WorldWideScience

Sample records for monolithic waveguide laser

  1. A Directly-Written Monolithic Waveguide-Laser Incorporating a DFB Waveguide-Bragg Grating

    CERN Document Server

    Marshall, Graham D; Ams, Martin; Piper, James A; Withford, Michael J

    2008-01-01

    We report the fabrication and performance of the first C-band directly-written monolithic waveguide-laser. The waveguide-laser device was created in an Erbium and Ytterbium doped phosphate glass host and consisted of an optical waveguide that included a distributed feedback Bragg grating structure. The femtosecond laser direct-write technique was used to create both the waveguide and the waveguide-Bragg grating simultaneously and in a single processing step. The waveguide-laser was optically pumped at approximately 980 nm and lased at 1537nm with a bandwidth of less than 4 pm.

  2. Monolithic DWDM Multi-channel planar waveguide laser

    DEFF Research Database (Denmark)

    Sckerl, Mads W.; Guldberg-Kjær, Søren Andreas; Laurent-Lund, Christian

    1999-01-01

    silica -on-silicon-based multi-channel waveguide laser with four outputs channel with ~ 50 GHz spacing is presented. Excellent control over channel positions and spacings is obtained by the method presented here. Remarkable temperature tuning properties have been obtained.......silica -on-silicon-based multi-channel waveguide laser with four outputs channel with ~ 50 GHz spacing is presented. Excellent control over channel positions and spacings is obtained by the method presented here. Remarkable temperature tuning properties have been obtained....

  3. Monolithically integrated DBR laser, detector, and transparent waveguide fabricated in a single growth step

    OpenAIRE

    Hofstetter, Daniel; Zappe, H. P.; Epler, J. E.; van Riel, P

    2008-01-01

    The monolithic integration of a GaAs-AlGaAs distributed Bragg reflector (DBR) laser with a nonabsorbing grating section, a transparent waveguide, and an absorbing photodetector is reported. Transparent and absorbing segments were defined after growth by vacancy-enhanced quantum-well disordering (VED). Laser output power was 5 mW with a threshold current of 22 mA. Detector current was linearly dependent on the laser output power and the emission from the grating side of the laser could be dire...

  4. Technological and Physical Compatibilities in Hybrid Integration of Laser and Monolithic Integration of Waveguide, Photodetector and CMOS Circuits on Silicon

    NARCIS (Netherlands)

    Zhou, M.J.; Ikkink, T.; Chalmers, J.; Kranenburg, H. van; Albers, H.; Holleman, J.; Lambeck, P.V.; Joppe, J.L.; Bekman, H.H.P.T.; Krijger, A.J.T. de

    1994-01-01

    In this paper, technological and physical compatibilities in hybrid integration of AlInGaP laser and monolithic integration of ZnO monomode waveguide, pin-photodetector, CMOS circuits for laser power control and signal amplification on silicon substrate are studied. Prospective problems and their po

  5. Technological and physical compatibilities in hybrid integration of laser and monolithic integration of waveguide, photodetector and CMOS circuits on silicon

    NARCIS (Netherlands)

    Zhou, Ming-Jiang; Ikkink, Ton; Chalmers, John; Kranenburg, van Herma; Albers, Hans; Holleman, Jisk; Lambeck, Paul; Joppe, Jan Leendert; Bekman, Herman; Krijger, de Ton; Lambeck, P.V.

    1994-01-01

    In this paper, technological and physical compatibilities in hybrid integration of AlInGaP laser and monolithic integration of ZnO monomode waveguide, pin-photodetector, CMOS circuits for laser power control and signal amplification on silicon substrate are studied. Prospective problems and their po

  6. Monolithic micro-laser with KTP ridge waveguides for injection seeding high power lasers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA Small Business Innovation Research Phase I project will develop a technique to greatly improve the direct coupling of a diode laser to an optical waveguide...

  7. Laser diode monolithically integrated with an electroabsorption modulator and dual-waveguide spot-size converter

    Science.gov (United States)

    Hou, Lianping; Wang, Wei; Feng, Wen; Liang, Song; Zhu, Hongliang; Zhou, Fan; Wang, Lufeng; Bian, Jing

    2005-06-01

    A 1.60-µm laser diode and electroabsorption modulator monolithically integrated with a dual-waveguide spot-size converter output for low-loss coupling to cleaved single-mode optical fiber is demonstrated. The devices emit in a single transverse and quasi-single longitudinal mode with a side mode suppression ratio of 25.6 dB. These devices exhibit a 3-dB modulation bandwidth of 16.0 GHz, and modulator extinction ratios of 16.2 dB dc. The beam divergence angle is about 7.3×10.6 deg, resulting in 3.0-dB coupling loss with cleaved single-mode optical fiber.

  8. Monolithic integration of GaAs/GaAlAs buried-heterostructure orthogonal facet laser and optical waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Ribot, H.; Sansonetti, P.; Brandon, J.; Carre, M.; Menigaux, L.; Azoulay, R.; Bouadma, N.

    1989-02-06

    Monolithic integration of a quarter-circle laser evanescently coupled to an optical waveguide located below the active layer is demonstrated on GaAs. The curved resonator consists of a 45-..mu..m-long straight part and a quarter circle with a curvature radius of 150 ..mu..m. The component exhibits a threshold current of 50 mA in a pulsed regime. A 10 mW emission is measured from a 415-..mu..m-long tangential straight waveguide for an injection current of 140 mA.

  9. Femtosecond laser fabrication of waveguides in Rhodamine B-doped GPTS/TEOS-derived organic/silica monolithic xerogel

    Science.gov (United States)

    Ferreira, P. H. D.; Otuka, A. J. G.; Barbano, E. C.; Manoel, D. S.; De Vicente, F. S.; Vollet, D. R.; Donatti, D. A.; Misoguti, L.; Mendonça, C. R.

    2015-09-01

    This paper reports on the fabrication and characterization of waveguides inside of a dye doped-organic/inorganic bulk material using femtosecond laser microfabrication. Rhodamine B-doped GPTS/TEOS-derived organic/silica monolithic xerogels with excellent optical quality were prepared by sol-gel method. The influence of the dye concentration on the samples optical properties was also investigated in order to choose the proper one to be used for producing the waveguides. After investigation of parameters to fabrication in xerogels, such as, scan speed effects and pulse energy, we produced waveguides in bulks doped with 0.5 mmol/L of Rhodamine B. Propagation losses in the single mode waveguides, at 632.8 nm wavelength, were obtained.

  10. Monolithically integrated laser diode and electroabsorption modulator with dual-waveguide spot-size converter input and output

    Science.gov (United States)

    Hou, Lianping; Wang, Wei; Zhu, Hongliang; Zhou, Fan; Wang, Lufeng; Bian, Jing

    2005-08-01

    We have demonstrated a 1.60 µm ridge-structure laser diode and electroabsorption modulator monolithically integrated with buried-ridge-structure dual-waveguide spot-size converters at the input and output ports for low-loss coupling to a cleaved single-mode optical fibre by means of selective area growth and asymmetric twin waveguide technologies. The devices emit in single transverse and quasi-single longitudinal modes with a side mode suppression ratio of 25.6 dB. These devices exhibit 3 dB modulation bandwidth of 15.0 GHz and modulator extinction ratios of 14.0 dB dc. The output beam divergence angles of the spot-size converter in the horizontal and vertical directions are as small as 7.3° × 10.6°, respectively, resulting in 3.0 dB coupling loss with a cleaved single-mode optical fibre.

  11. Monolithic resonant optical reflector laser diodes

    Science.gov (United States)

    Hirata, T.; Suehiro, M.; Maeda, M.; Hihara, M.; Hosomatsu, H.

    1991-10-01

    The first monolithic resonant optical reflector laser diode that has a waveguide directional coupler and two DBR reflectors integrated by compositional disordering of quantum-well heterostructures is described. A linewidth of 440 kHz was obtained, and this value is expected to be greatly decreased by reducing the propagation loss in the integrated waveguide.

  12. High-Quality Monolithic Distributed Bragg Reflector Cavities and Lasers in Alumina Channel Waveguides

    NARCIS (Netherlands)

    Bernhardi, Edward; van Wolferen, Hendricus A.G.M.; Worhoff, Kerstin; de Ridder, R.M.; Pollnau, Markus

    2011-01-01

    The design, fabrication, and characterization of surface relief Bragg gratings integrated with aluminum oxide ridge waveguides are reported. The grating lengths varied between 1.25 mm and 4.75 mm and were used to create various distributed Bragg reflector (DBR) cavities. The measured grating induced

  13. 1.5 GHz picosecond pulse generation from a monolithic waveguide laser with a graphene-film saturable output coupler.

    Science.gov (United States)

    Mary, Rose; Brown, Graeme; Beecher, Stephen J; Torrisi, Felice; Milana, Silvia; Popa, Daniel; Hasan, Tawfique; Sun, Zhipei; Lidorikis, Elefterios; Ohara, Seiki; Ferrari, Andrea C; Kar, Ajoy K

    2013-04-08

    We fabricate a saturable absorber mirror by coating a graphene- film on an output coupler mirror. This is then used to obtain Q-switched mode-locking from a diode-pumped linear cavity channel waveguide laser inscribed in Ytterbium-doped Bismuthate Glass. The laser produces 1.06 ps pulses at ~1039 nm, with a 1.5 GHz repetition rate, 48% slope efficiency and 202 mW average output power. This performance is due to the combination of the graphene saturable absorber and the high quality optical waveguides in the laser glass.

  14. Monolithic integration of a lithium niobate microresonator with a free-standing waveguide using femtosecond laser assisted ion beam writing

    Science.gov (United States)

    Fang, Zhiwei; Xu, Yingxin; Wang, Min; Qiao, Lingling; Lin, Jintian; Fang, Wei; Cheng, Ya

    2017-01-01

    We demonstrated integrating a high quality factor lithium niobate microdisk resonator with a free-standing membrane waveguide. Our technique is based on femtosecond laser direct writing which produces the pre-structure, followed by focused ion beam milling which reduces the surface roughness of sidewall of the fabricated structure to nanometer scale. Efficient light coupling between the integrated waveguide and microdisk was achieved, and the quality factor of the microresonator was measured as high as 1.67 × 105. PMID:28358135

  15. Dielectric Waveguide lasers

    NARCIS (Netherlands)

    Pollnau, Markus; Orlovic, V.A.; Pachenko, V.; Scherbakov, I.A.

    2007-01-01

    Our recent results on planar and channel waveguide fabrication and lasers in the dielectric oxide materials Ti:sapphire and rare-earth-ion-doped potassium yttrium double tungstate (KYW) are reviewed. We have employed waveguide fabrication methods such as liquid phase epitaxy and reactive ion etching

  16. Monolithic integration of erbium-doped amplifiers with silicon-on-insulator waveguides.

    Science.gov (United States)

    Agazzi, Laura; Bradley, Jonathan D B; Dijkstra, Meindert; Ay, Feridun; Roelkens, Gunther; Baets, Roel; Wörhoff, Kerstin; Pollnau, Markus

    2010-12-20

    Monolithic integration of Al2O3:Er3+ amplifier technology with passive silicon-on-insulator waveguides is demonstrated. A signal enhancement of >7 dB at 1533 nm wavelength is obtained. The straightforward wafer-scale fabrication process, which includes reactive co-sputtering and subsequent reactive ion etching, allows for parallel integration of multiple amplifier and laser sections with silicon or other photonic circuits on a chip.

  17. Monolithically integrated Ge CMOS laser

    Science.gov (United States)

    Camacho-Aguilera, Rodolfo

    2014-02-01

    Ge-on-Si devices are explored for photonic integration. Through the development of better growth techniques, monolithic integration, laser design and prototypes, it was possible to probe Ge light emitters with emphasis on lasers. Preliminary worked shows thermal photonic behavior capable of enhancing lamination at high temperatures. Increase luminescence is observed up to 120°C from L-band contribution. Higher temperatures show contribution from Δ -band. The increase carrier thermal contribution suggests high temperature applications for Ge light emitters. A Ge electrically pumped laser was probed under 0.2% biaxial strain and doping concentration ~4.5×1019cm-3 n-type. Ge pnn lasers exhibit a gain >1000cm-1 with 8mW power output, presenting a spectrum range of over 200nm, making Ge the ideal candidate for Si photonics. Large temperatures fluctuations and process limit the present device. Theoretically a gain of >4000cm- gain is possible with a threshold of as low as 1kA/cm2. Improvements in Ge work

  18. Monolithically integrated absolute frequency comb laser system

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  19. Optical waveguides in laser crystals

    NARCIS (Netherlands)

    Pollnau, Markus; Romanyuk, Yaroslav E.

