-11-18

We present a tunable, high power cladding-pumped holmium doped fiber laser. The laser generated >15 W CW average power across a wavelength range of 2.043 - 2.171 μm, with a maximum output power of 29.7 W at 2.120 μm. The laser also produced 18.2 W when operating at 2.171 µm. To the best of our knowledge this is the highest power operation of a holmium doped laser at a wavelength >2.15 µm. We discuss the significance of background losses and fiber design for achieving efficient operation in holmium doped fibers.

Synthesis of Er(III)/Yb(III)-doped BiF3 upconversion nanoparticles for use in optical thermometry.

Science.gov (United States)

Du, Peng; Yu, Jae Su

2018-03-23

The authors describe an ethylene glycol assisted precipitation method for synthesis of Er(III)/Yb(III)-doped BiF 3 nanoparticles (NPs) at room temperature. Under 980-nm light irradiation, the NPs emit upconversion (UC) emission of Er(III) ions as a result of a two-photon absorption process. The temperature-dependent green emissions (peaking at 525 and 545 nm) are used to establish an unambiguous relationship between the ratio of fluorescence intensities and temperature. The NPs have a maximum sensitivity of 6.5 × 10 -3  K -1 at 619 K and can be applied over the 291-691 K temperature range. The results indicate that these NPs are a promising candidate for optical thermometry. Graphical abstract Schematic of the room-temperature preparation of Er(III)/Yb(III)-doped BiF 3 nanoparticles with strongly temperature-dependent upconversion emission.

A broadening temperature sensitivity range with a core-shell YbEr@YbNd double ratiometric optical nanothermometer

Science.gov (United States)

Marciniak, L.; Prorok, K.; Francés-Soriano, L.; Pérez-Prieto, J.; Bednarkiewicz, A.

2016-02-01

The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle based optical nano-thermometer under single ~808 nm wavelength photo-excitation from around ΔT = 150 K to over ΔT = 300 K (150-450 K). Such engineered nanocrystals are suitable for remote optical temperature measurements in technology and biotechnology at the sub-micron scale.The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle

Self-stabilization of a mode-locked femtosecond fiber laser using a photonic bandgap fiber

DEFF Research Database (Denmark)

Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

2010-01-01

We demonstrate a self-stabilization mechanism of a semiconductor saturable absorber mode-locked linearcavity Yb-doped fiber laser using an intracavity photonic bandgap fiber. This mechanism relies on the spectral shift of the laser pulses to a spectral range of higher anomalous dispersion...... and higher loss of the photonic bandgap fiber, as a reaction to the intracavity power buildup. This, in particular, results in a smaller cavity loss for the stably mode-locked laser, as opposed to the Q-switched mode-locking scenario. The laser provides stable 39–49 pJ pulses of around 230 fs duration at 29...

Effect of initial chirp on near-infrared supercontinuum generation by a nanosecond pulse in a nonlinear fiber amplifier

International Nuclear Information System (INIS)

Song Rui; Hou Jing; Wang Ze-Feng; Lu Qi-Sheng; Xiao Rui

2013-01-01

Theoretical and experimental research on the effect of initial chirp on near-infrared supercontinuum generation by a nanosecond pulse in a nonlinear fiber amplifier is carried out. The complex Ginzburg—Landau equation is used to simulate the propagation of the pulse in the fiber amplifier and the results show that pulses with negative initial chirp produce the widest supercontinuum and pulses with positive initial chirp produce the narrowest supercontinuum when the central wavelength of the pump lies in the normal dispersion region of the gain fiber. A self-made line width narrowing system is utilized to control the initial chirp of the nanosecond pump pulse and a four-stage master oscillator power amplifier configuration is adopted to produce a high power near-infrared suppercontinuum. The experimental results are in good agreement with simulations which can provide some guidance on further optimization of the system in future work. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

The all-fiber cladding-pumped Yb-doped gain-switched laser.

Science.gov (United States)

Larsen, C; Hansen, K P; Mattsson, K E; Bang, O

2014-01-27

Gain-switching is an alternative pulsing technique of fiber lasers, which is power scalable and has a low complexity. From a linear stability analysis of rate equations the relaxation oscillation period is derived and from it, the pulse duration is defined. Good agreement between the measured pulse duration and the theoretical prediction is found over a wide range of parameters. In particular we investigate the influence of an often present length of passive fiber in the cavity and show that it introduces a finite minimum in the achievable pulse duration. This minimum pulse duration is shown to occur at longer active fibers length with increased passive length of fiber in the cavity. The peak power is observed to depend linearly on the absorbed pump power and be independent of the passive fiber length. Given these conclusions, the pulse energy, duration, and peak power can be estimated with good precision.

Efficient conversion from UV light to near-IR emission in Yb{sup 3+}-doped triple-layered perovskite CaLaNb{sub 3}O{sub 10}

Energy Technology Data Exchange (ETDEWEB)

Lu, Yuting; Li, Yuze; Qin, Lin; Huang, Yanlin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Qin, Chuanxiang, E-mail: qinchuanxiang@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Tsuboi, Taiju [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing 211816 (China); Huang, Wei, E-mail: wei-huang@njtech.edu.cn [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing 211816 (China)

2015-04-15

Graphical abstract: CaRNb{sub 3}O{sub 10} is a self-activated oxide due to charge transfer transition in octahedral NbO{sub 6} groups. CaLaNb{sub 3}O{sub 10}:Yb{sup 3+} presents intense IR emission due to the cooperative energy transfer from host (NbO{sub 6}) to Yb{sup 3+} is responsible. It could be expected to be potentially applicable for enhancing photovoltaic conversion efficiency of Si-based solar cells. - Abstract: Yb{sup 3+}-doped triple-layered perovskite CaLaNb{sub 3}O{sub 10} micro-particles were synthesized via the solid-state reaction method. The crystal structure and morphology of the polycrystalline samples were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) measurements, respectively. The reflectance spectra, photoluminescence (PL) excitation and emission spectra, the decay curves, and the absolute quantum efficiency (QE) of the near-infrared (NIR) emission (910–1100 nm) were measured. Under excitation of UV light, Yb{sup 3+}-doped perovskite shows an intense NIR emission attributed to the {sup 2}F{sub 5/2} → {sup 2}F{sub 7/2} transitions of Yb{sup 3+} ions, which could match maximum spectral response of a Si-based solar cell. This is beneficial for its possible application in an enhancement of the photovoltaic conversion efficiency of solar energy utilization. The efficient energy transfer in Yb{sup 3+}-doped CaLaNb{sub 3}O{sub 10} from NbO{sub 6} groups into Yb{sup 3+} ions was confirmed by the spectra and fluorescent decay measurements. Cooperative energy transfer (CET) was supposed to be the NIR emission mechanism.

Ultraviolet and near-infrared luminescence of LaBO3:Ce3+,Yb3+

Science.gov (United States)

Wei, Heng-Wei; Shao, Li-Ming; Jiao, Huan; Jing, Xi-Ping

2018-01-01

Ce3+ or Yb3+ singly doped LaBO3 and Ce3+-Yb3+ co-doped LaBO3 were prepared by conventional solid state reactions at 1100 °C and their photoluminescence (PL) properties were investigated. The emission spectrum of LaBO3:Ce3+,Yb3+ contains both the Ce3+ ultraviolet (UV) emissions (355 nm and 380 nm) and the Yb3+ near infrared (NIR) emission (975 nm) when excited by the UV light at 270 nm. By using the data of the Ce3+ decay curves and the PL intensities of both Ce3+ and Yb3+, the energy transfer efficiency (η) from Ce3+ to Yb3+, the actual energy transfer efficiency (AE) and the quantum efficiency (Q) of the Yb3+ emission were calculated. In the Ce3+-Yb3+ co-doped LaBO3, Ce3+ can transfer its absorbed energy to Yb3+ efficiently (η can be over 60%), and Yb3+ shows the Q value over 50% when it accepts the energy from Ce3+, which results in the low AE value ∼30%. The energy transfer process from Ce3+ to Yb3+ may be understood by the charge transfer mechanism: Ce3+ + Yb3+ ↔ Ce4+ + Yb2+. Particularly the Ce3+-Yb3+ co-doped LaBO3 phosphor gives the emissions mainly in the UV range and the NIR range with a portion of visible emissions in eye-insensitive range. This unique property may be suitable for applications in anti-counterfeiting techniques and public security affairs.

Radiation effects on erbium doped optical fibers: on the influence of the fiber composition

International Nuclear Information System (INIS)

Tortech, B.

2008-01-01

We have studied the erbium-doped fibers (EDF) sensitivity under irradiation and the induced defects. The first chapter presents the state of the art for the EDF under irradiation as well as some radiation generated silica defects. The second chapter details the radiations used in this thesis and the experimental set-ups implemented for the characterization of the fiber responses under irradiation and the radiation induced defects. In the third chapter, we present the response of several erbium-doped fibers irradiated with γ-rays, protons and pulsed X-rays. The erbium doped fibers have higher radiation induced sensitivity than the Telecom fibers (SMF28) or than erbium-doped fibers containing little aluminum. The aluminum presence in the EDF core composition is mainly responsible for the fiber performance degradation. Whatever the irradiation types, the radiation generated defects are related to the host matrix. Our studies also display that the erbium ions are only affected by the interaction with the created defects. The fourth chapter deals with the EDF under UV exposure and shows that the UV rays lead to the same effects than the gamma rays. The last chapter of this thesis presents the study of optical fiber amplifiers under γ irradiation. (author)

Structural and magnetic properties of Mg doped YbMnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Sattibabu, Bhumireddi, E-mail: bsb.satti@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Bhatnagar, Anil K., E-mail: anilb42@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); School of Physics, University of Hyderabad, Hyderabad 500046 (India); Rayaprol, Sudhindra [UGC-DAE CSR, Mumbai Centre, R-5 Shed, BARC, Mumbai 400085 (India); Mohan, Dasari; Das, Dibakar; Sundararaman, Mahadevan [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Siruguri, Vasudeva [UGC-DAE CSR, Mumbai Centre, R-5 Shed, BARC, Mumbai 400085 (India)

2014-09-01

We have studied the effect of Mg doping on structure and magnetism of multiferroic YbMnO{sub 3}. Room temperature neutron diffraction studies were carried out on polycrystalline Yb{sub 1−x}Mg{sub x}MnO{sub 3} (x=0.00 and 0.05) samples to determine phase formation as well as cation distribution and structural properties such as bond length and bond angles. The structural analysis shows that with Mg substitution, there is a marginal change in a and c parameters of the hexagonal unit cell, c/a ratio remains constant for x=0 and 0.05 samples. Due to changes in bond angle and bond lengths on substituting Mg, there is a slight decrease in the distortion of MnO{sub 5} polyhedra. Magnetic measurements show that the Néel temperature (T{sub N}) increases marginally from 85 K for x=0.00 to 89 K for x=0.05 sample.

A novel fiber laser development for photoacoustic microscopy

Science.gov (United States)

Yavas, Seydi; Aytac-Kipergil, Esra; Arabul, Mustafa U.; Erkol, Hakan; Akcaalan, Onder; Eldeniz, Y. Burak; Ilday, F. Omer; Unlu, Mehmet B.

2013-03-01

Photoacoustic microscopy, as an imaging modality, has shown promising results in imaging angiogenesis and cutaneous malignancies like melanoma, revealing systemic diseases including diabetes, hypertension, tracing drug efficiency and assessment of therapy, monitoring healing processes such as wound cicatrization, brain imaging and mapping. Clinically, photoacoustic microscopy is emerging as a capable diagnostic tool. Parameters of lasers used in photoacoustic microscopy, particularly, pulse duration, energy, pulse repetition frequency, and pulse-to-pulse stability affect signal amplitude and quality, data acquisition speed and indirectly, spatial resolution. Lasers used in photoacoustic microscopy are typically Q-switched lasers, low-power laser diodes, and recently, fiber lasers. Significantly, the key parameters cannot be adjusted independently of each other, whereas microvasculature and cellular imaging, e.g., have different requirements. Here, we report an integrated fiber laser system producing nanosecond pulses, covering the spectrum from 600 nm to 1100 nm, developed specifically for photoacoustic excitation. The system comprises of Yb-doped fiber oscillator and amplifier, an acousto-optic modulator and a photonic-crystal fiber to generate supercontinuum. Complete control over the pulse train, including generation of non-uniform pulse trains, is achieved via the AOM through custom-developed field-programmable gate-array electronics. The system is unique in that all the important parameters are adjustable: pulse duration in the range of 1-3 ns, pulse energy up to 10 μJ, repetition rate from 50 kHz to 3 MHz. Different photocoustic imaging probes can be excited with the ultrabroad spectrum. The entire system is fiber-integrated; guided-beam-propagation rendersit misalignment free and largely immune to mechanical perturbations. The laser is robust, low-cost and built using readily available components.

Radially polarized and passively Q-switched Yb-doped fiber laser based on intracavity birefringent mode discrimination

Science.gov (United States)

Sun, Xuehuan; Wu, Yongxiao; Chen, Sanbin; Li, Jianlang

2018-05-01

In this paper, we demonstrated a passive Q-switched ytterbium-doped fiber laser with radially polarized beam emission by using a c-cut YVO4 birefringent crystal as the intracavity polarization discriminator, and a Cr4+:YAG crystal as the saturable absorber and output coupler. The maximum averaged laser power reached 3.89 W with a high slope efficiency of 66.5%. The laser pulse had a peak power of 161 W, 160 ns duration, and 151 kHz repetition rate at the absorbed pump power of 6.48 W. Such a radially polarized pulse would facilitate numerous applications.

Structural properties of pure and Fe-doped Yb films prepared by vapor condensation

Energy Technology Data Exchange (ETDEWEB)

Rojas-Ayala, C., E-mail: chachi@cbpf.br [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180, RJ (Brazil); Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, Lima, P.O.B. 14-149, Lima 14 (Peru); Passamani, E.C. [Departamento de Física, Universidade Federal do Espírito Santo, Vitória 29075-910, ES (Brazil); Suguihiro, N.M. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180, RJ (Brazil); Litterst, F.J. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180, RJ (Brazil); Institut für Physik der Kondensierten Materie, Technische Universität Braunschweig, 38106 Braunschweig (Germany); Baggio Saitovitch, E. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180, RJ (Brazil)

2014-10-15

Ytterbium and iron-doped ytterbium films were prepared by vapor quenching on Kapton substrates at room temperature. Structural characterization was performed by X-ray diffraction and transmission electron microscopy. The aim was to study the microstructure of pure and iron-doped films and thereby to understand the effects induced by iron incorporation. A coexistence of face centered cubic and hexagonal close packed-like structures was observed, the cubic-type structure being the dominant contribution. There is an apparent thickness dependence of the cubic/hexagonal relative ratios in the case of pure ytterbium. Iron-clusters induce a crystalline texture effect, but do not influence the cubic/hexagonal volume fraction. A schematic model is proposed for the microstructure of un-doped and iron-doped films including the cubic- and hexagonal-like structures, as well as the iron distribution in the ytterbium matrix. - Highlights: • Pure and Fe-doped Yb films have been prepared by vapor condensation. • Coexistence of fcc- and hcp-type structures was observed. • No oxide phases have been detected. • Fe-clustering does not affect the fcc/hcp ratio, but favors a crystalline texture. • A schematic model is proposed to describe microscopically the microstructure.

Effects of Sm3+/Yb3+ co-doping and temperature on the Raman, IR spectra and structure of [TeO2-GeO2-K2O-Sm2O3/Yb2O3] glasses

International Nuclear Information System (INIS)

Shaltout, I.; Badr, Y.

2006-01-01

Effects of Sm 3+ /Yb 3+ co-doping on Raman scattering, IR absorption, temperature dependence of the Raman spectra up to 210 o C and the structure of two glass systems of the composition (80TeO 2 -10GeO 2 -8K 2 O-2Sm 2 O 3 /Yb 2 O 3 ) is discussed. It was found that the addition of Yb 3+ to the glass very strongly enhances the intensities of the antistokes' Raman bands at 155, 375, 557 and 828 cm -1 and quenches both the intensities of the stokes' vibration modes of the TeO 4 units in the range of 120-770 cm -1 and the intensities of the OH - stretching vibration modes in the range of 2600-3300 cm -1 . Sm 2 O 3 /Yb 2 O 3 rare earth co-doping has a great influence on removing and/or changing the nature of the OH - groups. The appearance and splitting of the stretching vibration modes of the OH - groups at lower frequencies (2770, 2970 cm -1 ) for the Sm +3 singly doped glass sample, compared to the band at ∼3200 cm -1 for the Sm 3+ /Yb 3+ co-doped glass sample, suggested that the OH - groups are more strongly bonded and incorporated with the glass matrix for the singly doped glass. Heating the sample up continuously weakens the hydrogen bonding of the OH - groups to the glass matrix leading to creation of NBO and breakdown of the connectivity of the OH - groups to the TeO 4 , TeO 3+1 and TeO 3 structural units. Raman bands at 286, 477, 666 and 769 cm -1 were assigned to its respective vibrations of Te 2 O 7 , TeO 4 -4 species, the (Te-O-Te) bending vibrations of the TeO 4 triagonal bipyramids (tbps), the axial symmetric stretching vibration modes (Te ax -O) s with bridging oxygen BO atoms and to the (Te-O) nbo non-bridging stretching vibration modes of the TeO 3+1 and/or TeO 3 pyramids

Aptamer biosensor for Salmonella typhimurium detection based on luminescence energy transfer from Mn2 +-doped NaYF4:Yb, Tm upconverting nanoparticles to gold nanorods

Science.gov (United States)

Cheng, Keyi; Zhang, Jianguo; Zhang, Liping; Wang, Lun; Chen, Hongqi

2017-01-01

A highly sensitive luminescent bioassay for the detection of Salmonella typhimurium was fabricated using Mn2 +-doped NaYF4:Yb,Tm upconversion nanoparticles (UCNPs) as the donor and gold nanorods (Au NRs) as the acceptor and utilizing an energy transfer (LET) system. Mn2 +-doped NaYF4:Yb,Tm UCNPs with a strong emission peak at 807 nm were obtained by changing the doped ion ratio. Carboxyl-terminated Mn2 +-doped NaYF4:Yb,Tm UCNPs were coupled with S. typhimurium aptamers, which were employed to capture and concentrate S. typhimurium. The electrostatic interactions shorten the distance between the negatively charged donor and the positively charged acceptor, which results in luminescence quenching. The added S. typhimurium leads to the restoration of luminescence due to the formation of UCNPs-aptamers-S. typhimurium, which repels the UCNPs-aptamers from the Au NRs. The LET system does not occur because of the nonexistence of the luminescence emission band of Mn2 +-doped NaYF4:Yb,Tm UCNPs, which had large spectral overlap with the absorption band of Au NRs. Under optimal conditions, the linear range of detecting S. typhimurium was 12 to 5 × 105 cfu/mL (R = 0.99). The limit of detection for S. typhimurium was as low as 11 cfu/mL in an aqueous buffer. The measurement of S. typhimurium in milk samples was satisfied in accordance with the plate-counting method, suggesting that the proposed method was of practical value in the application of food security.

Deep UV light generation by a fiber/bulk hybrid amplifier at 199 nm

International Nuclear Information System (INIS)

Urata, Yoshiharu; Shinozaki, Tatsuya; Wada, Yoshio; Kaneda, Yushi; Wada, Satoshi; Imai, Shinichi

2009-01-01

A high-pulse-repetition-frequency (PRF) pulsed light source in the deep ultraviolet region has been realized by a multiple wavelength conversion technique using a hybrid fiber/bulk amplifier system. Output of 199 nm with a power of 50 mW was achieved at 2.4 MHz PRF. The 1 μm amplifier consisted of a Yb-doped fiber amplifier and a Nd-doped YVO4 amplifier. A 1.5 μm fiber master-oscillator power amplifier was employed as the other fundamental source. The amplifiers exhibited good amplification properties in pulse energy, polarization extinction ratio, and spectrum for nonlinear wavelength conversion

Generation of 46 W green-light by frequency doubling of 96 W picosecond unpolarized Yb-doped fiber amplifier

Science.gov (United States)

Qi, Yaoyao; Yu, Haijuan; Zhang, Jingyuan; Zhang, Ling; He, Chaojian; Lin, Xuechun

2018-05-01

We demonstrated a high efficiency and high average power picosecond green light source based on SHG (second harmonic generation) of an unpolarized ytterbium-doped fiber amplifier chain. Using single-pass frequency doubling in two temperature-tuned type-I phase-matching LBO crystals, we were able to generate 46 W, >70 ps pulses at 532 nm from a fundamental beam at 1064 nm, whose output is 96 W, 4.8 μJ, with a repetition frequency of 20 MHz and nearly diffraction limited. The optical conversion efficiency was ∼48% in a highly compact design. To the best of our knowledge, this is the first reported on ps green source through SHG of an unpolarized fiber laser with such a high output and high efficiency.

Single-longitudinal mode distributed-feedback fiber laser with low-threshold and high-efficiency

Science.gov (United States)

Jiang, Man; Zhou, Pu; Gu, Xijia

2018-01-01

Single-frequency fiber laser has attracted a lot of interest in recent years due to its numerous application potentials in telecommunications, LIDAR, high resolution sensing, atom frequency standard, etc. Phosphate glass fiber is one of the candidates for building compact high gain fiber lasers because of its capability of high-concentration of rare-earth ions doping in fiber core. Nevertheless, it is challenging for the integration of UV-written intra-core fiber Bragg gratings into the fiber laser cavity due to the low photosensitivity of phosphate glass fiber. The research presented in this paper will focus on demonstration of UV-written Bragg gratings in phosphate glass fiber and its application in direct-written short monolithic single-frequency fiber lasers. Strong π-phase shift Bragg grating structure is direct-inscribed into the Er/Yb co-doped gain fiber using an excimer laser, and a 5-cm-long phase mask is used to inscribe a laser cavity into the Er/Yb co-doped phosphate glass fibers. The phase mask is a uniform mask with a 50 μm gap in the middle. The fiber laser device emits output power of 10.44 mW with a slope efficiency of 21.5% and the threshold power is about 42.8 mW. Single-longitudinal mode operation is validated by radio frequency spectrum measurement. Moreover, the output spectrum at the highest power shows an excellent optical signal to noise ratio of about 70 dB. These results, to the best of our knowledge, show the lowest power threshold and highest efficiency among the reports that using the same structure to achieve single-longitudinal mode laser output.

Status of fiber lasers study of on ytterbium doped fiber laser and laser spectroscopy of doped fibers; Etat de l`art des lasers a fibre, etude d`un laser a fibre dopee ytterbium et spectroscopie laser de fibres dopees

Energy Technology Data Exchange (ETDEWEB)

Magne, S

1994-07-01

This work shows all the advantages and drawbacks of the rare-earth-doped fiber lasers and fiber optical amplifiers, pointing out their potential use for instrumentation and optical fiber sensor technology. The theory of light propagation in optical fibers is presented in order to understand the manufacturing methods. A comparative study of preform surface and concentration analysis is performed. The gain behaviour is also thoroughly examined. A synthesis of all technological parameters of the fiber laser is then established and all technologies of the constituting integrated components are reviewed and compared. The experimental techniques mainly involve: site selective excitation tunability, cooperative luminescence, oxidation state changes induced by gamma irradiation, ytterbium-doped mono-mode continuous wave tunable three-level fiber laser. (TEC). 622 refs., 176 figs.

Violet and visible up-conversion emission in Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses

Energy Technology Data Exchange (ETDEWEB)

Yang Yanmin, E-mail: mihuyym@163.co [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Zhang Meixin [Forensic Science Lab, Hebei University, Baoding 071002 (China); Yang Zhiping [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Fu Zuoling [Key Laboratory of Coherent Light, Atomic and Molecular Spectroscopy, College of physics, Jilin University, Ministry of Education, Changchun 130023 (China)

2010-10-15

The up-conversion emission properties of Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses have been investigated with 980 nm excitation. The violet, blue, green and red emission bands at about 350, 485, 544 and 653 nm can be identified, respectively. Experimental results indicated that the relative intensity ratios of the peaks I{sub Red}/I{sub Green} increased with increasing B{sub 2}O{sub 3} concentration, which led to changing color of up-conversion emission from green at x=0 to yellow at x=40, to red at x=60. The violet emission at 350 nm was first reported in germanium-borate glass host and up-conversion mechanisms of the emissions were discussed. The Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses could be an alternative for the generation of violet and primary colors for application in solid-state displays.

Polarization-maintaining, double-clad fiber amplifier employing externally applied stress-induced birefringence

International Nuclear Information System (INIS)

Koplow, Jeffrey P.; Goldberg, Lew; Moeller, Robert P.; Kliner, Dahv A. V.

2000-01-01

We report a new approach to obtaining linear-polarization operation of a rare-earth-doped fiber amplifier in which the gain fiber is coiled under tension to induce birefringence. We demonstrated this method by constructing an Er/Yb-doped, double-clad, single-mode fiber amplifier with an output power of 530 mW and a polarization extinction ratio of >17 dB (when seeded with linearly polarized light) at a wavelength of ∼1.5 μm . The technique is achromatic, permits single- or multiple-pass operation of the amplifier, requires no additional components in the optical path, leaves the fiber ends unobstructed, and is inexpensive to implement. (c) 2000 Optical Society of America

Study of upconversion fluorescence property of novel Er3+/Yb3+ co-doped tellurite glasses.

Science.gov (United States)

Xu, Tie-Feng; Li, Guang-Po; Nie, Qiu-Hua; Shen, Xiang

2006-06-01

Er3+/Yb3+ co-doped TeO2-B2O3-Nb2O5-ZnO (TBN) glasses were prepared. The absorption spectra and upconversion luminescence spectra of TBN glasses were measured and analyzed. The upconversion emission bands centered at 530, 546 and 658 nm were observed under the excitation at 975 nm, corresponding to the transitions of 2H11/2-->4I15/2, 4S3/2-->4I15/2 and 4F9/2-->4I15/2 respectively. The ratio of red emission to green emission increases with an increasing of Yb3+ ions concentration. According to the quadratic dependence on excitation power, the possible upconversion mechanisms and processes were discussed.

Optical gain at 1.53 {mu}m in Er{sup 3+}-Yb{sup 3+} co-doped porous silicon waveguides

Energy Technology Data Exchange (ETDEWEB)

Najar, A. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Laboratoire de Spectroscopie Raman, Faculte des Sciences de Tunis, 2092 El Manar, Tunis (Tunisia)], E-mail: najar.adel@laposte.net; Charrier, J. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Ajlani, H. [Laboratoire de Spectroscopie Raman, Faculte des Sciences de Tunis, 2092 El Manar, Tunis (Tunisia); Lorrain, N.; Haesaert, S. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Oueslati, M. [Laboratoire de Spectroscopie Raman, Faculte des Sciences de Tunis, 2092 El Manar, Tunis (Tunisia); Haji, L. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France)

2008-01-15

Erbium-ytterbium (Er-Yb)-co-doped porous silicon planar waveguides were prepared from P{sup +}-type (1 0 0) oriented silicon wafer. Erbium and ytterbium ions were electrochemically introduced into the porous structure of the waveguide core. The doping profiles of erbium and ytterbium ions were determined by EDX analysis performed on sample cross-section. The mean concentration in the guiding layer is of about 1 x 10{sup 20} cm{sup -3}. The refractive indices were measured from co-doped porous silicon and undoped waveguides after the thermal treatments. The photoluminescence (PL) peak of optically activated erbium ions at 1.53 {mu}m was recorded. The PL enhancement is the result of the energy transfer from the excited state of Yb to the state of Er. Optical losses at 1.55 {mu}m were measured on these waveguides and were of about 2 dB/cm. An internal gain at 1.53 {mu}m of 5.8 dB/cm has been measured with a pump power of 65 mW at 980 nm.

Thermal analyzes of phosphate glasses doped with Yb{sup 3+} and ZnTe nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Freitas, A.M.; Bell, M.J.V. [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, MG (Brazil); Anjos, V., E-mail: virgilio@fisica.ufjf.br [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, MG (Brazil); Pinheiro, A.S.; Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física da Universidade Federal de Uberlândia, CP 593, CEP 38400-902 Uberlândia, MG (Brazil)

2016-01-15

This work studies the thermal properties of a glass matrix called PZABP doped with ZnTe and co-doped with Yb{sup 3+} with nominal composition 60P{sub 2}O{sub 5}, 15ZnO, 5Al{sub 2}O{sub 3}, 10BaO, and 10 PbO (mol%). The presence of ZnTe results in the formation of nanocrystals which are evidenced by optical absorption, X-Ray Diffraction (XRD) and Raman scattering. Thermal lens and Volumetric Heat Capacity techniques were used to investigate thermal diffusivity (D), thermal conductivity (K) and optical path variation with temperature (ds/dT). The outcomes indicate high values for the thermal diffusivity and a relatively small thermal conductivity, i.e., around 2.6×10{sup −3} cm{sup 2}/s and 3.4×10{sup −3} W cm{sup −1} K{sup −1}, respectively. On the other hand, a low ds/dT value, 1.0×10{sup −6} K{sup −1}, was obtained as required for an active laser medium. Moreover, it has been observed that the matrix allows high concentration of dopants without compromising its thermal properties. As a result, PZABP glasses may be pointed out as a promising material to applications in high power photonics devices. - Highlights: • UV transparentglass matrix (PZABP) is used for Yb{sup 3+}doping. • Bulk like and quantum dots like crystals of ZnTe were grown. • Thermal properties point out PZABP as a material to high power photonics devices.

Study on upconversion luminescence and thermal properties of Ho{sup 3+}/Yb{sup 3+} co-doped La{sub 2}O{sub 3}–TiO{sub 2}–ZrO{sub 2} glasses

Energy Technology Data Exchange (ETDEWEB)

Zhang, Minghui; Wen, Haiqin [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Yu, Huimei [Analysis and Testing Center of Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Ai, Fei [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Shao, Hui [School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212003 (China); Pan, Xiuhong; Tang, Meibo; Yu, Jianding; Gai, Lijun [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Liu, Yan, E-mail: liuyan@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China)

2016-07-05

Bulk Ho{sup 3+}/Yb{sup 3+} co-doped La{sub 2}O{sub 3}–TiO{sub 2}–ZrO{sub 2} glass spheres were fabricated by aerodynamic levitation method. High concentration of Yb{sup 3+} ions was successfully doped in glasses. The effects of Yb{sup 3+} concentration on mechanical properties, Raman, absorption spectra, thermal stability, and glass forming ability were studied systematically. Green, red, and infrared emissions centered at 550, 662, and 758 nm were obtained at 980 nm excitation. Yellow light from glass spheres can be easily observed by naked eyes. As Yb{sup 3+} concentration increases, the upconversion luminescence can be improved obviously. The upconversion luminescence mechanism is a two-photon process of energy transfer, excited state absorption, and energy back transfer. The emission intensity can be enhanced in the samples with high Yb{sup 3+} concentration, since the absorption for the incident laser and the energy transfer efficiency are increased, and the nonradiative relaxation probability is reduced. The light color referring to the ratio for red to green emissions can be tuned by Yb{sup 3+} concentration. Ho{sup 3+}/Yb{sup 3+} co-doped La{sub 2}O{sub 3}–TiO{sub 2}–ZrO{sub 2} glasses show promising comprehensive properties and are helpful to speed the application of upconversion luminescence materials. - Highlights: • Ho{sup 3+}/Yb{sup 3+} doped titanate glasses are prepared by containerless processing. • The effects of Yb{sup 3+} on thermal and mechanical properties have been studied. • High concentration of Yb{sup 3+} is favorable to upconversion luminescence. • The mechanisms are energy transfer, excited state absorption, energy back transfer.

A pure silica ytterbium-doped sol–gel-based fiber laser

International Nuclear Information System (INIS)

Baz, Assaad; El Hamzaoui, Hicham; Fsaifes, Ihsan; Bouwmans, Géraud; Bouazaoui, Mohamed; Bigot, Laurent

2013-01-01

In this letter it is demonstrated that the sol–gel route combined with fiber fabrication by the stack and draw method can be used to realize efficient fiber lasers. More precisely, a pure silica ytterbium-doped photonic crystal fiber with a core obtained by the sol–gel polymeric technique is studied, and a laser efficiency of more than 73% is achieved for a laser emission around 1034 nm. The optical and spectroscopic properties of the monolith and fiber are investigated, together with the sensitivity of the fiber to photodarkening. The dimensions of the ytterbium-doped monolith combined with the uniform doping and refractive index that are reported make this technique particularly interesting for the realization of large-mode area fibers. (letter)

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method.

Science.gov (United States)

Gavrilović, Tamara V; Jovanović, Dragana J; Lojpur, Vesna; Dramićanin, Miroslav D

2014-02-27

Synthesis of Eu(3+)- and Er(3+)/Yb(3+)-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each particle comprises a single crystallite. Eu(3+)-doped GdVO4 nanoparticles emit red light through downconversion upon UV excitation. Er(3+)/Yb(3+)-doped GdVO4 nanoparticles exhibit several functions; apart from the downconversion of UV radiation into visible green light, they act as upconvertors, transforming near-infrared excitation (980 nm) into visible green light. The ratio of green emissions from (2)H11/2 → (2)I15/2 and (4)S3/2 → (4)I15/2 transitions is temperature dependent and can be used for nanoscale temperature sensing with near-infrared excitation. The relative sensor sensitivity is 1.11%K(-1), which is among the highest sensitivities recorded for upconversion-luminescence-based thermometers.