    2007-01-01

    This article reviews the recent research on different types of planar and channel crystalline optical waveguides, fabrication methods such as liquid phase epitaxy, pulsed laser deposition, thermal bonding, reactive ion or ion beam etching, wet chemical etching, ion in-diffusion, proton exchange, ion

  20. Dielectric waveguide amplifiers and lasers

    NARCIS (Netherlands)

    Pollnau, Markus

    The performance of semiconductor amplifiers and lasers has made them the preferred choice for optical gain on a micro-chip. In the past few years, we have demonstrated that also rare-earth-ion-doped dielectric waveguides show remarkable performance, ranging from a small-signal gain per unit length

  1. Writing Waveguide in LN With fs Laser

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We investigated the waveguide formation in Lithium Niobate with Femtosecond laser pulse writing directly. The output optical field through waveguide has been observed and refractive-index change was characterized by using grating method.

  2. Monolithic integration of DUV-induced waveguides into plastic microfluidic chip for optical manipulation

    DEFF Research Database (Denmark)

    Khoury Arvelo, Maria; Vannahme, Christoph; Sørensen, Kristian Tølbøl

    2014-01-01

    A monolithic polymer optofluidic chip for manipulation of microbeads in flow is demonstrated. On this chip, polymer waveguides induced by Deep UV lithography are integrated with microfluidic channels. The optical propagation losses of the waveguides are measured to be 0.66±0.13 d...

  3. Improved optical planar waveguides for lasers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Demonstrate efficacy of a novel growth technique for planar waveguides (PWG) Enable PWG laser technology with improved performance, efficiency and manufacturability....

  4. Optimal design of a spectral readout type planar waveguide-mode sensor with a monolithic structure.

    Science.gov (United States)

    Wang, Xiaomin; Fujimaki, Makoto; Kato, Takafumi; Nomura, Ken-Ichi; Awazu, Koichi; Ohki, Yoshimichi

    2011-10-10

    Optical planar waveguide-mode sensor is a promising candidate for highly sensitive biosensing techniques in fields such as protein adsorption, receptor-ligand interaction and surface bacteria adhesion. To make the waveguide-mode sensor system more realistic, a spectral readout type waveguide sensor is proposed to take advantage of its high speed, compactness and low cost. Based on our previously proposed monolithic waveguide-mode sensor composed of a SiO2 waveguide layer and a single crystalline Si layer [1], the mechanism for achieving high sensitivity is revealed by numerical simulations. The optimal achievable sensitivities for a series of waveguide structures are summarized in a contour map, and they are found to be better than those of previously reported angle-scan type waveguide sensors.

  5. A widely tunable laser using silica-waveguide ring resonators

    Science.gov (United States)

    Yamazaki, Hiroyuki; Takahashi, Morio; Suzuki, Kouichi; Deki, Yukari; Takeuchi, Takeshi; Takaesu, Sekizen; Horie, Mika; Sato, Kenji; Kudo, Koji

    2005-10-01

    A Wide wavelength tunable laser is needed for Wavelength Division Multiplexing (WDM) and Reconfigurable Optical Add/Drop Multiplexing (ROADM) networks, since it realizes flexible network, effectively employing wavelength resources, and inventory cost reduction. Several types currently exist, but they all are difficult to produce; that is, their mass producibility is not high and they have many components. In particular, monolithically integrated wavelength tunable lasers, such as DFB array, and SG(Sampled Grating)-DBR based structures, have been developed. While these lasers have good performance, they require complex InP growth steps and processing. The external cavity lasers also have good performance, but require precise manual assembly and have moving parts. We have proposed novel tunable laser consisting of silica waveguide ring resonator connected directly to semiconductor optical amplifier. This laser structure has several advantages, such as a simple laser structure suitable for mass-production and high reliability due to having a stable thermal optic phase shifter and no moving parts. This paper gives recent progress in waveguide ring resonator based tunable laser. Low loss and high performance silica waveguide ring resonator, which was suitable for tunable laser, was successfully fabricated using high index contrast SiON core. Double-ring resonators successfully attained 45-nm and 160-nm wavelength tuning operations, which was the largest wavelength tuning range in a tunable laser with no mechanical moving parts reported to date. Triple-ring resonator demonstrated stable full L-band tuning operations with 50-GHz wavelength spacing. We believe that silica waveguide ring resonator based tunable laser is very suitable for not only mass production, but also widely wavelength tuning and stable single mode operations.

  6. Optical microwave generation using two parallel DFB lasers integrated with Y-branch waveguide coupler

    Institute of Scientific and Technical Information of China (English)

    Xie Hong-Yun; Wang Lu; Zhao Ling-Juan; Zhu Hong-Liang; Wang Wei

    2007-01-01

    A new device of two parallel distributed feedback (DFB) lasers integrated monolithically with Y-branch waveguide coupler was fabricated by means of quantum well intermixing. Optical microwave signal was generated in the Y-branch waveguide coupler through frequency beating of the two laser modes coming from two DFB laser in parallel, which had a small difference in frequency. Continuous rapid tuning of optical microwave signal from 13 to 42 GHz were realized by adjusting independently the driving currents injected into the two DFB lasers.

  7. Monolithic photonic integration of suspended light emitting diode, waveguide and photodetector

    CERN Document Server

    Wang, Yongjin; Gao, Xumin; Cai, Wei; Xu, Yin; Yuan, Jialei; Zhu, Guixia; Yang, Yongchao; Cao, Xun; Zhu, Hongbo; Gruenberg, Peter

    2015-01-01

    We report here a monolithic photonic integration of light emitting diode (LED) with waveguide and photodetector to build a highly-integrated photonic system to perform functionalities on the GaN-on-silicon platform. Suspended p-n junction InGaN/GaN multiple quantum wells (MQWs) are used for device fabrication. Part of the LED emission is coupled into suspended waveguide and then, the guided light laterally propagates along the waveguide and is finally sensed by the photodetector. Planar optical communication experimentally demonstrates that the proof-of-concept monolithic photonic integration system can achieve the on-chip optical interconnects. This work paves the way towards novel active electro-optical sensing system and planar optical communication in the visible range.

  8. Monolithically Peltier-cooled laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hava, S.; Hunsperger, R.G.; Sequeira, H.B.

    1984-04-01

    A new method of cooling a GaAs/GaAlAs laser in an optical integrated circuit or on a discrete chip, by adding an integral thermoelectric (Peltier) cooling and heat spreading device to the laser, is presented. This cooling both reduces and stabilizes the laser junction temperature to minimize such deleterious effects as wavelength drift due to heating. A unified description of the electrical and thermal properties of a monolithic semiconductor mesa structure is given. Here it is shown that an improvement in thermal characteristics is obtained by depositing a relatively thick metallic layer, and by using this layer as a part of an active Peltier structure. Experimental results reveal a 14-percent increase in emitted power (external quantum efficiency) due to passive heat spreading and a further 8-percent if its Peltier cooler is operated. Fabrication techniques used to obtain devices exhibiting the above performance characteristics are given. 21 references.

  9. Technology challenges for monolithically integrated waveguide demultiplexers Invited Paper

    Institute of Scientific and Technical Information of China (English)

    Lech Wosinski; Liu Liu; Ning Zhu; Lars Thylen

    2009-01-01

    A short overview of integrated waveguide demultiplexers for different applications in future highly inte- grated optical communication systems is presented. Some fabricated devices based on amorphous silicon nanowire technology are described.

  10. Fs-Laser structuring of ridge waveguides

    Science.gov (United States)

    Wortmann, D.; Gottmann, J.

    2008-10-01

    Thin films made by PLD from Er:ZBLAN and Nd:Gd3Ga5O12 are micro machined to form optical wave guiding structures using Ti:sapphire and Yb:glass fiber laser radiation. For the manufacturing of the ridge waveguides grooves are structured by ablation using femtosecond laser radiation. The fluence, the scanning velocity, the repetition rate, and the orientation of the polarization with respect to the scanning direction are varied. The resulting structures are characterized using optical microscopy and scanning electron microscopy. Damping and absorption coefficients of the waveguides are determined by observing the light scattered from the waveguides due to droplets in the thin films and the surface roughness of the structured edges. To discriminate between damping due to droplets and the structured edges, damping measurements in the non-structured films and the structured waveguides are performed. Ridge waveguides with non-resonant damping losses smaller than 3 dB/cm are achieved. Due to the high repetition rate of the Yb:glass fiber laser, the manufacturing time for one waveguide has been decreased by a factor of more than 100 compared to earlier results achieved with the Ti:sapphire laser.

  11. Highly efficient coupling between a monolithically integrated photonic crystal cavity and a bus waveguide

    Science.gov (United States)

    Debnath, Kapil; Welna, Karl; Ferrera, Marcello; Deasy, Kieran; Lidzey, David; Krauss, Thomas F.; O'Faolain, Liam

    2012-01-01

    We experimentally demonstrate a new optical filter design comprising of a photonic crystal cavity and a low index bus waveguide which are monolithically integrated on a silicon-on-insulator (SOI) platform. We have fabricated oxide clad PhC cavities with a silicon nitride waveguide positioned directly above, such that there is an overlap between the evanescent tails of the two modes. We have realised an extinction ratio of 7.5dB for cavities with total Q of 50,000.

  12. Fusion of Renewable Ring Resonator Lasers and Ultrafast Laser Inscribed Photonic Waveguides

    Science.gov (United States)

    Chandrahalim, Hengky; Rand, Stephen C.; Fan, Xudong

    2016-09-01

    We demonstrated the monolithic integration of reusable and wavelength reconfigurable ring resonator lasers and waveguides of arbitrary shapes to out-couple and guide laser emission on the same fused-silica chip. The ring resonator hosts were patterned by a single-mask standard lithography, whereas the waveguides were inscribed in the proximity of the ring resonator by using 3-dimensional femtosecond laser inscription technology. Reusability of the integrated ring resonator – waveguide system was examined by depositing, removing, and re-depositing dye-doped SU-8 solid polymer, SU-8 liquid polymer, and liquid solvent (toluene). The wavelength reconfigurability was validated by employing Rhodamine 6G (R6G) and 3,3‧-Diethyloxacarbocyanine iodide (CY3) as exemplary gain media. In all above cases, the waveguide was able to couple out and guide the laser emission. This work opens a door to reconfigurable active and passive photonic devices for on-chip coherent light sources, optical signal processing, and the investigation of new optical phenomena.

  13. Monolithic Rare Earth Doped PTR Glass Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of the project is to demonstrate the feasibility of a monolithic solid state laser on the basis of PTR glass co-doped with luminescent rare earth ions....

  14. Ultrafast Laser Fabrication of Bragg Waveguides in GLS Chalcogenide Glass

    Directory of Open Access Journals (Sweden)

    McMillen Ben

    2013-11-01

    Full Text Available We present work on the fabrication of Bragg waveguides in gallium-lanthanum-sulfide chalcogenide glass using an ultrafast laser. Waveguides were written with a single pass while modulating the writing beam. The spatial and temporal profile of the writing beam was ontrolled during waveguide fabrication in order to control the shape and size of the waveguide cross-section.

  15. Monolithic narrow-linewidth InGaAsP semiconductor laser for coherent optical communications

    Science.gov (United States)

    Palfrey, S. L.; Enstrom, R. E.; Longeway, P. A.

    1989-09-01

    A design for a monolithic narrow-linewidth InGaAsP diode laser has been developed using a multiple-quantum-well (MQW) extended-passive-cavity distributed-Bragg-reflector (DBR) laser design. Theoretical results indicate that this structure has the potential for a linewidth of 100 kHz or less. To realize this device, a number of the fabrication techniques required to integrate low-loss passive waveguides with active regions have been developed using a DBR laser structure. In addition, the MOCVD growth of InGaAs MQW laser structures has been developed, and threshold current densities as low as 1.6 kA/sq cm have been obtained from broad-stripe InGaAs/InGaAsP separate-confinement-heterostructure MQW lasers.

  16. Monolithic narrow-linewidth InGaAsP semiconductor laser for coherent optical communications

    Science.gov (United States)

    Palfrey, S. L.; Enstrom, R. E.; Longeway, P. A.

    1989-01-01

    A design for a monolithic narrow-linewidth InGaAsP diode laser has been developed using a multiple-quantum-well (MQW) extended-passive-cavity distributed-Bragg-reflector (DBR) laser design. Theoretical results indicate that this structure has the potential for a linewidth of 100 kHz or less. To realize this device, a number of the fabrication techniques required to integrate low-loss passive waveguides with active regions have been developed using a DBR laser structure. In addition, the MOCVD growth of InGaAs MQW laser structures has been developed, and threshold current densities as low as 1.6 kA/sq cm have been obtained from broad-stripe InGaAs/InGaAsP separate-confinement-heterostructure MQW lasers.

  17. Electrically Tunable Nd:YAG waveguide laser based on Graphene

    Science.gov (United States)

    Ma, Linan; Tan, Yang; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng

    2016-11-01

    We demonstrate a tunable hybrid Graphene-Nd:YAG cladding waveguide laser exploiting the electro-optic and the Joule heating effects of Graphene. A cladding Nd:YAG waveguide was fabricated by the ion irradiation. The multi-layer graphene were transferred onto the waveguide surface as the saturable absorber to get the Q-switched pulsed laser oscillation in the waveguide. Composing with appropriate electrodes, graphene based capacitance and heater were formed on the surface of the Nd:YAG waveguide. Through electrical control of graphene, the state of the hybrid waveguide laser was turned on or off. And the laser operation of the hybrid waveguide was electrically tuned between the continuous wave laser and the nanosecond pulsed laser.

  18. Monolithic optofluidic ring resonator lasers created by femtosecond laser nanofabrication.

    Science.gov (United States)

    Chandrahalim, Hengky; Chen, Qiushu; Said, Ali A; Dugan, Mark; Fan, Xudong

    2015-05-21

    We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ mm(-2). Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 10(4), which is limited by both solvent absorption and scattering loss. In particular, a Q-factor resulting from the scattering loss can be as high as 4.2 × 10(4), suggesting the feasibility of using a femtosecond laser to create high quality optical cavities.

  19. The role of monolithic integration in advanced laser products

    Science.gov (United States)

    Marsh, John H.

    2006-02-01

    The design and performance of single-mode high-power (>100 mW) semiconductor lasers suitable for integration into large arrays are reported. In 830 nm lasers, quantum well intermixing (QWI) has been used to increase the bandgap of the waveguide in the facet region by 120 meV, and the catastrophic optical damage threshold of uncoated devices increased by a factor of >3 as a result. The passive waveguides are relatively cool, bringing high reliability, improving the single-mode waveguide stability and enabling high-temperature operation. Furthermore, the passive waveguides relax the cleaving and packaging alignment tolerances, giving a high yield process suitable for manufacture. A far-field reduction layer is included in the lasers giving a fast axis divergence of <20° FWHM. Arrays in which each emitter operates at several 100 mW, have excellent uniformity of laser parameters such as kink power, operating power and optical beam profile.

  20. Monolithic distributed Bragg reflector cavities in Al2O3 with quality factors exceeding one million

    NARCIS (Netherlands)

    Bernhardi, Edward; van Wolferen, Hendricus A.G.M.; Worhoff, Kerstin; de Ridder, R.M.; Pollnau, Markus

    Monolithic distributed Bragg reflector (DBR) cavities with quality factors exceeding one million have been realized in aluminum oxide channel waveguides. This technology enabled the successful demonstration of the first DBR laser in this waveguide platform.

  1. Integrated laser with low-loss high index-contrast waveguides for OEICs

    Energy Technology Data Exchange (ETDEWEB)

    Welty, R J; Bond, T C; Behymer, E; Pocha, M; Loomis, G; Wolfe, J; Vernon, S

    2004-11-22

    Photonic integrated circuits require the ability to integrate both lasers and waveguides with low absorption and coupling loss. This technology is being developed at LLNL for digital logic gates for optical key generation circuits to facilitate secure communications. Here, we demonstrate an approach of integrating InGaAs DQW edge emitting lasers (EEL) with electron beam evaporated dielectric waveguides. The EELs are defined by electron cyclotron resonance etching (ECR). This approach results in highly anisotropic etched mirrors with smooth etched features (sidewall rms roughness = 28 {angstrom}, surface rms roughness = 10 {angstrom}). The mirror is etched to form both the laser cavity and define the waveguide mesa, which accommodates a dielectric stack, where the core is aligned with the active region of the laser to achieve maximum vertical mode overlapping. The waveguides are based on SiO{sub 2}/Ta{sub 2}O{sub 5}/SiO{sub 2} which yields a high index contrast of 0.6, resulting in low loss guides ({approx}2-3dB/cm). The design of the interface has taken into account the waveguide transmission loss, air gap spacing and tilt between the laser and waveguide. The critical feature for this deposition technique is its required high directionality or minimal sidewall deposition and corner effects. In the butt coupled EEL/waveguide system we have measured a slope efficiency to be as high as 0.45 W/A. We have in conclusion demonstrated a technology that allows direct coupling of a dielectric optical interconnect to a semiconductor laser monolithically fabricated on the semiconductor substrate.

  2. Efficient and ultra-narrow-linewidth integrated waveguide lasers in Al2O3:Yb and Al2O3:Er

    NARCIS (Netherlands)

    Bernhardi, Edward; van Wolferen, Hendricus A.G.M.; Worhoff, Kerstin; de Ridder, R.M.; Pollnau, Markus

    The ability to integrate Bragg grating structures with optical waveguides provides the opportunity to realize a variety of compact monolithic optical devices, such as distributed feedback (DFB) lasers, and distributed Bragg reflector (DBR) lasers. In this work, we report passive DBR cavities with

  3. An implantable neural probe with monolithically integrated dielectric waveguide and recording electrodes for optogenetics applications

    Science.gov (United States)

    Wu, Fan; Stark, Eran; Im, Maesoon; Cho, Il-Joo; Yoon, Eui-Sung; Buzsáki, György; Wise, Kensall D.; Yoon, Euisik

    2013-10-01

    Objective. Optogenetics promises exciting neuroscience research by offering optical stimulation of neurons with unprecedented temporal resolution, cell-type specificity and the ability to excite as well as to silence neurons. This work provides the technical solution to deliver light to local neurons and record neural potentials, facilitating local circuit analysis and bridging the gap between optogenetics and neurophysiology research. Approach. We have designed and obtained the first in vivo validation of a neural probe with monolithically integrated electrodes and waveguide. High spatial precision enables optical excitation of targeted neurons with minimal power and recording of single-units in dense cortical and subcortical regions. Main results. The total coupling and transmission loss through the dielectric waveguide at 473 nm was 10.5 ± 1.9 dB, corresponding to an average output intensity of 9400 mW mm-2 when coupled to a 7 mW optical fiber. Spontaneous field potentials and spiking activities of multiple Channelrhodopsin-2 expressing neurons were recorded in the hippocampus CA1 region of an anesthetized rat. Blue light stimulation at intensity of 51 mW mm-2 induced robust spiking activities in the physiologically identified local populations. Significance. This minimally invasive, complete monolithic integration provides unmatched spatial precision and scalability for future optogenetics studies at deep brain regions with high neuronal density.

  4. Compatible laser emission and optical waveguide modulation at 1.5 µm using Wannier-Stark localization

    Science.gov (United States)

    Bigan, E.; Harmand, J. C.; Allovon, M.; Carré, M.; Carenco, A.; Voisin, P.

    1992-04-01

    We investigate the electroabsorption properties of an InGaAs-InAlAs superlattice optical waveguide. When reverse biased, the structure exhibits large extinction ratios over short waveguide lengths with very low drive voltages by using low-energy oblique transitions below the superlattice band gap. Although the structure has been optimized for modulation, laser emission is observed under forward bias. The peak emission wavelength stands in the ``blue-shift'' region which opens a way to straightforward laser-modulator monolithic integration.

  5. Flexible polymer waveguide tunable lasers.

    Science.gov (United States)

    Kim, Kyung-Jo; Kim, Jun-Whee; Oh, Min-Cheol; Noh, Young-Ouk; Lee, Hyung-Jong

    2010-04-12

    A flexible polymeric Bragg reflector is fabricated for the purpose of demonstrating widely tunable lasers with a compact simple structure. The external feedback of the Bragg reflected light into a superluminescent laser diode produces the lasing of a certain resonance wavelength. The highly elastic polymer device enables the direct tuning of the Bragg wavelength by controlling the imposed strain and provides a much wider tuning range than silica fiber Bragg gratings or thermo-optic tuned polymer devices. Both compressive and tensile strains are applied within the range from -36000 microepsilon to 35000 microepsilon, so as to accomplish the continuous tuning of the Bragg reflection wavelength over a range of up to 100 nm. The external feedback laser with the tunable Bragg reflector exhibits a repetitive wavelength tuning range of 80 nm with a side mode suppression ratio of 35 dB.

  6. Arrays of distributed-Bragg-reflector waveguide lasers at 1536 nm in Yb/Er codoped phosphate glass

    Science.gov (United States)

    Veasey, David L.; Funk, David S.; Sanford, Norman A.; Hayden, Joseph S.

    1999-02-01

    We have demonstrated an array of monolithic, single-frequency-distributed-Bragg-reflector (DBR), waveguide lasers operating near 1536 nm wavelengths. The lasers were fabricated by forming waveguides in Yb/Er-codoped phosphate glass by ion exchange. The slope efficiency for each laser as a function of launched pump power is 26% and the thresholds occur at 50 mW of launched pump power. An output power of 80 mW was achieved with 350 mW of coupled pump power. Each laser exhibits stable operation on a single longitudinal mode and all have linewidths less than 500 kHz. A comb of waveguides with varying effective indices allows the selection of wavelength using a single-period grating.

  7. Monolithic integration of optical mode-size converter and high-speed electroabsorption modulators using laterally undercut waveguide

    Science.gov (United States)

    Wu, Tsu-Hsiu; Lin, Fang-Zheng; Yan, Hung-Jung; Wu, Jui-Pin; Chiu, Yi-Jen

    2010-02-01

    A new monolithic integration scheme of fabricating optical spot-size converter (SSC) is realized in this work. High-speed electroabsorption modulator (EAM) is used to integrate such SSC. By laterally tapering the active region of an optical waveguide through undercut active region, a vertically asymmetric waveguide coupler can be defined to form an SSC, where the top is a tapered active waveguide, and the bottom is a large core of passive waveguide mode-matched to single-mode fiber (SMF). Through the top tapered active waveguide, the effective index can be gradually varied in the propagation direction, momentarily matching the bottom low-index passive waveguide. It not only performs the resonant coupling in such asymmetric waveguide coupler, but also locks the transferred power by the tapered structure. InGaAsP/InP multiple quantum wells are used as active region of active waveguide. Based on the highly selective etching properties between InGaAsP and InP, the tapered active waveguide can be fabricated by a method, called selectively undercut-etching-active-region (UEAR), enabling the processing a narrow waveguide structure (up to submicron) by general wet etching from a large waveguide ridge. It also leads to good microwave performance of waveguide. By taking this advantage, a SSC-integrated EAM can perform high-speed electrical-to-optical (EO) response as well as low-insertion loss properties. A mode transfer efficiency of 70% is obtained in such SSC. By narrowing waveguide by UEAR, over 40 GHz of -3dB electrical-to-optical (EO) response is obtained from this device. The high efficient SSC integrated with high-speed EAM suggests that the UEAR technique can have potential for applications in high-speed optoelectronic fields.

  8. Atom laser dynamics in a tight waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Campo, A del; Lizuain, I; Muga, J G [Departamento de Quimica-Fisica, UPV-EHU, Apartado. 644, Bilbao (Spain); Pons, M [Departamento de Fisica Aplicada I, E.U.I.T. de Minas y Obras Publicas, UPV-EHU, 48901 Barakaldo (Spain); Moshinsky, M [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, 01000 Mexico D.F. (Mexico)], E-mail: adolfo.delcampo@ehu.es

    2008-02-15

    We study the transient dynamics that arise during the formation of an atom laser beam in a tight waveguide. The time dependent density profile develops a series of wiggles which are related to the diffraction in time phenomenon. The apodization of matter waves, which relies on the use of smooth aperture functions, allows to suppress such oscillations in a time interval, after which there is a revival of the diffraction in time. The revival time scale is directly related to the inverse of the harmonic trap frequency for the atom reservoir.

  9. An Integrated Optical Memory based on Laser Written Waveguides

    CERN Document Server

    Corrielli, Giacomo; Mazzera, Margherita; Osellame, Roberto; de Riedmatten, Hugues

    2016-01-01

    We report on the first realization of an integrated optical memory for light based on a laser written waveguide in a doped crystal. Using femto-second laser micromachining, we fabricate waveguides in Pr$^{3+}$:Y$_2$SiO$_5$ crystal. We demonstrate that the waveguide inscription does not affect the coherence properties of the material and that the light confinement in the waveguide increases the interaction with the active ions by a factor 6. We also demonstrate that, analogously to the bulk crystals, we can operate the optical pumping protocols necessary to prepare the population in atomic frequency combs, that we use to demonstrate light storage in excited and spin states of the Praseodymium ions. Our results represent the first realization of laser written waveguides in a Pr$^{3+}$:Y$_2$SiO$_5$ crystal and the first implementation of an integrated on-demand spin wave optical memory. They open new perspectives for integrated quantum memories.