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method

Science.gov (United States)

Gavrilović, Tamara V.; Jovanović, Dragana J.; Lojpur, Vesna; Dramićanin, Miroslav D.

2014-02-01

Synthesis of Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each particle comprises a single crystallite. Eu3+-doped GdVO4 nanoparticles emit red light through downconversion upon UV excitation. Er3+/Yb3+-doped GdVO4 nanoparticles exhibit several functions; apart from the downconversion of UV radiation into visible green light, they act as upconvertors, transforming near-infrared excitation (980 nm) into visible green light. The ratio of green emissions from 2H11/2 --> 2I15/2 and 4S3/2 --> 4I15/2 transitions is temperature dependent and can be used for nanoscale temperature sensing with near-infrared excitation. The relative sensor sensitivity is 1.11%K-1, which is among the highest sensitivities recorded for upconversion-luminescence-based thermometers.

Effect of silica surface coating on the luminescence lifetime and upconversion temperature sensing properties of semiconductor zinc oxide doped with gallium(III) and sensitized with rare earth ions Yb(III) and Tm(III).

Science.gov (United States)

Li, Yuemei; Li, Yongmei; Wang, Rui; Zheng, Wei

2018-02-26

Optical sensing of temperature by measurement of the ratio of the intensities of the 700 nm emission and the 800 nm emission of Ga(III)-doped ZnO (GZO) nanoparticles (NPs) and of GZO NPs coated with a silica shell are demonstrated at 980 nm excitation. It is found that the relative sensitivity of SiO 2 @Yb/Tm/GZO is 6.2% K -1 at a temperature of 693 K. This is ~3.4 times higher than that of Yb/Tm/GZO NPs. Obviously, the SiO 2 shell structure decreases the rate of the nonradiative decay. The decay time of the 800 nm emission of the Yb/Tm/GZO NPs (15 mol% Ga; 7 mol% Yb; 0.5 mol% Tm) displays a biexponential decay with a dominant decay time of 148 μs and a second decay time of ~412 μs. The lifetime of the Yb/Tm/GZO NPs at 293 K, and of the SiO 2 @Yb/Tm/GZO NPs are ~412 μs. Both the Yb/Tm/GZO and SiO 2 @Yb/Tm/GZO can be used up to 693 K. These results indicate that the SiO 2 shell on the Yb/Tm/GZO is beneficial in terms of sensitivity and resolution. Graphical abstract The enhancement the decay time and thermal sensitivity in the SiO 2 @Yb/Tm/GZO shell@core structure have been studied compared to the Ga(III)-doped Yb/Tm-doped ZnO (Yb/Tm/GZO). The SiO 2 @Yb/Tm/GZO have good thermal accuracy up to 693 °C.

Quantum efficiency of Yb{sup 3+}–ZnTe co-doped phosphate glass system

Energy Technology Data Exchange (ETDEWEB)

Falci, R.F.; Freitas, A.M.; Silva, G.H. [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG (Brazil); Pinheiro, A.S. [Centro Federal de EducaçãoTecnológica Celso Suckow da Fonseca (CEFET/RJ) - Campus Petrópolis, CEP 25620-003, Petrópolis - RJ (Brazil); Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física da Universidade Federal de Uberlândia, CP 593, CEP 38400-902, Uberlândia, MG (Brazil); Anjos, V., E-mail: virgilio@fisica.ufjf.br [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG (Brazil); Bell, M.J.V. [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG (Brazil)

2016-08-15

The present paper deals with optical properties of a highly transparent phosphate glass co-doped with Yb{sup 3+} and ZnTe nanocrystals. The presence of ZnTe nanocrystals is due to a sequential melting–nucleation procedure evidenced by optical absorption and Atomic Force Microscopy. From the perspective of compositional variation of the dopants, photoluminescence and lifetime measurements were performed. As a result, it was demonstrated that the ZnTe nanocrystals increase the Yb{sup 3+} emission by a factor up to five, when the pumping wavelength is resonant with the ZnTe absorption. It was also verified that the ZnTe nanocrystals inhibit the self-trapping of the rare earth luminescence. As a consequence, the quantum efficiency of the {sup 5}F{sub 7/2}→{sup 5}F{sub 5/2} transitions of the Yb{sup 3+} is considerably increased. Finally, we have found that the glass thermal diffusivity is not sensitive to temperature variations comprising the interval from room temperature to cryogenic temperatures. This can be an important property when considering this material to future applications in high-power photonic devices.

Up-conversion luminescence of Er3+/Yb3+/Nd3+-codoped tellurite glasses

International Nuclear Information System (INIS)

Lu Longjun; Nie Qiuhua; Xu Tiefeng; Dai Shixun; Shen Xiang; Zhang Xianghua

2007-01-01

Up-conversion luminescence and energy transfer (ET) processes in Nd 3+ -Yb 3+ -Er 3+ triply doped TeO 2 -ZnO-Na 2 O glasses have been studied under 800 nm excitation. Intense green up-conversion emissions around 549 nm, which can be attributed to the Er 3+ : 4 S 3/2 →4 I 15/2 transition, are observed in triply doped samples. In contrast, the green emissions are hardly observed in Er 3+ singly doped and Er 3+ -Yb 3+ codoped samples under the same condition. Up-conversion luminescence intensity exhibits dependence of Yb 2 O 3 -concentration and Nd 2 O 3 -concentration. Up-conversion mechanism in the triply doped glasses under 800 nm pump is discussed by analyzing the ET among Nd 3+ , Yb 3+ and Er 3+ . And a possible up-conversion mechanism based on sequential ET from Nd 3+ to Er 3+ through Yb 3+ is proposed for green and red up-conversion emission processes

Radiation resistance of GeO2-doped silica core optical fibers

International Nuclear Information System (INIS)

Shibata, Shuichi; Nakahara, Motohiro; Omori, Yasuharu

1985-01-01

Effects of hlogen addition to silica glass on the loss in optical fibers are examined by using halogen-free, chlorine-containing and fluorine-containing GeO 2 -doped silica core optical fibers. Measurements are made for dependence of induced loss in these optical fibers on various factors such as wavelength and total dose of gamma radiation as well as GeO 2 content. Ultraviolet absorption spectra are also observed. In addition, effects of halogens added to pure silica fibers are considered on the basis of Raman spectra of three different optical fibers (pure, F-doped, and F- and GeO 2 -codoped silica core). Thus, it is concluded that (1) addition of halogens (F and Cl) serves to decrease GeO defects and Ge(3) defects in GeO 2 -doped silica optical fibers ; (2) addition of halogens suppresses the increase in loss in GeO 2 -doped silica optical fibers induced by gamma radiation ; and (3) there are close relations between the increase in loss induced by gamma radiation and defects originally existing in the fibers. Effects of halogens added to GeO 2 -doped and pure silica optical fibers can be explained on the basis of the latter relations. (Nogami, K.)

Erbium-doped fiber ring resonator for resonant fiber optical gyro applications

Science.gov (United States)

Li, Chunming; Zhao, Rui; Tang, Jun; Xia, Meijing; Guo, Huiting; Xie, Chengfeng; Wang, Lei; Liu, Jun

2018-04-01

This paper reports a fiber ring resonator with erbium-doped fiber (EDF) for resonant fiber optical gyro (RFOG). To analyze compensation mechanism of the EDF on resonator, a mathematical model of the erbium-doped fiber ring resonator (EDFRR) is established based on Jones matrix to be followed by the design and fabrication of a tunable EDFRR. The performances of the fabricated EDFRR were measured and the experimental Q-factor of 2 . 47 × 108 and resonant depth of 109% were acquired separately. Compared with the resonator without the EDF, the resonant depth and Q-factor of the proposed device are increased by 2.5 times and 14 times, respectively. A potential optimum shot noise limited resolution of 0 . 042∘ / h can be obtained for the RFOG, which is promising for low-cost and high precise detection.

Cooperative up-conversion processes in SrAl{sub 4}O{sub 7}:Yb and SrAl{sub 4}O{sub 7}:Yb,Tb and their dependence on charge compensation by Na

Energy Technology Data Exchange (ETDEWEB)

Puchalska, M., E-mail: malgorzata.puchalska@chem.uni.wroc.pl [Faculty of Chemistry, University of Wroclaw, 14, F. Joliot-Curie Street, 50-383 Wroclaw (Poland); Zych, E. [Faculty of Chemistry, University of Wroclaw, 14, F. Joliot-Curie Street, 50-383 Wroclaw (Poland); Watras, A. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna Street, 50-422 Wrocław (Poland)

2017-03-15

A detailed analysis of the luminescence behaviour of Yb{sup 3+}-doped and Yb{sup 3+}-Tb{sup 3+} co-doped strontium aluminates powders: Sr{sub 1-x}Yb{sub x}Al{sub 4}O{sub 7} (x=0.002–0.07) and Sr{sub 1-x-y}Yb{sub x}Tb{sub y}Al{sub 4}O{sub 7} (x=0.03; y=0.002–0.02) were performed. The studies of singly doped samples show that direct excitation of Yb{sup 3+} by means of {sup 2}F{sub 7/2}-{sup 2}F{sub 5/2} absorption at 900–980 nm leads to Stokes Yb{sup 3+} emission in the range of 970–1130 nm as well as bluish-green Yb{sup 3+} cooperative luminescence (CL) whose energy doubles that of the NIR one. The effect of activator concentration and charge compensation through Na{sup +} co-doping on both Yb{sup 3+} emissions were also studied. It was found that Na{sup +} addition enhanced Stokes Yb{sup 3+} photoluminescence brightness, while the cooperative emission intensity appeared to be lower. In doubly Yb{sup 3+}-Tb{sup 3+} doped materials excitation at 980 nm led to cooperative sensitization of the Tb{sup 3+} {sup 5}D{sub 4} level giving rise to its green {sup 5}D{sub 4}→{sup 7}F{sub J} (J={sup 7}F{sub 6}-{sup 7}F{sub 3}) up-conversion luminescence with the dominant component around 542 nm. The cooperative energy transfer (CET) mechanism was proposed basing on the results obtained from emission and absorption spectra, decay kinetics as well as the dependence of UC luminescence intensity on NIR excitation power.

High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser.

Science.gov (United States)

Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

2016-07-15

We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900-2000 nm.

Optical properties of Mg2+, Yb3+, and Ho3+ tri-doped LiNbO3 crystals

Science.gov (United States)

Dai, Li; Liu, Chun-Rui; Tan, Chao; Yan, Zhe-Hua; Xu, Yu-Heng

2017-04-01

A series of LiNbO3 crystals tri-doped with Mg{}2+, Yb{}3+, and Ho{}3+ are grown by the conventional Czochraski technique. The concentrations of Mg{}2+, Yb{}3+, and Ho{}3+ ions in Mg:Yb:Ho:LiNbO3 crystals are measured by using an inductively coupled plasma atomic emission spectrometry. The x-ray diffraction is proposed to determine the lattice constant and analyze the internal structure of the crystal. The light-induced scattering of Mg:Yb:Ho:LiNbO3 crystal is quantitatively described via the threshold effect of incident exposure energy flux. The exposure energy ({E}{{r}}) is calculated to discuss the optical damage resistance ability. The exposure energy of Mg(7 mol):Yb:Ho:LiNbO3 crystal is 709.17 J/cm2, approximately 425 times higher than that of the Mg(1 mol):Yb:Ho:LiNbO3 crystal in magnitude. The blue, red, and very intense green bands of Mg:Yb:Ho:LiNbO3 crystal are observed under the 980-nm laser excitation to evaluate the up-conversion emission properties. The dependence of the emission intensity on pumping power indicates that the up-conversion emission is a two-photon process. The up-conversion emission mechanism is discussed in detail. This study indicates that Mg:Yb:Ho:LiNbO3 crystal can be applied to the fabrication of new multifunctional photoluminescence devices. Project supported by the National Natural Science Foundation of China (Grant No. 51301055), the Youth Science Fund of Heilongjiang Province, China (Grant No. QC2015061), the Special Funds of Harbin Innovation Talents in Science and Technology Research, China (Grant No. 2015RQQXJ045 ), and the Science Funds for the Young Innovative Talents of Harbin University of Science and Technology, China (Grant No. 201501).

Nanosecond laser ablation processes in aluminum-doped zinc-oxide for photovoltaic devices

Energy Technology Data Exchange (ETDEWEB)

Canteli, D., E-mail: david.canteli@ciemat.es [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Fernandez, S. [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Molpeceres, C. [Centro Laser, Universidad Politecnica de Madrid, Ctra. de Valencia Km 7.3, 28031 Madrid (Spain); Torres, I.; Gandia, J.J. [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain)

2012-09-15

Highlights: Black-Right-Pointing-Pointer A study of the ablation of AZO thin films deposited at different temperature conditions with nanosecond UV laser light for photovoltaic devices has been performed. Black-Right-Pointing-Pointer The ablation threshold of AZO thin films was measured and related with the absorption coefficient of the films at the laser wavelength, showing a direct correspondence. Black-Right-Pointing-Pointer A change in the material structure in the areas closest to the edges of laser grooves made in samples deposited at temperatures below 100 Degree-Sign C was observed and studied. - Abstract: Aiming to a future use in thin film solar modules, the processing of aluminum doped zinc oxide thin films with good optoelectronic properties with a nanosecond-pulsed ultraviolet laser has been studied. The ablation threshold fluence of the films has been determined and associated with the material properties. The ablation process has been optimized and grooves with good properties for photovoltaic devices have been obtained. The morphology of the ablated surfaces has been observed by confocal microscopy and its structure has been characterized by Raman spectroscopy. The influence of ablation parameters like focus distance, pulse energy and repetition frequency in the groove morphology has been studied with special attention to the thermal effects on the material structure.

Nanosecond laser ablation processes in aluminum-doped zinc-oxide for photovoltaic devices

International Nuclear Information System (INIS)

Canteli, D.; Fernandez, S.; Molpeceres, C.; Torres, I.; Gandía, J.J.

2012-01-01

Highlights: ► A study of the ablation of AZO thin films deposited at different temperature conditions with nanosecond UV laser light for photovoltaic devices has been performed. ► The ablation threshold of AZO thin films was measured and related with the absorption coefficient of the films at the laser wavelength, showing a direct correspondence. ► A change in the material structure in the areas closest to the edges of laser grooves made in samples deposited at temperatures below 100 °C was observed and studied. - Abstract: Aiming to a future use in thin film solar modules, the processing of aluminum doped zinc oxide thin films with good optoelectronic properties with a nanosecond-pulsed ultraviolet laser has been studied. The ablation threshold fluence of the films has been determined and associated with the material properties. The ablation process has been optimized and grooves with good properties for photovoltaic devices have been obtained. The morphology of the ablated surfaces has been observed by confocal microscopy and its structure has been characterized by Raman spectroscopy. The influence of ablation parameters like focus distance, pulse energy and repetition frequency in the groove morphology has been studied with special attention to the thermal effects on the material structure.

Laser-diode pumped 40-W Yb:YAG ceramic laser.

Science.gov (United States)

Hao, Qiang; Li, Wenxue; Pan, Haifeng; Zhang, Xiaoyi; Jiang, Benxue; Pan, Yubai; Zeng, Heping

2009-09-28

We demonstrated a high-power continuous-wave (CW) polycrystalline Yb:YAG ceramic laser pumped by fiber-pigtailed laser diode at 968 nm with 400 mum fiber core. The Yb:YAG ceramic laser performance was compared for different Yb(3+) ion concentrations in the ceramics by using a conventional end-pump laser cavity consisting of two flat mirrors with output couplers of different transmissions. A CW laser output of 40 W average power with M(2) factor of 5.8 was obtained with 5 mol% Yb concentration under 120 W incident pump power. This is to the best of our knowledge the highest output power in end-pumped bulk Yb:YAG ceramic laser.

Experimental study of a Q-switched ytterbium-doped double-clad fiber laser

International Nuclear Information System (INIS)

Anzueto S, G.; Estudillo A, M.; Martinez R, A.; Torres G, I.; Selvas A, R.

2008-01-01

We report an experimental characterization of a Q-switched operation of an all-fiber laser using , 30 m of a double-clad ytterbium-doped fiber spliced to a piece of single-mode un-doped holey fiber. Loss modulation in the splicing point between the active and un-doped fiber due to a substantial coupling of light into lossy cladding modes stimulates pulsed operation of the fiber laser. Pulse energy of ∼2.5 μJ was estimated and the repetition rate was measured in the range of 4-16 KHz. (Author)

Luminescent properties of LuAG:Yb and YAG:Yb single crystalline films grown by Liquid Phase Epitaxy method

International Nuclear Information System (INIS)

Zorenko, Yu; Zorenko, T.; Gorbenko, V.; Voznyak, T.; Popielarski, P.; Batentschuk, M.; Osvet, A.; Brabec, Ch; Kolobanov, V.; Spasky, D.; Fedorov, A.

2016-01-01

In this work, investigation of the spectroscopic parameters of the luminescence of Yb"3"+ ions in single crystalline films of Lu_3Al_5O_1_2 and Y_3Al_5O_1_2 garnets was performed using the synchrotron radiation excitation with the energy in the range of Yb"3"+ charge transitions (CT), exciton range and the onset of interband transitions of these garnets. The basic spectroscopic parameters of the Yb"3"+ CT luminescence in LuAG and YAG hosts were determined and summarized with taking into account the differences in the band gap structure of these garnets. - Highlights: • Single crystalline films of Yb doped LuAG and YAG garnets were grown by LPE method. • Yb"3"+ luminescence of LuAG:Yb and YAG:Yb film were studied using synchrotron radiation. • Basic parameters of Yb"3"+ charge transfer luminescence in LuAG and YAG were determined.

Conversion and quantum efficiency from ultraviolet light to near infrared emission in Yb{sup 3+}-doped pyrovanadates MZnV{sub 2}O{sub 7} (M = Ca, Sr, Ba)

Energy Technology Data Exchange (ETDEWEB)

Guan, Ying; Huang, Yanlin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Tsuboi, Taiju; Huang, Wei [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics and Information Displays and Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816 (China); Chen, Cuili; Cai, Peiqing [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical and Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical and Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

2014-12-15

Highlights: • Efficient convertors of Yb{sup 3+} doped pyrovanadates are prepared and characterized. • Broadband down-conversion from ultraviolet into near-infrared is realized. • High quantum efficiency of 18.5% can be reached. • Energy transfer from VO{sub 4} groups to Yb{sup 3+} ions is demonstrated on the base of the crystal structure. - Abstract: Yb{sup 3+}-doped CaZnV{sub 2}O{sub 7}, SrZnV{sub 2}O{sub 7} and BaZnV{sub 2}O{sub 7} were synthesized via the solid-state reaction. The polycrystalline samples were investigated by XRD and SEM measurements. The reflectance spectra, photoluminescence (PL) excitation and emission spectra, the absolute quantum efficiency (QE) of the IR emission (900–1100 nm) were measured. The efficient conversion from ultraviolet (UV) light to near-infrared (NIR) emission has been demonstrated in the Yb{sup 3+}-doped pyrovanadates by the broadband down conversion from VO{sub 4}{sup 3−} to Yb{sup 3+} ions. Under UV light excitation, an intense NIR emission around 1000 nm ascribed to the {sup 2}F{sub 5/2} → {sup 2}F{sub 7/2} transition of Yb{sup 3+} ions has been observed, which just corresponds to the spectral response of Si solar cells. The NIR emission efficiency is observed to depend on the lattice of pyrovanadate. The mechanism of the NIR emission ascribed to energy transfer is discussed by taking into account the experimental results and the crystal structures.

Holmium-doped fluorotellurite microstructured fibers for 2.1 μm lasing.

Science.gov (United States)

Yao, Chuanfei; He, Chunfeng; Jia, Zhixu; Wang, Shunbin; Qin, Guanshi; Ohishi, Yasutake; Qin, Weiping

2015-10-15

Holmium (Ho3+)-doped fluorotellurite microstructured fibers based on TeO2-BaF2-Y2O3 glasses are fabricated by using a rod-in-tube method. By using a 1.992 μm fiber laser as the pump source, lasing at 2.077 μm is obtained from a 27 cm long Ho3+-doped fluorotellurite microstructured fiber. The maximum unsaturated power is about 161 mW and the corresponding slope efficiency is up to 67.4%. The influence of fiber length on lasing at 2.1 μm is also investigated. Our results show that Ho3+-doped fluorotellurite microstructured fibers are promising gain media for 2.1 μm laser applications.

Solution-mediated cladding doping of commercial polymer optical fibers

Science.gov (United States)

Stajanca, Pavol; Topolniak, Ievgeniia; Pötschke, Samuel; Krebber, Katerina

2018-03-01

Solution doping of commercial polymethyl methacrylate (PMMA) polymer optical fibers (POFs) is presented as a novel approach for preparation of custom cladding-doped POFs (CD-POFs). The presented method is based on a solution-mediated diffusion of dopant molecules into the fiber cladding upon soaking of POFs in a methanol-dopant solution. The method was tested on three different commercial POFs using Rhodamine B as a fluorescent dopant. The dynamics of the diffusion process was studied in order to optimize the doping procedure in terms of selection of the most suitable POF, doping time and conditions. Using the optimized procedure, longer segment of fluorescent CD-POF was prepared and its performance was characterized. Fiber's potential for sensing and illumination applications was demonstrated and discussed. The proposed method represents a simple and cheap way for fabrication of custom, short to medium length CD-POFs with various dopants.

Optical Characterization of Doped Thermoplastic and Thermosetting Polymer-Optical-Fibers

Directory of Open Access Journals (Sweden)

Igor Ayesta

2017-03-01

Full Text Available The emission properties of a graded-index thermoplastic polymer optical fiber and a step-index thermosetting one, both doped with rhodamine 6G, have been studied. The work includes a detailed analysis of the amplified spontaneous emission together with a study of the optical gains and losses of the fibers. The photostability of the emission of both types of fibers has also been investigated. Comparisons between the results of both doped polymer optical fibers are presented and discussed.

Influence of mode competition on beam quality of fiber amplifier

International Nuclear Information System (INIS)

Xiao Qi-Rong; Yan Ping; Sun Jun-Yi; Chen Xiao; Ren Hai-Cui; Gong Ma-Li

2014-01-01

Theoretical and experimental studies of the influence of the mode competition on the output beam quality of fiber amplifiers are presented. Rate equations and modal decomposition method are used in the theoretical model. In the experiment, the output beam-quality factor of a fiber amplifier, which is based on a Yb-doped double-clad large mode area fiber as a function of the seed beam quality and the pump power of the amplifier, is measured. The experimental results are consistent with the theoretical analysis. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Hydrothermal synthesis of superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er core@shell monodisperse nanoparticles and their subsequent ligand exchange in water

Energy Technology Data Exchange (ETDEWEB)

Qin, Zhenli; Du, Sinan; Luo, Yang; Liao, Zhijian; Zuo, Fang, E-mail: polymerzf@swun.cn; Luo, Jianbin; Liu, Dong

2016-08-15

Graphical abstract: An efficient hydrothermal method was used to fabricate the superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2(*)+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures through a seed-growth procedure. Then using PEG phosphate ligand to displace oleate from the as-synthesized NPs, hydrophilic Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs with good water solubility are obtained. - Highlights: • Homogeneous size distribution of magnetic-upconversion core@shell structured nanoparticles (NPs) were synthesized. • The core@shell nanostructures were obtained by seed-growth method. • The oleic acid coated Fe{sub 3}O{sub 4} NPs were used as seeds and cores. • The magnetic-upconversion NPs emitted red luminescence under a 980 nm laser. • Synthesized magnetic-upconversion NPs were phase transferred using ligand exchange process. - Abstract: We report the use of an efficient hydrothermal method to synthesize superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures via a seed-growth procedure. Oleic acid coated Fe{sub 3}O{sub 4} (OA-Fe{sub 3}O{sub 4}) NPs were initially synthesized using a coprecipitation method. The as-synthesized OA-Fe{sub 3}O{sub 4} NPs were then used as seeds, on which the red upconversion luminescent shell (Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er) was formed. Furthermore, hydrophobic to hydrophilic surface modification of the Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs was achieved via a ligand exchange method where oleic acid was displaced by a PEG phosphate ligand [PEG = poly(ethylene glycol)]. These materials were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). The Fe{sub 3}O{sub 4} cores were uniformly coated with a Mn{sup 2+}-doped NaYF{sub 4}:Yb

Enhanced performance of an S-band fiber laser using a thulium-doped photonic crystal fiber

Science.gov (United States)

Muhammad, A. R.; Emami, S. D.; Hmood, J. K.; Sayar, K.; Penny, R.; Abdul-Rashid, H. A.; Ahmad, H.; Harun, S. W.

2014-11-01

This work proposes a new method to enhance the performance of an S-band fiber laser by using a thulium-doped photonic crystal fiber (PCF). The proposed method is based on amplified spontaneous emission (ASE) suppression provided by the thulium-doped PCF unique geometric structure. The enhanced performance of this filter based PCF is dependent on the short and long cut-off wavelength characteristics that define the fiber transmission window. Realizing the short wavelength cut-off location requires the PCF cladding to be doped with a high index material, which provides a refractive index difference between the core and cladding region. Achieving the long cut-off wavelength necessitates enlarging the size of the air holes surrounding the rare-earth doped core region. The PCF structure is optimized so as to achieve the desired ASE suppression regions of below 0.8 μm and above 1.8 μm. The laser performance is simulated for different host media, namely pure silica, alumino-silicate, and fluoride-based fiber ZBLAN based on this thulium-doped PCF design. The host media spectroscopic details, including lifetime variations and quantum efficiency effect on the lasing emission are also discussed. Information on the filter based PCF design is gathered via a full-vectorial finite element method analysis and specifically a numerical modelling solution for the energy level rate equation using the Runge-Kutta method. Results are analyzed for gain improvement, lasing cavity, laser efficiency and effect of core size diameter variation. Results are compared with conventional thulium-doped fiber and thulium-doped PCF for every single host media. We observe that the ZBLAN host media is the most promising candidate due to its greater quantum efficiency.

Enhanced performance of an S-band fiber laser using a thulium-doped photonic crystal fiber

International Nuclear Information System (INIS)

Muhammad, A R; Emami, S D; Penny, R; Ahmad, H; Harun, S W; Hmood, J K; Sayar, K; Abdul-Rashid, H A

2014-01-01

This work proposes a new method to enhance the performance of an S-band fiber laser by using a thulium-doped photonic crystal fiber (PCF). The proposed method is based on amplified spontaneous emission (ASE) suppression provided by the thulium-doped PCF unique geometric structure. The enhanced performance of this filter based PCF is dependent on the short and long cut-off wavelength characteristics that define the fiber transmission window. Realizing the short wavelength cut-off location requires the PCF cladding to be doped with a high index material, which provides a refractive index difference between the core and cladding region. Achieving the long cut-off wavelength necessitates enlarging the size of the air holes surrounding the rare-earth doped core region. The PCF structure is optimized so as to achieve the desired ASE suppression regions of below 0.8 μm and above 1.8 μm. The laser performance is simulated for different host media, namely pure silica, alumino-silicate, and fluoride-based fiber ZBLAN based on this thulium-doped PCF design. The host media spectroscopic details, including lifetime variations and quantum efficiency effect on the lasing emission are also discussed. Information on the filter based PCF design is gathered via a full-vectorial finite element method analysis and specifically a numerical modelling solution for the energy level rate equation using the Runge–Kutta method. Results are analyzed for gain improvement, lasing cavity, laser efficiency and effect of core size diameter variation. Results are compared with conventional thulium-doped fiber and thulium-doped PCF for every single host media. We observe that the ZBLAN host media is the most promising candidate due to its greater quantum efficiency. (paper)

1018 nm Yb-doped high-power fiber laser pumped by broadband pump sources around 915 nm with output power above 100 W

DEFF Research Database (Denmark)

Midilli, Yakup; Efunbajo, Oyewole Benjamin; Şimşek, Bartu

2017-01-01

laser were also addressed in this study. Finally, we have tested this system for high power experimentation and obtained 67% maximum optical-to-optical efficiency at an approximately 110 W output power level. To the best of our knowledge, this is the first 1018 nm ytterbium-doped all-fiber laser pumped...

High-power linearly-polarized operation of a cladding-pumped Yb fibre laser using a volume Bragg grating for wavelength selection.

Science.gov (United States)

Jelger, P; Wang, P; Sahu, J K; Laurell, F; Clarkson, W A

2008-06-23

In this work a volume Bragg grating is used as a wavelength selective element in a high-power cladding-pumped Yb-doped silica fiber laser. The laser produced 138 W of linearly-polarized single-spatial-mode output at 1066 nm with a relatively narrow linewidth of 0.2 nm for approximately 202 W of launched pump power at 976 nm. The beam propagation factor (M(2)) for the output beam was determined to be 1.07. Thermal limitations of volume Bragg gratings are discussed in the context of power scaling for fiber lasers.

Synthesis and Downconversion Emission Property of Yb2O3:Eu3+ Nanosheets and Nanotubes

Directory of Open Access Journals (Sweden)

Chao Qian

2013-01-01

Full Text Available Ytterbium oxide (Yb2O3 nanocrystals with different Eu3+ (1%, 2%, 5%, and 10% doped concentrations were synthesized by a facile hydrothermal method, subsequently by calcination at 700°C. The crystal phase, size, and morphology of prepared samples were characterized by X-ray diffraction (XRD and transmission electron microscopy (TEM. The results show that the as-prepared Yb2O3 nanocrystals with sheet- and tube-like shape have cubic phase structure. The Eu3+ doped Yb2O3 nanocrystals were revealed to have good down conversion (DC property and intensity of the DC luminescence can be modified by Eu3+ contents. In our experiment the 1% Eu3+ doped Yb2O3 nanocrystals showed the strongest DC luminescence among the obtained Yb2O3 nanocrystals.

Components for monolithic fiber chirped pulse amplification laser systems

Science.gov (United States)

Swan, Michael Craig

The first portion of this work develops techniques for generating femtosecond-pulses from conventional fabry-perot laser diodes using nonlinear-spectral-broadening techniques in Yb-doped positive dispersion fiber ampliers. The approach employed an injection-locked fabry-perot laser diode followed by two stages of nonlinear-spectral-broadening to generate sub-200fs pulses. This thesis demonstrated that a 60ps gain-switched fabry-perot laser-diode can be injection-locked to generate a single-longitudinal-mode pulse and compressed by nonlinear spectral broadening to 4ps. Two problems have been identified that must be resolved before moving forward with this approach. First, gain-switched pulses from a standard diode-laser have a number of characteristics not well suited for producing clean self-phase-modulation-broadened pulses, such as an asymmetric temporal shape, which has a long pulse tail. Second, though parabolic pulse formation occurs for any arbitrary temporal input pulse profile, deviation from the optimum parabolic input results in extensively spectrally modulated self-phase-modulation-broadened pulses. In conclusion, the approach of generating self-phase-modulation-broadened pulses from pulsed laser diodes has to be modified from the initial approach explored in this thesis. The first Yb-doped chirally-coupled-core ber based systems are demonstrated and characterized in the second portion of this work. Robust single-mode performance independent of excitation or any other external mode management techniques have been demonstrated in Yb-doped chirally-coupled-core fibers. Gain and power efficiency characteristics are not compromised in any way in this novel fiber structure up to the 87W maximum power achieved. Both the small signal gain at 1064nm of 30.3dB, and the wavelength dependence of the small signal gain were comparable to currently deployed large-mode-area-fiber technology. The efficiencies of the laser and amplifier were measured to be 75% and 54

Application of Nd/sup 3+/-doped silica fibers to radiation sensing devices

International Nuclear Information System (INIS)

Imamura, K.; Suzuki, T.; Gozen, T.; Tanaka, H.; Okamoto, S.

1987-01-01

Applications of rare-earth-ion-doped optical fibers to radiation sensing devices have been studied. It was revealed that rare-earth-ion-doped optical fibers are highly sensitive to radioactive rays such as gamma ray and thermal neutron flux and that they have little dependence on ambient temperature and optical power. An experimental distributed radiation sensing system incorporating Nd/sup 3+/-doped optical fibers, radiation resistant optical fibers and an OTDR was made and tested. The results proved that the distributed sensing system is practically adaptable to the measurement of the radioactive rays

LD-cladding-pumped 50 pm linewidth Tm 3+ -doped silica fiber laser.

Science.gov (United States)

Yunjun, Zhang; Baoquan, Yao; Youlun, Ju; Hui, Zhou; Yuezhu, Wang

2008-05-26

We report on a Tm(3+)-doped fiber laser source operating at 1936.4 nm with a very narrow linewidth (50 pm) laser output. Up to 2.4 W cw laser power was obtained from an 82 cm long Tm(3+)-doped multimode-core fiber cladding pumped by a 792 nm laser diode (LD). The fiber laser cavity included a high-reflective dichroic and a low-reflective FBG output coupler. The multimode fiber Bragg grating (FBG) transmission spectrum and output laser spectrum were measured. By adjusting the distance between the dichroic and the Tm(3+)-doped fiber end, the multipeak laser spectrum changed to a single-peak laser spectrum.

All fiber passively mode locked zirconium-based erbium-doped fiber laser

Science.gov (United States)

Ahmad, H.; Awang, N. A.; Paul, M. C.; Pal, M.; Latif, A. A.; Harun, S. W.