  10. Progress Toward a Monolithically Integrated Coherent Diode Laser Array.

    Science.gov (United States)

    1981-02-20

    B-i C. DBR AND ACTIVE-PASSIVE LASER FABRICATION PROCEDURE ............... C-I D. ELECTROCHEMICAL DEPOSITION OF OHMIC CONTACTS FOR DIODE... LASER FABRICATION PROCEDURE C.1 SAMPLE EXAMINATION 1. Etch sample in 1:1:8 A-B etch (A:B:H 20 mp) for 5 sec. 2. Photograph all four corners of sample to...GaAlAs waveguide att ,uation coeffi- cients; 1 6 the assumption that K remains the same for both DBRs simplifies con- siderably the actual DBR laser

  11. Ultrafast laser fabrication of Bragg waveguides in chalcogenide glass.

    Science.gov (United States)

    McMillen, Ben; Li, Mingshan; Huang, Sheng; Zhang, Botao; Chen, Kevin P

    2014-06-15

    Bragg waveguides are fundamental components in photonic integrated circuits and are particularly interesting for mid-IR applications in high index, highly nonlinear materials. In this work, we present Bragg waveguides fabricated in bulk chalcogenide glass using an ultrafast laser. Waveguides with near circularly symmetric cross sections and low propagation loss are obtained through spatial and temporal beam shaping. Using a single-pass technique, the waveguide and Bragg structure are formed at the same time. First through sixth order gratings with strengths of up to 25 dB are realized, and performance is evaluated based on the modulation duty cycle of the writing beam.

  12. Monolithic Y-branch dual wavelength DBR diode laser at 671nm for shifted excitation Raman difference spectroscopy

    Science.gov (United States)

    Maiwald, M.; Fricke, J.; Ginolas, A.; Pohl, J.; Sumpf, B.; Erbert, G.; Tränkle, G.

    2013-05-01

    A dual-wavelength laser diode source suitable for shifted excitation Raman difference spectroscopy (SERDS) is presented. This monolithic device contains two ridge waveguide (RW) sections with wavelengths adjusted distributed Bragg reflection (DBR) gratings as rear side mirrors. An integrated Y-branch coupler guides the emission into a common output aperture. The two wavelengths are centered at 671 nm with a well-defined spectral spacing of about 0.5 nm, i.e. 10 cm-1. Separate RW sections can be individually addressed by injection current. An output power up to 110 mW was achieved. Raman experiments demonstrate the suitability of these devices for SERDS.

  13. Nonlinear light propagation in fs laser-written waveguide arrays

    Directory of Open Access Journals (Sweden)

    Szameit A.

    2013-11-01

    Full Text Available We report on recent achievements in the field of nonlinear light propagation in fs laser-written waveguide lattices. Particular emphasis is thereby given on discrete solitons in such systems.

  14. GaAs/AlGaAs GRIN-SCH-SQW DBR Laser Diodes with Passive Waveguides Integrated by Compositional Disordering of the Quantum Well Using Ion Implantation

    Science.gov (United States)

    Hirata, Takaaki; Maeda, Minoru; Suehiro, Masayuki; Hosomatsu, Haruo

    1990-06-01

    GaAs/AlGaAs GRIN-SCH-SQW DBR laser diodes are fabricated by ion implantation and two-step MOVPE growth. Passive waveguides are monolithically integrated by compositional disordering of quantum well heterostructures using silicon ion implantation. Waveguide losses of partially disordered GRIN-SCH-SQW passive waveguides are measured, and propagation losses as low as 4.4 cm-1 are observed at the lasing wavelength. Stable single mode operation is obtained, and the narrowest linewidth achieved is 840 kHz. The results show that this fabrication process is useful for photonic integrated circuits.

  15. All-optical thermal microscopy of laser-excited waveguides

    OpenAIRE

    He, R.; De Aldana, J.R.V.; Pedrola, G.L.; Chen, F.; JAQUE, D.

    2016-01-01

    We report on a unique combination of high-resolution confocal microscopy and ratiometric luminescence thermometry to obtain thermal images of 800 nm pumped ultrafast laser-inscribed waveguides in a Nd:YAG crystal. Thermal images evidence a strong localization of thermal load in the waveguide active volume. Comparison between experimental data and numerical simulations reveals that ultrafast laser-inscribed damage tracks in Nd:YAG crystals behave both as low-index and low-thermal conductivity ...

  16. High Peak Power Gain Switched Flared Waveguide Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chow, W.W.; Indik, R.; Koch, S.W.; Mar, Alan, Vawter, G. Allen; Moloney, J.

    1999-08-05

    We gain-switch flared waveguide lasers to obtain 14.5 W peak powers and 0.5 nJ pulse energies with laser structures compatible with the generation of diffraction-limited beams. The results are in excellent agreement with a microscopic laser model.

  17. Single-transverse-mode Ti:sapphire rib waveguide laser

    NARCIS (Netherlands)

    Grivas, C.; Shepherd, D.P.; May-Smith, T.C.; Eason, R.W.; Pollnau, M.

    2005-01-01

    Laser operation of Ti:sapphire rib waveguides fabricated using photolithography and ion beam etching in pulsed laser deposited layers is reported. Polarized laser emission was observed at 792.5 nm with an absorbed pump power threshold of 265 mW, which is more than a factor of 2 lower in comparison t

  18. Solgel grating waveguides for distributed Bragg reflector lasers.

    Science.gov (United States)

    Fardad, M A; Luo, H; Beregovski, Y; Fallahi, M

    1999-04-01

    Solgel grating waveguides and their application to the fabrication of external-cavity distributed Bragg reflector (DBR) lasers are demonstrated. A new composition of aluminosilicate material is developed for the fabrication of single-mode waveguides and Bragg reflectors. An average loss of <0.2 dB/cm is measured in the single-mode waveguides at 1550 nm. The reflectors show filtering greater than 97% near 1530 nm, with a bandwidth of ~0.6 nm . The Bragg reflectors are used as feedback resonators for DBR lasers. Single-mode lasing with a sidemode suppression of better than 25 dB is demonstrated.

  19. Progress toward a monolithically integrated coherent diode laser array

    Science.gov (United States)

    Evans, G. A.; Garmire, E. M.; Stoll, H. M.; Osmer, J. A.; Soady, W. E.; Lee, A. B.; Ziegler, M. P.

    1981-02-01

    Progress toward the design and fabrication of a GaAlAs semiconductor laser array capable of high average power levels (0.1 to 1.0 watt) and low (approx 1 millirad) beam divergence is reported. A large optical cavity (LOC) configuration is grown by liquid phase epitaxy. The LOC structure is characterized by photoluminescence scans, ion microprobe mass analysis (IMMA), and optical waveguiding measurements. Fabry-Perot, active-passive, and DBR lasers are fabricated using chemical and ion beam etching. Gratings formed using holographic and ion beam etching techniques provide third order feedback for the DBR lasers, and are also used as distributed beam deflectors (DBDs) and output couplers. Comparisons of the results of experiments performed on DBR lasers, DBDs, and coupled lasers are made with theoretical models. Details of the material growth, material characterization, device fabrication, experiments, and theoretical models are presented in this report.

  20. Laser deposition and structuring of laser active planar waveguides of Er:ZBLAN, Nd:YAG and Nd:GGG for integrated waveguide lasers

    Science.gov (United States)

    Gottmann, Jens; Moiseev, Leonid; Wortmann, Dirk; Vasilief, Ion; Starovoytova, Larisa; Ganser, Dimitri; Wagner, Ralph

    2007-02-01

    Laser radiation is used both for the deposition of the laser active thin films and for the micro structuring to define wave guiding structures for the fabrication of waveguide lasers. Thin films of Er:ZBLAN (a glass consisting of ZrF 4, BaF II, LaF 3, AlF 3, NaF, ErF 3) for green upconversion lasers (545 nm), Nd:YAG (Y 3Al 5O 12) and Nd:GGG (Gd 3Ga 5O 12) for infrared lasers (1064 nm) are produced. Manufacturing of the laser active waveguides by micro-structuring is done using fs laser ablation of the deposited films. The structural and optical properties of the films and the damping losses of the structured waveguides are determined in view of the design and the fabrication of compact and efficient diode pumped waveguide lasers. The resulting waveguides are polished, provided with resonator mirrors, pumped using diode lasers and characterized. Laser operation of a ridge waveguide structure grown by pulsed laser deposition and structured by fs laser ablation is demonstrated. A 1 μm thick, 100 μm wide and 3 mm long structured waveguide consisting of amorphous neodymium doped Gd 3Ga 5O 12 has shown laser activity at 1.068 μm when pumped by a diode laser at 808 nm.

  1. Ion-exchanged Tm3+:glass channel waveguide laser.

    Science.gov (United States)

    Choudhary, Amol; Kannan, Pradeesh; Mackenzie, Jacob I; Feng, Xian; Shepherd, David P

    2013-04-01

    Continuous wave laser action around 1.9 μm has been demonstrated in a Tm(3+)-doped germanate glass channel waveguide laser fabricated by ion-exchange. Laser action was observed with an absorbed power threshold of only 44 mW and a slope efficiency of up to 6.8% was achieved. Propagation loss at the lasing wavelength was measured to be 0.3 dB/cm. We believe this to be the first ion-exchanged Tm(3+)-doped glass waveguide laser.

  2. Material Engineering for Monolithic Semiconductor Mode-Locked Lasers

    DEFF Research Database (Denmark)

    Kulkova, Irina

    This thesis is devoted to the materials engineering for semiconductor monolithic passively mode-locked lasers (MLLs) as a compact energy-efficient source of ultrashort optical pulses. Up to the present day, the achievement of low-noise sub-picosecond pulse generation has remained a challenge....... This work has considered the role of the combined ultrafast gain and absorption dynamics in MLLs as a main factor limiting laser performance. An independent optimization of MLL amplifier and saturable absorber active materials was performed. Two promising approaches were considered: quantum dot (QD...... application in MLLs. Improved QW laser performance was demonstrated using the asymmetric barrier layer approach. The analysis of the gain characteristics showed that the high population inversion beneficial for noise reduction cannot be achieved for 10 GHz QW MLLs and would have required lowering the modal...

  3. Holmium-doped 2.1 μm waveguide chip laser with an output power > 1 W.

    Science.gov (United States)

    Lancaster, D G; Stevens, V J; Michaud-Belleau, V; Gross, S; Fuerbach, A; Monro, T M

    2015-12-14

    We demonstrate the increasing applicability of compact ultra-fast laser inscribed glass guided-wave lasers and report the highest-power glass waveguide laser with over 1.1 W of output power in monolithic operation in the short-infrared near 2070 nm achieved (51% incident slope efficiency). The holmium doped ZBLAN chip laser is in-band pumped by a 1945 nm thulium fiber laser. When operated in an extended-cavity configuration, over 1 W of output power is realized in a linearly polarized beam. Broad and continuous tunability of the extended-cavity laser is demonstrated from 2004 nm to 2099 nm. Considering its excellent beam quality of M² = 1.08, this laser shows potential as a flexible master oscillator for single frequency and mode-locking applications.

  4. Manufacturing of Er:ZBLAN ridge waveguides by pulsed laser deposition and ultrafast laser micromachining for green integrated lasers

    Energy Technology Data Exchange (ETDEWEB)

    Gottmann, Jens [Lehrstuhl fuer Lasertechnik, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen (Germany)], E-mail: jens.gottmann@llt.rwth-aachen.de; Moiseev, Leonid; Vasilief, Ion; Wortmann, Dirk [Lehrstuhl fuer Lasertechnik, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen (Germany)

    2008-01-15

    Laser radiation is used both for the deposition of the laser active thin films and for the microstructuring to define wave guiding structures for the fabrication of waveguide lasers. Thin films of Er:ZBLAN (a fluoride glass consisting of ZrF{sub 4}, BaF{sub 2}, LaF{sub 3}, AlF{sub 3}, NaF, ErF{sub 3}) for green up-conversion lasers (545 nm) are produced by pulsed laser deposition using ArF excimer laser radiation (wavelength 193 nm). Manufacturing of the laser active waveguides by microstructuring is done using fs-laser ablation of the deposited films. The structural and optical properties of the films and the damping losses of the structured waveguides are determined in view of the design and the fabrication of compact and efficient diode pumped waveguide lasers. The resulting waveguides are polished, provided with resonator mirrors, pumped using diode lasers and characterized.

  5. Remote Sensing with Commutable Monolithic Laser and Detector

    Science.gov (United States)

    2016-01-01

    The ubiquitous trend toward miniaturized sensing systems demands novel concepts for compact and versatile spectroscopic tools. Conventional optical sensing setups include a light source, an analyte interaction region, and a separate external detector. We present a compact sensor providing room-temperature operation of monolithic surface-active lasers and detectors integrated on the same chip. The differentiation between emitter and detector is eliminated, which enables mutual commutation. Proof-of-principle gas measurements with a limit of detection below 400 ppm are demonstrated. This concept enables a crucial miniaturization of sensing devices. PMID:27785455

  6. Understanding How Femtosecond Laser Waveguide Fabrication in Glasses Works

    Energy Technology Data Exchange (ETDEWEB)

    Reichman III, Wilbur Jordan [Univ. of California, Davis, CA (United States)

    2006-01-01

    In order to understand the physical processes associated with fs-laser waveguide writing in glass, the effects of the laser repetition rate, the material composition and feature size were studied. The resulting material changes were observed by collecting Raman and fluorescence spectra with a confocal microscope. The guiding behavior of the waveguides was evaluated by measuring near field laser coupling profiles in combination with white light microscopy. Waveguides and Bragg gratings were fabricated in fused silica using pulse repetition rates from 1 kHz to 1 MHz and a wide range of scan speeds and pulse energies. Two types of fluorescence were detected in fused silica, depending on the fabrication conditions. Fluorescence from self trapped exciton (E'δ) defects, centered at 550 nm, were dominant for conditions with low total doses, such as using a 1 kHz laser with a scan speed of 20 μm/s and pulse energies less than 1 μJ. For higher doses a broad fluorescence band, centered at 650 nm, associated with non-bridging oxygen hole center (NBOHC) defects was observed. Far fewer NBOHC defects were formed with the 1 MHz laser than with the kHz lasers possibly due to annealing of the defects during writing. We also observed an increase in the intensity of the 605 cm-1 Raman peak relative to the total Raman intensity, corresponding to an increase in the concentration of 3-membered rings for all writing conditions. The magnitude of this increase in waveguides fabricated with a 1 MHz laser was nearly twice that of waveguides fabricated with a 1 kHz laser. Additional waveguides were fabricated in soda lime silicate glasses to assess the effects of changing the glass composition. These waveguides formed around, not inside the exposed regions. This is distinctly different from fused silica in which the waveguides are inside the exposed regions. A comprehensive analysis of all the experimental results indicates that good waveguides are formed below

  7. Laser-diode-pumped 1319-nm monolithic non-planar ring single-frequency laser

    Institute of Scientific and Technical Information of China (English)

    Qing Wang(王青); Chunqing Gao(高春清); Yan Zhao(赵严); Suhui Yang(杨苏辉); Guanghui Wei(魏光辉); Dongmei Hong(洪冬梅)

    2003-01-01

    Single-frequency 1319-nm laser was obtained by using a laser-diode-pumped monolithic Nd:YAG crystalwith a non-planar ring oscillator (NPRO). When the NPRO laser was pumped by an 800-μm fiber coupledlaser diode, the output power of the single-frequency 1319-nm laser was 220 mW, and the slope efficiencywas 16%. With a 100-μm fiber coupled diode laser pumped, 99-mW single-frequency 1319-nm laser wasobtained with a slope efficiency of 29%.

  8. Porous waveguide facilitated low divergence quantum cascade laser*

    Institute of Scientific and Technical Information of China (English)

    Yin Wen; Lu Quanyong; Liu Wannfeng; Zhang Jinchuan; Wang Lijun; Liu Junqi; Li Lu; Liu Fengqi; Wang Zhanguo

    2011-01-01

    A quantum cscade laser with a porous waveguide structure emitting at 4.5 μm is reported. A branchlike porous structure filled with metal material was fabricated on both sides of the laser ridge by an electrochemical etching process. In contrast to the common ridge waveguide laser, devices with a porous structure give rather better beam quality. Utilizing this porous structure as a high-order mode absorber, the device exhibited fundamental transverse mode emission with a nearly diffraction limited far-field beam divergence angle of 4.9°.

  9. Cold atom dynamics in crossed laser beam waveguides

    CERN Document Server

    Torrontegui, E; Ruschhaupt, A; Guéry-Odelin, D; Muga, J G

    2010-01-01

    We study the dynamics of neutral cold atoms in an $L$-shaped crossed-beam optical waveguide formed by two perpendicular red-detuned lasers of different intensities and a blue-detuned laser at the corner. Complemented with a vibrational cooling process this setting works as a one-way device or "atom diode".

  10. Spectral control of diode lasers using external waveguide circuits

    NARCIS (Netherlands)

    Oldenbeuving, Ruud

    2013-01-01

    We investigated spectral control of diode lasers using external waveguide circuits. The purpose of this work is to investigate such external control for providing a new class of diode lasers with technologically interesting properties, such as a narrow spectral bandwidth and spectrally tunable

  11. Transversely rf-excited CO/sub 2/ waveguide laser

    Energy Technology Data Exchange (ETDEWEB)

    Lachambre, J.; Macfarlane, J.; Otis, G.; Lavigne, P.

    1978-05-15

    An electrodeless CO/sub 2/ waveguide laser with transverse rf pumping is described. In the rf cw mode, the laser emits up to 0.6 W at 100 Torr. In the rf pulse mode, atmospheric operation has been achieved with pulse duration of 20 ..mu..s and peak power of a few watts at a repetition rate of 300 Hz.

  12. Spectral control of diode lasers using external waveguide circuits

    NARCIS (Netherlands)

    Oldenbeuving, R.M.

    2013-01-01

    We investigated spectral control of diode lasers using external waveguide circuits. The purpose of this work is to investigate such external control for providing a new class of diode lasers with technologically interesting properties, such as a narrow spectral bandwidth and spectrally tunable outpu

  13. Direct femtosecond laser waveguide writing inside zinc phosphate glass

    NARCIS (Netherlands)

    Fletcher, L.; Witcher, J.J.; Troy, N.; Reis, S.T.; Brow, R.K.; Krol, D.M.

    2011-01-01

    We report the relationship between the initial glass composition and the resulting microstructural changes after direct femtosecond laser waveguide writing with a 1 kHz repetition rate Ti:sapphire laser system. A zinc polyphosphate glass composition with an oxygen to phosphorus ratio of 3.25 has dem

  14. Transverse modes of a diode-laser pumped monolithic unidirectional non-planar ring laser

    Institute of Scientific and Technical Information of China (English)

    Keying Wu(吴克瑛); Suhui Yang(杨苏辉); Guanghui Wei(魏光辉)

    2003-01-01

    Diode-laser pumped monolithic single-frequency non-planar ring laser has the advantages of compactness,reliability and high efficiency. But when the pump power is high enough, the thermal effect will be seriousand the high-order transverse modes will appear. Therefore the single-mode output power is limited. Inthis paper, the mechanism of generating the high-order transverse modes in the monolithic unidirectionalnon-planar ring cavity is analyzed using ray tracing method. The calculated results are in agreement withthe experiments.

  15. Monolithic mode locked DBR laser with multiple-bandgap MQW structure realized by selective area growth

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, M.; Bouayad-Amine, J.; Feeser, T.; Haisch, H.; Kuehn, E.; Lach, E.; Satzke, K.; Weber, J.; Zielinski, E. [Alcatel Telecom, Stuttgart (Germany). Research Div.

    1996-12-31

    The realization of novel monolithically integrated multiple-segment pulse laser sources in InGaAsP MQW technology is reported. The MQW layers for all functional sections of these devices, the modulator, the active (gain) and the passive waveguide, as well as the Bragg section were grown in a single selective area growth (SAG) step by LP-MOVPE on SiO{sub 2} patterned 2 inch InP substrates. Due to a properly selected pattern geometry 3 different bandgap regions with smooth interfaces are thereby formed along the laser cavity. The more than 4 mm long DBR lasers which exhibit a threshold current as low as 30 mA were mode locked by an intra-cavity electroabsorption modulator applying a sinusoidal voltage at around 10 GHz. In this way an optical pulse train with pulse widths < 13 ps (measured with a streak camera) and high extinction ratio was generated. A time-bandwidth product of 0.5 close to the Fourier limit is obtained. This device is very attractive for signal generation in 40 Gb/s OTDM transmission systems at 1.55 {micro}m wavelength.

  16. A porous silicon Bragg grating waveguide by direct laser writing

    Energy Technology Data Exchange (ETDEWEB)

    Rea, Ilaria; Iodice, Mario; Coppola, Giuseppe; Rendina, Ivo; De Stefano, Luca [National Council of Research, Institute for Microelectronic and Microsystems, Department of Naples, Via P Castellino 111, I-80131 Naples (Italy); Marino, Antigone [Department of Physics, ' Federico II' University of Naples, Via Cinthia, I-80126 Naples (Italy)], E-mail: ilaria.rea@na.imm.cnr.it

    2008-09-10

    We have designed, fabricated and characterized a porous silicon-based Bragg grating integrated in an optical waveguide, by using a low cost and fast technique, direct laser writing. A periodic optical structure with a pitch of 10 {mu}m, resonant in the near-infrared wavelength region, has been obtained. The simulated transmission spectra, calculated by the transfer matrix method and waveguide modal computation, are in good qualitative agreement with the experimental ones. The waveguide transmission losses have been quantified as 22 dB cm{sup -1}.

  17. Widely tunable frequency conversion in monolithic semiconductor waveguides at 2.4  μm.

    Science.gov (United States)

    Abolghasem, Payam; Kang, Dongpeng; Logan, Dylan F; Lungwitz, Mandy; Helmy, Amr S

    2014-06-15

    We report on the generation of continuous-wave widely tunable light between 2360 and 2530 nm using difference-frequency generation with a pump tuned between 938 and 952 nm and a signal tuned between 1490 and 1590 nm in a type-II phase-matched monolithic semiconductor waveguide. The device internal conversion efficiency is estimated to be 0.29%  W(-1)  cm(-2). This design which uses a single-sided Bragg reflection waveguide has the potential for on-chip spectroscopy, as well as environmental monitoring applications, where a tunable source of coherent radiation tuned between 2 and 3 μm wavelength is desired.

  18. Optically amplifying planar glass waveguides: Laser on a chip

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas

    with UV-light and that permanent Bragg-gratings can be induced. Planar waveguide lasers with integrated Bragg-gratings are manufactured and characterised. It is shown that linewidths below 125 kHz and output powers around 0.5 mW can be obtained, and that the manufactured lasers are resistant to mechanical......The objective of this work was to devlop optically amplifying planar wavguides, using erbium-doped germano-silicate glass films deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition). The waveguides should exhibit enough gain to be useful as optical amplifiers in integrated planar...... lightwave circuits, as well as provide the gain medium for integrated planar waveguide lasers. The work and the obtained results are presented in this thesis: The manufacturing of silica thin films is described and it is shown that the refractive index of the films can be controlled by germanium co...

  19. Planar waveguide laser in Er/Al-doped germanosilicate

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas; Hübner, Jörg; Kristensen, Martin;

    1999-01-01

    A singlemode DBR laser is demonstrated in an Er/Al-doped germanosilicate planar waveguide. 0.4 mW of output power has been obtained at 1.553 mu m using internal Bragg reflectors produced by UV-induced index modulations.......A singlemode DBR laser is demonstrated in an Er/Al-doped germanosilicate planar waveguide. 0.4 mW of output power has been obtained at 1.553 mu m using internal Bragg reflectors produced by UV-induced index modulations....

  20. Interference microscopy of femtosecond laser written waveguides in phosphate glass

    Science.gov (United States)

    Esser, D.; Mahlmann, D.; Wortmann, D.; Gottmann, J.

    2009-08-01

    By focusing fs-laser radiation in the volume of a transparent material the refractive index can be changed locally, leading to 3-dimensional waveguiding structures. Waveguides are written in phosphate glass (IOG from Schott) at a depth of 100 μm below the surface. The pulse energy and the scan velocity are varied. For the first time the optical path difference caused by the waveguides and therefore the refractive index distribution of the waveguides and their cross sections are determined using interference microscopy. The optical path difference measured in the written structures and their cross sections is analyzed by a phase-shift algorithm. Thus, the refractive index distribution both along a line perpendicular to the waveguide and in the plane of a cross section is determined. The results are visualized as 2-dimensional graphics. Several regions of opposite sign of the refractive index change are observed in the cross sections of waveguides generated by femtosecond laser pulses. The number and the size of these regions are increasing with increasing pulse energy and decreasing scan velocity.

  1. Planar waveguide amplifiers and laser in erbium doped silica

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas; Kristensen, Martin

    1999-01-01

    The objective of this work was to develop optically amplifying planar waveguides, using erbium-doped germano-silicate glass films deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition). The waveguides should exhibit enough gain to be useful as optical amplifiers in integrated planar ligh...... as well as thermal influence. A simple method for producing an array of planar waveguide lasers is presented and it is shown that the difference in output wavelength of the individual lasers can be controlled with great accuracy.......The objective of this work was to develop optically amplifying planar waveguides, using erbium-doped germano-silicate glass films deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition). The waveguides should exhibit enough gain to be useful as optical amplifiers in integrated planar...... fluorescence level. In addition the first measurement of the diffusion coefficient of erbim in silica is presented and it is shown that erbium rich precipitates are formed in areas of high erbium concentration. The manufacturing of planar waveguide structures using RIE (Reactive Ion Etching) is described...

  2. Rayleigh length dependent SHG conversion at 488nm using a monolithic DBR tapered diode laser

    Science.gov (United States)

    Blume, G.; Uebernickel, M.; Fiebig, C.; Paschke, K.; Ginolas, A.; Eppich, B.; Güther, R.; Erbert, G.