2012-04-01

All passively mode locked erbium-doped fiber laser with a zirconium host is demonstrated. The fiber laser utilizes the Non-Linear Polarization Rotation (NPR) technique with an inexpensive fiber-based Polarization Beam Splitter (PBS) as the mode-locking element. A 2 m crystalline Zirconia-Yttria-Alumino-silicate fiber doped with erbium ions (Zr-Y-Al-EDF) acts as the gain medium and generates an Amplified Spontaneous Emission (ASE) spectrum from 1500 nm to 1650 nm. The generated mode-locked pulses have a spectrum ranging from 1548 nm to more than 1605 nm, as well as a 3-dB bandwidth of 12 nm. The mode-locked pulse train has an average output power level of 17 mW with a calculated peak power of 1.24 kW and energy per pulse of approximately 730 pJ. The spectrum also exhibits a Signal-to-Noise Ratio (SNR) of 50 dB as well as a repetition rate of 23.2 MHz. The system is very stable and shows little power fluctuation, in addition to being repeatable.

Structural, spectroscopic, and tunable laser properties of Yb3+ -doped NaGd(WO4)2

Science.gov (United States)

Cascales, C.; Serrano, M. D.; Esteban-Betegón, F.; Zaldo, C.; Peters, R.; Petermann, K.; Huber, G.; Ackermann, L.; Rytz, D.; Dupré, C.; Rico, M.; Liu, J.; Griebner, U.; Petrov, V.

2006-11-01

Single crystals of Yb3+ -doped NaGd(WO4)2 with up to 20mol% ytterbium content have been grown by the Czochralski technique in air or in N2+O2 atmosphere and cooled to room temperature at different rates (4-250°C/h) . Only the noncentrosymmetric tetragonal space group I4¯ accounts for all reflections observed in the single crystal x-ray diffraction analysis. The distortion of this symmetry with respect to the centrosymmetric tetragonal space group I41/a is much lower for crystals cooled at a fast rate. Na+ , Gd3+ , and Yb3+ ions share the two nonequivalent 2b and 2d sites of the I4¯ structure, but Yb3+ (and Gd3+ ) ions are found preferentially in the 2b site. Optical spectroscopy at low (5K) temperature provides additional evidence of the existence of these two sites contributing to the line broadening. The comparison with the F7/22(n) and F5/22(n') Stark energy levels calculated using the crystallographic Yb-O bond distances allows to correlate the experimental optical bands with the 2b and 2d sites. As a novel uniaxial laser host for Yb3+ , NaGd(WO4)2 is characterized also with respect to its transparency, band-edge, refractive indices, and main optical phonons. Continuous-wave Yb3+ -laser operation is studied at room temperature both under Ti:sapphire and diode laser pumping. A maximum slope efficiency of 77% with respect to the absorbed power is achieved for the π polarization by Ti:sapphire laser pumping in a three-mirror cavity with Brewster geometry. The emission is tunable in the 1014-1079nm spectral range with an intracavity Lyot filter. Passive mode locking of this laser produces 120fs long pulses at 1037.5nm with an average power of 360mW at ≈97MHz repetition rate. Using uncoated samples of Yb:NaGd(WO4)2 at normal incidence in simple two-mirror cavities, output powers as high as 1.45W and slope efficiencies as high as 51% are achieved with different diode laser pump sources.

Infrared to visible upconversion luminescence in Er3+/Yb3+ co-doped CeO2 inverse opal

International Nuclear Information System (INIS)

Yang, Zhengwen; Wu, Hangjun; Liao, Jiayan; Li, Wucai; Song, Zhiguo; Yang, Yong; Zhou, Dacheng; Wang, Rongfei; Qiu, Jianbei

2013-01-01

Highlights: • UC emission of Er 3+ was modified by introducing the structure of inverse opal. • Color tuning of CeO 2 :Yb, Er inverse opal was realized by inhibition of UC emission. • Two-photon excitation processes were observed in CeO 2 :Yb, Er inverse opal. -- Abstract: Infrared to visible upconversion luminescence has been investigated in Er 3+ /Yb 3+ co-doped CeO 2 inverse opal. Under the excitation of 980 nm diode lasers, visible emissions centered at 525, 547, 561, 660 and 680 nm are observed, which are assigned to the Er 3+ transitions of 2 H 11/2 → 4 I 15/2 (525 nm), 4 S 3/2 → 4 I 15/2 (547, 561 nm), 4 F 9/2 → 4 I 15/2 (660 and 680 nm), respectively. The effect of photonic band gap on the upconversion luminescence intensity was also obtained. Additionally, the upconversion luminescence mechanism was studied. The dependence of Er 3+ upconversion emission intensity on pump power reveals that it is a two-photon excitation process

Theoretical Investigation of Oxazine 170 Perchlorate Doped Polymeric Optical Fiber Amplifier

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Piotr Miluski

2017-01-01

Full Text Available Optical signal amplification in the waveguiding structure of optical fibers can be used for optical telecommunication systems and new light sources constructions. Organic dyes doped materials are interesting for new applications in polymeric optical fibers technology due to their benefits (efficient fluorescence, high absorption cross section, and easy processing. This article presents a numerical simulation of gain in poly(methyl methacrylate optical fiber doped by Oxazine 170 Perchlorate. The calculated gain characteristic for the used dye molar concentration (0.2·10-6–1.4·10-6 and pump power (1–10 kW is presented. The fabricated fluorescent polymeric optical fiber is also shown. The presented analysis can be used for optical amplifier construction based on dye-doped polymeric optical fiber (POF.

Upconversion luminescence of Er3+/Yb3+ doped Sr5(PO4)3OH phosphor powders

Science.gov (United States)

Mokoena, P. P.; Swart, H. C.; Ntwaeaborwa, O. M.

2018-04-01

Sr5(PO4)3OH co-doped with Er3+and Yb3+ powder phosphors were synthesized by urea combustion method. The crystal structure was analyzed using X-ray diffraction (XRD). Particle morphology was analyzed using a Jeol JSM 7800F thermal field emission scanning electron microscope (FE-SEM) and the chemical composition analysis was carried out using an Oxford Instruments AzTEC energy dispersive spectrometer (EDS) attached to the FE-SEM. Upconversion emission was measured by using a FLS980 Spectrometer equipped with a 980 nm NIR laser as the excitation source, and a photomultiplier (PMT) detector. The XRD data of the Sr5(PO4)3OH powder exhibited characteristic diffraction patterns of the hexagonal structure referenced in the standard JCPDS card number 00-033-1348. The sharp peaks revealed the formation of crystalline Sr5(PO4)3OH. The powders were made up of hexagonal nanospheres. The enhanced red emission due to the 4F9/2 → 4I15/2 transitions of Er3+ was observed and was attributed to up conversion (UC) energy transfer from Yb3+. The upconversion energy transfer mechanism from Yb3+ to Er3+ is discussed.

2μm all fiber multi-wavelength Tm/Ho co-doped fiber laser

Science.gov (United States)

Zhang, Junhong; Jiang, Qiuxia; Wang, Xiaofa

2017-10-01

A 2 μm all fiber multi-wavelength Tm/Ho co-doped fiber laser based on a simple ring cavity is experimentally demonstrated. Compared with other 2 μm multi-wavelength Tm/Ho co-doped fiber lasers, the multi-wavelength fiber laser is obtained by the gain saturation effect and inhomogeneous broadening effect without any frequency selector component, filter component or polarization-dependent component. When the pump power is about 304 mW, the fiber laser enters into single-wavelength working state around 1967.76 nm. Further increasing the pump power to 455 mW, a stable dual-wavelength laser is obtained at room temperature. The bimodal power difference between λ1 and λ2 is 5.528 dB. The fluctuations of wavelength and power are less than 0.03 nm and 0.264 dB in an hour, which demonstrates that the multi-wavelength fiber laser works at a stable state. Furthermore, a research about the relationship between the pump power and the output spectra has been made.

Wavelength dependence of the Brillouin spectral width of boron doped germanosilicate optical fibers.

Science.gov (United States)

Law, Pi-Cheng; Dragic, Peter D

2010-08-30

Boron co-doped germanosilicate fibers are investigated via the Brillouin light scattering technique using two wavelengths, 1534 nm and 1064 nm. Several fibers are investigated, including four drawn from the same preform but at different draw temperatures. The Stokes' shifts and the Brillouin spectral widths are found to increase with increasing fiber draw temperature. A frequency-squared law has adequately described the wavelength dependence of the Brillouin spectral width of conventional Ge-doped fibers. However, it is found that unlike conventional Ge-doped fibers these fibers do not follow the frequency-squared law. This is explained through a frequency-dependent dynamic viscosity that modifies this law.

Biocompatible Er, Yb co-doped fluoroapatite upconversion nanoparticles for imaging applications

Science.gov (United States)

Anjana, R.; K. M., Kurias; M. K., Jayaraj

2017-08-01

Upconversion luminescence, visible emission on infra red (IR) excitation was achieved in a biocompatible material, fluoroapatite. Fluoroapatite crystals are well known biomaterials, which is a component of tooth enamel. Also it can be considered as an excellent host material for lanthanide doping since the ionic radii of lanthanide is similar to that of calcium ion(Ca2+) hence successful incorporation of dopants within the lattice is possible. Erbium (Er), Ytterbium (Yb) co-doped fluorapatite (FAp) nanoparticles were prepared by precipitation method. The particles show intense visible emission when excited with 980 nm laser. Since upconversion luminescence is a multiphoton process the excitation power dependence on emission will give number of photons involved in the emission of single photon. Excitation power dependence studies show that two photons are involved in the emission of single photons. The value of slope was different for different emission peak because of the difference in intermediate energy level involved. The crystal structure and morphology of the particle were determined using X-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM). These particles with surface functionalisation can be used for live cell imaging.

Electron spin resonance in Yb-based Kondo-lattice systems; Elektronenspinresonanz in Yb-basierten Kondogitter-Systemen

Energy Technology Data Exchange (ETDEWEB)

Wykhoff, Jan

2010-07-07

The systems Yb{sub 1-w}A{sub 1-w}(Rh{sub 1-x}Co{sub x})(Si{sub 1-y}Ge{sub y}){sub 2} with A=La respectively Lu, as well as YbIr{sub 2}Si{sub 2} are studied. The measurements are presented sortedly for systems, dopings, and external parameters. Beside these external parameters furthermore the orientation of the sample related to the quasistatic magnetic field and the microwave magnetic field was varied.

Thermoluminescence and optically stimulated luminescence properties of nanocrystalline Er3+ and Yb3+ doped Y3Al5O12 exposed to β-rays

International Nuclear Information System (INIS)

RodrIguez, R A; Rosa, E de la; Salas, P; Melendrez, R; Barboza-Flores, M

2005-01-01

The thermoluminescence (TL) and optically stimulated luminescence (OSL) characterization of Er 3+ and Yb 3+ doped Y 3 Al 5 O 12 nanocrystalline samples prepared by the precipitation process and exposed to β-rays are discussed. The TL as well as the OSL were two orders of magnitude higher in Er 3+ doped than in Yb 3+ specimens. The charge trapping and the radiative thermally stimulated recombination processes in Y 3 Al 5 O 12 : Er 3+ involve four trapping states at 166, 243, 342 and 424 deg. C, but just two trapping levels at 219 and 413 deg. C for Y 3 Al 5 O 12 : Yb 3+ at a heating rate of 10 deg. C s -1 . The photostimulation with 470 nm light causes in both phosphors a radiative recombination of the optically free charge carriers belonging to the same trapping states. The TL and the OSL as a function of radiation dose behaviour were linear in the 10-100 Gy dose range. The results provide evidence of the potential uses of these materials in radiation storage and dosimeter devices

Nanosecond Q-switched operation of coupled Yb and Tm fibre lasers

Energy Technology Data Exchange (ETDEWEB)

Tsang, Yuen H [Laser Photonics Research Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Qamar, Fadi [Laser Photonics Research Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); King, Terence A [Laser Photonics Research Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Ko, Do-Kyeong [Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-Gu, Gwangju 500-712 (Korea, Republic of); Lee, Jongmin [Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-Gu, Gwangju 500-712 (Korea, Republic of)

2005-05-07

A small scale coupled Yb-silica and Tm-silica fibre laser system is described with output at 1.9 {mu}m and with Q-switching using an acousto-optic modulator and also by mechanical optical modulation. The Yb-fibre laser pump source exhibited strong self-pulsation with high-intensity pulses due to stimulated Brillouin scattering. But regular Q-switched pulses were generated from the Tm-fibre laser with an energy of {approx}2.4 {mu}J and duration (FWHM) of {approx}280 ns for modulation frequencies of 1-20 kHz when using acousto-optic modulation. The main effects that limit the Q-switched pulse peak power are the onset of gain-switched pulsing during the low-Q state and strong pump excited state absorption.

Experimental demonstration of an Er-doped fiber ring laser mode-locked with a Tm–Ho co-doped fiber saturable absorber

International Nuclear Information System (INIS)

Tao, Mengmeng; Wu, Junjie; Wu, Yong; Yang, Pengling; Ye, Xisheng; Peng, Junsong

2013-01-01

Mode-locking operation of an Er-doped fiber laser with a Tm–Ho co-doped fiber saturable absorber is demonstrated for the first time. Q-switching, Q-switched mode-locking and CW mode-locking operation modes are observed sequentially with increase of the pump power. In the mode-locking operation mode, a repetition rate at the fundamental cavity frequency of 9.05 MHz is obtained with a pulse duration of 46.3 ns. By rotating the polarization controller, a repetition rate up to 887 MHz is achieved, and the pulse duration is shortened to 0.548 ns. (paper)

Sol-Gel Derived Active Material for Yb Thin-Disk Lasers.

Science.gov (United States)

Almeida, Rui M; Ribeiro, Tiago; Santos, Luís F

2017-09-02

A ytterbium doped active material for thin-disk laser was developed based on aluminosilicate and phosphosilicate glass matrices containing up to 30 mol% YbO 1.5 . Thick films and bulk samples were prepared by sol-gel processing. The structural nature of the base material was assessed by X-ray diffraction and Raman spectroscopy and the film morphology was evidenced by scanning electron microscopy. The photoluminescence (PL) properties of different compositions, including emission spectra and lifetimes, were also studied. Er 3+ was used as an internal reference to compare the intensities of the Yb 3+ PL peaks at ~ 1020 nm. The Yb 3+ PL lifetimes were found to vary between 1.0 and 0.5 ms when the Yb concentration increased from 3 to 30 mol%. Based on a figure of merit, the best active material selected was the aluminosilicate glass composition 71 SiO₂-14 AlO 1.5 -15 YbO 1.5 (in mol%). An active disk, ~ 36 μm thick, consisting of a Bragg mirror, an aluminosilicate layer doped with 15 mol% Yb and an anti-reflective coating, was fabricated.

Enhanced oxidation resistance of carbon fiber reinforced lithium aluminosilicate composites by boron doping

International Nuclear Information System (INIS)

Xia, Long; Jin, Feng; Zhang, Tao; Hu, Xueting; Wu, Songsong; Wen, Guangwu

2015-01-01

Highlights: • C f /LAS composites exhibit enhanced oxidation resistance by boron doping. • Boron doping is beneficial to the improvement of graphitization degree of carbon fibers. • Graphitization of carbon fibers together with the decrease of viscosity of LAS matrix is responsible to the enhancement of oxidation resistance of C f /LAS composites. - Abstract: Carbon fiber reinforced lithium aluminosilicate matrix composites (C f /LAS) modified with boron doping were fabricated and oxidized for 1 h in static air. Weight loss, residual strength and microstructure were analyzed. The results indicate that boron doping has a remarkable effect on improving the oxidation resistance for C f /LAS. The synergism of low viscosity of LAS matrix at high temperature and formation of graphite crystals on the surface of carbon fibers, is responsible for excellent oxidation resistance of the boron doped C f /LAS.

Proton irradiation effects on optical attenuation in doped- and pure-silica fibers

International Nuclear Information System (INIS)

Sakasai, Kaoru; Bueker, H.; Haesing, F.W.; Pfeiffer, F.

1999-05-01

Optical attenuation in doped- and pure-silica fibers was measured at wavelengths of 470 nm, 660 nm, and 850 nm during and after 20 MeV proton irradiation. In the experiment the fibers were arranged on a holder to make one layer' so that uniform proton irradiation can be achieved to them. The induced loss of the doped-silica fiber increased strongly at the beginning of the first irradiation, and decreased slowly after stopping of the beam. In the second irradiation, however, the developed loss was not so large. On the other hand, the loss of the pure-silica fiber increased gradually in the first irradiation, and decreased very quickly after the beam stopped. The loss increased stepwise at the very beginning of the second irradiation. Small luminescence from the fibers during irradiation was observed also. The luminescence of the pure-silica fiber was slightly larger than that of the doped-silica fiber. The induced loss of HCP fibers was also measured when a SiO 2 plate was set in front of the fibers. It may be possible to estimate the proton dose in materials using fiber-optic technique. Proton sensitivities of doped- and pure-silica fibers were, respectively, 1.0 x 10 -10 at 660 nm and 5.5 x 10 -12 at 470 nm in units of (dB/m)/(protons/cm 2 ), where the values were estimated from the slope of the loss growth curves at the beginning of the first irradiation. (author)

Growth of Yb3+-doped Y2O3 single crystal rods by the micro-pulling-down method

International Nuclear Information System (INIS)

Mun, J.H.; Novoselov, A.; Yoshikawa, A.; Boulon, G.; Fukuda, T.

2005-01-01

The rare-earth sesquioxides (RE 2 O 3 , RE = Lu, Y and Sc) are very promising host crystals for advanced laser diode (LD)-pumped Yb 3+ -doped solid-state lasers due to unusual combination, almost unique of favourable structural, thermal and spectroscopic properties which are described. In spite of these favourable properties, the bulk single crystal growth technology for the rare-earth sesquioxides has not been established yet. The extremely high melting temperature at around 2400 deg. C has prevented it. However, we shall show that yttrium oxide crystals (Yb x Y 1-x ) 2 O 3 , x = 0.0, 0.005, 0.05, 0.08 and 0.15 of cylindrical shape as laser rods with 4.2 mm in diameter and 15-20 mm in length have been grown from rhenium crucibles by the micro-pulling-down method. The crystal quality characterisation of undoped Y 2 O 3 crystal was determined using X-ray rocking curve (XRC) analysis. Yb were homogeneously distributed in Y 2 O 3 host crystal

Cutting and drilling of carbon fiber reinforced plastics (CFRP) by 70W short pulse nanosecond laser

Science.gov (United States)

Jaeschke, Peter; Stolberg, Klaus; Bastick, Stefan; Ziolkowski, Ewa; Roehner, Markus; Suttmann, Oliver; Overmeyer, Ludger

2014-02-01

Continuous carbon fibre reinforced plastics (CFRP) are recognized as having a significant lightweight construction potential for a wide variety of industrial applications. However, a today`s barrier for a comprehensive dissemination of CFRP structures is the lack of economic, quick and reliable manufacture processes, e.g. the cutting and drilling steps. In this paper, the capability of using pulsed disk lasers in CFRP machining is discussed. In CFRP processing with NIR lasers, carbon fibers show excellent optical absorption and heat dissipation, contrary to the plastics matrix. Therefore heat dissipation away from the laser focus into the material is driven by heat conduction of the fibres. The matrix is heated indirectly by heat transfer from the fibres. To cut CFRP, it is required to reach the melting temperature for thermoplastic matrix materials or the disintegration temperature for thermoset systems as well as the sublimation temperature of the reinforcing fibers simultaneously. One solution for this problem is to use short pulse nanosecond lasers. We have investigated CFRP cutting and drilling with such a laser (max. 7 mJ @ 10 kHz, 30 ns). This laser offers the opportunity of wide range parameter tuning for systematic process optimization. By applying drilling and cutting operations based on galvanometer scanning techniques in multi-cycle mode, excellent surface and edge characteristics in terms of delamination-free and intact fiber-matrix interface were achieved. The results indicate that nanosecond disk laser machining could consequently be a suitable tool for the automotive and aircraft industry for cutting and drilling steps.

Submicrosecond Q-Switching Er-Doped All-Fiber Ring Laser Based on Black Phosphorus

Directory of Open Access Journals (Sweden)

Yao Cai

2017-01-01

Full Text Available Black phosphorus (BP, a new two-dimensional (2D material, has been deeply developed for extensive applications in electronics and optoelectronics due to its similar physical structure to graphene and thickness dependent direct band gap. Here, we demonstrated a submicrosecond passive Q-switching Er-doped fiber laser with BP as saturable absorber (SA. The BP saturable absorber was fabricated by mechanical exfoliation method. By taking full advantage of the ultrafast relaxation time of BP-SA and careful design of compact ring cavity, we obtained stable Q-switching pulses output with a shortest duration as narrow as 742 ns. With increasing the pump power, the pulse repetition rate accreted gradually almost linearly from 9.78 to 61.25 kHz, and the pulse duration declined rapidly at lower pump power regime and retained approximate stationary at higher pump power regime from 3.05 to 0.742 μs. The experimental results indicate that BP-SA can be an effective SA for nanosecond Q-switching pulse generation.

Infrared emissions in MgSrAl10O17:Er3+ phosphor co-doped with Yb3+/Ba2+/Ca2+ obtained by solution combustion route

International Nuclear Information System (INIS)

Singh, Vijay; Kumar Rai, Vineet; Venkatramu, V.; Chakradhar, R.P.S.; Hwan Kim, Sang

2013-01-01

An intense infrared emitting MgSrAl 10 O 17 :Er 3+ phosphor co-doped with Yb 3+ , Ba 2+ and Ca 2+ ions have been prepared by a solution combustion method. Phase purity of the derived compounds was confirmed by X-ray diffraction technique. The vibrational properties of MgSrAl 10 O 17 phosphor was studied by Fourier transform infrared spectroscopy. The broad and strong infrared emission of Er 3+ ions at around 1.53 μm was observed upon excitation at 980 nm. Effect of co-doping with the Yb 3+ , Ba 2+ and Ca 2+ ions on the infrared luminescence intensity of Er 3+ ions and the mechanism responsible for the variation in the infrared intensity have been discussed. The results indicate that these materials may be suitable for the optical telecommunication window and wavelength division multiplexing applications. - Highlights: ► The hexagonal phase of MgSrAl 10 O 17 could be obtained by the low temperature combustion method. ► The broad and strong infrared emission of Er 3+ ions at around 1.53 μm was observed. ► Effect of co-doping with the Yb 3+ , Ba 2+ and Ca 2+ ions on the infrared luminescence intensity of Er 3+ were reported.

Energy transfer processes in Yb{sup 3+}-Tm{sup 3+} co-doped sodium alumino-phosphate glasses with improved 1.8 {mu}m emission

Energy Technology Data Exchange (ETDEWEB)

Camargo, Andrea S S de; Terra, Idelma A A; Nunes, Luiz Antonio de O; Li, M Siu [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, 13560-970, Sao Carlos-SP (Brazil)], E-mail: andreasc@ifsc.usp.br

2008-06-25

Sodium alumino-phosphate glasses co-doped with Yb{sup 3+} and Tm{sup 3+} ions have been prepared with notably low OH{sup -} content, and characterized from the viewpoint of their spectroscopic properties. In these glasses, Yb{sup 3+} acts as an efficient sensitizer of excitation energy at 0.98 {mu}m-which can be provided by high power and low cost diode lasers, and subsequently undergoes non-resonant energy transfer to Tm{sup 3+} ions ({sup 2}F{sub 5/2}, {sup 3}H{sub 6} {yields} {sup 2}F{sub 7/2}, {sup 3}H{sub 5}). Through this process, the emitting level {sup 3}F{sub 4} is rapidly populated, generating improved emission at 1.8 {mu}m ({sup 3}F{sub 4} {yields} {sup 3}H{sub 6}). In order to guarantee the efficiency of such favorable energy transfer, energy losses via multiphonon decay, Yb-Yb radiative trapping, and non-radiative transfer to OH{sup -} groups were evaluated, and minimized when possible. The dipole-dipole energy transfer microscopic parameters corresponding to Yb{sup 3+} {yields} Tm{sup 3+}, Yb{sup 3+} {yields} Yb{sup 3+} and Tm{sup 3+} {yields} Tm{sup 3+} transfers, calculated by the Foerster-Dexter model, are C{sub Yb-Tm} = 2.9 x 10{sup -40} cm{sup 6} s{sup -1}, C{sub Yb-Yb} = 42 x 10{sup -40} cm{sup 6} s{sup -1} and C{sub Tm-Tm} = 43 x 10{sup -40} cm{sup 6} s{sup -1}, respectively.

Yb3+ sensitized Tm3+ upconversion in tellurite lead oxide glass.

Science.gov (United States)

Mohanty, Deepak Kumar; Rai, Vineet Kumar; Dwivedi, Y

2012-04-01

Triply ionized thulium/thulium--ytterbium doped/codoped TeO2-Pb3O4 (TPO) glasses have been fabricated by classical quenching method. The upconversion emission spectra in the Tm3+/Tm3+-Yb3+ doped/codoped glasses upon excitation with a diode laser lasing at ∼980 nm has been studied. Effect of the addition of the Yb3+ on the upconversion emission intensity in the visible and near infrared regions of the Tm3+ doped in TPO glass has been studied and the processes involved explored. Copyright © 2011 Elsevier B.V. All rights reserved.

Spectral and laser properties of Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 crystal at 1.55 µm

Science.gov (United States)

Gong, Guoliang; Chen, Yujin; Lin, Yanfu; Huang, Jianhua; Gong, Xinghong; Luo, Zundu; Huang, Yidong

2018-04-01

An Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 (CNGS) crystal was grown by the Czochralski method. Spectral properties of the crystal, including the polarized absorption and fluorescence spectra, the fluorescence decay, as well as the energy transfer efficiency from Yb3+ to Er3+ were investigated in detail. End-pumped by a 976 nm diode laser, a 1556 nm continuous-wave laser with a maximum output power of 202 mW and a slope efficiency of 11.4% was achieved in the Er,Yb,Ce:CNGS crystal. The results indicate the Er,Yb,Ce:CNGS crystal is a promising 1.55 µm laser gain medium.

Spatially selective Er/Yb-doped CaF2 crystal formation by CO2 laser exposure

International Nuclear Information System (INIS)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo

2014-01-01

Highlights: • Oxyfluoride glass–ceramics containing CaF 2 nanocrystals doped with Er 3+ and Yb 3+ ions were formed on the glass surface by CO 2 laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF 2 nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO 2 laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF 2 and miner Ca 2 SiO 4 nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment

Spatially selective Er/Yb-doped CaF2 crystal formation by CO2 laser exposure

International Nuclear Information System (INIS)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo

2015-01-01

Highlights: • Oxyfluoride glass–ceramics containing CaF 2 nanocrystals doped with Er 3+ and Yb 3+ ions were formed on the glass surface by CO 2 laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF 2 nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO 2 laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF 2 and miner Ca 2 SiO 4 nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment

Thermoluminescence characteristics of Ge-doped optical fibers with different dimensions for radiation dosimetry

International Nuclear Information System (INIS)

Begum, Mahfuza; Rahman, A.K.M. Mizanur; Abdul-Rashid, H.A.; Yusoff, Z.; Begum, Mahbuba; Mat-Sharif, K.A.; Amin, Y.M.; Bradley, D.A.

2015-01-01

Important thermoluminescence (TL) properties of five (5) different core sizes Ge-doped optical fibers have been studied to develop new TL material with better response. These are drawn from same preform applying different speed and tension during drawing phase to produce Ge-doped optical fibers with five (5) different core sizes. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge-doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (SEM) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in Secondary Standard Dosimetry Lab (SSDL) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are TL linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 °C for 1 h period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 h at 400 °C and subsequently 2 h at 100 °C to yield the highest sensitivity. TL responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z eff ) is found in the range (13.25–13.69) which is higher than soft tissue (7.5) however within the range of human-bone (11.6–13.8). All the fibers can also be re-used several times as a detector after annealing. TL properties of the Ge-doped optical fibers indicate promising applications in

Gain-switched, Yb-doped, all-fiber laser with narrow bandwidth

DEFF Research Database (Denmark)

Larsen, Casper; Giesberts, Martin; Nyga, Sebastian

2013-01-01

We demonstrate that an all-fiber, narrow bandwidth, high pulse energy pulsed laser can be constructed from commercially available components by applying gain-switching. After single-stage amplification the pulses are frequency doubled in ppSLT with high efficiency....

Self-induced laser line sweeping in double-clad Yb-doped fiber-ring lasers

Czech Academy of Sciences Publication Activity Database

Peterka, Pavel; Navrátil, P.; Maria, J.; Dussardier, B.; Slavík, Radan; Honzátko, Pavel; Kubeček, V.

2012-01-01

Roč. 9, č. 6 (2012), s. 445-450 ISSN 1612-2011 R&D Projects: GA MŠk(CZ) ME10119 Institutional support: RVO:67985882 Keywords : fiber laser * tunable laser * ytterbium Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 7.714, year: 2012

Sub?40?fs, 1060?nm Yb?fiber laser enhances penetration depth in nonlinear optical microscopy of human skin

OpenAIRE

Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

2015-01-01

© 2015 The Authors. Advancing the practical utility of nonlinear optical microscopy requires continued improvement in imaging depth and contrast. We evaluated second-harmonic generation (SHG) and third-harmonic generation images from ex vivo human skin and showed that a sub-40 fs, 1060-nm Yb-fiber laser can enhance SHG penetration depth by up to 80% compared to a > 100 fs, 800 nm Ti:sapphire source. These results demonstrate the potential of fiber-based laser systems to address a key perform...

Highly photosensitive polymethyl methacrylate microstructured polymer optical fiber with doped core

DEFF Research Database (Denmark)

Sáez-Rodríguez, D.; Nielsen, Kristian; Rasmussen, Henrik K.

2013-01-01

, providing a grating with a strong transmission rejection of −23  dB with an inscription time of only 13 min. The fabrication method has a big advantage compared to doping step index fiber since it enables doping of the fiber without using extra dopants to compensate for the index reduction in the core...

Characterization and Computation of Yb/TiO2 and Its Photocatalytic Degradation with Benzohydroxamic Acid

Directory of Open Access Journals (Sweden)

Xianping Luo

2017-11-01

Full Text Available Yb-doped TiO2 (Yb/TiO2 compositions were synthesized by sol-gel method, and the prepared materials were characterized by X-ray Diffraction (XRD, X-ray photoelectron spectroscopy (XPS, UV-visible diffuse-reflectance spectrum (UV-Vis DRS, transmission electron microscope (TEM and high resolution transmission electron microscope (HRTEM, energy dispersive spectrometer (EDS, and N2 adsorption. A beneficiation reagent of benzohydroxamic acid (BHA was used to test the photocatalytic activity of Yb/TiO2. The characterizations indicate that the doping of Yb could inhibit the crystal growth of TiO2, enhance the specific surface area, increase the binding energy of Ti2p, and also slightly expand the adsorption ranges to visible light. Furthermore, the computation of band structure also indicates that Yb-doped TiO2 could make the forbidden band narrower than pure anatase TiO2, which presents a red shift in the absorption spectrum. As a result of the photodegradation experiment on BHA, Yb/TiO2 (0.50% in mass sintered at 450 °C displayed the highest catalytic activity for BHA when compared with pure TiO2 or other doped Yb/TiO2 compositions, and more than 89.2% of the total organic carbon was removed after 120 min. Almost all anions, including Cl−, HCO3−, NO3−, and SO42−, inhibited the degradation of BHA by Yb/TiO2, and their inhibition effects followed the order of HCO3− > NO3− > SO42− > Cl−. Cations of Na+, K+, Ca2+, and Mg2+ displayed a slight suppressing effect due to the impact of Cl− coexisting in the solution. In addition, Yb/TiO2 maintained a high photocatalytic ability with respect to BHA after four runs. It is hypothesized that ·OH is one of the main species involved in the photodegradation of BHA, and the mutual transformation of Yb3+ and Yb2+ could promote the separation of electron-hole pairs.

Transverse mode instability in high-power ytterbium doped fiber ampliers

DEFF Research Database (Denmark)

Hansen, Kristian Rymann

The last couple of decades have brought an impressive growth in the output power of rare-earth doped fiber lasers and amplifiers, reaching the kW average power regime in both CW and pulsed systems. As a result, even though fiber lasers have excellent heat dissipation properties, thermal effects due...... is to provide a theoretical understanding of the thermo-optical effects in high-power ytterbium doped fiber amplifiers, with a particular emphasis on understanding the aforementioned mode instability issue. Two main approaches to the problem have been used. The first is the development of a numerical model...