    2008-02-01

    We present a study of the single pass SHG conversion as a function of the Rayleigh length (RL) and beam diameter (BD) using a monolithic distributed Bragg reflector (DBR) tapered laser. The DBR tapered laser has a 6th order surface grating and a ridge waveguide. Single longitudinal mode emission at 978nm with a side-mode suppression ratio of more than 40dB and at an output power of 2.7W at 15°C have been obtained in continuous wave operation. The beam was collimated using an aspheric and a cylindrical lens and focused using a variety of lenses with various focal lengths. The resulting caustics were acquired using a camera and used for SHG in a 5cm periodically poled LiNbO 3 (PPLN) crystal. This allowed an investigation of the dependency of the SHG conversion efficiency on the RLs and BDs. We obtained 330mW of output power at 488nm using the optimal focus length. The experiments showed that an optimum conversion requires longer focal length's then forecasted by Boyd-Kleinman's theory, which is explained due to the partial coherence. We developed an extension of that theory to account for that partial coherence, which bases in principle on a mismatch related general Agrawal's nonlinear integration kernel. We use this theory to explain the dependence of the SHG efficiency from the beam propagation factor M2.

  3. Laser Acceleration in Vacuum and Gases with Capillary Waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Ming

    1999-02-01

    A unified framework is developed to overcome all three major limitations on acceleration and distance and hence on the feasibility of two classes of laser acceleration. The three limitations are due to laser diffraction, acceleration phase slippage, and structure damage by high power laser if solid-state optical waveguide is used. The two classes of laser acceleration are direct-field acceleration and ponderomotive-driven acceleration. Thus this letter and its companion [1] provide solutions that are crucial to all mainstream approaches for laser acceleration, either in vacuum, gases or plasmas.

  4. Cr:ZnSe planar waveguide mid-IR laser

    Science.gov (United States)

    Willimas, J. E.; Martyshkin, D. V.; Fedorov, V. V.; Moskalev, I. S.; Camata, R. P.; Mirov, S. B.

    2011-02-01

    Middle infrared (mid-IR) chromium-doped zinc selenide (Cr:ZnSe) bulk lasers have attracted a lot of attention due to their unique combination of optical and laser properties facilitating a wide range of potential scientific, industrial, and medical applications. Utilization of thin film waveguide geometry enabling good thermal management and control of beam quality is a viable pathway for compact chip-integrated optical laser design. Cr:ZnSe thin films are also promising as saturable absorbers and mode-lockers of the cavities of solid state lasers operating over 1.3-2.1 μm. We recently reported the first successful demonstration of mid-IR Cr:ZnSe planar waveguide lasing at 2.6 μm under gain-switched short-pulse (5 ns) 1.56 μm excitation as well as the passive Q-switching of the cavity of a fiber-pumped Er:YAG laser operating at 1645 nm using a highly doped Cr:ZnSe thin film. PLD grown Cr:ZnSe waveguide were fabricated on sapphire substrates (Cr:ZnSe/sapphire) with chromium concentration of 1018-1019 cm-3. Further development of mid-IR lasing in the Cr:ZnSe planar waveguide under continuous wave excitation were investigated. In addition, deposition of Cr:ZnSe-based thin film structures on n-type GaAs substrates were also investigated for possible mid-IR electroluminescence.

  5. Monolithic single mode interband cascade lasers with wide wavelength tunability

    Science.gov (United States)

    von Edlinger, M.; Weih, R.; Scheuermann, J.; Nähle, L.; Fischer, M.; Koeth, J.; Kamp, M.; Höfling, S.

    2016-11-01

    Monolithic two-section interband cascade lasers offering a wide wavelength tunability in the wavelength range around 3.7 μm are presented. Stable single mode emission in several wavelength channels was realized using the concept of binary superimposed gratings and two-segment Vernier-tuning. The wavelength selective elements in the two segments were based on specially designed lateral metal grating structures defined by electron beam lithography. A dual-step dry etch process provided electrical separation between the segments. Individual current control of the segments allowed wavelength channel selection as well as continuous wavelength tuning within channels. A discontinuous tuning range extending over 158 nm in up to six discrete wavelength channels was achieved. Mode hop free wavelength tuning up to 14 nm was observed within one channel. The devices can be operated in continuous wave mode up to 30 °C with the output powers of 3.5 mW around room temperature.

  6. Graphene Q-switched Yb:KYW planar waveguide laser

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Wan; Young Choi, Sun; Jun Ahn, Kwang; Yeom, Dong-Il, E-mail: diyeom@ajou.ac.kr, E-mail: rotermun@ajou.ac.kr; Rotermund, Fabian, E-mail: diyeom@ajou.ac.kr, E-mail: rotermun@ajou.ac.kr [Department of Energy Systems Research and Department of Physics, Ajou University, 443-749 Suwon (Korea, Republic of); Aravazhi, Shanmugam; Pollnau, Markus [Integrated Optical Micro Systems Groups, MESA+ Institute of Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands); Griebner, Uwe; Petrov, Valentin [Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin (Germany); Bae, Sukang [Soft Innovative Materials Research Center, Korea Institute of Science and Technology, Jeonbuk 565-905 (Korea, Republic of)

    2015-01-15

    A diode-pumped Yb:KYW planar waveguide laser, single-mode Q-switched by evanescent-field interaction with graphene, is demonstrated for the first time. Few-layer graphene grown by chemical vapor deposition is transferred onto the top of a guiding layer, which initiates stable Q-switched operation in a 2.4-cm-long waveguide laser operating near 1027 nm. Average output powers up to 34 mW and pulse durations as short as 349 ns are achieved. The measured output beam profile, clearly exhibiting a single mode, agrees well with the theoretically calculated mode intensity distribution inside the waveguide. As the pump power is increased, the repetition rate and pulse energy increase from 191 to 607 kHz and from 7.4 to 58.6 nJ, respectively, whereas the pulse duration decreases from 2.09 μs to 349 ns.

  7. Graphene Q-switched Yb:KYW planar waveguide laser

    Directory of Open Access Journals (Sweden)

    Jun Wan Kim

    2015-01-01

    Full Text Available A diode-pumped Yb:KYW planar waveguide laser, single-mode Q-switched by evanescent-field interaction with graphene, is demonstrated for the first time. Few-layer graphene grown by chemical vapor deposition is transferred onto the top of a guiding layer, which initiates stable Q-switched operation in a 2.4-cm-long waveguide laser operating near 1027 nm. Average output powers up to 34 mW and pulse durations as short as 349 ns are achieved. The measured output beam profile, clearly exhibiting a single mode, agrees well with the theoretically calculated mode intensity distribution inside the waveguide. As the pump power is increased, the repetition rate and pulse energy increase from 191 to 607 kHz and from 7.4 to 58.6 nJ, respectively, whereas the pulse duration decreases from 2.09 μs to 349 ns.

  8. Continuous-wave and Q-switched operation of a compact, diode-pumped Yb3+:KY(WO4)2 planar waveguide laser.

    Science.gov (United States)

    Bain, F M; Lagatsky, A A; Kurilchick, S V; Kisel, V E; Guretsky, S A; Luginets, A M; Kalanda, N A; Kolesova, I M; Kuleshov, N V; Sibbett, W; Brown, C T A

    2009-02-02

    A diode-pumped LPE-grown Yb:KYW planar waveguide laser is demonstrated in a microchip monolithic cavity configuration. Output powers as high as 148 mW and thresholds as low as 40 mW were demonstrated during continuous-wave operation. Pulses of 170 ns duration with maximum pulse energy of 44 nJ at a 722 kHz repetition rate were generated when Q-switched using a semiconductor saturable absorber mirror.

  9. Monolithic integration of microfluidic channels and optical waveguides in silica on silicon

    DEFF Research Database (Denmark)

    Friis, Peter; Hoppe, Karsten; Leistiko, Otto

    2001-01-01

    Sealing of the flow channel is an important aspect during integration of microfluidic channels and optical waveguides. The uneven topography of many waveguide-fabrication techniques will lead to leakage of the fluid channels. Planarization methods such as chemical mechanical polishing or the etch......-back technique are possible, but troublesome. We present a simple but efficient alternative: By means of changing the waveguide layout, bonding pads are formed along the microfluidic channels. With the same height as the waveguide, they effectively prevent leakage and hermetically seal the channels during...

  10. Monolithically integrated semiconductor optical amplifier and electroabsorption modulator with dual-waveguide spot-size converter input and output

    Science.gov (United States)

    Hou, Lianping; Zhu, Hongliang; Zhou, Fan; Wang, Lufeng; Bian, Jing; Wang, Wei

    2005-09-01

    We have demonstrated an electroabsorption modulator and semiconductor optical amplifier monolithically integrated with novel dual-waveguide spot-size converters (SSC) at the input and output ports for low-loss coupling to a planar light-guide circuit silica waveguide or cleaved single-mode optical fibre. The device was fabricated by means of selective-area MOVPE growth, quantum well intermixing and asymmetric twin waveguide technologies with only a three-step low-pressure MOVPE growth. For the device structure, in the SOA/EAM section, a double ridge structure was employed to reduce the EAM capacitances and enable high bit-rate operation. In the SSC sections, buried ridge structure (BRS) was incorporated. Such a combination of ridge, ATG and BRS structure is reported for the first time in which it can take advantage of easy processing of the ridge structure and the excellent mode characteristic of BRS. At the wavelength range of 1550-1600 nm, lossless operation with extinction ratios of 25 dB dc and more than 10 GHz 3 dB bandwidth is successfully achieved. The beam divergence angles of the input and output ports of the device are as small as 8.0° × 12.6°, resulting in 3.0 dB coupling loss with a cleaved single-mode optical fibre.

  11. Semiconductor optical amplifier monolithically integrated with an electroabsorption modulator and dual-waveguide spot-size converters

    Science.gov (United States)

    Hou, Lianping; Zhu, Hongliang; Wang, Baojun; Zhou, Fan; Wang, Lufeng; Bian, Jing; Wang, Wei

    2005-09-01

    We have demonstrated an electroabsorption modulator and semiconductor optical amplifier monolithically integrated with novel dual-waveguide spot-size converters (SSC) at the input and output ports for low-loss coupling to planar light-guide circuit silica waveguide or cleaved single-mode optical fiber. The device was fabricated by means of selective-area MOVPE growth, quantum well intermixing and asymmetric twin waveguide technologies with only a three steps low-pressure MOVPE growth. For the device structure, in SOA/EAM section, double ridge structure was employed to reduce the EAM capacitances and enable high bit-rate operation. In the SSC sections, buried ridge structure (BRS) were incorporated. Such combination of ridge, ATG and BRS structure is reported for the first time in which it can take advantage of easy processing of ridge structure and the excellent mode characteristic of BRS. At the wavelength range of 1550~1600nm, lossless operation with extinction ratios of 25 dB dc and more than 10 GHz 3-dB bandwidth is successfully achieved. The beam divergence angles of the input and output ports of the device are as small as 8.0°×12.6°, resulting in 3.0 dB coupling loss with cleaved single-mode optical fiber.

  12. Electroabsorption-modulated DFB laser integrated with dual-waveguide spot-size converter

    Science.gov (United States)

    Hou, Lianping; Wang, Wei; Zhu, Hongliang; Wang, Baojun; Zhou, Fan

    2005-11-01

    A 1.55-μm ridge DFB laser and electroabsorption modulator monolithically integrated with a buried-ridge-stripe dual-waveguide spot-size converter at the output port for low-loss coupling to a cleaved single-mode optical fiber was fabricated by means of selective area growth, quantum well intermixing and dual-core technologies. These devices exhibit threshold current of 28 mA, side mode suppression ratio of 38.0 dB, 3-dB modulation bandwidth of 12.0 GHz, modulator extinction ratios of 25.0 dB dc. The output beam divergence angles of the spot-size converter in the horizontal and vertical directions are as small as 8.0°×12.6°, respectively, resulting in 3.2 dB coupling loss with a cleaved single-mode optical fiber.

  13. Graphene Q-switched Yb:KYW planar waveguide laser

    NARCIS (Netherlands)

    Kim, Jun Wan; Choi, Sun Young; Aravazhi, Shanmugam; Pollnau, Markus; Griebner, Uwe; Petrov, Valentin; Bae, Sukang; Ahn, Kwang Jun; Yeom, Dong-Il; Rotermund, Fabian

    2015-01-01

    A diode-pumped Yb:KYW planar waveguide laser, single-mode Q-switched by evanescent-field interaction with graphene, is demonstrated for the first time. Few-layer graphene grown by chemical vapor deposition is transferred onto the top of a guiding layer, which initiates stable Q-switched operation in

  14. Long all-active monolithic mode-locked lasers with surface-etched bragg gratings

    OpenAIRE

    Larsson, David; Yvind, Kresten; Hvam, Jørn Märcher

    2007-01-01

    We have fabricated 4.4-mm-long monolithic InAlGaAsP–InP mode-locked lasers with integrated deeply surface etched distributed Bragg reflector (DBR) mirrors. The lasers produce 3.7-ps transform-limited Gaussian pulses with 10-mW average output power and 250-fs absolute timing jitter. The performance of the DBR lasers is compared to the performance of Fabry–PÉrot mode-locked lasers from the same wafer and to the performance of earlier reported long monolithic DBR mode-locked lasers and is found ...

  15. Long all-active monolithic mode-locked lasers with surface-etched bragg gratings

    DEFF Research Database (Denmark)

    Larsson, David; Yvind, Kresten; Hvam, Jørn Märcher

    2007-01-01

    We have fabricated 4.4-mm-long monolithic InAlGaAsP–InP mode-locked lasers with integrated deeply surface etched distributed Bragg reflector (DBR) mirrors. The lasers produce 3.7-ps transform-limited Gaussian pulses with 10-mW average output power and 250-fs absolute timing jitter. The performance...... of the DBR lasers is compared to the performance of Fabry–PÉrot mode-locked lasers from the same wafer and to the performance of earlier reported long monolithic DBR mode-locked lasers and is found to be better....

  16. Design and performance of monolithic integrated electro-absorption modulated distributed feedback laser

    Science.gov (United States)

    Cheng, YuanBing; Pan, JiaoQing; Zhou, Fan; Wang, BaoJun; Zhu, Hongliang; Zhao, Lingjuan; Wang, Wei

    2007-11-01

    High performance InGaAsP/InGaAsP strained compensated multiple-quantum-well (MQW) electroabsorption modulators (EAM) monolithically integrated with a DFB laser diode have been designed and realized by ultra low metal-organic vapor phase epitaxy (MOVPE) based on a novel butt-joint scheme. The optimization thickness of upper SCH layer for DFB and EAM was obtained of the proposed MQW structure of the EAM through numerical simulation and experiment. The device containing 250 μm DFB and 170 μm EAM shows good material quality and exhibits a threshold current of 17mA, an extinction ratio of higher than 30 dB and a very high modulation efficiency (12dB/V) from 0V to 1V. By adopting a high-mesa ridge waveguide and buried polyimide, the capacitance of the modulator is reduced to about 0.30 pF corresponding to a 3dB bandwidth more than 20GHz.

  17. Components for monolithic fiber chirped pulse amplification laser systems

    Science.gov (United States)

    Swan, Michael Craig

    % respectively. With the inherent design tradeoff between the fundamental mode loss and higher order mode suppression, loss effects on system efficiency in different configurations were investigated. From these investigations it was seen that the slope-efficiency depends only on the total loss of the active fiber, and that when loss is present, the counter-propagating configuration has substantial advantages over the co-propagating case. In this thesis chirally-coupled-core fiber as the technological basis for the next generation of monolithic high power fiber laser systems has been established.

  18. Monolithic narrow-linewidth InGaAsP semiconductor laser for coherent optical communications. Final report, 6 August 1987-9 June 1989

    Energy Technology Data Exchange (ETDEWEB)

    Palfrey, S.L.; Enstrom, R.E.; Longeway, P.A.

    1989-09-01

    A design for a monolithic narrow-linewidth InGaAsP diode laser has been developed using a multiple-quantum-well (MQW) extended-passive-cavity distributed-Bragg-reflector (DBR) laser design. Theoretical results indicate that this structure has the potential for a linewidth of 100 kHz or less. To realize this device, a number of the fabrication techniques required to integrate low-loss passive waveguides with active regions have been developed using a DBR laser structure. In addition, the MOCVD growth of InGaAs MQW laser structures has been developed, and threshold current densities as low as 1.6 kA/sq cm have been obtained from broad-stripe InGaAs/InGaAsP separate-confinement-heterostructure MQW lasers.

  19. Monolithic integration of microfluidic channels and optical waveguides in silica on silicon.

    Science.gov (United States)

    Friis, P; Hoppe, K; Leistiko, O; Mogensen, K B; Hübner, J; Kutter, J P

    2001-12-01

    Sealing of the flow channel is an important aspect during integration of microfluidic channels and optical waveguides. The uneven topography of many waveguide-fabrication techniques will lead to leakage of the fluid channels. Planarization methods such as chemical mechanical polishing or the etch-back technique are possible, but troublesome. We present a simple but efficient alternative: By means of changing the waveguide layout, bonding pads are formed along the microfluidic channels. With the same height as the waveguide, they effectively prevent leakage and hermetically seal the channels during bonding. Negligible influence on light propagation is found when 10-mum-wide bonding pads are used. Fabricated microsystems with application in absorbance measurements and flow cytometry are presented.

  20. Encapsulated and monolithic resonant structures for laser applications

    Science.gov (United States)

    Pung, Aaron Joseph

    Typically, the composition of a laser system includes a gain medium, a pump illumination source, and an external feedback cavity. This cavity consists of a highly reflective mirror and an outcoupler component. The geometry of the outcoupler can be engineered to tailor the reflected or transmitted beam's spatial and spectral distribution. Functionally, the transmitted beam profile is dependent on the laser application. Broadband reflection profiles can be obtained by utilizing a distributed Bragg reflector (DBR). A DBR device consists of multiple layers of alternating materials. Constructive interference of the reflected light off each interface between different materials produces the spectrally broadband response. The spectral response is a function of the fabrication and material parameters of the DBR. In contrast, guided-mode resonance filters (GMRF) exploit phase matching between evanescent- and guided-waves to provide a strong reflection. Based on the materials in the structure, the spectral response can demonstrate broadband or narrowband reflectivity. The operation wavelength of a GMRF is dependent on the structural parameters of the device as well as the angle of incidence. However, conventional designs of resonant optics leave critical aspects of the structure exposed to the surrounding environment. Additional damage or contamination to the waveguide or grating layer will significantly alter the device's spectral response. This dissertation introduces two GMRF geometries aimed at device integration, development of similar-material resonant devices, and full-device protection from outside influence. Unlike distributed Bragg reflectors, these geometries do not rely heavily on strict material and deposition requirements. Instead, they take advantage of the deposition processes to minimize coating deposition, achieve high reflectivity and demonstrate control over polarization dependence. Given their versatility in design and ability to withstand high power

  1. Novel design of low-jitter 10 GHz all-active monolithic mode-locked lasers

    DEFF Research Database (Denmark)

    Larsson, David; Yvind, Kresten; Christiansen, Lotte Jin

    2004-01-01

    Using a novel design, we have fabricated 10 GHz all-active monolithic mode-locked semiconductor lasers that generate 1.4 ps pulses with record-low timing jitter. The dynamical properties of lasers with 1 and 2 QWs are compared.......Using a novel design, we have fabricated 10 GHz all-active monolithic mode-locked semiconductor lasers that generate 1.4 ps pulses with record-low timing jitter. The dynamical properties of lasers with 1 and 2 QWs are compared....

  2. An Innovative Gas Sensor with On-Chip Reference Using Monolithic Twin Laser

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-Gang; TIAN Zhao-Bing; ZHANG Xiao-Jun; GU Yi; LI Ai-Zhen; ZHU Xiang-Rong; ZHENG Yan-Lan; LIU Sheng

    2007-01-01

    An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one photodiode is used to catch both absorption and reference signals by time division multiplexing. The detection of nitrous oxide adopting this scheme using a 2.1 μm antimonide laser and an InGaAs photodiode has been demonstrated experimentally with detection limit below 1 ppm. Using this on chip reference scheme the fluctuations from the optical path and devices can be compensated effectively; the sensor system is simplified distinctly.

  3. Fluorescence imaging of lattice re-distribution on step-index direct laser written Nd:YAG waveguide lasers

    Energy Technology Data Exchange (ETDEWEB)

    Martínez de Mendívil, Jon; Pérez Delgado, Alberto; Lifante, Ginés; Jaque, Daniel [Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049 (Spain); Ródenas, Airán [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Tarragona 43007 (Spain); Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Benayas, Antonio, E-mail: antonio.benayas@emt.inrs.ca [Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049 (Spain); Institut National de la Recherche Scientifique, Centre – Énergie Matériaux et Télécommunications, 1650, Boul. Lionel Boulet Varennes, Quebec J3X 1S2 (Canada); Aguiló, Magdalena; Diaz, Francesc [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Tarragona 43007 (Spain); Kar, Ajoy K. [Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2015-01-14

    The laser performance and crystalline micro-structural properties of near-infrared step-index channel waveguides fabricated inside Neodymium doped YAG laser ceramics by means of three-dimensional sub-picosecond pulse laser direct writing are reported. Fluorescence micro-mapping of the waveguide cross-sections reveals that an essential crystal lattice re-distribution has been induced after short pulse irradiation. Such lattice re-distribution is evidenced at the waveguide core corresponding to the laser written refractive index increased volume. The waveguides core surroundings also present diverse changes including slight lattice disorder and bi-axial strain fields. The step-index waveguide laser performance is compared with previous laser fabricated waveguides with a stress-optic guiding mechanism in absence of laser induced lattice re-distribution.

  4. Fluorescence imaging of lattice re-distribution on step-index direct laser written Nd:YAG waveguide lasers

    Science.gov (United States)

    Martínez de Mendívil, Jon; Ródenas, Airán; Benayas, Antonio; Aguiló, Magdalena; Diaz, Francesc; Pérez Delgado, Alberto; Lifante, Ginés; Jaque, Daniel; Kar, Ajoy K.

    2015-01-01

    The laser performance and crystalline micro-structural properties of near-infrared step-index channel waveguides fabricated inside Neodymium doped YAG laser ceramics by means of three-dimensional sub-picosecond pulse laser direct writing are reported. Fluorescence micro-mapping of the waveguide cross-sections reveals that an essential crystal lattice re-distribution has been induced after short pulse irradiation. Such lattice re-distribution is evidenced at the waveguide core corresponding to the laser written refractive index increased volume. The waveguides core surroundings also present diverse changes including slight lattice disorder and bi-axial strain fields. The step-index waveguide laser performance is compared with previous laser fabricated waveguides with a stress-optic guiding mechanism in absence of laser induced lattice re-distribution.

  5. Monolithic thermally bonded Er3+, Yb3+:glass/Co2+:MgAl2O4 microchip lasers

    Science.gov (United States)

    Mlynczak, Jaroslaw; Belghachem, Nabil

    2015-12-01

    The highest ever reported 10 kW peak power in monolithic thermally bonded Er3+, Yb3+:glass/Co2+:MgAl2O4 microchip laser was achieved. To show the superiority of monolithic microchip lasers over those with external mirrors the laser generation characteristics of the same samples in both cases were compared.

  6. Femtosecond direct-write überstructure waveguide Bragg gratings in ZBLAN.

    Science.gov (United States)

    Gross, Simon; Ams, Martin; Lancaster, David G; Monro, Tanya M; Fuerbach, Alexander; Withford, Michael J

    2012-10-01

    Strong waveguide Bragg gratings (10.5 dB transmission dip) were fabricated using the femtosecond (fs) laser direct-write technique in ZBLAN glass. The Bragg gratings are based on depressed cladding waveguides and consist of planes, periodic according to the Bragg condition, which are constructed from a transverse hexagonal lattice of smaller point features. Such gratings are a key step toward the realization of mid-infrared monolithic waveguide lasers using the fs laser direct-write technique.

  7. Laser emission from diode-pumped Nd:YAG ceramic waveguide lasers realized by direct femtosecond-laser writing technique.

    Science.gov (United States)

    Salamu, Gabriela; Jipa, Florin; Zamfirescu, Marian; Pavel, Nicolaie

    2014-03-10

    We report on realization of buried waveguides in Nd:YAG ceramic media by direct femtosecond-laser writing technique and investigate the waveguides laser emission characteristics under the pump with fiber-coupled diode lasers. Laser pulses at 1.06 μm with energy of 2.8 mJ for the pump with pulses of 13.1-mJ energy and continuous-wave output power of 0.49 W with overall optical efficiency of 0.13 were obtained from a 100-μm diameter circular cladding waveguide realized in a 0.7-at.% Nd:YAG ceramic. A circular waveguide of 50-μm diameter yielded laser pulses at 1.3 μm with 1.2-mJ energy.

  8. Carbon dioxide waveguide lasers with folds and tilted mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Hill, C.A.; Jackson, P.E. (Heriot-Watt University, Physics Department, Optoelectronics Lasar Engineering, Edinburgh EH14 4AS, U.K. (GB)); Hall, D. (Royal Signals Radar Establishment, Malvern, Worcs WR14 3PS, (UK))

    1990-05-20

    We present theoretical and experimental results for an rf-excited z-fold CO{sub 2} waveguide laser. We describe how the output power, output rotational line(s) and transverse mode(s) vary as functions of elbow mirror tilt and obtain good agreement with predictions from a multimode matrix resonator model. Observations of multilining and/or multifrequency operation are partly explained by the near equality of gain/loss ratios for two or more resonator modes.