Spectral properties and laser performances of Yb3+:LaCa4O(BO3)3 crystal with high concentration doping

International Nuclear Information System (INIS)

Ji, Yuexia; Cao, Jiafeng; Xu, Jinlong; You, Zhenyu; Zhu, Zhaojie; Li, Jianfu; Wang, Yan; Tu, Chaoyang

2013-01-01

Highlights: •Yb 3+ :LaCa 4 O(BO 3 ) 3 single crystal was grown with high concentration doping. •Laser potentiality was evaluated based on the spectral and laser parameters. •Continuous wave laser operation was realized. •An output power of 0.77 W and a slope efficiency of 15.71% at 1077 nm were obtained. •The spectra and laser properties of Yb 3+ :LaCa 4 O(BO 3 ) 3 crystal were firstly reported. -- Abstract: High concentration of 15 at.% Yb 3+ doped LaCa 4 O(BO 3 ) 3 (LaCOB) crystal was grown by Czochralski technique. The absorption cross section was conclulated to be 0.63 × 10 −20 cm 2 at 977 nm and the emission cross section to be 0.39 × 10 −20 cm 2 at 1030 nm, with the FWHM of 6.15 and 33 nm respectively. Laser potentiality was evaluated based on the gain cross section σ g , the minimum inversion fraction β min and the minimum pump intensity I min , which were calculated to be 0.18 × 10 −20 cm 2 , 0.05 and 0.47 kw/cm 2 , respectively. Continuous wave laser operation was realized with an output power of 0.77 W and a slope efficiency of 15.71%. The laser emitted around 1077 nm. The radiation trapping and continuous pump mode are contributed to the lasing wavelength for present crystal

Compact frequency-modulation Q-switched single-frequency fiber laser at 1083 nm

International Nuclear Information System (INIS)

Zhang, Yuanfei; Feng, Zhouming; Xu, Shanhui; Mo, Shupei; Yang, Changsheng; Li, Can; Gan, Jiulin; Chen, Dongdan; Yang, Zhongmin

2015-01-01

A compact frequency-modulation Q-switched single-frequency fiber laser is demonstrated at 1083 nm. The short linear resonant cavity consists of a 12 mm long homemade Yb 3+ -doped phosphate fiber and a pair of fiber Bragg gratings (FBGs) in which the Q-switching and the frequency excursion is achieved by a tensile-induced period modulation. Over 375 MHz frequency-tuning range is achieved with a modulation frequency varying from tens to hundreds of kilohertz. The highest peak power of the output pulse reaching 6.93 W at the repetition rate of 10 kHz is obtained. (paper)

Fibercore AstroGain fiber: multichannel erbium doped fibers for optical space communications

Science.gov (United States)

Hill, Mark; Gray, Rebecca; Hankey, Judith; Gillooly, Andy

2014-03-01

Fibercore have developed AstroGainTM fiber optimized for multichannel amplifiers used in optical satellite communications and control. The fiber has been designed to take full advantage of the photo-annealing effect that results from pumping in the 980nm region. The proprietary trivalent structure of the core matrix allows optimum recovery following radiation damage to the fiber, whilst also providing a market leading Erbium Doped Fiber Amplifier (EDFA) efficiency. Direct measurements have been taken of amplifier efficiency in a multichannel assembly, which show an effective photo-annealing recovery of up to 100% of the radiation induced attenuation through excitation of point defects.

Radiation hardening techniques for rare-earth based optical fibers and amplifiers

International Nuclear Information System (INIS)

Girard, Sylvain; Marcandella, Claude; Vivona, Marilena; Prudenzano, Luciano Mescia F.; Laurent, Arnaud; Robin, Thierry; Cadier, Benoit; Pinsard, Emmanuel; Ouerdane, Youcef; Boukenter, Aziz; Cannas, Marco; Boscaino, Roberto

2012-01-01

Er/Yb doped fibers and amplifiers have been shown to be very radiation sensitive, limiting their integration in space. We present an approach including successive hardening techniques to enhance their radiation tolerance. The efficiency of our approach is demonstrated by comparing the radiation responses of optical amplifiers made with same lengths of different rare-earth doped fibers and exposed to gamma-rays. Previous studies indicated that such amplifiers suffered significant degradation for doses exceeding 10 krad. Applying our techniques significantly enhances the amplifier radiation resistance, resulting in a very limited degradation up to 50 krad. Our optimization techniques concern the fiber composition, some possible pre-treatments and the interest of simulation tools used to harden by design the amplifiers. We showed that adding cerium inside the fiber phospho-silicate-based core strongly decreases the fiber radiation sensitivity compared to the standard fiber. For both fibers, a pre-treatment with hydrogen permits to enhance again the fiber resistance. Furthermore, simulations tools can also be used to improve the tolerance of the fiber amplifier by helping identifying the best amplifier configuration for operation in the radiative environment. (authors)

The all-fiber cladding-pumped Yb-doped gain-switched laser

DEFF Research Database (Denmark)

Larsen, Casper; Hansen, K. P.; Mattsson, Kent Erik

2014-01-01

Gain-switching is an alternative pulsing technique of fiber lasers, which is power scalable and has a low complexity. From a linear stability analysis of rate equations the relaxation oscillation period is derived and from it, the pulse duration is defined. Good agreement between the measured pulse...

Characterization of an erbium doped fiber amplifier starting from its experimental parameters

International Nuclear Information System (INIS)

Bello J, M.; Kuzin, E.A.; Ibarra E, B.; Tellez G, R.

2007-01-01

In this paper we describe a method to characterize the gain of an erbium-doped fiber amplifier (EDFA) through the numerical simulation of the signal beam along the amplifier. The simulation is based on a model constituted by the propagation and rate equations for an erbium-doped fiber. The manipulation of these equations allows us to regroup the parameters present in an EDFA, which we have named the A, B, C, D parameters, and they can be obtained experimentally from an erbium-doped fiber. Experimental results show that the measurement of these parameters allow us to estimate with very good correspondence the amplifier gain. (Author)

Up conversion luminescence of Yb3+–Er3+ codoped CeO2 nanocrystals with imaging applications

International Nuclear Information System (INIS)

Cho, Jung-Hyun; Bass, Michael; Babu, Suresh; Dowding, Janet M.; Self, William T.; Seal, Sudipta

2012-01-01

The effects of Yb 3+ doping on up conversion in Yb 3+ –Er 3+ co-doped cerium oxide nanocrystals are reported. Green emission around 545 and 560 nm attributed to the 2 H 11/2 , 4 S 3/2 → 4 I 15/2 transitions and red emission around 660 and 680 nm due to 4 F 9/2 → 4 I 15/2 transitions under 975 nm excitation were studied at room temperature. Both green and red emission intensities increase as the Yb 3+ concentration increases from 0%. Emission strength starts to decrease after the Yb 3+ concentration exceeds a critical amount. The green emission strength peaks around 1% Yb 3+ concentration while the red emission strength peaks around 4%. An explanation of competition between different decay mechanisms is presented to account for the luminescence dependence on Yb 3+ concentration. Also, the application of up converting nanoparticles in biomedical imaging is demonstrated. - Highlights: ► Up conversion in Yb 3+ –Er 3+ co-doped cerium oxide nanocrystals. ► Different decay mechanisms determine luminescence efficiency. ► Up converting nanoparticles in biomedical imaging is demonstrated.

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method

OpenAIRE

Gavrilović, Tamara V.; Jovanović, Dragana J.; Lojpur, Vesna; Dramićanin, Miroslav D.

2014-01-01

Synthesis of Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each ...

Characterization of the lasing properties of a 5%Yb doped Lu.sub.2./sub.SiO.sub.5./sub. crystal along its three optical axes

Czech Academy of Sciences Publication Activity Database

Toci, G.; Pirri, A.; Beitlerová, Alena; Shoji, Y.; Yoshikawa, A.; Hybler, Jiří; Nikl, Martin; Vannini, M.

2015-01-01

Roč. 23, č. 10 (2015), s. 13210-13221 ISSN 1094-4087 Institutional support: RVO:68378271 Keywords : Lu 2 SiO 5 * Yb-doped * laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.148, year: 2015

Growth and continuous-wave laser operation of disordered crystals of Yb3+:NaLa(WO4)2 and Yb3+:NaLa(MoO4)2

Science.gov (United States)

Liu, J.; Cano-Torres, J. M.; Cascales, C.; Esteban-Betegón, F.; Serrano, M. D.; Volkov, V.; Zaldo, C.; Rico, M.; Griebner, U.; Petrov, V.

2005-03-01

Single crystals of disordered NaLa(WO4)2 and NaLa(MoO4)2 doped with Yb3+ are grown by the Czochralski method from the melt. Continuous-wave laser operation with Ti:sapphire laser pumping is demonstrated at room temperature without special cooling. Tunability from 1017 to 1057 nm and from 1015 to 1053 nm is achieved for Yb:NaLa(WO4)2 and Yb:NaLa(MoO4)2, respectively. A maximum output power of 205 mW is obtained with Yb:NaLa(WO4)2.

Optimum position of isolators within erbium-doped fibers

DEFF Research Database (Denmark)

Lumholt, Ole; Schüsler, Kim; Bjarklev, Anders Overgaard

1992-01-01

An isolator is used as an amplified spontaneous emission suppressing component within an erbium-doped fiber. The optimum isolator placement is both experimentally and theoretically determined and found to be slightly dependent upon pump power. Improvements of 4 dB in gain and 2 dB in noise figure...... are measured for the optimum isolator location at 25% of the fiber length when the fiber is pumped with 60 mW of pump power at 1.48 μm...

Red, green, blue and white light upconversion emission in Yb3+/Tm3+/Ho3+ co-doped tellurite glasses

International Nuclear Information System (INIS)

Desirena, H; De la Rosa, E; Meza, O; Salas, P

2011-01-01

Several Yb 3+ /Tm 3+ /Ho 3+ co-doped transparent TeO 2 -ZnO-Na 2 O-Yb 2 O 3 -Ho 2 O 3 -Tm 2 O 3 glasses were prepared and luminescence properties were characterized. Simultaneous red, green and blue (RGB) emission were obtained after excitation at 970 nm. Colour emission was tuned from multicolour to white light with colour coordinate (0.32, 0.33) matching very well with the white reference (0.33, 0.33). Changes in colour emission were obtained by varying the intensity ratios between RGB bands that are strongly concentration dependent because of the interaction of co-dopants. The colour tunability, high quality of white light and high intensity of the emitted signal make these transparent glasses excellent candidates for applications in solid-state lighting.

Optical bistability of optical fiber ring doped by Erbium and quantum dots

International Nuclear Information System (INIS)

Safari, S.; Tofighi, S.; Bahrampour, A.; Sajad, B.; Shahshahani, F.

2012-01-01

In this paper, theoretical analysis of the steady state behavior of the optical bistability in an optical fiber ring doped by Erbium and quantum dots is presented. The up and down switching power is calculated and the dependence of the switching power on different fiber ring parameters is investigated. The switching power for this type of optical bistability device is obtained much lower than the fiber ring which its half length is doped by Erbium ion.

Spin reorientation behavior in Yb doped YMnO3

International Nuclear Information System (INIS)

Sharma, Neetika; Das, A.

2014-01-01

RMnO 3 with smaller rare-earths ions (R = Ho to Lu and Y) crystallize in the non-centrosymmetric hexagonal space group P6 3 cm. The magnetic structure of RMnO 3 compounds with (R=Er,Yb.Lu) are described by irreducible representations (IR) Γ 2,4 and Γ 1,3 for those with higher ionic radii (R=Ho,Y,Y-Er). Of recent the magnetic structure of YMnO 3 has been found to be better described by Γ 3 + Γ 4 IR. YbMnO 3 is another hexagonal manganite, with almost similar transition temperature, and basically shares all the physical properties of YMnO 3 , except for the magnetic structure. The magnetic structure of YbMnO 3 can be explained by Γ 2 or Γ 4 . The non collinear nature of magnetic ordering in these compounds arises due to the frustration inherent in these compounds. In this study we have probed the effect of a magnetic ion (Yb) on the magnetic structure of these frustrated isostructural compounds

Towards diode-pumped mid-infrared praseodymium-ytterbium-doped fluoride fiber lasers

Science.gov (United States)

Woodward, R. I.; Hudson, D. D.; Jackson, S. D.

2018-02-01

We explore the potential of a new mid-infrared laser transition in praseodymium-doped fluoride fiber for emission around 3.4 μm, which can be conveniently pumped by 0.975 μm diodes via ytterbium sensitizer co-doping. Optimal cavity designs are determined through spectroscopic measurements and numerical modeling, suggesting that practical diode-pumped watt-level mid-infrared fiber sources beyond 3 μm could be achieved.

Spectral-converting behaviors of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} doped YOCl phosphors

Energy Technology Data Exchange (ETDEWEB)

Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2014-01-25

Highlights: • Luminescent materials of YOCl:Er,Yb were prepared using NH{sub 4}Cl flux. • Interesting spectral-converting behaviors were observed in the phosphors. • 980 or 1550 nm diode laser was irradiated for up-converting study. • A multi-photon process in the phosphors was calculated. -- Abstract: Luminescent materials composed of Y{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m = 0.001–0.1, n = 0.005–0.1) were prepared via a solid-state reaction using NH{sub 4}Cl flux. Photoluminescence spectra, the dependence of the luminescent intensity as a function of Er{sup 3+} content, and their CIE coordinates of the Er{sup 3+}-doped layered YOCl compounds were also investigated under near-ultraviolet (NUV) and visible lights. The spectral up-converting properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} in YOCl phosphors were elucidated under 980 and 1550 nm diode laser irradiations. This up-conversion emission spectra and the pump power dependence versus emission intensity observed in the Y{sub 0.9}Er{sub 0.1}OCl up-conversion phosphors gave rise to one- and two-photon processes. The up-conversion mechanism of Er{sup 3+} and Yb{sup 3+} ions in YOCl was described by a schematic energy-level diagram. Through the use of these up-conversion luminescent materials, the desired emitting lights throughout the orange and red regions of the spectra were achieved.

NIR luminescent Er{sup 3+}/Yb{sup 3+} co-doped SiO{sub 2}-ZrO{sub 2} nanostructured planar and channel waveguides: Optical and structural properties

Energy Technology Data Exchange (ETDEWEB)

Cunha, Cesar dos Santos [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto/SP (Brazil); Ferrari, Jefferson Luis [Grupo de Pesquisa em Quimica de Materiais - (GPQM), Departamento de Ciencias Naturais, Universidade Federal de Sao Joao Del Rei, Campus Dom Bosco, Praca Dom Helvecio, 74, 36301-160, Sao Joao Del Rei, MG (Brazil); Oliveira, Drielly Cristina de [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto/SP (Brazil); Maia, Lauro June Queiroz [Grupo Fisica de Materiais, Instituto de Fisica, UFG, Campus Samambaia, Caixa Postal 131, 74001-970, Goiania/GO (Brazil); Gomes, Anderson Stevens Leonidas [Departamento de Fisica, Universidade Federal de Pernambuco, Cidade Universitaria, Recife/PE, 50670-901 (Brazil); Ribeiro, Sidney Jose Lima [Laboratorio de Materiais Fotonicos, Instituto de Quimica, UNESP, Caixa Postal 355, 14801-970, Araraquara/SP (Brazil); and others

2012-09-14

Optical and structural properties of planar and channel waveguides based on sol-gel Er{sup 3+} and Yb{sup 3+} co-doped SiO{sub 2}-ZrO{sub 2} are reported. Microstructured channels with high homogeneous surface profile were written onto the surface of multilayered densified films deposited on SiO{sub 2}/Si substrates by a femtosecond laser etching technique. The densification of the planar waveguides was evaluated from changes in the refractive index and thickness, with full densification being achieved at 900 Degree-Sign C after annealing from 23 up to 500 min, depending on the ZrO{sub 2} content. Crystal nucleation and growth took place together with densification, thereby producing transparent glass ceramic planar waveguides containing rare earth-doped ZrO{sub 2} nanocrystals dispersed in a silica-based glassy host. Low roughness and crack-free surface as well as high confinement coefficient were achieved for all the compositions. Enhanced NIR luminescence of the Er{sup 3+} ions was observed for the Yb{sup 3+}-codoped planar waveguides, denoting an efficient energy transfer from the Yb{sup 3+} to the Er{sup 3+} ion. Highlights: Black-Right-Pointing-Pointer Sol-gel high NIR luminescent nanostructured planar and channel waveguides. Black-Right-Pointing-Pointer Microstructured channels written by a femtosecond laser etching technique. Black-Right-Pointing-Pointer Transparent glass ceramic with rare earth-doped ZrO{sub 2} nanocrystals in a silica host. Black-Right-Pointing-Pointer Enhanced NIR luminescence, efficient energy transfer from the Yb{sup 3+} to the Er{sup 3+} ion. Black-Right-Pointing-Pointer New planar channel waveguides to be applied as EDWA in the C telecommunication band.

Neodymium-doped phosphate fiber lasers with an all-solid microstructured inner cladding.

Science.gov (United States)

Zhang, Guang; Zhou, Qinling; Yu, Chunlei; Hu, Lili; Chen, Danping

2012-06-15

We report on high-power fiber lasers based on index-guiding, all-solid neodymium-doped (Nd-doped) phosphate photonic crystal fiber (PCF) with a hexagonal-shaped inner cladding. The optimum fiber laser with a 36 cm length active fiber, generated up to 7.92 W output power at 1053 nm, which benefited from a high absorption coefficient for pump power due to its noncircular inner cladding. The guiding properties of the all-solid PCF were also investigated. A stable mode with a donut-shaped profile and a power-dependent laser beam quality have been observed experimentally and analyzed.

Synthesis and up-conversion emissions of Yb3+/Er3+, Yb3+/Tm3+

Indian Academy of Sciences (India)

42

which has received considerable attention for material studies [25-28]. ... Though the energy gap between the ground state 8S7/2 and the first excited state 6P7/2 of ... XRD pattern (Figure 1a) of the 20 mol% Yb3+, 2 mol% Er3+ co-doped ...

Continuously tunable S and C+L bands ultra wideband erbium-doped fiber ring laser

International Nuclear Information System (INIS)

Wang, Q; Yu, Q X

2009-01-01

This paper presents an ultra wideband tunable silica-based erbium doped fiber ring laser (EDFRL) that can be continuously tuned in S and C+L bands from 1475 to 1619 nm. It is the first time that a fiber ring laser's tuning range reaches 144 nm using a standard silica-based C-band erbium-doped fiber as gain media. In the laser configuration two isolators are used in the fiber loop for suppressing the ASE in C-band and elevating the lasing gain in S-band. As a result the available lasing wavelength is extended toward the shorter wavelength of the gain bandwidth. The optimized erbium-doped fiber length, output coupling ratio and pumping laser power have been obtained through experimental study. This ring fiber laser has simple configuration, low threshold, flat laser spectral distribution and high signal-to-ASE-noise ratio. The laser will have many potential applications in fiber sensor wavelength interrogation, high-resolution spectroscopy and fiber optic communications

Growth and spectroscopic properties of Yb{sup 3+}-doped Li{sub 6}Y(BO{sub 3}){sub 3} single crystal

Energy Technology Data Exchange (ETDEWEB)

Brenier, A. [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS no 5620, Universite Claude Bernard-Lyon1, 10 rue Ampere, 69622 Villeurbanne (France)]. E-mail: brenier@pcml.univ-lyon1.fr; Yoshikawa, A. [Institute of Multidisciplinary for Advanced Materials, Tohoku University, Sendai 980 8577 (Japan); Lebbou, K. [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS no 5620, Universite Claude Bernard-Lyon1, 10 rue Ampere, 69622 Villeurbanne (France); Jouini, A. [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS no 5620, Universite Claude Bernard-Lyon1, 10 rue Ampere, 69622 Villeurbanne (France); Institute of Multidisciplinary for Advanced Materials, Tohoku University, Sendai 980 8577 (Japan); Aloui-Lebbou, O. [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS no 5620, Universite Claude Bernard-Lyon1, 10 rue Ampere, 69622 Villeurbanne (France); Boulon, G. [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS no 5620, Universite Claude Bernard-Lyon1, 10 rue Ampere, 69622 Villeurbanne (France); Institute of Multidisciplinary for Advanced Materials, Tohoku University, Sendai 980 8577 (Japan); Fukuda, T. [Institute of Multidisciplinary for Advanced Materials, Tohoku University, Sendai 980 8577 (Japan)

2007-10-15

The spectroscopic properties of high-quality Czochralski grown 20% Yb{sup 3+}-doped Li{sub 6}Y(BO{sub 3}){sub 3} single crystal as new promising laser material are presented. The crystal was seeded-grown in the <0 1 0> direction and its crystallinity was measured using X-ray rocking curve analysis. Low temperature transmission spectrum exhibits broad bands in a short range of wavelengths and two sharp lines at 972.5 and 978 nm, interpreted as two zero-lines of two nonequivalent Yb{sup 3+} centers inside the lattice. The fluorescence lifetimes associated to these two intense lines are different: 0.867 and 1.33 ms. An attempt of determination of the Stark sublevels energies of the {sup 4}F{sub 5/2} and {sup 4}F{sub 7/2} manifolds of the two Yb{sup 3+} nonequivalent ions is given. The polarized absorption and emission spectra were also recorded at room temperature and we conclude that the most favorable emission line for laser application could be around 1042 nm in n {sub g} polarization.

650-nJ pulses from a cavity-dumped Yb:fiber-pumped ultrafast optical parametric oscillator

Science.gov (United States)

Lamour, Tobias P.; Reid, Derryck T.

2011-08-01

Sub-250-fs pulses with energies of up to 650 nJ and peak powers up to 2.07 MW were generated from a cavity-dumped optical parametric oscillator, synchronously-pumped at 15.3 MHz with sub-400-fs pulses from an Yb:fiber laser. The average beam quality factor of the dumped output was M2 ~1.2 and the total relative-intensity noise was 8 mdBc, making the system a promising candidate for ultrafast laser inscription of infrared materials.

BaYb2F8, a new radiation hard Cherenkov radiator for electromagnetic calorimeters

International Nuclear Information System (INIS)

Aseev, A.A.; Devitsin, E.G.; Komar, A.A.; Kozlov, V.A.; Hovsepyan, Yu.I.; Potashov, S.Yu.; Sokolovsky, K.A.; Uvarova, T.V.; Vasilchenko, V.G.

1992-01-01

Radiation hardness and optical properties of a new Cherenkov radiator, heavy fluoride BaYb 2 F 8 doped with various elements, have been studied. The above mentioned crystal has the density of 7 g/cm 3 , the radiation length is 1.28 cm and the Moliere radius 2.44 cm. High radiation hardness has been demonstrated for BaYb 2 F 8 doped with Tm, Pr, Tb. (orig.)

Radiation Effects on Ytterbium-doped Optical Fibers

Science.gov (United States)

2014-06-02

conducted on Er- doped fiber amplifiers (Lezius, et al., 2012; Ahrens, et al., 1999; Ahrens, Jaques , LuValle, DiGiovanni, & Windeler, 2001; Ott, 2004...Ahrens, R. G., Abate, J. A., Jaques , J. J., Presby, H. M., Fields, A. B., DiGiovanni, D. J., LuValle, M. J. (1999). Radiation reliability of rare... Jaques , J. J., LuValle, M. J., DiGiovanni, D. J., & Windeler, R. S. (2001). Radiation effects on optical fibers and amplifiers. Testing, Reliability

Multiparameter-dependent spontaneous emission in PbSe quantum dot-doped liquid-core multi-mode fiber

International Nuclear Information System (INIS)

Zhang, Lei; Zhang, Yu; Wu, Hua; Zhang, Tieqiang; Gu, Pengfei; Chu, Hairong; Cui, Tian; Wang, Yiding; Zhang, Hanzhuang; Zhao, Jun; Yu, William W.

2013-01-01

A theoretical model was established in this paper to analyze the properties of 3.50 and 4.39 nm PbSe quantum dot-doped liquid-core multi-mode fiber. This model was applicable to both single- and multi-mode fiber. The three-level system-based light-propagation equations and rate equations were used to calculate the guided spontaneous emission spectra. Considering the multi-mode in the fiber, the normalized intensity distribution of transversal model was improved and simplified. The detailed calculating results were thus obtained and explained using the above-mentioned model. The redshift of the peak position and the evolution of the emission power were observed and analyzed considering the influence of the fiber length, fiber diameter, doping concentration, and the pump power. The redshift increased with the increases of fiber length, fiber diameter, and doping concentration. The optimal fiber length, fiber diameter, and doping concentration were analyzed and confirmed, and the related spontaneous emission power was obtained. Besides, the normalized emission intensity increased with the increase of pump power in a nearly linear way. The calculating results fitted well to the experimental data

Ultrafast, high repetition rate, ultraviolet, fiber-laser-based source: application towards Yb+ fast quantum-logic.

Science.gov (United States)

Hussain, Mahmood Irtiza; Petrasiunas, Matthew Joseph; Bentley, Christopher D B; Taylor, Richard L; Carvalho, André R R; Hope, Joseph J; Streed, Erik W; Lobino, Mirko; Kielpinski, David

2016-07-25

Trapped ions are one of the most promising approaches for the realization of a universal quantum computer. Faster quantum logic gates could dramatically improve the performance of trapped-ion quantum computers, and require the development of suitable high repetition rate pulsed lasers. Here we report on a robust frequency upconverted fiber laser based source, able to deliver 2.5 ps ultraviolet (UV) pulses at a stabilized repetition rate of 300.00000 MHz with an average power of 190 mW. The laser wavelength is resonant with the strong transition in Ytterbium (Yb+) at 369.53 nm and its repetition rate can be scaled up using high harmonic mode locking. We show that our source can produce arbitrary pulse patterns using a programmable pulse pattern generator and fast modulating components. Finally, simulations demonstrate that our laser is capable of performing resonant, temperature-insensitive, two-qubit quantum logic gates on trapped Yb+ ions faster than the trap period and with fidelity above 99%.

Combustion synthesis and photoluminescence properties of LaAlO{sub 3} nanophosphors doped with Yb{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Dhahri, A. [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, B.P. 73, Soliman 8027 (Tunisia); Horchani-Naifer, K., E-mail: karima_horchani@yahoo.com [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, B.P. 73, Soliman 8027 (Tunisia); Benedetti, A. [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, F. [CIVEN – Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via Delle Industrie 5, Marghera, Venice 30175 (Italy); Ferid, M. [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, B.P. 73, Soliman 8027 (Tunisia)

2014-09-15

Ytterbium doped lanthanum aluminate (LaAlO{sub 3}) nanophosphors have been prepared by a combustion process with glycine as a fuel. The structures of the powders were determined by X-ray diffraction (XRD), the morphology of the annealed materials was observed using scanning electron microscopy (SEM), the average crystalline grain sizes have been determined by transmission electron microscopy (TEM) and photoluminescence properties using fluorescence spectroscopy. Pure LaAlO{sub 3} phase was obtained at 800 °C heated for 4 h, with an average crystal size, as determined by TEM, of 60 nm. Emission spectra and decay times of main luminescence transitions were measured at room temperature. A strong emission is reported at 986 nm from the ({sup 2}F{sub 5/2}→{sup 2}F{sub 7/2}) transition, whose intensity depends on Yb concentration. - Highlights: • Ytterbium doped lanthanum aluminate (LaAlO{sub 3}) nanophosphors have been prepared by a combustion process with glycine as a fuel. • Powders were characterized by DRX, FTIR, TEM and fluorescence spectroscopy. • Pure LaAlO{sub 3} phase was obtained at 800 °C heated for 4 h, with an average crystal size of 60 nm. • A strong emission is reported at 986 nm from the ({sup 2}F{sub 5/2}→{sup 2}F{sub 7/2}) transition, whose intensity depends on Yb concentration.

Wideband multi-element Er-doped fiber amplifier

International Nuclear Information System (INIS)

Thipparapu, N K; Jain, S; May-Smith, T C; Sahu, J K

2014-01-01

A multi-element Er-doped fiber amplifier (MEEDFA) is demonstrated in which the gain profile is extended into the S and L bands. Each fiber element of the MEEDFA is found to provide a maximum gain of 37 dB and a noise figure of < 4 dB in the C-band. The gain profile of the amplifier is shifted towards longer wavelength by cascading fiber elements. The novel geometry of the multi-element fiber (MEF) could allow for the development of a broadband amplifier in a split-band configuration. The proposed amplifier can operate in the wavelength band of 1520 to 1595 nm (75 nm), with a minimum gain of 20 dB. (letter)

Evaluation of TeO2 content on the optical and spectroscopic properties of Yb3 +-doped calcium borotellurite glasses

Science.gov (United States)

Lima, A. M. O.; Gomes, J. F.; Hegeto, F. L.; Medina, A. N.; Steimacher, A.; Barboza, M. J.

2018-03-01

This paper reports the synthesis and the characterization of Yb3 +-doped calcium borotellurite (CaBTeX) glasses with composition 10CaF2-(29.5 - 0.4x)CaO-(60 - 0.6x)B2O3-xTeO2-0.5Yb2O3 (x = 10, 16, 22, 31 and 54 mol%). The results of XRD confirm the amorphous character of all the samples. The density, molar volume, refractive index and electronic polarizability values show an increase with TeO2 content. Otherwise, the optical band gap energy shows a decrease with the increase of TeO2 content. The replacement of CaO and B2O3 by TeO2 changes the glass structure, which decreases the excited Yb3 +/cm3 and, consequently, the luminescence intensity. The temperature dependence of luminescence was studied for all the samples up to 420 K. The fluorescence lifetime does not change significantly due to TeO2 addition. In addition, absorption and emission cross section were calculated and present high values as compared to other tellurite and phosphate glasses.

The upconversion luminescence and magnetism in Yb3+/Ho3+ co-doped LaF3 nanocrystals for potential bimodal imaging

Science.gov (United States)

Syamchand, Sasidharanpillai S.; George, Sony

2016-12-01

Biocompatible upconversion nanoparticles with multifunctional properties can serve as potential nanoprobes for multimodal imaging. Herein, we report an upconversion nanocrystal based on lanthanum fluoride which is developed to address the imaging modalities, upconversion luminescence imaging and magnetic resonance imaging (MRI). Lanthanide ions (Yb3+ and Ho3+) doped LaF3 nanocrystals (LaF3 Yb3+/Ho3+) are fabricated through a rapid microwave-assisted synthesis. The hexagonal phase LaF3 nanocrystals exhibit nearly spherical morphology with average diameter of 9.8 nm. The inductively coupled plasma mass spectrometry (ICP-MS) analysis estimated the doping concentration of Yb3+ and Ho3+ as 3.99 and 0.41%, respectively. The nanocrystals show upconversion luminescence when irradiated with near-infrared (NIR) photons of wavelength 980 nm. The emission spectrum consists of bands centred at 542, 645 and 658 nm. The stronger green emission at 542 nm and the weak red emissions at 645 and 658 nm are assigned to 5S2 → 5I8 and 5F5 → 5I8 transitions of Ho3+, respectively. The pump power dependence of luminescence intensity confirmed the two-photon upconversion process. The nanocrystals exhibit paramagnetism due to the presence of lanthanide ion dopant Ho3+ and the magnetization is 19.81 emu/g at room temperature. The nanocrystals exhibit a longitudinal relaxivity ( r 1) of 0.12 s-1 mM-1 and transverse relaxivity ( r 2) of 28.18 s-1 mM-1, which makes the system suitable for developing T2 MRI contrast agents based on holmium. The LaF3 Yb3+/Ho3+ nanocrystals are surface modified by PEGylation to improve biocompatibility and enhance further functionalisation. The PEGylated nanocrystals are found to be non-toxic up to 50 μg/mL for 48 h of incubation, which is confirmed by the MTT assay as well as morphological studies in HeLa cells. The upconversion luminescence and magnetism together with biocompatibility enables the adaptability of the present system as a nanoprobe for potential

Enhanced exciton emission from ZnO nano-phosphor induced by Yb3+ ions

CSIR Research Space (South Africa)

Kabongo, GL

2014-01-01

Full Text Available In this work, the sol–gel method was used to prepare Ytterbium (Yb(sup3+)) doped ZnO nano-phosphors with different concentrations of Yb(sup3+) ions. Their structural, morphological, photoluminescence, electronic states and the chemical composition...

Ridge optical waveguide in an Er3+/Yb3+ co-doped phosphate glass produced by He+ ion implantation combined with Ar+ ion beam etching

International Nuclear Information System (INIS)

Tan Yang; Chen Feng; Hu Lili; Xing Pengfei; Chen Yanxue; Wang Xuelin; Wang Keming

2007-01-01

This paper reports on the fabrication and characterization of a ridge optical waveguide in an Er 3+ /Yb 3+ co-doped phosphate glass. The He + ion implantation (at energy of 2.8 MeV) is first applied onto the sample to produce a planar waveguide substrate, and then Ar + ion beam etching (at energy of 500 eV) is carried out to construct rib stripes on the sample surface that has been deposited by a specially designed photoresist mask. According to a reconstructed refractive index profile of the waveguide cross section, the modal distribution of the waveguide is simulated by applying a computer code based on the beam propagation method, which shows reasonable agreement with the experimentally observed waveguide mode by using the end-face coupling method. Simulation of the incident He ions at 2.8 MeV penetrating into the Er 3+ /Yb 3+ co-doped phosphate glass substrate is also performed to provide helpful information on waveguide formation

Incoherent beam combining of fiber lasers by an all-fiber 7 × 1 signal combiner at a power level of 14 kW.

Science.gov (United States)

Lei, Chengmin; Gu, Yanran; Chen, Zilun; Wang, Zengfeng; Zhou, Pu; Ma, Yanxing; Xiao, Hu; Leng, Jinyong; Wang, Xiaolin; Hou, Jing; Xu, Xiaojun; Chen, Jinbao; Liu, Zejin

2018-04-16

We demonstrate an all-fiber 7 × 1 signal combiner with an output core diameter of 50 μm for high power incoherent beam combining of seven self-made Yb-doped single-mode fiber lasers around a wavelength of 1080 nm and output power of 2 kW. 14.1 kW combined output power is achieved with a total transmission efficiency of higher than 98.5% and a beam quality of M 2 = 5.37, which is close to the theoretical results based on finite-difference beam propagation technique. To the best of our knowledge, this is the highest output power ever reported for all-fiber structure beam combining generation, which indicates the feasibility and potential of >10 kW high brightness incoherent beam combining based on an all-fiber signal combiner.

ZnMoO4:Er3+,Yb3+ phosphor with controlled morphology and enhanced upconversion through alkali ions doping

Science.gov (United States)

Luitel, Hom Nath; Chand, Rumi; Watari, Takanori

2018-04-01

A facile hydrothermal method was used to synthesize ZnMoO4:Er3+,Yb3+ nanoparticles. The shapes and sizes of the nanoparticles were well tuned by simply monitoring the pH of the starting solution. Microballs consisting of agglomerated nanograins were observed at strong acidic condition. At mild pH, plates and rectangular particles were realized, while strong basic pH stabilized rods. Further increasing pH to extremely basic conditions (pH > 13), rods changed to fragile hairy structures. The nucleation and growth mechanism of nanograins to form different morphology nanoparticles were studied and illustrated. XRD patterns confirmed well crystalline, triclinic structure despite small amount of aliovalent metal ions doping. Under 980 nm excitation, the ZnMoO4:Er3+,Yb3+ nanophosphor exhibited strong green (centered at 530 and 560 nm) and weak red (centered at 660 nm) upconversion (UC) emissions. Substitution of part of the Zn2+ ions by monovalent alkali ions intensified the UC emission intensities drastically. The order of intensification was K+>Na+>Li+>Rb+>no alkali ion. When Zn2+ ions were substituted with 10 at% K+ ions, the green and red UC emissions intensities increased by more than 50 and 15 folds, respectively. Time dependent measurements confirmed efficient Yb to Er energy transfer in the ZnMoO4:Er3+,Yb3+,K+ nanophosphor. The optimized ZnMoO4:Er3+,Yb3+,K+ phosphor exhibited intense UC emissions with 0.31% quantum yield. The upconverted light is visible to naked eye while pumping by laser of less than 1 mW power and opens door for variety of novel applications.

Spectral dynamics of square pulses in passively mode-locked fiber lasers

Science.gov (United States)

Semaan, Georges; Komarov, Andrey; Niang, Alioune; Salhi, Mohamed; Sanchez, François

2018-02-01

We investigate experimentally and numerically the spectral dynamics of square pulses generated in passively mode-locked fiber lasers under the dissipative soliton resonance. The features of the transition from the single-peak spectral profile to the doublet spectrum with increasing pump power are studied. The used master equation takes into account the gain saturation, the quadratic frequency dispersion of the gain and the refractive index, and the cubic-quintic nonlinearity of the losses and refractive index. Experimental data are obtained for an Er:Yb-doped fiber ring laser. The theoretical and experimental results are in good agreement with each other.

Spatially selective Er/Yb-doped CaF{sub 2} crystal formation by CO{sub 2} laser exposure

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo, E-mail: kslim@chungbuk.ac.kr

2014-10-30

Highlights: • Oxyfluoride glass–ceramics containing CaF{sub 2} nanocrystals doped with Er{sup 3+} and Yb{sup 3+} ions were formed on the glass surface by CO{sub 2} laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF{sub 2} nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO{sub 2} laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF{sub 2} and miner Ca{sub 2}SiO{sub 4} nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment.

Spatially selective Er/Yb-doped CaF{sub 2} crystal formation by CO{sub 2} laser exposure

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo, E-mail: kslim@chungbuk.ac.kr

2015-04-15

Highlights: • Oxyfluoride glass–ceramics containing CaF{sub 2} nanocrystals doped with Er{sup 3+} and Yb{sup 3+} ions were formed on the glass surface by CO{sub 2} laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF{sub 2} nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO{sub 2} laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF{sub 2} and miner Ca{sub 2}SiO{sub 4} nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment.

Upconversion emission and cathodoluminescence of Er"3"+-doped NaYbF_4 nanoparticles for low-temperature thermometry and field emission displays

International Nuclear Information System (INIS)

Du, Peng; Yu, Jae Su; Luo, Laihui

2017-01-01

The Er"3"+-doped NaYbF_4 nanoparticles were fabricated by a hydrothermal method. The green and red emissions located at around 525, 542 and 657 nm corresponding to the "2H_1_1_/_2 → "4I_1_5_/_2, "4S_3_/_2 → "4I_1_5_/_2 and "4F_9_/_2 → "4I_1_5_/_2 transitions of Er"3"+ ions, respectively, were observed when pumped at 980 nm light. Furthermore, with the help of the fluorescence intensity ratio technique, the thermometric properties of as-prepared products from the thermally coupled "2H_1_1_/_2 and "4S_3_/_2 levels of Er"3"+ ions were studied by analyzing temperature-dependent upconversion (UC) emission spectra. The maximum sensitivity for the Er"3"+-doped NaYbF_4 nanoparticles was found to be around 0.0043 K"- "1 with a temperature range of 93-293 K. In addition, the cathodoluminescence (CL) spectrum of the synthesized nanoparticles was nearly the same as the UC emission spectrum and the CL emission intensity did not exhibit saturation with the increase of accelerating voltage and filament current. (orig.)

A stabilized optical frequency comb based on an Er-doped fiber femtosecond laser

Science.gov (United States)

Xia, Chuanqing; Wu, Tengfei; Zhao, Chunbo; Xing, Shuai

2018-03-01

An optical frequency comb based on a 250 MHz home-made Er-doped fiber femtosecond laser is presented in this paper. The Er-doped fiber laser has a ring cavity and operates mode-locked in femtosecond regime with the technique of nonlinear polarization rotation. The pulse duration is 118 fs and the spectral width is 30 nm. A part of the femtosecond laser is amplified in Er-doped fiber amplifier before propagating through a piece of highly nonlinear fiber for expanding the spectrum. The carrier-envelope offset frequency of the comb which has a signal-to-noise ratio more than 35 dB is extracted by means of f-2f beating. It demonstrates that both carrier-envelope offset frequency and repetition frequency keep phase locked to a Rubidium atomic clock simultaneously for 2 hours. The frequency stabilized fiber combs will be increasingly applied in optical metrology, attosecond pulse generation, and absolute distance measurement.

Conductivity and Ambient Stability of Halogen-Doped Carbon Nanotube Fibers

Science.gov (United States)

Gaier, J. R.; Chirino, C. M.; Chen, M.; Waters, D. L.; Tran, Mai Kim; Headrick, R.; Young, C. C.; Tsentalovich, D.; Whiting, B.; Pasquali, M.;

2-LP mode few-mode fiber amplifier employing ring-core erbium-doped fiber.

Science.gov (United States)

Ono, Hirotaka; Hosokawa, Tsukasa; Ichii, Kentaro; Matsuo, Shoichiro; Nasu, Hitoshi; Yamada, Makoto

2015-10-19

A fiber amplifier supporting 2 LP modes that employs a ring-core erbium-doped fiber (RC-EDF) is investigated to reduce differential modal gain (DMG). The inner and outer radii of the ring-core of the RC-EDF are clarified for 2-LP mode operation of the amplifier, and are optimized to reduce the DMG. It is shown that using the overlap integral between the erbium-doped core area and the signal power mode distribution is a good way to optimize the inner and outer radii of the ring-core of the RC-EDF and thus minimize the DMG. A fabricated RC-EDF and a constructed 2-LP mode EDFA are described and a small DMG of around 1 dB is realized for LP01, LP11 and LP21 pumping.

Microstructural and electrical characteristics of rare earth oxides doped ZnO varistor films

Science.gov (United States)

Jiao, Lei; Mei, Yunzhu; Xu, Dong; Zhong, Sujuan; Ma, Jia; Zhang, Lei; Bao, Li

2018-02-01

ZnO-Bi2O3 varistor films doped with two kinds of rare earth element oxides (Lu2O3 and Yb2O3) were prepared by the sol-gel method. The effects of Lu2O3/Yb2O3 doping on the microstructure and electrical characteristics of ZnO-Bi2O3 varistor films were investigated. All samples show a homogenized morphology and an improved nonlinear relationship between the electric field (E) and current density (I). Both Yb2O3 and Lu2O3 doping can decrease the grain size of ZnO-Bi2O3 varistor films and improve the electrical properties, which have a positive effect on the development of ZnO varistor ceramics. Yb2O3 doping significantly increases the dielectric constant at low frequency. 0.2 mol. % Yb2O3 doped ZnO-Bi2O3 varistor films exhibit the highest nonlinear coefficient (2.5) and the lowest leakage current (328 μA) among Lu2O3/Yb2O3 doped ZnO-Bi2O3 varistor films. Similarly, 0.1 mol. % Lu2O3 doping increases the nonlinear coefficient to 1.9 and decrease the leakage current to 462 μA.

A comprehensive phononics of phonon assisted energy transfer in the Yb3+ aided upconversion luminescence of Tm3+ and Ho3+ in solids

International Nuclear Information System (INIS)

Debnath, Radhaballabh; Bose, Saptasree

2015-01-01

The theory of phonon assisted energy transfer is being widely used to explain the Yb 3+ ion aided normal and upconversion emission of various rare earth ions in different Yb 3+ co-doped solids. The reported phonon dynamics in many of these studies are either incomplete or erroneous. Here we report Yb 3+ aided upconversion luminescence properties of Tm 3+ and Ho 3+ in (Yb 3+ /Tm 3+ ) and (Yb 3+ /Ho 3+ ) co-doped two BaO–tellurite glasses and explain their phononics in the light of Dexter's theory by proposing a comprehensive scheme. The approach is valid for other systems of different phonon structures. - Highlights: • Yb 3+ aided upconversion luminescence properties of Tm 3+ and Ho 3+ in (Yb 3+ /Tm 3+ ) and (Yb 3+ /Ho 3+ ) co-doped two BaO–tellurite glasses, are reported. • Phonon assisted energy transfer in these systems are explained in the light of Dexter's theory by proposing a comprehensive scheme of phononics. • The approach is valid for other systems of different phonon structures

Boron-doped MnO{sub 2}/carbon fiber composite electrode for supercapacitor

Energy Technology Data Exchange (ETDEWEB)

Chi, Hong Zhong, E-mail: hzchi@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Zhu, Hongjie [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Gao, Linhui [Center of Materials Engineering, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

2015-10-05

Highlights: • Interstitial ion in MnO{sub 2} lattice. • Porous film composed by interlocking worm-like nanostructure. • Boron-doped birnessite-type MnO{sub 2}/carbon fiber composite electrode. • Enhanced capacitive properties through nonmetal element doping. - Abstract: The boron-doped MnO{sub 2}/carbon fiber composite electrode has been prepared via in situ redox reaction between potassium permanganate and carbon fibers in the presence of boric acid. The addition of boron as dopant results in the increase of growth-rate of MnO{sub 2} crystal and the formation of worm-like nanostructure. Based on the analysis of binding energy, element boron incorporates into the MnO{sub 2} lattice through interstitial mode. The doped electrode with porous framework is beneficial to pseudocapacitive reaction and surface charge storage, leading to higher specific capacitance and superior rate capability. After experienced 1000 cycles, the boron-doped MnO{sub 2} still retain a higher specific capacitance by about 80% of its initial value. The fall in capacitance is blamed to be the combination of the formation of soluble Mn{sup 2+} and the absence of active site on the outer surface.

Electron spin resonance in Yb-based Kondo-lattice systems

International Nuclear Information System (INIS)

Wykhoff, Jan

2010-01-01

The systems Yb 1-w A 1-w (Rh 1-x Co x )(Si 1-y Ge y ) 2 with A=La respectively Lu, as well as YbIr 2 Si 2 are studied. The measurements are presented sortedly for systems, dopings, and external parameters. Beside these external parameters furthermore the orientation of the sample related to the quasistatic magnetic field and the microwave magnetic field was varied.

Enhancing upconversion emission of Er, Yb co-doped highly transparent YF3 films by synergistic tuning nano-textured morphology and crystallinity

International Nuclear Information System (INIS)

Qu, Ming-Hao; Wang, Ru-Zhi; Chen, Yan; Zhang, Ying; Li, Kai-Yu; Zhou, Hua; Yan, Hui

2014-01-01

Highly transparent Er, Yb codoped YF 3 upconversion films were successfully prepared by electron beam deposition method. The effects of the substrate temperature on the morphology, crystallinity and emission characteristics of Er, Yb codoped YF 3 films were studied carefully. It was found that the morphology and crystallinity varied from smooth amorphous to root-intertwined polycrystalline structure with the substrate temperature increase. Besides, the emission characteristics of the films can be modulated by the synergy of their surface morphologies and crystallinities. Remarkably, a large enhancement of the upconversion emission, up to five decades while only an insignificant decrease of the optical transmittance (10% at most), was achieved by forming root-intertwined polycrystalline structures. These highly transparent upconversion films may have good potential for enhancing the conversion efficiency of wide band-gap solar cells. -- Highlights: • Er, Yb co-dopedYF 3 upconversion films have been successfully prepared. • The upconversion property can be modulated by morphology and crystallinity. • The upconversion transparent YF 3 films are promising for solar cells applications

Study of the electrical and nanosecond third order nonlinear optical properties of ZnO films doped with Au and Pt nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Trejo-Valdez, Martin, E-mail: martin.trejo@laposte.net [ESIQIE, Instituto Politécnico Nacional, México, D.F. 07738, México (Mexico); Sobral, Hugo [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Apartado Postal 70-186, México, D.F. 04510, México (Mexico); Martínez-Gutiérrez, Hugo [Centro de Nanociencias y Micro y Nanotecnologías del Instituto Politécnico Nacional, México, D.F. 07738, México (Mexico); Torres-Torres, Carlos [Sección de Estudios de Posgrado e Investigación, ESIME ZAC, Instituto Politécnico Nacional, México, D.F. 07738, México (Mexico)

2016-04-30

Zinc oxide films doped with platinum and gold nanoparticles were deposited by the spray pyrolysis technique on glass substrates. A titanium dioxide sol–gel solution containing gold and platinum aqueous ions was employed for synthesizing the nanoparticles by ultraviolet-light irradiation. The conductive properties of the samples were characterized by the electrochemical impedance spectroscopy technique. Our results showed that the impedance of zinc oxide films doped with metallic nanoparticles was, by far, lower than typical measurements in zinc oxide films. A strong enhancement in the nanosecond nonlinear optical response was also obtained in the studied metallic doped films. A vectorial two-mixing experiment performed at 532 nm and 4 ns allowed us to evaluate the sample with a third order optical nonlinearity described by approximately | χ{sub 1111}{sup (3)}| = 2.6 × 10{sup −8} esu. - Highlights: • ZnO films doped with Pt and Au nanoparticles were synthetized. • The inclusion of metallic nanoparticles in the film improves optical nonlinearities. • Conductivity of the films was enhanced by the contribution of the nanoparticles.

Stimulated Brillouin scattering threshold in fiber amplifiers

International Nuclear Information System (INIS)

Liang Liping; Chang Liping

2011-01-01

Based on the wave coupling theory and the evolution model of the critical pump power (or Brillouin threshold) for stimulated Brillouin scattering (SBS) in double-clad fiber amplifiers, the influence of signal bandwidth, fiber-core diameter and amplifier gain on SBS threshold is simulated theoretically. And experimental measurements of SBS are presented in ytterbium-doped double-clad fiber amplifiers with single-frequency hundred nanosecond pulse amplification. Under different input signal pulses, the forward amplified pulse distortion is observed when the pulse energy is up to 660 nJ and the peak power is up to 3.3 W in the pulse amplification with pulse duration of 200 ns and repetition rate of 1 Hz. And the backward SBS narrow pulse appears. The pulse peak power equals to SBS threshold. Good agreement is shown between the modeled and experimental data. (authors)

Bright white upconversion luminescence from Er3+/Tm3+/Yb3+-doped titanate-based glasses prepared by aerodynamic levitation method

Science.gov (United States)

Zhang, Minghui; Yu, Jianding; Jiang, Wan; Liu, Yan; Ai, Fei; Wen, Haiqin; Jiang, Meng; Yu, Huimei; Pan, Xiuhong; Tang, Meibo; Gai, Lijun

2017-10-01

Aerodynamic levitation method was employed to prepare Er3+/Tm3+/Yb3+-doped titanate-based glasses. DTA results show that the glass performs high thermal stability with the glass transition temperature of 799 °C. The interaction among rare earth ions has been discussed by adjusting the relative concentration. Er3+ ions can quench the upconversion luminescence of Tm3+ ions. Tm3+ ions play a strong role in quenching the emissions of Er3+ and Tm3+ when the content of Tm3+ ions is greater than or equal 0.05. From the view of the ratio of red emission to green emission, Tm3+ ions can improve the red emission of Er3+ ions to some extent in contrast with the green emissions of Er3+ ions. 980 nm incident laser can be efficiently absorbed by Yb3+ ions. The relative intensity of red, green, and blue upconversion luminescence has been tuned to obtain white light. The composition with white upconversion luminescence of the color coordinate (0.291, 0.3292) has been found. Moreover, white upconversion luminescence mechanism is a two-photon process of ET, ESA, and cooperative sensitization. Rare earth ions doped titanate-based glasses with bright upconversion luminescence perform potential applications in color display, back light, et al.

Growth and continuous-wave laser operation of disordered crystals of Yb3+:NaLa(WO4)2 and Yb3+:NaLa(MoO4)2

International Nuclear Information System (INIS)

Liu, J.; Rico, M.; Griebner, U.; Petrov, V.; Cano-Torres, J.M.; Cascales, C.; Esteban-Betegon, F.; Serrano, M.D.; Volkov, V.; Zaldo, C.

2005-01-01

Single crystals of disordered NaLa(WO 4 ) 2 and NaLa(MoO 4 ) 2 doped with Yb 3+ are grown by the Czochralski method from the melt. Continuous-wave laser operation with Ti:sapphire laser pumping is demonstrated at room temperature without special cooling. Tunability from 1017 to 1057 nm and from 1015 to 1053 nm is achieved for Yb:NaLa(WO 4 ) 2 and Yb:NaLa(MoO 4 ) 2 , respectively. A maximum output power of 205 mW is obtained with Yb:NaLa(WO 4 ) 2 . (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Luminescence property and emission enhancement of YbAlO3:Mn4+ red phosphor by Mg2+ or Li+ ions

Science.gov (United States)

Cao, Renping; Luo, Wenjie; Xu, Haidong; Luo, Zhiyang; Hu, Qianglin; Fu, Ting; Peng, Dedong

2016-03-01

YbAlO3:Mn4+, YbAlO3:Mn4+, Li+, and YbAlO3:Mn4+, Mg2+ phosphors are synthesized by high temperature solid-state reaction method in air. Their crystal structures and luminescence properties are investigated. Photoluminescence excitation (PLE) spectrum monitored at 677 nm contains broad PLE band with three PLE peaks located at ∼318, 395, and 470 nm within the range 220-600 nm. Emission spectra with excitation 318 and 470 nm exhibit three emission band peaks located at ∼645, 677, and 700 nm in the range of 610-800 nm and their corresponding chromaticity coordinates are about (x = 0.6942, y = 0.3057). The possible luminous mechanism of Mn4+ ion is analyzed by the simple energy level diagram of Mn4+ ion. The optimum Mn4+-doped concentration in YbAlO3:Mn4+ phosphor is about 0.4 mol% and the luminescence lifetime of YbAlO3:0.4%Mn4+ phosphor is ∼0.59 ms. Emission intensity of YbAlO3:0.4%Mn4+ phosphor can be enhanced ∼6 times after Mg2+ ion is co-doped and it is ∼2 times when Li+ ion is co-doped. The content in the paper is useful to research new Mn4+-doped luminescence materials and improve luminescence property of other Mn4+-doped phosphors.

Structural, thermal, and optical properties of Er3+/Yb3+ co-doped oxyhalide tellurite glasses, glass-ceramics and ceramics

International Nuclear Information System (INIS)

Joshi, C.; Rai, R.N.; Rai, S.B.

2012-01-01

Glass-ceramics and ceramics containing nano-crystals of different phases doped with Er 3+ /Yb 3+ ions have been successfully prepared by heat treatment of the precursor oxyhalide glasses synthesized by the melt-quench method. X-ray diffraction patterns and transmission electron microscopy (TEM) images verify the precipitation of nano-crystals. Emission of Er 3+ enhances several times when Yb 3+ ion is added with the matrix. The Stark splitting and the intensity of different emission bands increase to a great extent when we approach to ceramics from glasses via glass-ceramics. The intensity of the blue and green emission bands increases much faster than the red and NIR emission bands. Intense upconversion emission observed by the naked eye has been quantified in terms of standard chromaticity diagram (CIE). Power dependence study shows that the upconversion of NIR radiation to visible radiation takes place mainly via photon avalanche (PA) process.

Cathodoluminescence study of ytterbium doped GaSb

International Nuclear Information System (INIS)

Hidalgo, P.; Mendez, B.; Ruiz, C.; Bermudez, V.; Piqueras, J.; Dieguez, E.

2005-01-01

Yb-doped GaSb ingots have been grown by the Bridgman method. The defect structure and compositional homogeneity of the crystals have been investigated by cathodoluminescence and X-ray microanalysis in the scanning electron microscope. The nature of the point defects has been found to depend on the position along the growth axis. Doping with Yb has been found to reduce the luminescence intensity of GaSb and no infrared emission related to intra-ionic transitions of the Yb 3+ ions has been detected

Effect of silver nanoparticles on the 1.53 μm fluorescence in Er3+/Yb3+ codoped tellurite glasses

Science.gov (United States)

Wu, Libo; Zhou, Yaxun; Zhou, Zizhong; Cheng, Pan; Huang, Bo; Yang, Fengjing; Li, Jun

2016-07-01

Improving the spectroscopic properties of rare earth (RE) doped glass materials is a challenging task. In the present work the metallic silver nanoparticles (Ag NPs) were embedded into Er3+/Yb3+ codoped tellurite glasses with composition TeO2-Bi2O3-TiO2, prepared using melt-quenching and subsequent heat-treated techniques, and the improved effect of Ag NPs on the 1.53 μm band fluorescence of Er3+ ions was investigated. About 24 h heat-treatment of Er3+/Yb3+ codoped tellurite glass containing 1 mol % amount of AgNO3 at the temperature 370 °C yielded the well-dispersed and near-spherical Ag NPs with ∼11.4 nm average diameter as evidenced by transmission electron microscopy (TEM) image. The intense 1.53 μm band fluorescence was observed in the prepared Er3+/Yb3+ codoped tellurite glasses under the excitation of 980 nm and was further improved with the presence of Ag NPs in the glass matrix, which is attributed to the enhanced local electric field around doped RE ions induced by Ag NPs and the possible energy transfer from Ag NPs to Er3+ ions. The enhanced local electric field was well demonstrated by comparing the variation of emission spectra of hypersensitive probe Eu3+ ions in tellurite glasses with and without Ag NPs. From the Judd-Ofelt analysis, it was also found that the value of Ω6 intensity parameter increased slightly with the increase of Ag NPs concentration in a certain range, also confirming the possibility of realizing strong fluorescence emission. In addition, the amorphous structural nature was demonstrated by the measured X-ray diffraction (XRD) patterns with no sharp diffraction peak. The enhanced 1.53 μm band fluorescence indicates that the Er3+/Yb3+ codoped tellurite glass with an appropriate amount of Ag NPs is a promising candidate for the development of Er3+-doped fiber amplifiers (EDFAs) applied in the WDM systems.

Electrochemical characterization of doped diamond-coated carbon fibers at different boron concentrations

Energy Technology Data Exchange (ETDEWEB)

Almeida, E.C. [INPE, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil)]. E-mail: erica@las.inpe.br; Diniz, A.V. [INPE, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Trava-Airoldi, V.J. [INPE, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Ferreira, N.G. [CTA-Divisao de Materiais, Sao Jose dos Campos, SP 12228-904 (Brazil)

2005-08-01

Doped diamond films have been deposited on carbon fibers (felt) obtained from polyacrylonitrile at different levels of boron doping. For a successful coating of the fibers, an ultrasonic pretreatment in a bath of diamond powder dissolved in hexane was required. Films were grown on both sample sides, simultaneously, by hot filament-assisted chemical vapour deposition technique at 750 deg. C from a 0.5% H{sub 2}/CH{sub 4} mixture at a total pressure of 6.5 x 10{sup 3} Pa. Boron was obtained from H{sub 2} forced to pass through a bubbler containing B{sub 2}O{sub 3} dissolved in methanol. The doping level studied corresponds to films with acceptor concentrations in the range of 6.5 x 10{sup 18} to 1.5 x 10{sup 21} cm{sup -} {sup 3}, obtained from Mott-Schottky plots. Scanning electron microscopy analyses evidenced fibers totally covered with high quality polycrystalline boron-doped diamond film, also confirmed by Raman spectroscopy spectra. Diamond electrodes grown on carbon fibers demonstrated similar electrochemical behavior obtained from films on Si substrate, for ferri/ferrocyanide redox couple as a function of boron content. The boron content influences electrochemical surface area. A lower boron concentration provides a higher growth rate that results in a higher surface area.

Compact all-fiber optical Faraday components using 65-wt%-terbium-doped fiber with a record Verdet constant of -32 rad/(Tm).

Science.gov (United States)

Sun, L; Jiang, S; Marciante, J R

2010-06-07

A compact all-fiber Faraday isolator and a Faraday mirror are demonstrated. At the core of each of these components is an all-fiber Faraday rotator made of a 4-cm-long, 65-wt%-terbium-doped silicate fiber. The effective Verdet constant of the terbium-doped fiber is measured to be -32 rad/(Tm), which is 27 x larger than that of silica fiber. This effective Verdet constant is the largest value measured to date in any fiber and is 83% of the Verdet constant of commercially available crystal used in bulk optics-based isolators. Combining the all-fiber Faraday rotator with fiber polarizers results in a fully fusion spliced all-fiber isolator whose isolation is measured to be 19 dB. Combining the all-fiber Faraday rotator with a fiber Bragg grating results in an all-fiber Faraday mirror that rotates the polarization state of the reflected light by 88 +/- 4 degrees .

2.05 µm holmium-doped all-fiber laser diode-pumped at 1.125 µm

Science.gov (United States)

Kir'yanov, A. V.; Barmenkov, Y. O.; Villegas Garcia, I.

2017-08-01

We report a holmium-doped all-fiber laser oscillating at ~2.05 µm in continuous wave at direct in-core pumping by a 1.125 µm laser diode. Two types of home-made holmium-doped alumino-germano-silicate fiber (HDF), differentiated in the Ho3+ doping level, were fabricated to implement the laser, for revealing the effect of Ho3+ concentration upon the laser output. Firstly, the fibers were characterized thoroughly from the material and optical viewpoints. Then, laser action with both HDFs was assessed using the simplest Fabry-Perot cavity, assembled by a couple of spectrally adjusted fiber Bragg gratings, also made-in-house. In the best case, when using the lower-doped HDF of proper length (1.4 m), low threshold (~370 mW) and moderate slope efficiency (~13%) of ~2.05 µm lasing were obtained at 1.125 µm diode pumping. Long-term stability, high brightness, low noise, and purely CW operation are shown to be the laser’s attractive features. Yet, when utilizing the heavier-doped HDF, laser output is revealed to be overall worse, with a possible reason being the deteriorating Ho3+ concentration-related effects.

SBS management in Yb-fiber-amplifiers using multimode seeds and pulse-shaping

International Nuclear Information System (INIS)

Jolly, Alain; Fikri Serdar Gokhan; Bello, Ramatou; Dupriez, Pascal

2014-01-01

We present a comprehensive analysis of the technique of Longitudinal-Mode-Filling (LMF) to reduce Stimulated Brillouin Scattering (SBS) limitations in Ytterbium Doped Fibre Amplifiers (YDFA), for the generation of nanosecond, temporally shaped pulses. A basic Master-Oscillator-Power-Amplifier (MOPA) system, comprising an output YDFA with 10 μm-core active fibre, is experienced for benchmarking purposes. Input pulse-shaping is operated thanks to direct current modulation in highly multimode laser-diode seeds, either based on the use of Distributed Feed-Back (DFB) or of a Fibre Bragg Grating (FBG). These seeds enable wavelength control. We verify the effectiveness of the combination of LMF, with appropriate mode spacing, in combination with natural chirp effects from the seed to control the SBS threshold in a broad range of output energies, from a few to some tens of μJ. These variations are discussed versus all the parameters of the laser system. In accordance with the proposal of a couple of basic principles and with the addition of gain saturation effects along the active fibre, we develop a full-vectorial numerical model. Fine fits between experimental results and theoretical expectations are demonstrated. The only limitation of the technique arises from broadband beating noise, which is analysed thanks to a simplified, but fully representative description to discuss the signal-to-noise ratio of the amplified pulses. This provides efficient tools for application to the design of robust and cost-effective MOPAs, aiming to the generation of finely shaped and energetic nanosecond pulses without the need for any additional electro-optics. (authors)

Strong broad green UV-excited photoluminescence in rare earth (RE = Ce, Eu, Dy, Er, Yb) doped barium zirconate

Energy Technology Data Exchange (ETDEWEB)

Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Ciudad de Mexico, D. F. 07730 (Mexico); Meza, O. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico)

2011-10-25

Highlights: > Trivalent rare earth (RE) substitution on Zr{sup 4+} sites in BaZrO{sub 3} lead to band gap narrowing. > RE substitution lead to enhanced blue-green intrinsic emission of nanocrystalline BaZrO{sub 3} > Blue-green hue of BaZrO3:RE depends on RE dopant and excitation UV wavelength > BaZrO3: Dy{sup 3+} PL chromatic coordinates correspond to pure white color coordinates of CIE 1931 model - Abstract: The wet synthesis hydrothermal method at 100 deg. C was used to elaborate barium zirconate (BaZrO{sub 3}) unpurified with 0.5 mol% of different rare earth ions (RE = Yb, Er, Dy, Eu, Ce). Morphological, structural and UV-photoluminescence properties depend on the substituted rare earth ionic radii. While the crystalline structure of RE doped BaZrO{sub 3} remains as a cubic perovskite for all substituted RE ions, its band gap changes between 4.65 and 4.93 eV. Under 267 nm excitation the intrinsic green photoluminescence of the as synthesized BaZrO{sub 3}: RE samples is considerably improved by the substitution on RE ions. For 1000 deg. C annealed samples, under 267 nm, the photoluminescence is dominated by the intrinsic BZO emission. It is interesting to notice that Dy{sup 3+}, Er{sup 3+} and Yb{sup 3+} doped samples present whitish emissions that might be useful for white light generation under 267 nm excitation. CIE color coordinates are reported for all samples.

Single-mode operation of a coiled multimode fiber amplifier

International Nuclear Information System (INIS)

Koplow, Jeffrey P.; Kliner, Dahv A. V.; Goldberg, Lew

2000-01-01

We report a new approach to obtaining single-transverse-mode operation of a multimode fiber amplifier in which the gain fiber is coiled to induce significant bend loss for all but the lowest-order mode. We demonstrated this method by constructing a coiled amplifier using Yb-doped, double-clad fiber with a core diameter of 25 μm and a numerical aperture of ∼0.1 (V≅7.4) . When the amplifier was operated as an amplified-spontaneous-emission source, the output beam had an M 2 value of 1.09±0.09 ; when seeded at 1064 nm, the slope efficiency was similar to that of an uncoiled amplifier. This technique will permit scaling of pulsed fiber lasers and amplifiers to significantly higher pulse energies and peak powers and cw fiber sources to higher average powers while maintaining excellent beam quality. (c) 2000 Optical Society of America

Sub-40 fs, 1060-nm Yb-fiber laser enhances penetration depth in nonlinear optical microscopy of human skin

Science.gov (United States)

Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

2015-12-01

Advancing the practical utility of nonlinear optical microscopy requires continued improvement in imaging depth and contrast. We evaluated second-harmonic generation (SHG) and third-harmonic generation images from ex vivo human skin and showed that a sub-40 fs, 1060-nm Yb-fiber laser can enhance SHG penetration depth by up to 80% compared to a >100 fs, 800 nm Ti:sapphire source. These results demonstrate the potential of fiber-based laser systems to address a key performance limitation related to nonlinear optical microscopy (NLOM) technology while providing a low-barrier-to-access alternative to Ti:sapphire sources that could help accelerate the movement of NLOM into clinical practice.

Synthesis and photocatalytic activity of ytterbium-doped titania/diatomite composite photocatalysts

International Nuclear Information System (INIS)

Tang, Wenjian; Qiu, Kehui; Zhang, Peicong; Yuan, Xiqiang

2016-01-01

Graphical abstract: - Highlights: • Yb-doped TiO_2/diatomite composite photocatalysts were prepared by a sol-gel method. • Yb-doped TiO_2/diatomite photocatalysts show much higher photocatalytic activity. • The higher photodegradation rate is due to the effect of diatomite and Yb doping. - Abstract: Ytterbium-doped titanium dioxide (Yb-TiO_2)/diatomite composite materials with different Yb concentrations were prepared by sol–gel method. The phase structure, morphology, and chemical composition of the as-prepared composites were well characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and ultraviolet–visible (UV–vis) diffuse reflection spectroscopy. The XRD and Raman spectroscopy analysis indicated that the TiO_2 existed in the form of pure anatase in the composites. The SEM images exhibited the well deposition and dispersion of TiO_2 nanoparticles with little agglomeration on the surfaces of diatoms. The UV–vis diffuse reflection spectra showed that the band gap of TiO_2 could be narrowed by the introduction of Yb species, which was further affected by doping concentration of Yb. The photocatalytic activity of synthesized samples was investigated by the degradation of methylene blue (MB) under UV light irradiation. It was observed that the photocatalytic degradation followed a pseudo-first-order kinetics according to the Langmuir–Hinshelwood model. Compared to TiO_2 and TiO_2/diatomite, the Yb-TiO_2/diatomite composites exhibited higher photocatalytic activity toward degradation of MB using UV light irradiation.

Synthesis and photocatalytic activity of ytterbium-doped titania/diatomite composite photocatalysts

Energy Technology Data Exchange (ETDEWEB)

Tang, Wenjian; Qiu, Kehui; Zhang, Peicong; Yuan, Xiqiang

2016-01-30

Graphical abstract: - Highlights: • Yb-doped TiO{sub 2}/diatomite composite photocatalysts were prepared by a sol-gel method. • Yb-doped TiO{sub 2}/diatomite photocatalysts show much higher photocatalytic activity. • The higher photodegradation rate is due to the effect of diatomite and Yb doping. - Abstract: Ytterbium-doped titanium dioxide (Yb-TiO{sub 2})/diatomite composite materials with different Yb concentrations were prepared by sol–gel method. The phase structure, morphology, and chemical composition of the as-prepared composites were well characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and ultraviolet–visible (UV–vis) diffuse reflection spectroscopy. The XRD and Raman spectroscopy analysis indicated that the TiO{sub 2} existed in the form of pure anatase in the composites. The SEM images exhibited the well deposition and dispersion of TiO{sub 2} nanoparticles with little agglomeration on the surfaces of diatoms. The UV–vis diffuse reflection spectra showed that the band gap of TiO{sub 2} could be narrowed by the introduction of Yb species, which was further affected by doping concentration of Yb. The photocatalytic activity of synthesized samples was investigated by the degradation of methylene blue (MB) under UV light irradiation. It was observed that the photocatalytic degradation followed a pseudo-first-order kinetics according to the Langmuir–Hinshelwood model. Compared to TiO{sub 2} and TiO{sub 2}/diatomite, the Yb-TiO{sub 2}/diatomite composites exhibited higher photocatalytic activity toward degradation of MB using UV light irradiation.

Practical Method for engineering Erbium-doped fiber lasers from step-like pulse excitations

International Nuclear Information System (INIS)

Causado-Buelvas, J D; Gomez-Cardona, N D; Torres, P

2011-01-01

A simple method, known as 'easy points', has been applied to the characterization of Erbium-doped fibers, aiming for the engineering of fiber lasers. Using low- optical-power flattop pulse excitations it has been possible to determine both the attenuation coefficients and the intrinsic saturation powers of doped single-mode fibers at 980 and 1550 nm. Laser systems have been projected for which the optimal fiber length and output power have been determined as a function of the input power. Ring and linear laser cavities have been set up, and the characteristics of the output laser have been obtained and compared with the theoretical predictions based on the 'easy points' parameters.

Vibration-resistant Er-doped superfluorescent fiber source incorporating a Faraday rotator mirror

Science.gov (United States)

Zhang, Enkang; Yang, Liu; Gao, Zhongxing; Xue, Bing; Zhang, Yonggang

2018-04-01

Improvement in the mean wavelength vibration stability is crucial to the realization of a high-precision fiber-optic gyroscope. We design a vibration-resistant Er-doped superfluorescent fiber source (VR-EDSFS) incorporated with a Faraday rotator mirror and compare it with the conventional Er-doped superfluorescent fiber source (ED-SFS) under different vibration conditions. As shown by experimental results, the mean wavelength vibration stability of the VR-EDSFS is much better than that of the conventional ED-SFS. Under the 1000 to 2000 Hz vibration condition, the former is just 3.4 ppm, which is about 7 ppm less than the latter over 2 h.

The three-electron bond =SiYb absorption center of pre-darkened ytterbium-doped silica

DEFF Research Database (Denmark)

Mattsson, Kent Erik

2013-01-01

The formation and bleaching of color centers during annealing of pre-darkened ytterbium-doped silica fibers is modeled by three-electron bond (TEB) = Si... bonds is described in terms of a Markov statistical model with state change set by Bose-Einstein phonon statistics. The center hold one terminal and four active states with activation energies for transitions among these found to match bond energies of molecular oxygen in ionic character bonds of 1...... and 1½ bond order. Experimentally observed in- and decrease in absorption during ramp and isothermal annealing of pre-darkened ytterbium co-doped silica fibers are hereby matched by a set of = Si

Yb:Lu{sub 2}O{sub 3} hydrothermally-grown single-crystal and ceramic absorption spectra obtained between 298 and 80 K

Energy Technology Data Exchange (ETDEWEB)

Moore, Cheryl A. [Snake Creek Lasers LLC, 26741 State Route 267, Friendsville, PA 18818 (United States); Department of Chemistry and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634-0973 (United States); Brown, David C., E-mail: dbrown@snakecreeklasers.com [Snake Creek Lasers LLC, 26741 State Route 267, Friendsville, PA 18818 (United States); Sanjeewa, Liurukara D.; McMillen, Colin D.; Kolis, Joseph W. [Department of Chemistry and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634-0973 (United States)

2016-06-15

The hydrothermal growth, doping, and low temperature spectral characterization of Yb doped Lu{sub 2}O{sub 3} was investigated. The absorption of the lutetia-based sesquioxide laser material Yb:Lu{sub 2}O{sub 3} at temperatures of 80, 150, 200, 250, and 298 K, in the wavelength range of 850–1100 nm are reported. Data for both single crystal and ceramic Yb:Lu{sub 2}O{sub 3} were obtained. The resulting absorption cross-section data will enable the further evaluation of Yb:Lu{sub 2}O{sub 3} as a very promising high power cryogenic laser material.

Improvement of a triple-wavelength erbium-doped fiber laser using a Fabry–Perot laser diode

International Nuclear Information System (INIS)

Peng, P C; Hu, H L; Wang, J B

2013-01-01

This work demonstrates the feasibility of a simple construct of a tunable triple-wavelength fiber ring laser using a Fabry–Perot laser diode (FP-LD) and an optical tunable bandpass filter. An optical tunable bandpass filter is used within the cavity of an erbium-doped fiber laser to select the lasing wavelength. Because the Fabry–Perot laser diode is in combination with the tunable bandpass filter, the erbium-doped fiber laser can stably lase three wavelengths simultaneously. Moreover, this laser is easily tuned dynamically. This triple-wavelength output performs satisfactorily, with its optical side-mode-suppression-ratio (SMSR) exceeding 40 dB. Furthermore, the wavelength tuning range of this triple-wavelength erbium-doped fiber laser is greater than 27 nm. (paper)

Few-mode erbium-doped fiber amplifier with photonic lantern for pump spatial mode control

NARCIS (Netherlands)

Lopez-Galmiche, G.; Eznaveh, Z. Sanjabi; Antonio-Lopez, J.E.; Benitez, A. M. Velazquez; Rodriguez-Asomoza, Jorge; Mondragon, J. J. Sanchez; Gonnet, C.; Sillard, P.; Li, G.; Schülzgen, A.; Okonkwo, C.M.; Amezcua Correa, R.

2016-01-01

We demonstrate a few-mode erbium-doped fiber amplifier employing a mode-selective photonic lantern for controlling the modal content of the pump light. Amplification of six spatial modes in a 5 m long erbium-doped fiber to x223C;6.2x2009;x2009;dBm average power is obtained while maintaining high

2-kW single-mode fiber laser employing bidirectional-pump scheme

Science.gov (United States)

Zhang, Fan; Zheng, Wenyou; Shi, Pengyang; Zhang, Xinhai

2018-01-01

2kW single-mode fiber laser with two cascade home-made cladding light strippers (CLSs) by employing bidirectionalpump scheme has been demonstrated. 2.009 kW signal power is obtained when pump power is 2.63 kW and the slope efficiency is 76.6%. Raman Stokes light is less than -47 dB at 2.009 kW even with a 10-m delivery fiber with core/inner cladding diameter of 20/400um. The beam quality M2<=1.2 and the spectral FWHM bandwidth is 4.34nm. There is no transverse mode instability and the output power stability of +/-0.14% is achieved by special thermal management for a more uniform temperature distribution on the Yb-doped gain fiber.

Photocatalytic activity of Sulfer-doped TiO2 fiber under visible light illumination (Joint research)

International Nuclear Information System (INIS)

Takeyama, Akinori; Yamamoto, Shunya; Yoshikawa, Masahito; Hasegawa, Yoshio; Awatsu, Satoshi

2007-03-01

The Sol-Gel derived precursor fiber was annealed under hydrogen disulfeid (H 2 S) following oxygen atmosphere, Sulfur-doped TiO 2 fiber was obtained. Crystal structure of the fiber was identified as anatase phase of TiO 2 . The energy band gap of the fiber was narrower by about 0.06 eV than that of anatase, which showed that it could absorb visible light. The fiber contains about 0.58 atomic % of Sulfur, and they located at the oxygen lattice site of TiO 2 . Under visible light illumination, the fiber degraded Trichloroethylen (TCE) and produced carbon dioxide (CO 2 ). This shows Sulfur-doped TiO 2 fiber has the photocatalytic activity under visible light illumination. (author)

Efficient high power 2 micron Tm3+-Doped Fiber Laser, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This proposal is for the development of new Tm3+ doped germanate glass fibers for efficient high power 2 micron fiber lasers capable of generating an output power of...

1887 nm lasing in Tm3+-doped TeO2-BaF2-Y2O3 glass microstructured fibers

Science.gov (United States)

Wang, Shunbin; Yao, Chuanfei; Jia, Zhixu; Qin, Guanshi; Qin, Weiping

2017-04-01

In this paper, we demonstrate ∼2 μm lasing in Tm3+-doped fluorotellurite microstructured fibers. The Tm3+-doped fibers are based on TeO2-BaF2-Y2O3 glasses and fabricated by using a rod-in-tube method. Under the pump of a 1570 nm Er3+-doped fiber laser, lasing at 1887 nm is obtained in a ∼42.5 cm long Tm3+-doped fiber with a threshold pump power of 94 mW. As the pump power increases to 780 mW, the obtained maximum unsaturated power reaches up to ∼408 mW with a slop efficiency of ∼58.1%. This result indicates that the Tm3+-doped fluorotellurite fibers are promising gain media for ∼2 μm fiber lasers.

Photon up-conversion production in Tb{sup 3+}–Yb{sup 3+} co-doped CaF{sub 2} phosphors prepared by combustion synthesis

Energy Technology Data Exchange (ETDEWEB)

Rakov, Nikifor, E-mail: nikifor.gomez@univasf.edu.br [PG—Ciência dos Materiais, Universidade Federal do Vale do São Francisco, 48902-300 Juazeiro, BA (Brazil); Guimarães, Renato B. [Instituto de Física, Universidade Federal Fluminense, 24210-346 Niterói, RJ (Brazil); Maciel, Glauco S., E-mail: glauco@if.uff.br [Instituto de Física, Universidade Federal Fluminense, 24210-346 Niterói, RJ (Brazil)

2016-02-15

Graphical abstract: Up-conversion luminescence from Tb{sup 3+} obtained by energy transfer from Yb{sup 3+} pairs in CaF{sub 2} powder prepared by combustion synthesis. - Highlights: • Calcium fluoride (CaF{sub 2}) powders were prepared by combustion synthesis. • Rare-earth ions doped in this material were found in interstitial sites. • Cooperative up-conversion was observed in Tb{sup 3+}:Yb{sup 3+}:CaF{sub 2} powder. • Energy transfer between Tb{sup 3+} and pairs of Yb{sup 3+} was analyzed using rate equations. - Abstract: Calcium fluoride (CaF{sub 2}) crystalline powders were successfully prepared by the combustion synthesis method. The powder material containing luminescent rare-earth ions, more specifically terbium (Tb{sup 3+}) and ytterbium (Yb{sup 3+}), was studied by X-ray diffraction, scanning electronic microscopy and optical spectroscopy. These ions are allocated in charge compensated interstitial positions of tetragonal (C{sub 4v}) and trigonal (C{sub 3v}) symmetry sites of the cubic (O{sub h}) CaF{sub 2} lattice. Up-conversion (UC) luminescence in Tb{sup 3+} was achieved using a low power diode laser operating at 975 nm. Tb{sup 3+} is insensitive to near-infrared radiation but UC can be achieved via energy transfer from pairs of Yb{sup 3+} ions to Tb{sup 3+} ions. The UC luminescence dynamics of Tb{sup 3+} was used to study the energy transfer mechanism.

Micro-processing of NiMnGa shape memory alloy by using a nanosecond fiber laser

Science.gov (United States)

Biffi, C. A.; Tuissi, A.

2016-04-01

The interest on Ferromagnetic Shape Memory Alloys (FSMAs), such as NiMnGa, is growing up, thanks to their functional properties to be employed in a new class of micro-devices. The most evident critical issue, limiting the use of these systems in the production of industrial devices, is the brittleness of the bulk material; its workability by using convectional processing methods is very limited. Thus, alternative processing methods, including laser processing, are encouraged for the manufacture of FSMAs based new devices. In this work, the effect of the nanosecond laser microprocessing on Ni45Mn33Ga22 [at%] has been studied. Linear grooves were realized by a nanosecond 30 W fiber laser; the machined surfaces were analyzed with scanning electron microscopy, coupled with energetic dispersion spectroscopy for the composition analysis. The morphology of the grooves was affected by the laser scanning velocity and the number of laser pulses while the measured material removal rate appeared to be influenced mainly by the number of laser pulses. Compositional modification, associated to the loss of Ga content, was detected only for the lower scanning velocity, because of the high fluence. On the contrary, by increasing the velocity up to 1000 mm/s no Ga loss can be seen, making possible the laser processing of this functional alloy without its chemical modification. The use of short pulses allowed also to reduce the amount of recast material and the compositional change with respect to long pulses. Finally, the calorimetric analysis indicated that laser nanosecond microprocessing could affect the functional properties of this alloy: a larger decrease of the characteristic temperatures of the martensitic transformation was observed in correspondence of the low scanning velocity.

BDK-doped core microstructured PMMA optical fiber for effective Bragg grating photo-inscription

DEFF Research Database (Denmark)

Hu, Xuehao; Woyessa, Getinet; Kinet, Damien

2017-01-01

An endlessly single-mode doped microstructured poly(methyl methacrylate) (PMMA) optical fiber is produced for effective fiber Bragg grating (FBG) photo-inscription by means of a 400 nm femtosecond pulsed laser and the phase mask technique. The fiber presents a uniform benzyl dimethyl ketal (BDK......) distribution in its core without drastic loss increase. It was produced using the selected center hole doping technique, and the BDK dopant acts as a photoinitiator. In this Letter, we report a rapidly growing process of the grating reflection band. For an 11 mW mean laser power, the FBG reflectivity reaches...

Effect of low dose rate irradiation on doped silica core optical fibers

International Nuclear Information System (INIS)

Friebele, E.J.; Askins, C.G.; Gingerich, M.E.

1984-01-01

The optical attenuation induced in multimode doped silica core optical fiber waveguides by a year's exposure to low dose rate (1 rad/day) ionizing radiation was studied, allowing a characterization of fibers deployed in these environments and a determination of the permanent induced loss in the waveguides. Variations in the induced attenuation at 0.85 μm have been observed with changes in the dose rate between 1 rad/day and 9000 rads/min. These dose rate dependences have been found to derive directly from the recovery that occurs during the exposure; the recovery data predict little or no dose rate dependence of the damage at 1.3 μm. The low dose rate exposure has been found to induce significant permanent attenuation in the 0.7-1.7-μm spectral region in all fibers containing P in the core, whether doped uniformly across the diameter or constrained to a narrow spike on the centerline. Whereas permanent loss was induced at 0.85 μm in a P-free binary Ge-doped silica core fiber by the year's exposure, virtually no damage was observed at 1.3 μm

Synthesis–property relationship in thermoelectric Sr 1− x Yb x TiO 3− δ ceramics

KAUST Repository

Bhattacharya, S

2014-08-22

The electronic transport properties of a series of Sr1-xYbxTiO3-delta (x = 0.05, 0.1) ceramics are investigated as a function of solid-state reaction (SSR) parameters, specifically calcination steps. It was found that the electrical conductivity (sigma) increases almost by a factor of 6, through the optimization of SSR parameters. The enhancement in the electrical conductivity leads to an enhancement in the thermoelectric power factor by a factor of 3. In addition, the lattice thermal conductivity (k(L)) of the Sr1-xYbxTiO3-delta ceramics is suppressed with increasing Yb-doping, supposedly due to heavier atomic mass of Yb substituted at the Sr site and a smaller ionic radii of Yb+3 with respect to Sr+2 ions. However, our model calculations indicate that strain-field effect, which occurs due to the difference in ionic radii, is the more prominent phonon scattering mechanism in the Yb-doped SrTiO3. This work is an extension of our previous study on the underlying phonon scattering mechanisms in the Y-doped SrTiO3, which would provide new insight into thermal transport in doped SrTiO3 and could be used as a guideline for more effective material synthesis.

Linear all-fiber temperature sensor based on macro-bent erbium doped fiber

International Nuclear Information System (INIS)

Hajireza, P; Cham, C L; Kumar, D; Abdul-Rashid, H A; Emami, S D; Harun, S W

2010-01-01

A new all fiber temperature sensor is proposed and demonstrated based on a pair of 1 meter erbium-doped fiber (EDF), which are respectively macro-bent and straight. The sensor has a linear normalized loss (dB) response to temperature at 6.5 mm bending radius and 1580 nm input wavelength. The main advantage of this sensor is high temperature resolution (less than 1°C) and sensitivity (0.03 dB/°C) due to combination of temperature dependence of EDF and bending loss. The proposed silica based sensor, has the potential for wide range and high temperature applications in harsh environments

Noise in distributed erbium-doped fibers

DEFF Research Database (Denmark)

Rottwitt, Karsten; Povlsen, Jørn Hedegaard; Bjarklev, Anders Overgaard

1993-01-01

Theoretical limits in noise figure for a long-haul transmission line based on lumped amplification are contrasted with distributed amplification. The latter results in a reduction of approximately 60% of the required number of pump power stations. The distributed optical amplification is provided...... by an erbium-doped fiber and comparisons of aluminum and germanium as codopant materials are shown. The pump power consumption and noise figure are analyzed with respect to the background loss...

Erbium Doped Fiber Optic Gravimeter

International Nuclear Information System (INIS)

Pérez-Sánchez, G G; Pérez-Torres, J R; Flores-Bravo, J A; Álvarez-Chávez, J A; Martínez-Piñón, F

2017-01-01

Gravimeters are devices that can be used in a wide range of applications, such as mining, seismology, geodesy, archeology, geophysics and many others. These devices have great sensibility, which makes them susceptible to external vibrations like electromagnetic waves. There are several technologies regarding gravimeters that are of use in industrial metrology. Optical fiber is immune to electromagnetic interference, and together with long period gratings can form high sensibility sensors of small size, offering advantages over other systems with different technologies. This paper shows the development of an optical fiber gravimeter doped with Erbium that was characterized optically for loads going from 1 to 10 kg in a bandwidth between 1590nm to 1960nm, displaying a weight linear response against power. Later on this paper, the experimental results show that the previous described behavior can be modeled as characteristic function of the sensor. (paper)

15 W high OSNR kHz-linewidth linearly-polarized all-fiber single-frequency MOPA at 1.6 μm.

Science.gov (United States)

Yang, Changsheng; Guan, Xianchao; Zhao, Qilai; Lin, Wei; Li, Can; Gan, Jiulin; Qian, Qi; Feng, Zhouming; Yang, Zhongmin; Xu, Shanhui

2018-05-14

A 1603 nm high optical signal-to-noise ratio (OSNR) kHz-linewidth linearly-polarized all-fiber single-frequency master-oscillator power amplifier (MOPA) is demonstrated. To suppress the amplified spontaneous emission from Yb 3+ /Er 3+ ions with the customized filters and optimize the length of the double cladding active fiber, an over 15 W stable single-longitudinal-mode laser is achieved with an OSNR of >70 dB. A measured laser linewidth of 4.5 kHz and a polarization-extinction ratio of >23 dB are obtained at the full output power. This L-band high-power single-frequency MOPA is promising for high-resolution molecular spectroscopy and pumping of Tm 3+ -doped or Tm 3+ /Ho 3+ co-doped laser.

Temperature Sensor Using a Multiwavelength Erbium-Doped Fiber Ring Laser

Directory of Open Access Journals (Sweden)

Silvia Diaz

2017-01-01

Full Text Available A novel temperature sensor is presented based on a multiwavelength erbium-doped fiber ring laser. The laser is comprised of fiber Bragg grating reflectors as the oscillation wavelength selecting filters. The performance of the temperature sensor in terms of both wavelength and laser output power was investigated, as well as the application of this system for remote temperature measurements.

Optimization of E r-density profile for efficient pumping and high signal gain in Erbium-doped fiber amplifiers

International Nuclear Information System (INIS)

Arzi, E.; Hassani, A.; Esmaili Seraji, F.

2000-01-01

Recently, the Erbium-Doped Fiber Amplifier has been shown to have a great potentiality in Fiber-Optics Communication. A model is suggested for calculating the E r-density profile, using the propagation and rate equations of a homogeneous two-level laser medium in Erbium-Doped Fiber Amplifier, such that efficient pumping and high signal gain is achieved for different fiber waveguide structure. The result of this numerical calculation shows that the gain, compared with the gain of the existing Erbium-Doped Fiber Amplifier, is higher by a factor of 3.5. This model is applicable in all active waveguides and any other dopant as well

Effect of Yb substitution on room temperature magnetic and dielectric properties of bismuth ferrite nanoparticles

Science.gov (United States)

Remya, K. P.; Amirthapandian, S.; Manivel Raja, M.; Viswanathan, C.; Ponpandian, N.

2016-10-01

Effect of the Yb dopant on the structural, magnetic, and electrical properties of the multiferroic BiFeO3 have been studied. The structural properties of sol-gel derived Bi1-xYbxFeO3 (x = 0.0, 0.1, and 0.2) nanoparticles reveal the formation of a rhombohedrally distorted perovskite in XRD and a reduction in the average grain size have been observed with an increase in the Yb concentration. Microstructural studies exhibited the formation of sphere like morphology with decreasing particle size with increase in the dopant concentration. The effective doping also resulted in larger magnetization as well as coercivity with the maximum of 257 Oe and 1.76 emu/g in the Bi0.8Yb0.2FeO3 nanoparticles. Ferroelectric as well as dielectric properties of the nanoparticles were also improved on doping. The best results were obtained for the BiFeO3 nanoparticles having Yb concentration x = 0.2.

High Power Narrow Linewidth 1.26 Micron Ho-Doped Fiber Amplifier, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This proposal is for the development of an innovative, high power, and extremely reliable 1.26-micron Ho-doped fluoride fiber amplifier. The proposed fiber amplifier...

High Power Narrow Linewidth 1.26 Micron Ho-Doped Fiber Amplifier, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This proposal is for the development of an innovative, high power, and extremely reliable 1.26-micron Ho-doped fluoride fiber amplifier. The proposed fiber amplifier...

Up-conversion monodispersed spheres of NaYF4:Yb3+/Er3+: green and red emission tailoring mediated by heating temperature, and greatly enhanced luminescence by Mn2+ doping.

Science.gov (United States)

Zhu, Qi; Song, Caiyun; Li, Xiaodong; Sun, Xudong; Li, Ji-Guang

2018-04-09

Submicron sized, monodispersed spheres of Mn2+, Yb3+/Er3+ and Mn2+/Yb3+/Er3+ doped α-NaYF4 were easily autoclaved from mixed solutions of the component nitrates and ammonium fluoride (NH4F), in the presence of EDTA-2Na. Detailed characterizations of the resultant phosphors were obtained using XRD, Raman spectroscopy, FE-SEM, HR-TEM, STEM, PLE/PL spectroscopy, and fluorescence decay analysis. Finer structure and better crystal perfection was observed at a higher calcination temperature, and the spherical shape and excellent dispersion of the original particles was retained at temperatures up to 600 °C. Under the 980 nm infrared excitation, the Yb3+/Er3+-doped sample (calcined at 400 °C) exhibits a stronger green emission centered at ∼524 nm (2H11/2 → 4I15/2 transition of Er3+) and a weaker red emission centered at ∼657 nm (4F9/2 → 4I15/2 transition of Er3+). A 200 °C increase in the temperature from 400 °C to 600 °C resulted in the dominant red emission originating from the 4F9/2 → 4I15/2 transition of Er3+, instead of the previously dominant green one. Mn2+ doping induced a remarkable more enhanced intensity at ∼657 nm and ∼667 nm (red emission area) than that at ∼524 nm and ∼546 nm (green emission area), because of the non-radiative energy transfer between Mn2+ and Er3+. However, a poor thermal stability was induced by Mn2+ doping. The observed upconversion luminescence of the samples calcined at 400 °C and 600 °C followed the two photon process and the four photon process, respectively.

A comprehensive phononics of phonon assisted energy transfer in the Yb{sup 3+} aided upconversion luminescence of Tm{sup 3+} and Ho{sup 3+} in solids

Energy Technology Data Exchange (ETDEWEB)

Debnath, Radhaballabh, E-mail: drdebnathr@gmail.com; Bose, Saptasree

2015-05-15

The theory of phonon assisted energy transfer is being widely used to explain the Yb{sup 3+} ion aided normal and upconversion emission of various rare earth ions in different Yb{sup 3+} co-doped solids. The reported phonon dynamics in many of these studies are either incomplete or erroneous. Here we report Yb{sup 3+} aided upconversion luminescence properties of Tm{sup 3+} and Ho{sup 3+} in (Yb{sup 3+}/Tm{sup 3+}) and (Yb{sup 3+}/Ho{sup 3+}) co-doped two BaO–tellurite glasses and explain their phononics in the light of Dexter's theory by proposing a comprehensive scheme. The approach is valid for other systems of different phonon structures. - Highlights: • Yb{sup 3+} aided upconversion luminescence properties of Tm{sup 3+} and Ho{sup 3+} in (Yb{sup 3+}/Tm{sup 3+}) and (Yb{sup 3+}/Ho{sup 3+}) co-doped two BaO–tellurite glasses, are reported. • Phonon assisted energy transfer in these systems are explained in the light of Dexter's theory by proposing a comprehensive scheme of phononics. • The approach is valid for other systems of different phonon structures.

BDK-doped core microstructured PMMA optical fiber for effective Bragg grating photo-inscription.

Science.gov (United States)

Hu, Xuehao; Woyessa, Getinet; Kinet, Damien; Janting, Jakob; Nielsen, Kristian; Bang, Ole; Caucheteur, Christophe

2017-06-01

An endlessly single-mode doped microstructured poly(methyl methacrylate) (PMMA) optical fiber is produced for effective fiber Bragg grating (FBG) photo-inscription by means of a 400 nm femtosecond pulsed laser and the phase mask technique. The fiber presents a uniform benzyl dimethyl ketal (BDK) distribution in its core without drastic loss increase. It was produced using the selected center hole doping technique, and the BDK dopant acts as a photoinitiator. In this Letter, we report a rapidly growing process of the grating reflection band. For an 11 mW mean laser power, the FBG reflectivity reaches 83% in only 40 s.

Tunable and switchable multi-wavelength erbium-doped fiber laser with highly nonlinear photonic crystal fiber and polarization controllers

International Nuclear Information System (INIS)

Liu, X M; Lin, A; Zhao, W; Lu, K Q; Wang, Y S; Zhang, T Y; Chung, Y

2008-01-01

We have proposed a novel multi-wavelength erbium-doped fiber laser by using two polarization controllers and a sampled chirped fiber Bragg grating(SC-FBG). On the assistance of SC-FBG, the proposed fiber lasers with excellent stability and uniformity are tunable and switchable by adjusting the polarization controllers. Our laser can stably lase two waves and up to eight waves simultaneously at room temperature

Saturable absorber Q- and gain-switched all-Yb3+ all-fiber laser at 976 and 1064 nm.

Science.gov (United States)

Tsai, Tzong-Yow; Fang, Yen-Cheng; Huang, Huai-Min; Tsao, Hong-Xi; Lin, Shih-Ting

2010-11-08

We demonstrate a novel passively pulsed all-Yb3+ all-fiber laser pumped by a continuous-wave 915-nm pump laser diode. The laser was saturable absorber Q-switched at 976 nm and gain-switched at 1064 nm, using the method of mode-field-area mismatch. With a pump power of 
105 mW, the laser iteratively produced a 976-nm pulse with an energy of 2.8 μJ and a duration of 280 ns, followed by a 1064-nm pulse with 1.1 μJ and a 430-ns duration at a repetition rate of 9 kHz. A set of rate equations was established to simulate the self-balancing mechanism and the correlation between the Q- and gain-switched photon numbers and the populations of the gain and absorber fibers.

Frequency upconversion fluorescence studies of Er{sup 3+}/Yb{sup 3+}-codoped KNbO{sub 3} phosphors

Energy Technology Data Exchange (ETDEWEB)

Balakrishnaiah, R. [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Kim, Dong Woo [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.k [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Kim, Kwang Duk; Kim, Sung Hoon [Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Jang, Kiwan; Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

2009-05-29

Different concentrations of Er{sup 3+} and Yb{sup 3+} ions-doped potassium niobate (K{sub 0.9}NbO{sub 3}:Yb{sub (x)}Er{sub (0.1-x)} for x = 0, 0.01, 0.05, 0.09 and 0.1) polycrystalline powder phosphors were prepared by the conventional solid state reaction method and were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Energy transfer and upconversion fluorescence properties of the Yb{sup 3+} and Er{sup 3+}-codoped phosphors have been discussed. The XRD data has shown mono-phase for pure KNbO{sub 3} while the doped samples represented additional phase formation. The SEM micrographs represented the rectangular crystal growth habit for the KNbO{sub 3} phosphors when doped with 0.1 mol of Er{sup 3+} ions. An intense green emission at 557 nm along with a red emission at 674 nm was observed when the doped samples were excited with 975 nm IR radiation. The upconversion mechanism has been discussed based on the excited state absorption and energy transfer mechanisms.

Record power, ultra-broadband supercontinuum source based on highly GeO2 doped silica fiber

DEFF Research Database (Denmark)

Jain, Deepak; Sidharthan, R.; Moselund, Peter M.

2016-01-01

the potential of germania based photonic crystal fiber or a step-index fiber supercontinuum source for high power ultra-broad band emission being by pumped a 1060 nm or a 1550 nm laser source. To the best of our knowledge, this is the record power, ultra-broadband, and all-fiberized supercontinuum light source...... based on silica and germania fiber ever demonstrated to the date. (C) 2016 Optical Society of America......We demonstrate highly germania doped fibers for mid-infrared supercontinuum generation. Experiments ensure a highest output power of 1.44 W for a broadest spectrum from 700 nm to 3200 nm and 6.4 W for 800 nm to 2700 nm from these fibers, while being pumped by a broadband Erbium-Ytterbium doped...

Miniature fiber-optic multiphoton microscopy system using frequency-doubled femtosecond Er-doped fiber laser.

Science.gov (United States)

Huang, Lin; Mills, Arthur K; Zhao, Yuan; Jones, David J; Tang, Shuo

2016-05-01

We report on a miniature fiber-optic multiphoton microscopy (MPM) system based on a frequency-doubled femtosecond Er-doped fiber laser. The femtosecond pulses from the laser source are delivered to the miniature fiber-optic probe at 1.58 µm wavelength, where a standard single mode fiber is used for delivery without the need of free-space dispersion compensation components. The beam is frequency-doubled inside the probe by a periodically poled MgO:LiNbO3 crystal. Frequency-doubled pulses at 786 nm with a maximum power of 80 mW and a pulsewidth of 150 fs are obtained and applied to excite intrinsic signals from tissues. A MEMS scanner, a miniature objective, and a multimode collection fiber are further used to make the probe compact. The miniature fiber-optic MPM system is highly portable and robust. Ex vivo multiphoton imaging of mammalian skins demonstrates the capability of the system in imaging biological tissues. The results show that the miniature fiber-optic MPM system using frequency-doubled femtosecond fiber laser can potentially bring the MPM imaging for clinical applications.

Luminescence properties and energy transfer processes in YAG:Yb,Er single crystalline films

International Nuclear Information System (INIS)

Zorenko, Yu.; Gorbenko, V.; Savchyn, V.; Batentschuk, M.; Osvet, A.; Brabec, C.

2013-01-01

The paper is dedicated to the study of the optical properties of YAG:Yb,Er single-crystalline films (SCF) grown by liquid phase epitaxy. The absorption, cathodoluminescence and time-resolved photoluminescence spectra and photoluminescence decay curves were measured for the SCFs with different doping levels of Er 3+ (from 0.6 to 4.2 at.%) and Yb 3+ (from 0.1 to 0.6 at.%). The spectra, excited by synchrotron radiation in the fundamental absorption range of the YAG and in the intraionic absorption bands of both dopants, reveal energy transfer from the YAG host to the Er 3+ and Yb 3+ ions and between these ions. -- Highlights: •Growth of YAG:Yb,Er single crystalline films by LPE method. •Peculiarities of luminescence of YAG:Yb,Er films with different Er–Yb content. •Yb–Er energy transfer processes in YAG hosts

Cladding-pumped 70-kW-peak-power 2-ns-pulse Er-doped fiber amplifier

Science.gov (United States)

Khudyakov, M. M.; Bubnov, M. M.; Senatorov, A. K.; Lipatov, D. S.; Guryanov, A. N.; Rybaltovsky, A. A.; Butov, O. V.; Kotov, L. V.; Likhachev, M. E.

2018-02-01

An all-fiber pulsed erbium laser with pulse width of 2.4 ns working in a MOPA configuration has been created. Cladding pumped double clad erbium doped large mode area fiber was used in the final stage amplifier. Peculiarity of the current work is utilization of custom-made multimode diode wavelength stabilized at 981+/-0.5 nm - wavelength of maximum absorption by Er ions. It allowed us to shorten Er-doped fiber down to 1.7 m and keep a reasonably high pump-to signal conversion efficiency of 8.4%. The record output peak power for all-fiber amplifiers of 84 kW was achieved within 1555.9+/-0.15 nm spectral range.

Sol-gel processing to form doped sol-gel monoliths inside hollow core optical fiber and sol-gel core fiber devices made thereby

Science.gov (United States)

Shaw, Harry C. (Inventor); Ott, Melanie N. (Inventor); Manuel, Michele V. (Inventor)

2002-01-01

A process of fabricating a fiber device includes providing a hollow core fiber, and forming a sol-gel material inside the hollow core fiber. The hollow core fiber is preferably an optical fiber, and the sol-gel material is doped with a dopant. Devices made in this manner includes a wide variety of sensors.

Spectroscopic properties of Yb3+ and Er3+ ions in heavy metal glasses

International Nuclear Information System (INIS)

Pisarski, Wojciech A.; Grobelny, Lukasz; Pisarska, Joanna; Lisiecki, Radoslaw; Ryba-Romanowski, Witold

2011-01-01

Highlights: → Heavy metal glasses doubly doped with Yb 3+ and Er 3+ were examined. → NIR luminescence at about 1530 nm and green and red up-conversion spectra were detected. → The unusual large spectral linewidth nearly close to 110 nm for 4 I 13/2 - 4 I 15/2 transition of Er 3+ ions in Yb-Er co-doped lead borate glass was obtained. → Long-lived NIR luminescence was detected in lead germanate glass. → The NIR luminescence and up-conversion phenomena strongly depend on stretching vibrations of glass host. - Abstract: Selected heavy metal glasses containing Yb 3+ and Er 3+ ions have been studied. Near-infrared luminescence spectra at 1.53 μm and up-conversion spectra of Er 3+ ions were registered under excitation of Yb 3+ ions by 975 nm diode laser line. The luminescence bands correspond to 4 I 13/2 - 4 I 15/2 (NIR), 4 S 3/2 - 4 I 15/2 (green) and 4 F 9/2 - 4 I 15/2 (red) transitions of Er 3+ , respectively. The optical transitions of rare earth ions have been examined as a function of glass host. The unusual large spectral linewidth nearly close to 110 nm for 4 I 13/2 - 4 I 15/2 transition of Er 3+ ions in Yb-Er co-doped lead borate glass was obtained, whereas long-lived NIR luminescence at 1.53 μm was detected in lead germanate glass. The NIR luminescence and up-conversion phenomena strongly depend on stretching vibrations of glass host, which was confirmed by FT-IR spectroscopy.

Optimized radiation-hardened erbium doped fiber amplifiers for long space missions

Science.gov (United States)

Ladaci, A.; Girard, S.; Mescia, L.; Robin, T.; Laurent, A.; Cadier, B.; Boutillier, M.; Ouerdane, Y.; Boukenter, A.

2017-04-01

In this work, we developed and exploited simulation tools to optimize the performances of rare earth doped fiber amplifiers (REDFAs) for space missions. To describe these systems, a state-of-the-art model based on the rate equations and the particle swarm optimization technique is developed in which we also consider the main radiation effect on REDFA: the radiation induced attenuation (RIA). After the validation of this tool set by confrontation between theoretical and experimental results, we investigate how the deleterious radiation effects on the amplifier performance can be mitigated following adequate strategies to conceive the REDFA architecture. The tool set was validated by comparing the calculated Erbium-doped fiber amplifier (EDFA) gain degradation under X-rays at ˜300 krad(SiO2) with the corresponding experimental results. Two versions of the same fibers were used in this work, a standard optical fiber and a radiation hardened fiber, obtained by loading the previous fiber with hydrogen gas. Based on these fibers, standard and radiation hardened EDFAs were manufactured and tested in different operating configurations, and the obtained data were compared with simulation data done considering the same EDFA structure and fiber properties. This comparison reveals a good agreement between simulated gain and experimental data (vulnerability in terms of gain. The presented approach is a complementary and effective tool for hardening by device techniques and opens new perspectives for the applications of REDFAs and lasers in harsh environments.

Long-Period Gratings in Highly Germanium-Doped, Single-Mode Optical Fibers for Sensing Applications

Science.gov (United States)

Schlangen, Sebastian; Bremer, Kort; Zheng, Yulong; Böhm, Sebastian; Steinke, Michael; Wellmann, Felix; Neumann, Jörg; Overmeyer, Ludger

2018-01-01

Long-period fiber gratings (LPGs) are well known for their sensitivity to external influences, which make them interesting for a large number of sensing applications. For these applications, fibers with a high numerical aperture (i.e., fibers with highly germanium (Ge)-doped fused silica fiber cores) are more attractive since they are intrinsically photosensitive, as well as less sensitive to bend- and microbend-induced light attenuations. In this work, we introduce a novel method to inscribe LPGs into highly Ge-doped, single-mode fibers. By tapering the optical fiber, and thus, tailoring the effective indices of the core and cladding modes, for the first time, an LPG was inscribed into such fibers using the amplitude mask technique and a KrF excimer laser. Based on this novel method, sensitive LPG-based fiber optic sensors only a few millimeters in length can be incorporated in bend-insensitive fibers for use in various monitoring applications. Moreover, by applying the described inscription method, the LPG spectrum can be influenced and tailored according to the specific demands of a particular application. PMID:29702600

Long-Period Gratings in Highly Germanium-Doped, Single-Mode Optical Fibers for Sensing Applications

Directory of Open Access Journals (Sweden)

Sebastian Schlangen

2018-04-01

Full Text Available Long-period fiber gratings (LPGs are well known for their sensitivity to external influences, which make them interesting for a large number of sensing applications. For these applications, fibers with a high numerical aperture (i.e., fibers with highly germanium (Ge-doped fused silica fiber cores are more attractive since they are intrinsically photosensitive, as well as less sensitive to bend- and microbend-induced light attenuations. In this work, we introduce a novel method to inscribe LPGs into highly Ge-doped, single-mode fibers. By tapering the optical fiber, and thus, tailoring the effective indices of the core and cladding modes, for the first time, an LPG was inscribed into such fibers using the amplitude mask technique and a KrF excimer laser. Based on this novel method, sensitive LPG-based fiber optic sensors only a few millimeters in length can be incorporated in bend-insensitive fibers for use in various monitoring applications. Moreover, by applying the described inscription method, the LPG spectrum can be influenced and tailored according to the specific demands of a particular application.

Thermoluminescence of Ge- and Al-doped SiO2 optical fibers subjected to 0.2-4.0 Gy external photon radiotherapeutic dose

International Nuclear Information System (INIS)

Hossain, I.; Wagiran, H.; Yaakob, N.H.

2013-01-01

In this work, we studied the thermoluminescence response of Ge- and Al-doped optical fibers, its linearity, energy dependence, and sensitivity. The Ge-doped optical fibers demonstrate useful TL properties and represent an excellent candidate for use in TL dosimetry of ionizing radiation. The TL response increases monotonically over a wide photon dose range, from 0.2 Gy to 4.0 Gy. The TL results for these fibers have been compared with similar TL data for phosphor TLD-100. Commercially available Al- and Ge-doped optical fibers have both been found to yield a linear dose-TL signal relationship, although the Al-doped fiber provides only 5 % of the sensitivity of the Ge-doped fibers. The TL characteristics of Ge-doped optical fiber, plus its small size (125 μm diameter), high flexibility, ease of handling, and low cost compared with other TL materials, make this commercial optical fiber a very promising TL material for use in medicine, industry, reactor operation, and a variety of other areas. (author)

Optimization of Multiple Active Ion Doped Fiber Amplifiers for Three Communication Windows

Directory of Open Access Journals (Sweden)

Chun Jiang

2009-01-01

Full Text Available We present for the first time a theoretical model of Er3+-Tm3+-Pr3+ codoped fiber pumped with both 800 nm and 980 nm lasers to explore possibility of this co-doped system as all-wave fiber amplifier. The rate and power propagation equations of the model are solved numerically and the dependence of the gains at 1310, 1470, 1530, 1600, 1650 nm windows on fiber length is calculated. The results show that with pump power of 200 mW/200 mW, when the concentrations of Pr3+, Tm3+, Er3+ are around 1.7×1024, 3.9×1024, 1.2×1024 (ions/m3, respectively, the signals at 1310, 1470, 1530, 1600, 1650 nm may be nearly equally amplified with gain of 13–16.0 dB in the active fiber with length of 23.5 m; the co-doping concentrations and fiber length and pump powers may be further optimized to reduce the ripple.

Graphene Oxide-Based Q-Switched Erbium-Doped Fiber Laser

International Nuclear Information System (INIS)

Yap, Y. K.; Harun, S. W.; Ahmad, H.; Huang, N. M.

2013-01-01

We demonstrate a pulsed ring erbium-doped fiber laser based on graphene oxide (GO), employing a simplified Hummer's method to synthesize the GO via chemical oxidation of graphite flakes at room temperature. By dipping a fiber ferrule end face onto the GO suspension, GO is successfully coated onto the end face, making it a simple saturable absorption device. A stable Q-switched pulsed fiber laser is achieved with a low pump threshold of 9.5 mW at 980 nm. The pulse repetition rate ranges from 16.0 to 57.0 kHz. The pulse width and the pulse energy are studied and discussed

Upconversion emission and cathodoluminescence of Er{sup 3+}-doped NaYbF{sub 4} nanoparticles for low-temperature thermometry and field emission displays

Energy Technology Data Exchange (ETDEWEB)

Du, Peng; Yu, Jae Su [Kyung Hee University, Department of Electronics and Radio Engineering, Yongin (Korea, Republic of); Luo, Laihui [Ningbo University, Department of Microelectronic Science and Engineering, Ningbo (China)

2017-03-15

The Er{sup 3+}-doped NaYbF{sub 4} nanoparticles were fabricated by a hydrothermal method. The green and red emissions located at around 525, 542 and 657 nm corresponding to the {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, respectively, were observed when pumped at 980 nm light. Furthermore, with the help of the fluorescence intensity ratio technique, the thermometric properties of as-prepared products from the thermally coupled {sup 2}H{sub 11/2} and {sup 4}S{sub 3/2} levels of Er{sup 3+} ions were studied by analyzing temperature-dependent upconversion (UC) emission spectra. The maximum sensitivity for the Er{sup 3+}-doped NaYbF{sub 4} nanoparticles was found to be around 0.0043 K{sup -} {sup 1} with a temperature range of 93-293 K. In addition, the cathodoluminescence (CL) spectrum of the synthesized nanoparticles was nearly the same as the UC emission spectrum and the CL emission intensity did not exhibit saturation with the increase of accelerating voltage and filament current. (orig.)

Germanium-doped optical fiber for real-time radiation dosimetry

International Nuclear Information System (INIS)

Mizanur Rahman, A.K.M.; Zubair, H.T.; Begum, Mahfuza; Abdul-Rashid, H.A.; Yusoff, Z.; Ung, N.M.; Mat-Sharif, K.A.; Wan Abdullah, W.S.; Amouzad Mahdiraji, Ghafour; Amin, Y.M.; Maah, M.J.; Bradley, D.A.

2015-01-01

Over the past three decades growing demand for individualized in vivo dosimetry and subsequent dose verification has led to the pursuit of newer, novel and economically feasible materials for dosimeters. These materials are to facilitate features such as real-time sensing and fast readouts. In this paper, purposely composed SiO 2 :Ge optical fiber is presented as a suitable candidate for dosimetry. The optical fiber is meant to take advantage of the RL/OSL technique, providing both online remote monitoring of dose rate, and fast readouts for absorbed dose. A laboratory-assembled OSL reader has been used to acquire the RL/OSL response to LINAC irradiations (6 MV photons). The notable RL characteristics observed include constant level of luminescence for the same dose rate (providing better consistency compared to TLD-500), and linearity of response in the radiotherapy range (1 Gy/min to 6 Gy/min). The OSL curve was found to conform to an exponential decay characteristic (illumination with low LED source). The Ge doping resulted in an effective atomic number, Z eff , of 13.5 (within the bone equivalent range). The SiO 2 :Ge optical fiber sensor, with efficient coupling, can be a viable solution for in vivo dosimetry, besides a broad range of applications. - Highlights: • Purposely fabricated Ge doped silica fiber for real-time dose measurements. • Constant RL response for dose rates in radiotherapy range. • Linearity of RL curve during irradiation using LINAC. • RL response comparison between SiO 2 :Ge optical fiber and TLD-500.

Scintillators for fiber optics: system sensitivity and bandwidth as a function of fiber length

International Nuclear Information System (INIS)

Lutz, S.S.; Franks, L.A.; Fluornoy, J.M.; Lyons, P.B.

1981-01-01

Scintillators have been employed for several years as ionizing radiation-to-light converters in plasma diagnostic experiments that utilize fiber optics. Until recently, nanosecond and subnanosecond scintillators were available only in the near ultraviolet. However, the bandwidth and transmission properties of fiber optics both strongly favor operation at longer wavelengths. More recently, nanosecond and subnanosecond scintillators with emission peaks around 480 nm have been reported. A time-resolved plasma-imaging experiment using one of these scintillators and 100 channels of graded-index fiber, each 500 m long, has been successfully tested on a nuclear event at the Nevada Test Site. During the past year we have developed several new scintillator systems with emission wavelengths more compatible with fiber optics and with response times in the nanosecond and subnanosecond time region. One scintillator, based on Kodak dye 14567 (DCM), has an emission maximum at 650 nm and a response time (FWHM) of 1.2 ns. Experimental data on system sensitivity and bandwidth versus fiber length are presented for three fluor-fiber systems. Data on fluor formulation, response time, and linearity-of-response are given, and a model for scintillator nonlinearity, based on solvent, radiation-induced, transient absorption, is presented

Preparation and up-conversion luminescence of SrAlF{sub 5}:Yb{sup 3+}/Er{sup 3+} nanorods

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jun [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China); Hua, Ruinian, E-mail: rnhua@dlnu.edu.cn [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Zhang, Wei; Feng, Zhiqing; Tang, Dongxin; Na, Liyan [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Chen, Baojiu, E-mail: chenmbj@sohu.com [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China)

2014-03-05

Graphical abstract: The SrAlF{sub 5} nanorods co-doped with various Yb{sup 3+}/Er{sup 3+} concentrations was synthetized via a microemulsion-hydrothermal process for the first time. It was found that the optimum doping concentration of Yb{sup 3+} and Er{sup 3+} in SrAlF{sub 5} matrix was about 4 mol%. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence. Highlights: • SrAlF{sub 5}:Yb{sup 3+}/Er{sup 3+} nanorods were synthesized via a microemulsion-hydrothermal process. • Crystal structure and morphology were characterized by using XRD and FESEM. • The upconversion luminescence intensity depend on LD working current was studied. • The post heat-treatment could greatly improve upconversion luminescence. -- Abstract: Yb{sup 3+} and Er{sup 3+} co-doped SrAlF{sub 5} nanorods with average diameter of 35 nm and average length of 400 nm were synthesized via a microemulsion-hydrothermal process, and their crystal structure and morphology were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The optimum doping concentration of Yb{sup 3+}/Er{sup 3+} in SrAlF{sub 5} matrix was about 4 mol%. The upconversion luminescence intensity dependence on the laser diode (LD) working current was studied and the possible upconversion mechanism was analyzed. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence.

Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

Energy Technology Data Exchange (ETDEWEB)

Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z. [Multimedia University, Faculty of Engineering, 63100 Cyberjaya, Selangor Darul Ehsan (Malaysia); Begum, M. [Bangladesh Atomic Energy Commission, E-12/A, Agargaon, Sher-e-Blanga Nagar Dhaka-1207 (Bangladesh); Mat-Sharif, K. A. [Lingkaran Teknokrat Timur, Telekom Research and Development, 63000 Cyberjaya, Selangor Darul Ehsan (Malaysia); Amin, Y. M. [University of Malaya, Faculty of Science, Depatment of Physics, 50603 Kuala Lumpur (Malaysia); Bradley, D. A., E-mail: go2munmun@yahoo.com [University of Surrey, Department of Physics, Guildford GU2 7XH (United Kingdom)

2014-08-15

Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z{sub eff}) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

International Nuclear Information System (INIS)

Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z.; Begum, M.; Mat-Sharif, K. A.; Amin, Y. M.; Bradley, D. A.

2014-08-01

Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z eff ) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

Upconversion emission study of Er3+/Yb3+ doped barium titanate phosphor prepared by co-precipitation method

International Nuclear Information System (INIS)

Mahata, M.K.; Dey, R.; Kumar, K.; Rai, V.K.; Rai, S.B.

2012-01-01

In the present work we have successfully synthesized the Er 3+ , Yb 3+ doped barium titanate phosphor via co-precipitation synthesis method. Under 980 nm excitation, tri-color upconversion fluorescence has been observed. The Fourier Transform Infrared measurement was done to check the presence of organic impurities. In order to find out how many photons are involved in each emission band, the variation of UC emission intensity of the codoped phosphor is studied with increase in excitation power. Upconversion emission spectra show that as the annealing temperature of the powder is increased, intensity of red emission decreases and intensity of green emission increases due to the decrease in maximum phonon frequency of the host material. (author)

Upconversion studies of Er3+/Yb3+ doped SrO.TiO2 borosilicate glass ceramic system

International Nuclear Information System (INIS)

Maheshwari, Aditya; Om Prakash; Kumar, Devendra; Rai, S.B.

2011-01-01

Upconversion behaviour has been studied in various matrices and fine powders of SrTiO 3 by previous workers. In present work, Er 3+ /Yb 3+ were doped in appropriate ratio in SrO.TiO 2 borosilicate glass ceramic system to study the upconversion phenomenon. Dielectric properties of this class of glass ceramic system have been extensively investigated by Thakur et al. It has been observed that both upconversion efficiency and dielectric constant increases with transformation of glass into glass ceramic. Therefore, present investigation is based upon the study of optical as well as the electrical properties of same glass ceramic system. In order to prepare different crystalline matrices, two different Er 3+ /Yb 3+ :SrO.TiO 2 borosilicate glasses with same amount of Er 2 O 3 and Yb 2 O 3 were prepared by melt quench method. Glasses were transparent with light-wine colour. Glass ceramics were prepared from the glasses by heat treatment based on DTA (Differential thermal analysis) results. Glass ceramics were fully opaque with brownish-cream colour. Powder X-ray diffraction (XRD) patterns confirmed that two different crystalline matrices, Sr 3 Ti 2 O 7 , Ti 10 O 19 and SrTiO 3 , TiO 2 were present in two glass ceramic samples respectively. Luminescence properties of glass and glass ceramic samples with 976nm laser irradiation showed that the intensities of the green and red emission increased multiple times in glass ceramic than that of the glass. Possible mechanisms responsible for upconversion eg. Energy Transfer (ET) and Excited State Absorption (ESA), were studied through laser pumping power log dependence

Three mode Er3+ ring-doped fiber amplifier for mode-division multiplexed transmission

NARCIS (Netherlands)

Jung, Y.; Kang, Q.; Sleiffer, V.A.J.M.; Inan, B.; Kuschnerov, M.; Veljanovski, V.; Corbett, B.; Winfield, R.; Li, Z.; Teh, P.S.; Dhar, A.; Sahu, J.K.; Poletti, F.; Alam, S.U.; Richardson, D.J.

2013-01-01

We successfully fabricate three-mode erbium doped fiber with a confined Er3+ doped ring structure and experimentally characterize the amplifier performance with a view to mode-division multiplexed (MDM) transmission. The differential modal gain was effectively mitigated by controlling the relative

Optical Amplification at 1525 nm in BaYF5: 20% Yb3+, 2% Er3+ Nanocrystals Doped SU-8 Polymer Waveguide

Directory of Open Access Journals (Sweden)

Pengcheng Zhao

2014-01-01

Full Text Available We demonstrated optical amplification in BaYF5: 20% Yb3+, 2% Er3+ (BYF nanocrystals doped polymer waveguide. BYF nanocrystals with an average size of ∼13 nm were synthesized by a high-boiling solvent process. Intense 1.53 μm fluorescence was obtained in the nanocrystals under excitation at 980 nm. An optical polymer waveguide was fabricated by using BYF nanocrystals doped SU-8 polymer as the core material. A relative optical gain of ∼10.4 dB at 1525 nm was achieved in a 1.1 cm long waveguide for an input signal power of ∼0.09 mW and a pump power of ∼212 mW.

Investigating the evolution of local structure around Er and Yb in ZnO:Er and ZnO:Er, Yb on annealing using X-ray absorption spectroscopy

Science.gov (United States)

Anjana, R.; Jayaraj, M. K.; Yadav, A. K.; Jha, S. N.; Bhattacharyya, D.

2018-04-01

The local structure around Er and Yb centre in ZnO favouring upconversion luminescence was studied using EXAFS (Extended X-ray absorption fine structure spectroscopy). Due to the ionic radii difference between Zn and Er, Yb ions, the dopants cannot replace Zn in the ZnO lattice properly. Er2O3 and Yb2O3 impurity phases are formed at the grain boundaries of ZnO. It is found that the local structure around the Er centre in ZnO is modified on annealing in air. The symmetry around both erbium and ytterbium reduces with increase in annealing temperature. Symmetry reduction will favour the intra-4f transition and the energy transitions causing upconversion luminescence. By fitting the EXAFS data with theoretically simulated data, it is found that the Er centre forms a local structure similar to C4ν symmetry which is a distorted octahedron. On annealing the sample to 1200 °C, all the erbium centres are transformed to C4ν symmetry causing enhanced upconversion emission. Yb centre has also been modified on annealing. The decrease in co-ordination number with annealing temperature will decrease the symmetry and increase the near infrared absorption cross section. The decrease in symmetry around both the erbium and ytterbium centre and formation of C4ν symmetry around Er centre is the reason behind the activation of upconversion luminescence with high temperature annealing in both Er doped and Er, Yb co-doped ZnO samples. The study will be useful for the synthesis of high efficiency upconversion materials.

Enhanced pump absorption efficiency in coiled and twisted double-clad thulium-doped fibers

Czech Academy of Sciences Publication Activity Database

Koška, Pavel; Peterka, Pavel; Aubrecht, Jan; Podrazký, Ondřej; Todorov, Filip; Becker, M.; Baravets, Yauhen; Honzátko, Pavel; Kašík, Ivan

2016-01-01

Roč. 24, č. 1 (2016), s. 102-107 ISSN 1094-4087 R&D Projects: GA TA ČR(CZ) TH01010997; GA MŠk(CZ) LD15122 Institutional support: RVO:67985882 Keywords : Thulium-doped fiber s * Fiber lasers * Double clad fiber s Subject RIV: BH - Optics , Masers, Lasers Impact factor: 3.307, year: 2016

Q-switched oscillation in thulium-doped fiber lasers using preloaded dynamic microbending technique

Science.gov (United States)

Sakata, H.; Takahashi, N.; Ushiro, Y.

2018-01-01

We demonstrate Q-switched pulse generation in thulium-doped fiber lasers by introducing piezoelectric-driven microbend with preloaded stress. We employed a pair of corrugated chips each attached on piezoelectric actuators (PAs) to clamp the fiber in a ring laser resonator. The thulium-doped fiber is pumped by a laser diode emitting at 1.63 μm and generates the Q-switched laser pulses at around 1.9 μm by switching off the PAs. The laser pulse performance is improved by optimizing the preload and switch-off period for the PAs. The Q-switched pulses with a peak power of 2.8 W and a pulsewidth of 900 ns are observed for a launched pump power of 161 mW. We expect that the in-fiber Q-switching technique will provide efficient laser systems for environmental sensing and medical applications.

Microstructured silicon created with a nanosecond neodymium-doped yttrium aluminum garnet laser

Energy Technology Data Exchange (ETDEWEB)

Mandeville, W.J. [MITRE Corporation, Colorado Springs, CO (United States); Shaffer, M.K.; Lu, Yalin; O' Keefe, D.; Knize, R.J. [United States Air Force Academy, USAFA, CO (United States)

2011-08-15

We produce microstructured silicon using frequency doubled, nanosecond Nd:YAG pulses in SF{sub 6} gas. The micro-penitentes formed are up to 20 {mu}m tall with a sulfur concentration of 0.5% near the surface. The infrared absorption is increased to near unity and extends well below the original bandgap far into the infrared. These data are similar to results reported by others using more complicated and less economical femtosecond titanium sapphire and picosecond and nanosecond excimer lasers. (orig.)

Growth of rare-earth doped single crystal yttrium aluminum garnet fibers

Science.gov (United States)

Bera, Subhabrata; Nie, Craig D.; Harrington, James A.; Cheng, Long; Rand, Stephen C.; Li, Yuan; Johnson, Eric G.

2018-02-01

Rare-earth doped single crystal (SC) yttrium aluminum garnet (YAG) fibers have great potential as high-power laser gain media. SC fibers combine the superior material properties of crystals with the advantages of a fiber geometry. Improving processing techniques, growth of low-loss YAG SC fibers have been reported. A low-cost technique that allows for the growth of optical quality Ho:YAG single crystal (SC) fibers with different dopant concentrations have been developed and discussed. This technique is a low-cost sol-gel based method which offers greater flexibility in terms of dopant concentration. Self-segregation of Nd ions in YAG SC fibers have been observed. Such a phenomenon can be utilized to fabricate monolithic SC fibers with graded index.

Detailed design analysis of erbium-doped fiber amplifiers

DEFF Research Database (Denmark)

Pedersen, Bo; Bjarklev, Anders Overgaard; Lumholt, Ole

1991-01-01

When pumping the erbium-doped fiber amplifier at 0.98 and 1.48 mu m, the optimum cutoff wavelength for step profiles with arbitrary numerical aperture is shown to be 0.80 and 0.90 mu m, respectively. The use of a confined erbium profile can improve the gain coefficient up to 45%. The index raising...

SiCO-doped carbon fibers with unique dual superhydrophilicity/superoleophilicity and ductile and capacitance properties.

Science.gov (United States)

Lu, Ping; Huang, Qing; Mukherjee, Amiya; Hsieh, You-Lo

2010-12-01

Silicon oxycarbide (SiCO) glass-doped carbon fibers with an average diameter of 163 nm were successfully synthesized by electrospinning polymer mixtures of preceramic precursor polyureasilazane (PUS) and carbon precursor polyacrylonitrile (PAN) into fibers then converting to ceramic/carbon hybrid via cross-linking, stabilization, and pyrolysis at temperatures up to 1000 °C. The transformation of PUS/PAN polymer precursors to SiCO/carbon structures was confirmed by EDS and FTIR. Both carbon and SiCO/carbon fibers were amorphous and slightly oxidized. Doping with SiCO enhanced the thermal stability of carbon fibers and acquired new ductile behavior in the SiCO/carbon fibers with significantly improved flexibility and breaking elongation. Furthermore, the SiCO/carbon fibers exhibited dual superhydrophilicity and superoleophilicity with water and decane absorbing capacities of 873 and 608%, respectively. The cyclic voltammetry also showed that SiCO/carbon composite fibers possess better capacitor properties than carbon fibers.

Infrared emissions in MgSrAl{sub 10}O{sub 17}:Er{sup 3+} phosphor co-doped with Yb{sup 3+}/Ba{sup 2+}/Ca{sup 2+} obtained by solution combustion route

Energy Technology Data Exchange (ETDEWEB)

Singh, Vijay, E-mail: vijayjiin2006@yahoo.com [Physical Chemistry, Institute for Pure and Applied Chemistry and Center of Interface Science, University of Oldenburg, 26129 Oldenburg (Germany); Kumar Rai, Vineet [Department of Applied Physics, Indian School of Mines, Dhanbad 826 004 (India); Venkatramu, V. [Department of Physics, Yogi Vemana University, Kadapa 516 003 (India); Chakradhar, R.P.S. [CSIR-National Aerospace, Bangalore 560 017 (India); Hwan Kim, Sang [Department of Chemical Engineering, Konkuk University, Seoul 143-701 (Korea, Republic of)

2013-02-15

An intense infrared emitting MgSrAl{sub 10}O{sub 17}:Er{sup 3+} phosphor co-doped with Yb{sup 3+}, Ba{sup 2+} and Ca{sup 2+} ions have been prepared by a solution combustion method. Phase purity of the derived compounds was confirmed by X-ray diffraction technique. The vibrational properties of MgSrAl{sub 10}O{sub 17} phosphor was studied by Fourier transform infrared spectroscopy. The broad and strong infrared emission of Er{sup 3+} ions at around 1.53 {mu}m was observed upon excitation at 980 nm. Effect of co-doping with the Yb{sup 3+}{sub ,} Ba{sup 2+} and Ca{sup 2+} ions on the infrared luminescence intensity of Er{sup 3+} ions and the mechanism responsible for the variation in the infrared intensity have been discussed. The results indicate that these materials may be suitable for the optical telecommunication window and wavelength division multiplexing applications. - Highlights: Black-Right-Pointing-Pointer The hexagonal phase of MgSrAl{sub 10}O{sub 17} could be obtained by the low temperature combustion method. Black-Right-Pointing-Pointer The broad and strong infrared emission of Er{sup 3+} ions at around 1.53 {mu}m was observed. Black-Right-Pointing-Pointer Effect of co-doping with the Yb{sup 3+}{sub ,} Ba{sup 2+} and Ca{sup 2+} ions on the infrared luminescence intensity of Er{sup 3+} were reported.

Investigation of Upconversion, downshifting and quantum –cutting behavior of Eu3+, Yb3+, Bi3+ co-doped LaNbO4 phosphor as a spectral conversion material

Science.gov (United States)

Dwivedi, A.; Mishra, K.; Rai, S. B.

2018-06-01

This work presents the spectral conversion characteristics [upconversion (UC), downshifting (DS) and quantum–cutting (QC) optical processes] of Eu3+, Yb3+ and Bi3+ co-doped LaNbO4 (LBO) phosphor samples synthesized by solid state reaction technique. The crystal structure and the pure phase formation have been confirmed by x-ray diffraction (XRD) measurements. The surface morphology and particle size are studied by scanning electron microscopy (SEM). The rarely observed intense red UC emission from Eu3+ ion has been successfully obtained in Eu3+/Yb3+ co-doped LaNbO4 phosphor (on excitation with 980 nm) by optimizing the concentrations of Eu3+ and Yb3+ ions. The downshifting (DS) behavior has been studied by photoluminescence (PL) measurements on excitation with 265 nm wavelength from a Xe lamp source. A broad blue emission in the region 300–550 nm with its maximum ∼415 nm due to charge transfer band (CTB) of the host and large number of sharp peaks due to f-f transitions of Eu3+ ion have been observed. The energy transfer has been observed from (NbO4)3‑ to Eu3+ ion and the fluorescence emission has been optimized by varying the concentration of Eu3+ ion. An intense red emission has also been observed corresponding to 5D0 → 7F2 transition of Eu3+ ion at 611 nm in LBO: 0.09Eu3+ phosphor on excitation with 394 nm. The luminescence properties of Eu3+ ion are enhanced further through the sensitization effect of Bi3+ ion. The near infra-red (NIR) quantum cutting (QC) behavior due to Yb3+ ion has been monitored on excitation with 265 as well as 394 nm. The NIR QC is observed due to 2F5/2 → 2F7/2 transition of Yb3+ ion via co-operative energy transfer (CET) process from (NbO4)3‑ as well as Eu3+ ions to Yb3+ ion. This multimodal behavior (UC, DS and QC) makes this a promising phosphor material for multi-purpose spectral converter.

Micro Extrinsic Fiber-Optic Fabry-Perot Interferometric Sensor Based on Erbium- and Boron-Doped Fibers

International Nuclear Information System (INIS)

Yun-Jiang, Rao; Bing, Xu; Zeng-Ling, Ran; Yuan, Gong

2010-01-01

Micro extrinsic Fabry–Perot interferometers (MEFPIs), with cavity lengths of up to ∼ 9 μm and maximum fringe contrast of ∼ 19 dB, are fabricated by chemically etching Er- and B-doped optical fibers and then splicing the etched fiber to a single-mode fiber, for the first time to the best of our knowledge. The strain and temperature responses of the MEFPI sensors are investigated experimentally. Good linearity and high sensitivity are achieved. Such a type of MEFPI sensor is cost-effective and suitable for mass production, indicating its great potential for a wide range of applications. (fundamental areas of phenomenology(including applications))

Up-conversion emission of Er{sup 3+}/Yb{sup 3+}co-doped BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) phosphors

Energy Technology Data Exchange (ETDEWEB)

Façanha, M.X., E-mail: marcello.facanha@uece.br [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Faculdade de Educação de Crateús (FAEC), Universidade Estadual do Ceará (UECE), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Nascimento, J.P.C. do [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Silva, M.A.S., E-mail: marceloassilva@yahoo.com.br [Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); and others

2017-03-15

On this paper, polycrystalline samples of the tetragonal systems BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) and BBN co-doped with Er{sup 3+}/Yb{sup 3+} (BBN: 0.04Er{sup 3+}yYb{sup 3+}, where y=0.02, 0.04, 0.06 and 0.08 mol%) were synthesized by the solid state method. The crystalline structure and photoluminescent properties of the ceramic phosphors were investigated by powder X-ray diffraction (PXRD), Raman spectroscopy and spectral analysis of up-conversion (UC) emission. The results reveal that all compositions crystallize in the I4/mmm space group at room temperature, and show UC green emissions (centered at 525 nm and 550 nm) and red (around 660 nm) coming from ({sup 2}H{sub 11/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2}) and ({sup 4}F{sub 9/2}→{sup 4}I{sub 15/2}) transitions, respectively, under excitation at 980 nm. Increasing variations of the Yb{sup 3+} sensitizer concentration in the host BBN, lead to a significant intensity increase in both UC emissions due to the efficiency of the energy-transfer process. The BBN: 0.04 mol%Er{sup 3+}0.08 mol%Yb{sup 3+} composition showed the higher intensity bands, thus establishing the BBN as an alternative host material for luminescent centers.

The complexity of the CaF2:Yb system: evidence that CaF2:Yb2+ is not an impurity trapped exciton system

Science.gov (United States)

Mackeen, Cameron; Bridges, Frank; Kozina, Michael; Mehta, Apurva; Reid, M. F.; Wells, J.-P. R.; BarandiaráN, Zoila

Fluorite crystal structures doped with rare-earth elements exhibit an anomalous redshifted luminescence upon UV excitation, generally attributed to the relaxation of impurity trapped excitons (ITE). We find that the intensity of this luminescence decreases as the total concentration of Yb 2+ increases in unexposed samples, which is in conflict with the currently accepted ITE model. Further, using x-ray absorption spectroscopy and UV-vis studies of CaF2:Yb, we find a large (but reversible) Yb valence reduction upon x-ray exposure at 200 K - from mostly 3+ to 2+. This valence reduction is stable for long time periods at low T ITE model; the data appear more consistent with an intervalence charge transfer (IVCT) model. It is likely that many similar ITE systems have also been misidentified.

Fabrication and Photostability of Rhodamine-6G Gold Nanoparticle Doped Polymer Optical Fiber

International Nuclear Information System (INIS)

Sebastian, Suneetha; Ajina, C; Vallabhan, C. P. G; Nampoori, V. P. N.; Radhakrishnan, P.; Kailasnath, M.

2013-01-01

We report on fabrication of a rhodamine-6G-gold-nanoparticle doped polymer optical fiber. The gold nanoparticle is synthesized directly into the monomer solution of the polymer using laser ablation synthesis in liquid. The size of the particle is found from the transmission electron microscopy. Rhodamine-6G is then mixed with the nanoparticle-monomer solution and optical characterization of the solution is investigated. It is found that there is a pronounced quenching of fluorescence of rhodamine 6G due to fluorescence resonance energy transfer. The monomer solution containing rhodamine 6G and gold nanoparticles is now made into a cylindrical rod and drawn into a polymer optical fiber. Further, the photostability is calculated with respect to the pure dye doped polymer optical fiber

High-Power Yb-Doped Solid-Core Photonic Bandgap Fiber Amplifier at 1150-1200nm

DEFF Research Database (Denmark)

Maruyama, H.; Shirakawa, A.; Ueda, K.

2008-01-01

Solid-core photonic-bandgap fiber amplification at the long-wavelength edge of ytterbium band is reported. A 32W output at 1156nm with a 66% slope efficiency and 9.1W output at 1178nm were succesfully obtained.......Solid-core photonic-bandgap fiber amplification at the long-wavelength edge of ytterbium band is reported. A 32W output at 1156nm with a 66% slope efficiency and 9.1W output at 1178nm were succesfully obtained....

Polymer-Optical-Fiber Lasers and Amplifiers Doped with Organic Dyes

Directory of Open Access Journals (Sweden)

Joseba Zubia

2011-07-01

Full Text Available Polymer optical fibers (POFs doped with organic dyes can be used to make efficient lasers and amplifiers due to the high gains achievable in short distances. This paper analyzes the peculiarities of light amplification in POFs through some experimental data and a computational model capable of carrying out both power and spectral analyses. We investigate the emission spectral shifts and widths and on the optimum signal wavelength and pump power as functions of the fiber length, the fiber numerical aperture and the radial distribution of the dopant. Analyses for both step-index and graded-index POFs have been done.

Highly matched spectrum needed for photosynthesis in Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramics

Energy Technology Data Exchange (ETDEWEB)

Wang, Weirong; Gao, Huiping [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China); Mao, Yanli, E-mail: ylmao@henu.edu.cn [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China)

2015-11-05

A series of oxyfluoride glass ceramics containing CaF{sub 2} nano-crystals tri-doped with Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} ions were prepared by high temperature melting method and subsequent heat treatment. The structural properties were examined by X-ray diffraction measurements. The absorption, excitation, and emission spectra of the glass ceramics were investigated. Difference in erbium emission spectra between glass and glass ceramics had been studied. The emission bands originating from the {sup 4}F{sub 9/2} state of Er{sup 3+} were enhanced when the CaF{sub 2} nano-crystal created. By down-converting the ultraviolet wavelength region (280∼400 nm) light and up-converting the near-infrared wavelength region (900∼1100 nm) light, the glass ceramics can also emit strong reddish orange emission. The emission spectra consisting of bluish violet (400∼500 nm) and reddish orange (640∼680 nm) bands match well with the action spectrum of photosynthesis and absorption spectra of chlorophylls. Our materials will be favored to promote the development of glass greenhouses for green plant. - Highlights: • Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramics were prepared by high temperature melting method. • 668 nm red emission was obtained under 320 nm, 380 nm and 980 nm excitation, respectively. • The emission of samples matched well with the spectrum for photosynthesis.

Indium-modified Yb:KLu(WO{sub 4}){sub 2} crystal: Growth, spectroscopy and laser operation

Energy Technology Data Exchange (ETDEWEB)

Serres, J.M. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA), Universitat Rovira i Virgili (URV), Campus Sescelades, c/ Marcellí Domingo, s/n., Tarragona E-43007 (Spain); Mateos, X., E-mail: xavier.mateos@urv.cat [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA), Universitat Rovira i Virgili (URV), Campus Sescelades, c/ Marcellí Domingo, s/n., Tarragona E-43007 (Spain); Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 2A Max-Born-Str., Berlin D-12489 (Germany); Loiko, P. [ITMO University, 49 Kronverkskiy pr., St. Petersburg 197101 (Russian Federation); Griebner, U.; Petrov, V. [Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 2A Max-Born-Str., Berlin D-12489 (Germany); Yumashev, K. [Center for Optical Materials and Technologies (COMT), Belarusian National Technical University, 65/17 Nezavisimosti Ave., Minsk 220013 (Belarus); Aguiló, M.; Díaz, F. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA), Universitat Rovira i Virgili (URV), Campus Sescelades, c/ Marcellí Domingo, s/n., Tarragona E-43007 (Spain)

2017-03-15

We report on the growth, spectroscopic and laser characterization of a novel monoclinic laser crystal, Yb,In:KLu(WO{sub 4}){sub 2} (Yb,In:KLuW). The absorption, stimulated-emission and gain cross-section spectra of 3.5 at% Yb, 5.5 at% In-doped KLuW are determined at room temperature with polarized light and compared with those for Yb,In:KYW, as well as singly Yb-doped KLuW and KYW crystals. It is found that the introduction of In results in a decrease of the transition cross-sections and in a spectral broadening of the absorption and emission bands. Such a broadening is more pronounced for light polarization E ||N{sub p}. For Yb,In:KLuW, the maximum σ{sub abs} is 9.9×10{sup –20} cm{sup 2} at 980.9 nm for E ||N{sub m} and the corresponding bandwidth of the absorption peak is 3.7 nm. The radiative lifetime for Yb{sup 3+} ions is 237±5 µs. The stimulated-emission cross-sections are σ{sub SE}(m)=2.4×10{sup –20} cm{sup 2} at 1022.4 nm and σ{sub SE}(p)=1.3×10{sup –20} cm{sup 2} at 1039.1 nm corresponding to an emission bandwidth of >30 nm and >35 nm, respectively. The diode-pumped N{sub g}-cut Yb,In:KLuW microchip laser generated 4.11 W at 1042–1048 nm with a slope efficiency of 78%. The Yb,In:KLuW crystal is very promising for the generation of sub-100 fs pulses in mode-locked lasers due to its broadband emission characteristics.

Infrared to near-infrared and visible upconversion mechanisms in LiYF 4: Yb3+, Ho3+

NARCIS (Netherlands)

Martín-Rodríguez, R.; Meijerink, A.|info:eu-repo/dai/nl/075044986

2014-01-01

Upconversion materials have regained interest in recent years due to their potential to enhance the efficiency of solar cells. The research has focused on lanthanide based upconverters, especially Er3+- and Yb 3+-doped materials. In this paper we report Ho3+ and Yb3+ upconversion after excitation

Improving the photoluminescence response of Er-Tm: Al2O3 films by Yb codoping

International Nuclear Information System (INIS)

Xiao Zhisong; Serna, R.; Afonso, C.N.; Cheng Guoan; Vickridge, I.

2007-01-01

Amorphous Al 2 O 3 films doped with Er, Tm and Yb have been prepared by pulsed laser deposition. A broadband emission in the range 1400-1700 nm with two peaks around 1540 and 1640 nm has been observed, both in the Er-Tm and Er-Tm-Yb codoped films. The Tm-related photoluminescence (PL) intensity at 1640 nm is enhanced when codoping with Yb thus suggesting the existence of multiple energy transfer processes from Yb to Er and Er to Tm. The Er-Tm-Yb codoped film exhibits a broadband emission with a full-width half-maximum of 184 nm similar to that of the film codoped with Tm and Er but having higher Tm to Er concentration ratio and higher PL lifetime values

Thermal effect-resilient design of large mode area double-cladding Yb-doped photonic crystal fibers

DEFF Research Database (Denmark)

Coscelli, Enrico; Poli, Federica; Johansen, Mette Marie

2013-01-01

The effects of thermally-induced refractive index change on the guiding properties of different large mode area fibers have been numerically analyzed. A simple but accurate model has been applied to obtain the refractive index change in the fiber cross-section, and a full-vector modal solver base...

Pulsed laser deposition and thermoelectric properties of In-and Yb-doped CoSb3 skutterudite thin films

KAUST Repository

Sarath Kumar, S. R.

2011-07-29

In-and Yb-doped CoSb3 thin films were prepared by pulsed laser deposition. Process optimization studies revealed that a very narrow process window exists for the growth of single-phase skutterudite films. The electrical conductivity and Seebeck coefficient measured in the temperature range 300-700 K revealed an irreversible change on the first heating cycle in argon ambient, which is attributed to the enhanced surface roughness of the films or trace secondary phases. A power factor of 0.68 W m-1 K-1 was obtained at ∼700 K, which is nearly six times lower than that of bulk samples. This difference is attributed to grain boundary scattering that causes a drop in film conductivity. Copyright © Materials Research Society 2011.

Latest developments on fibered MOPA in mJ range with hollow-core fiber beam delivery and fiber beam shaping used as seeder for large scale laser facilities (Conference Presentation)

Science.gov (United States)

Gleyze, Jean-François; Scol, Florent; Perrin, Arnaud; Gouriou, Pierre; Valentin, Constance; Bouwmans, Géraud; Hugonnot, Emmanuel

2017-05-01

The Laser Megajoule (LMJ) is a French large scale laser facility dedicated to inertial fusion and plasma physics research. LMJ front-ends are based on fiber laser technology at nanojoule range [1]. Scaling the energy of those fiber seeders to the millijoule range is a way to upgrade LMJ's front ends architecture and could also be used as seeder for lasers for ELI project for example. However, required performances are so restrictive (optical-signal-to-noise ratio higher than 50 dB, temporally-shaped nanosecond pulses and spatial single-mode top-hat beam output) that such fiber systems are very tricky to build. High-energy fiber amplifiers In 2015, we have demonstrated, an all-fiber MOPA prototype able to produce a millijoule seeder, but unfortunately not 100% conform for all LMJ's performances. A major difficulty was to manage the frequency modulation used to avoid stimulated Brillouin scattering, to amplitude modulation (FM-AM) conversion, this limits the energy at 170µJ. For upgrading the energy to the millijoule range, it's necessary to use an amplifier with a larger core fiber. However, this fiber must still be flexible; polarization maintaining and exhibit a strictly single-mode behaviour. We are thus developing a new amplifier architecture based on an Yb-doped tapered fiber: its core diameter is from a narrow input to a wide output (MFD 8 to 26 µm). A S² measurement on a 2,5m long tapered fiber rolled-up on 22 cm diameter confirmed that this original geometry allows obtaining strictly single-mode behaviour. In a 1 kHz repetition rate regime, we already obtain 750 µJ pulses, and we are on the way to mJ, respecting LMJ performances. Beam delivery In LMJ architecture the distance between the nanojoule fiber seeder and the amplifier stages is about 16 m. Beam delivery is achieved with a standard PM fiber, such a solution is no longer achievable with hundreds of kilowatt peak powers. An efficient way to minimize nonlinear effects is to use hollow-core (HC

Erbium-doped fiber lasers as deep-sea hydrophones

International Nuclear Information System (INIS)

Bagnoli, P.E.; Beverini, N.; Bouhadef, B.; Castorina, E.; Falchini, E.; Falciai, R.; Flaminio, V.; Maccioni, E.; Morganti, M.; Sorrentino, F.; Stefani, F.; Trono, C.

2006-01-01

The present work describes the development of a hydrophone prototype for deep-sea acoustic detection. The base-sensitive element is a single-mode erbium-doped fiber laser. The high sensitivity of these sensors makes them particularly suitable for a wide range of deep-sea acoustic applications, including geological and marine mammals surveys and above all as acoustic detectors in under-water telescopes for high-energy neutrinos

Tunable multicolor and enhanced red emission of monodisperse CaF2:Yb3+/Ho3+ microspheres via Mn2+ doping

Science.gov (United States)

Wang, Rui; Yuan, Maohui; Zhang, Chaofan; Wang, Hongyan; Xu, Xiaojun

2018-05-01

Transition metal ions (e.g. Mn2+) and lanthanide co-doped upconversion (UC) materials have attracted wide attention in recent years due to their promising application in multicolor display. Here, we report the hydrothermal synthesis and characterization of Mn2+ doped monodisperse CaF2:Yb3+/Ho3+ microspheres. The results of X-ray diffraction (XRD) revealed that Mn2+ doping does not change the cubic phase of CaF2 material but will lead to diffraction peaks shifting slightly towards higher angle due to the substitution of larger Ca2+ by the relatively smaller Mn2+. Under the excitation of 980 nm continuous wave (CW) laser, these microspheres exhibit green-yellow-red tuning colors and remarkable enhancement of both red to green ratio (R/G) and red to blue ratio (R/B) when increasing Mn2+ concentration from 0 to 30 mol%. The energy migration process between Ho3+ and Mn2+ was proposed and supported by time-decay and power dependence measurements of Ho3+ UC emission. These upconversion materials may have potential applications in optical devices, color display, nanoscale lasers and biomedical imaging.

200-W single frequency laser based on short active double clad tapered fiber

Science.gov (United States)

Pierre, Christophe; Guiraud, Germain; Yehouessi, Jean-Paul; Santarelli, Giorgio; Boullet, Johan; Traynor, Nicholas; Vincont, Cyril

2018-02-01

High power single frequency lasers are very attractive for a wide range of applications such as nonlinear conversion, gravitational wave sensing or atom trapping. Power scaling in single frequency regime is a challenging domain of research. In fact, nonlinear effect as stimulated Brillouin scattering (SBS) is the primary power limitation in single frequency amplifiers. To mitigate SBS, different well-known techniques has been improved. These techniques allow generation of several hundred of watts [1]. Large mode area (LMA) fibers, transverse acoustically tailored fibers [2], coherent beam combining and also tapered fiber [3] seem to be serious candidates to continue the power scaling. We have demonstrated the generation of stable 200W output power with nearly diffraction limited output, and narrow linewidth (Δν<30kHz) by using a tapered Yb-doped fiber which allow an adiabatic transition from a small purely single mode input to a large core output.

Hybrid Ytterbium-doped large-mode-area photonic crystal fiber amplifier for long wavelengths

DEFF Research Database (Denmark)

Petersen, Sidsel Rübner; Alkeskjold, Thomas T.; Poli, Federica

2012-01-01

A large-mode-area Ytterbium-doped photonic crystal fiber amplifier with build-in gain shaping is presented. The fiber cladding consists of a hexagonal lattice of air holes, where three rows are replaced with circular high-index inclusions. Seven missing air holes define the large-mode-area core. ...

Highly optimized tunable Er3+-doped single longitudinal mode fiber ring laser, experiment and model

DEFF Research Database (Denmark)

Poulsen, Christian; Sejka, Milan

1993-01-01

A continuous wave (CW) tunable diode-pumped Er3+-doped fiber ring laser, pumped by diode laser at wavelengths around 1480 nm, is discussed. Wavelength tuning range of 42 nm, maximum slope efficiency of 48% and output power of 14.4 mW have been achieved. Single longitudinal mode lasing...... with a linewidth of 6 kHz has been measured. A fast model of erbium-doped fiber laser was developed and used to optimize output parameters of the laser...

Optical and magnetic properties of Yb ion-doped cobalt-based ZnO ...

Indian Academy of Sciences (India)

Administrator

The X-ray photoelectron spectral peaks for Yb 4f ions ... temperature with high coercivity due to the contribution of both 3d and 4f exchange interaction with the host ... Mn,4,5 Co,6–9 Ni2,10 Fe11–13 and Cu,2,14 and reported to .... water separately under stirring. .... different concentrations of Yb added ZnO : Co, nanopar-.

Fabrication of Y{sub 2}Ti{sub 2}O{sub 7}:Yb{sup 3+},Ho{sup 3+} nanoparticles by a gel-combustion approach and upconverting luminescent properties

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhongsheng, E-mail: zhshcheng@ecit.cn [State Key Laboratory Breeding Base of Nuclear Resources and Environment, East China Institute of Technology, Nanchang, Jiangxi 330013 (China); Wang, Min; Wang, Haiqing; Le, Zhanggao; Huang, Guolin; Zou, Lixia; Liu, Zhirong [State Key Laboratory Breeding Base of Nuclear Resources and Environment, East China Institute of Technology, Nanchang, Jiangxi 330013 (China); Wang, Dianyuan; Wang, Qingkai [College of Science, Jiujiang University, Jiujiang, Jiangxi 332005 (China); Gong, Weiping [Electronic Science Department, Huizhou University, Huizhou, Guangdong 516001 (China)

2014-09-01

Highlights: • Co-doped (Y{sub 0.99−x}Ho{sub 0.01}Yb{sub x}){sub 2}Ti{sub 2}O{sub 7} nanophosphors were fabricated by gel-combustion method. • The effect of calcination and Yb{sup 3+} doping on upconverting spectra of nanophosphors was studied. • The dependence of upconverting intensity on the excitation power was examined. - Abstract: Yb{sup 3+}, Ho{sup 3+} co-doped pyrochlore-structured (Y{sub 0.99−x}Ho{sub 0.01}Yb{sub x}){sub 2}Ti{sub 2}O{sub 7} (x = 0, 2.5, 5.0, 7.5, 10.0 and 12.5 mol%) nanoparticles (NPs) were successfully fabricated via a gel-combustion approach. The products as-obtained were characterized by various techniques, i.e. X-ray diffraction, transmission electron microscope, Fourier transformed infrared spectra and upconverting spectra. The results indicate that the bright green (∼540 nm) and red (∼660 nm) emissions are observed in Y{sub 2}Ti{sub 2}O{sub 7}:Ho{sup 3+},Yb{sup 3+} NPs under the 980 nm excitation, which is ascribed to the radiative transitions ({sup 5}F{sub 4},{sup 5}S{sub 2}) → {sup 5}I{sub 8} and {sup 5}F{sub 5} → {sup 5}I{sub 8} of Ho{sup 3+} ions, respectively. It is also found that the calcining temperature and Yb{sup 3+} ion doping level have a great influence on the upconverting spectra of (Y{sub 0.99−x}Ho{sub 0.01}Yb{sub x}){sub 2}Ti{sub 2}O{sub 7} NPs. The emission intensities increase initially and then fall down from 800 to 1000 °C. The optimum doping level of Yb{sup 3+} ions is 7.5 mol%, and the intensity of upconverting emissions for (Y{sub 0.915}Ho{sub 0.01}Yb{sub 0.075}){sub 2}Ti{sub 2}O{sub 7} NPs is enhanced by the fold of 32 compared to the Yb{sup 3+}-free samples. The dependence of upconverting intensity on the excitation power reveals the contribution of two photons to both the green and red upconverting process under lower excitation power, and the possible upconverting mechanisms have been proposed accordingly.

Discrete tuning concept for fiber-integrated lasers based on tailored FBG arrays and a theta cavity layout.

Science.gov (United States)

Tiess, Tobias; Becker, Martin; Rothhardt, Manfred; Bartelt, Hartmut; Jäger, Matthias

2017-03-15

We demonstrate a novel tuning concept for pulsed fiber-integrated lasers with a fiber Bragg grating (FBG) array as a discrete and tailored spectral filter, as well as a modified laser design. Based on a theta cavity layout, the structural delay lines originating from the FBG array are balanced, enabling a constant repetition rate and stable pulse properties over the full tuning range. The emission wavelength is electrically tuned with respect to the filter properties based on an adapted temporal gating scheme using an acousto-optic modulator. This concept has been investigated with an Yb-doped fiber laser, demonstrating excellent emission properties with high signal contrast (>35  dB) and narrow linewidth (<150  pm) over a tuning range of 25 nm.

Effects of ion pairs on the dynamics of erbium doped fiber laser in the inhomogeneous model

International Nuclear Information System (INIS)

Keyvaninia, Sh.; Karvar, M.; Bahrampour, A.

2006-01-01

In a high concentration erbium doped fiber, the erbium ions are so closed together that the ion pairs and clusters are formed. In such fiber amplifiers, the ion pairs and clusters acting as a saturable absorber are distributed along the fiber laser. The inhomogeneous rate equations for the laser modes in a high-concentration EDFA are written. The governing equations are an uncountable system of partial differential equations. For the first time we introduced an approximation method that the system of partial differential equations is converted to a finite system of ordinary differential equations. The effects of ion pairs concentration on erbium doped fiber are analyzed that is in good agreement whit the experimental result.

Lattice dynamics and substrate-dependent transport properties of (In, Yb)-doped CoSb3 skutterudite thin films

KAUST Repository

Sarath Kumar, S. R.

2011-10-24

Lattice dynamics, low-temperature electrical transport, and high-temperature thermoelectric properties of (In, Yb)-doped CoSb3thin films on different substrates are reported. Pulsed laser deposition under optimized conditions yielded single-phase polycrystalline skutterudite films. Raman spectroscopy studies suggested that In and Yb dopants occupy the cage sites in the skutterudite lattice. Low-temperature electrical transport studies revealed the n-type semiconducting nature of the films with extrinsic and intrinsic conduction mechanisms, in sharp contrast to the degenerate nature reported for identical bulk samples. Calculations yielded a direct bandgap close to 50 meV with no evidence of an indirect gap. The carrier concentration of the films was identical to that reported for the bulk and increased with temperature beyond 250 K. The higher resistivity exhibited is attributed to the enhanced grain boundary scattering in films with a high concentration of grains. The maximum power factor of ∼0.68 W m−1 K−1 obtained at 660 K for the film on glass is found to be nearly four times smaller compared to that reported for the bulk. The observed difference in the power factors of the films on different substrates is explained on the basis of the diffusion of oxygen from the substrates and the formation of highly conducting CoSb2 phase upon the oxidation of CoSb3.

Upconversion photoluminescence of epitaxial Yb{sup 3+}/Er{sup 3+} codoped ferroelectric Pb(Zr,Ti)O{sub 3} films on silicon substrates

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yang, E-mail: zhangy_acd@hotmail.com [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Kämpfe, Thomas [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Bai, Gongxun [Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong (China); Mietschke, Michael; Yuan, Feifei; Zopf, Michael [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Abel, Stefan [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Eng, Lukas M. [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Hühne, Ruben [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Fompeyrine, Jean [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Ding, Fei, E-mail: f.ding@ifw-dresden.de [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Schmidt, Oliver G. [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, Reichenhainer strasse 70, 09107 Chemnitz (Germany)

2016-05-31

Thin films of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} (PZT:Yb/Er) have been epitaxially grown on the SrTiO{sub 3} buffered Si wafer by pulsed laser deposition. Strong upconversion photoluminescence was observed in the PZT:Yb/Er thin film. Using piezoresponse force microscopy, polar domains in the PZT:Yb/Er film can be reversibly switched with a phase change of 180°. Ferroelectric hysteresis loop shape with a well-saturated response was observed. The epitaxially grown lanthanide-doped PZT on silicon opens up a promising route to the integration of luminescent functional oxides on the silicon platform. - Highlights: • Epitaxial growth of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} films on SrTiO{sub 3} buffered silicon • Upconversion emissions were obtained from the lanthanide ion doped thin films. • Saturated ferroelectric hysteresis loops were observed. • Polar domains were switched by PFM with a phase change of 180°.

Multi-wavelength Brillouin Raman erbium-doped fiber laser generation in a linear cavity

International Nuclear Information System (INIS)

Shirazi, M R; Harun, S W; Ahmad, H

2014-01-01

A multi-wavelength Brillouin Raman erbium-doped fiber laser is proposed and demonstrated. The setup uses a 7.7 km dispersion compensating fiber simultaneously as the Brillouin and Raman nonlinear gain media and operates in conjunction with a 3 m erbium-doped fiber as the linear gain medium. At a Brillouin pump (BP) wavelength of 1530 nm, where Raman and erbium gains overlap each other, 34 Brillouin Stokes lines having line spacing of 0.075 nm are created by using a Raman pump power of only 24.1 dBm, an erbium pump power of about 22.1 dBm, and a BP power of 6.5 dBm in the proposed linear cavity. The system is highly efficient and is able to generate many comparable peak-power lines at a low pump power. (paper)

Electrospun dye-doped fiber networks: lasing emission from randomly distributed cavities

DEFF Research Database (Denmark)

Krammer, Sarah; Vannahme, Christoph; Smith, Cameron

2015-01-01

Dye-doped polymer fiber networks fabricated with electrospinning exhibit comb-like laser emission. We identify randomly distributed ring resonators being responsible for lasing emission by making use of spatially resolved spectroscopy. Numerical simulations confirm this result quantitatively....

Tunable single-polarization single-longitudinal-mode erbium-doped fiber ring laser employing a CMFBG filter and saturable absorber

Science.gov (United States)

Feng, Suchun; Lu, Shaohua; Peng, Wanjing; Li, Qi; Feng, Ting; Jian, Shuisheng

2013-04-01

A tunable single-polarization single-longitudinal-mode (SLM) erbium-doped fiber ring laser is proposed and demonstrated. For the first time as we know, a chirped moiré fiber Bragg grating (CMFBG) filter with ultra-narrow transmission band and a uniform fiber Bragg grating (UFBG) are used to select the laser longitudinal mode. The stable SLM operation of the fiber laser is guaranteed by the combination of the CMFBG filter and 3 m unpumped erbium-doped fiber acting as a saturable absorber. The single polarization operation of the fiber laser is obtained by using an inline broadband polarizer. A tuning range of about 0.7 nm with about 0.1 nm step is achieved by stretching the uniform FBG.

Effect of radiative trapping on measurement of the spectroscopic properties of Yb sup 3 sup + :phosphate glasses

CERN Document Server

Dai Shi Xun; Wen Lei; Hu Li Li; Jiang Zhong Hon

2003-01-01

The effect of radiative trapping on measurement of the spectroscopic properties of Yb sup 3 sup + -doped phosphate glasses was investigated as a function of Yb sup 3 sup + concentration at different thicknesses. It was found that radiative trapping exists generally in Yb sup 3 sup + :phosphate glasses, even at low concentration. As a result, the measured lifetime of Yb sup 3 sup + in phosphate glasses is usually larger than the calculated one. The maximum discrepancies between them at high concentration are found to be <42%. The calculated lifetime should be used as a reference in determining the true value of the measured lifetime because of it being lengthened largely by radiative trapping. On the other hand, the shape of fluorescence spectrum exhibits remarkable changes due to the radiative trapping. What is more, the intensity increase of DELTA lambda sub e sub f sub f at high concentration is greater than that of low doping. The DELTA lambda sub e sub f sub f increases 36% from 53 to 72 nm with thickn...

Fingermark detection on non-porous and semi-porous surfaces using YVO4:Er,Yb luminescent upconverting particles.

Science.gov (United States)

Ma, Rongliang; Shimmon, Ronald; McDonagh, Andrew; Maynard, Philip; Lennard, Chris; Roux, Claude

2012-04-10

This article describes the use of an anti-Stokes luminescent material (upconverter), yttrium vanadate doped with ytterbium and erbium (YVO(4):Er,Yb), for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes luminescent materials emit light at shorter wavelengths than the excitation wavelength. This property is unusual in both natural and artificial materials commonly found as exhibits in forensic science casework. As a result, fingermark detection techniques based on anti-Stokes luminescence are potentially extremely sensitive and selective. Latent fingermarks on non-luminescent and inherently luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with YVO(4):Er,Yb by dry powder and wet powder techniques. The effectiveness of YVO(4):Er,Yb for fingermark detection was compared with that of cyanoacrylate fuming and of sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF(4):Er,Yb). The results illustrate some benefit of luminescent up-converting phosphors over traditional luminescence techniques for the detection of latent fingermarks. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Empirical multichannel power consumption model for erbium-doped fiber amplifiers

DEFF Research Database (Denmark)

Saldaña Cercos, Silvia; de Paiva, Getulio E. R.; Argentato, Marcio Colazza

2015-01-01

In this paper we report on the first experimental power consumption analysis and model of single and multi-stage booster erbium-doped fiber amplifiers (EDFAs) with automatic gain control (AGC), accounting for channel number dependency. Results show that the amount of channels being amplified simu......-users, it is relevant to study channel number dependent power consumption for devising EDFA power efficient control and design.......In this paper we report on the first experimental power consumption analysis and model of single and multi-stage booster erbium-doped fiber amplifiers (EDFAs) with automatic gain control (AGC), accounting for channel number dependency. Results show that the amount of channels being amplified...... simultaneously contributes significantly, up to 48%, to the total power consumption due to the circuitry used for controlling the EDFA. As the number of simultaneous amplified WDM channels in high capacity long and medium reach transmission links reflects closely traffic patterns generated by end...

Mitigating of modal instabilities in linearly-polarized fiber amplifiers by shifting pump wavelength

International Nuclear Information System (INIS)

Tao, Rumao; Ma, Pengfei; Wang, Xiaolin; Zhou, Pu; Liu, Zejin

2015-01-01

We investigated the effect of pump wavelength on the modal instabilities (MI) in high-power linearly polarized Yb-doped fiber amplifiers. We built a novel semi-analytical model to determine the frequency coupling characteristics and power threshold of MI, which indicates promising MI suppression through pumping at an appropriate wavelength. By pumping at 915 nm, the threshold can be enhanced by a factor of 2.1 as compared to that pumped at 976 nm. Based on a high-power linearly polarized fiber amplifier platform, we studied the influence of pump wavelength experimentally. A maximal enhancement factor of 1.9 has been achieved when pumped at 915 nm, which agrees with the theoretical calculation and verified our theoretical model. Furthermore, we show that MI suppression by detuning the pump wavelength is weakened for fiber with a large core-to-cladding ratio. (paper)

Erbium-doped fiber ring laser with SMS modal interferometer for hydrogen sensing

Science.gov (United States)

Zhang, Ya-nan; Zhang, Lebin; Han, Bo; Peng, Huijie; Zhou, Tianmin; Lv, Ri-qing

2018-06-01

A hydrogen sensor based on erbium-doped fiber ring laser with modal interferometer is proposed. A single mode-multimode-single mode (SMS) modal interferometer structure coated with Pd/WO3 film is used as the sensing head, due to that it is easy to be fabricated and low cost. The sensing structure is inserted into an erbium-doped fiber ring laser in order to solve the problem of spectral confusion and improve the detection limit of the hydrogen sensor based on the SMS modal interferometer. The SMS sensing structure is acted as a fiber band-pass filter. When hydrogen concentration around the sensor is changed, it will induce the refractive index and strain variations of the Pd/WO3 film, and then shift the resonant spectrum of the SMS modal interferometer as well as the laser wavelength of the fiber ring laser. Therefore, the hydrogen concentration can be measured by monitoring the wavelength shift of the laser, which has high intensity and narrow full width half maximum. Experimental results demonstrate that the sensor has high sensitivity of 1.23 nm/%, low detection limit of 0.017%, good stability and excellent repeatability.

High power, ultra-broadband supercontinuum source based on highly GeO2 doped silica fiber