  9. Short Pulse UV-Visible Waveguide Laser.

    Science.gov (United States)

    1980-07-01

    millimeters of the capillary tube ends. 7 A perimetric study of the laser operation was conducted in which the gas pressure, gas mixture, applied voltage, gas...removal rate through an increase in the V-T vibrational relaxation rate. When the dye laser was adjusted to the red side of the blue transition

  10. Laser-induced break-up of water jet waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Couty, P.; Hoffmann, P. [EPFL/STI/IOA/Advanced Photonics Laboratory, Lausanne BM, 1015, Lausanne (Switzerland); Spiegel, A.; Vago, N. [Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest (Hungary); Ugurtas, B.I. [EPFL/STI/IMHEF/Laboratory Fluid Mechanics, Lausanne, 1015, Lausanne (Switzerland)

    2004-06-01

    In this article, an optical method to control the break-up of high-speed liquid jets is proposed. The method consists of focusing the light of a pulsed laser source into the jet behaving as a waveguide. Experiments were performed with the help of a Q-switched frequency doubled Nd:Yag laser ({lambda}=532 nm). The jet diameter was 48 {mu}m and jet velocities from 100 to 200 m/s. To study the laser-induced water jet break-up, observations of the jet coupled with the high power laser were performed for variable coupling and jet velocity conditions. Experimentally determined wavelength and growth rate of the laser-generated disturbance were also compared with the ones predicted by linear stability theory of free jets. (orig.)

  11. Femtosecond laser writing of waveguide retarders in fused silica for polarization control in optical circuits.

    Science.gov (United States)

    Fernandes, Luís A; Grenier, Jason R; Herman, Peter R; Aitchison, J Stewart; Marques, Paulo V S

    2011-09-12

    Femtosecond laser (300 fs, 500 kHz, 522 nm) fabrication of optical waveguides in bulk silica glass is extended to waveguide retarders. We study the merits of nanograting orientation (perpendicular or parallel to the waveguide) for generating high and low birefringence waveguides. This is used together with other exposure condition to control the waveguide birefringence between 10⁻⁵ and 10⁻⁴ permitting for the simultaneous fabrication of the waveguides and the tuning of the retardance demonstrating quarter and half-wave retarders in the 1200 nm to 1700 nm spectrum. The wavelength dependence of the birefringence is also characterized over a range of exposure conditions.

  12. Tuning of betatron radiation in laser-plasma accelerators via multimodal laser propagation through capillary waveguides

    Science.gov (United States)

    Curcio, A.; Giulietti, D.; Petrarca, M.

    2017-02-01

    The betatron radiation from laser-plasma accelerated electrons in dielectric capillary waveguides is investigated. The multimode laser propagation is responsible for a modulated plasma wakefield structure, which affects the electron transverse dynamics, therefore influencing the betatron radiation spectra. Such a phenomenon can be exploited to tune the energy spectrum of the betatron radiation by controlling the excitation of the capillary modes.

  13. Transverse Writing of Multimode Interference Waveguides inside Silica Glass by Femtosecond Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    LIU Da-Yong; LI Yan; DOU Yan-Ping; GUO Heng-Chang; YANG Hong; GONG Qi-Huang

    2008-01-01

    Multi-mode interference waveguides are fabricated inside silica glass by transverse writing geometry with femtosecond laser pulses. The influences of several writing and reading factors on the output mode are systematically studied. The experimental results of straight waveguides are in good agreement with the simulations by the beam propagation method. By integrating a straight waveguide with a bent waveguide, a 1×2 multi-mode splitter is formed and 2×3 lobes are observed in the output mode.

  14. Plasmonic Waveguide-Integrated Nanowire Laser

    DEFF Research Database (Denmark)

    Bermudez-Urena, Esteban; Tutuncuoglu, Gozde; Cuerda, Javier

    2017-01-01

    Next-generation optoelectronic devices and photonic circuitry will have to incorporate on-chip compatible nanolaser sources. Semiconductor nanowire lasers have emerged as strong candidates for integrated systems with applications ranging from ultrasensitive sensing to data communication technolog......Next-generation optoelectronic devices and photonic circuitry will have to incorporate on-chip compatible nanolaser sources. Semiconductor nanowire lasers have emerged as strong candidates for integrated systems with applications ranging from ultrasensitive sensing to data communication...... technologies. Despite significant advances in their fundamental aspects, the integration within scalable photonic circuitry remains challenging. Here we report on the realization of hybrid photonic devices consisting of nanowire lasers integrated with wafer-scale lithographically designed V-groove plasmonic...

  15. Adaptive slit beam shaping for direct laser written waveguides.

    Science.gov (United States)

    Salter, P S; Jesacher, A; Spring, J B; Metcalf, B J; Thomas-Peter, N; Simmonds, R D; Langford, N K; Walmsley, I A; Booth, M J

    2012-02-15

    We demonstrate an improved method for fabricating optical waveguides in bulk materials by means of femtosecond laser writing. We use an LC spatial light modulator (SLM) to shape the beam focus by generating adaptive slit illumination in the pupil of the objective lens. A diffraction grating is applied in a strip across the SLM to simulate a slit, with the first diffracted order mapped onto the pupil plane of the objective lens while the zeroth order is blocked. This technique enables real-time control of the beam-shaping parameters during writing, facilitating the fabrication of more complicated structures than is possible using nonadaptive methods. Waveguides are demonstrated in fused silica with a coupling loss to single-mode fibers in the range of 0.2 to 0.5 dB and propagation loss <0.4 dB/cm.

  16. Hybrid Neodymium-doped passively Q-switched waveguide laser

    Energy Technology Data Exchange (ETDEWEB)

    Salas-Montiel, Rafael [IMEP-LAHC, 3 Parvis Louis Neel BP 257, 38016 Grenoble Cedex 1 (France); Bastard, Lionel [IMEP-LAHC, 3 Parvis Louis Neel BP 257, 38016 Grenoble Cedex 1 (France)], E-mail: lionel.bastard@minatec.inpg.fr; Grosa, Gregory; Broquin, Jean-Emmanuel [IMEP-LAHC, 3 Parvis Louis Neel BP 257, 38016 Grenoble Cedex 1 (France)

    2008-03-25

    In the mid 80s, the doping of optical fibers' core with rare earth atoms has been a major breakthrough in the field of optical telecommunications since it allowed the realization of in line optical amplifiers. However, erbium-doped fiber amplifiers are a few meters long and a huge effort has been made in order to realize compact and efficient active devices based on rare-earth-doped waveguides. For this purpose the use of phosphate glasses instead of silicate ones has been investigated because they allow a better solubility of the inserted rare earths. In this paper we present the realization of a hybrid Neodymium-doped passively Q-switched waveguide laser made by an ion-exchange on a Schott IOG-1 phosphate laser glass combined with the deposition of a bis(4-dimethylaminodithiobenzil)nickel (BDN) saturable absorber diluted in a cellulose acetate polymer cladding. In a first step, we present the continuous wave (CW) operation of the laser with an undoped cladding. We show that for a 3.5 {mu}m wide, 1.5 cm long waveguide realized by a silver-sodium ion-exchange, a 6 mW output has been achieved by creating a Fabry-Perot cavity with dielectric multilayers mirrors sticked to the chip facets. Then, the characterizations performed on the BDN-doped layers are presented. It is shown that a proper selection of the hybrid guiding condition and saturable absorber concentration entail a non-saturated excess absorption of 3.4 dB/cm. Finally, we present the results we obtained on the Q-switched behaviour of the laser. Indeed a repetition rate of 330 kHz is achieved for a pulse energy of 10 nJ and a peak power of 1 W.

  17. Design and fabrication of multi-channel photodetector array monolithic with arrayed waveguide grating

    Science.gov (United States)

    Qian-Qian, Lv; Pan, Pan; Han, Ye; Dong-Dong, Yin; Yu-Bing, Wang; Xiao-Hong, Yang; Qin, Han

    2016-03-01

    We have provided optical simulations of the evanescently coupled waveguide photodiodes integrated with a 13-channels AWGs. The photodiode could exhibit high internal efficiency by appropriate choice of layers geometry and refractive index. Aseamless joint structure has been designed and fabricated for integrating the output waveguides of AWGs with the evanescently coupled waveguide photodiode array. The highest simulation quantum efficiency could achieve 92% when the matching layer thickness of the PD is 120 nm and the insertion length is 2 μm. The fabricated PD with 320-nm-thick matching layer and 2-μm-length insertion matching layer present a responsivity of 0.87 A/W. Project supported by the National High Technology Research and Development Program of China (Grant Nos. 2013AA031401, 2015AA016902, and 2015AA016904), the National Natural Science Foundation of China (Grant Nos. 61176053, 61274069, and 61435002), and the National Basic Research Program of China (Grant Nos. 2012CB933503 and 2013CB932904).

  18. Characterization of Bragg gratings in Al2O3 waveguides fabricated by focused ion beam milling and laser interference lithography

    NARCIS (Netherlands)

    Ay, F.; Bernhardi, Edward; Agazzi, L.; Bradley, J.; Worhoff, Kerstin; Pollnau, Markus; de Ridder, R.M.

    Optical grating cavities in Al2O3 channel waveguides were successfully defined by focused ion beam milling and laser interference lithography. Both methods are shown to be suitable for realizing resonant structures for on-chip waveguide lasers.

  19. Inscription of 3D waveguides in diamond using an ultrafast laser

    CERN Document Server

    Courvoisier, Arnaud; Salter, Patrick S

    2016-01-01

    Three dimensional waveguides within the bulk of diamond are manufactured using ultrafast laser fabrication. High intensities within the focal volume of the laser cause breakdown of the diamond into a graphitic phase leading to a stress induced refractive index change in neighboring regions. Type II waveguiding is thus enabled between two adjacent graphitic tracks, but supporting just a single polarization state. We show that adaptive aberration correction during the laser processing allows the controlled fabrication of more complex structures beneath the surface of the diamond which can be used for 3D waveguide splitters and Type III waveguides which support both polarizations.

  20. Inscription of 3D waveguides in diamond using an ultrafast laser

    Science.gov (United States)

    Courvoisier, Arnaud; Booth, Martin J.; Salter, Patrick S.

    2016-07-01

    Three dimensional waveguides within the bulk of diamond are manufactured using ultrafast laser fabrication. High intensities within the focal volume of the laser cause breakdown of the diamond into a graphitic phase leading to a stress induced refractive index change in neighboring regions. Type II waveguiding is thus enabled between two adjacent graphitic tracks, but supporting just a single polarization state. We show that adaptive aberration correction during the laser processing allows the controlled fabrication of more complex structures beneath the surface of the diamond which can be used for 3D waveguide splitters and Type III waveguides which support both polarizations.

  1. Femtosecond-laser-written Tm:KLu(WO4)2 waveguide lasers.

    Science.gov (United States)

    Kifle, Esrom; Mateos, Xavier; de Aldana, Javier Rodríguez Vázquez; Ródenas, Airan; Loiko, Pavel; Choi, Sun Yung; Rotermund, Fabian; Griebner, Uwe; Petrov, Valentin; Aguiló, Magdalena; Díaz, Francesc

    2017-03-15

    Depressed-index channel waveguides with a circular and photonic crystal cladding structures are prepared in a bulk monoclinic Tm:KLu(WO4)2 crystal by 3D direct femtosecond laser writing. The channel waveguide structures are characterized and laser operation is achieved using external mirrors. In the continuous-wave mode, the maximum output power of 46 mW is achieved at 1912 nm corresponding to a slope efficiency of 15.2% and a laser threshold of only 21 mW. Passive Q-switching of a waveguide with a circular cladding is realized using single-walled carbon nanotubes. Stable 7 nJ/50 ns pulses are achieved at a repetition rate of 1.48 MHz. This first demonstration of ∼2  μm fs-laser-written waveguide lasers based on monoclinic double tungstates is promising for further lasers of this type doped with Tm3+ and Ho3+  ions.

  2. A Kilowatt Radio-Frequency Excited Diffusively Cooled All-Metal Slab Waveguide CO2 Laser

    Institute of Scientific and Technical Information of China (English)

    SHA Peng-Fei; Xin Jian-Guo

    2009-01-01

    A new type of rf excited diffusively cooled all-metal slab waveguide CO2 laser is presented, in which the waveguide channel is constructed by two copper side walls and two copper electrodes, and the discharge is confined in the slab waveguide channel in terms of the voltage division structure. From this type of structure, over 1 kW laser power is obtained with an efficiency of more than 13%.

  3. RF excited diffusively cooled all-metal slab waveguide CO2 laser

    Institute of Scientific and Technical Information of China (English)

    Jianguo Xin; Shuna Yao; Ning Su; Zhiming Li; Yanhong Zhong

    2005-01-01

    @@ In this paper, a new type of radio frequency (RF) excited diffusively cooled all-metal slab waveguide CO2 laser is presented, in which the waveguide channel is constructed by two aluminum side walls and two aluminum electrodes, the discharge is confined in the slab waveguide channel in terms of the voltage division structure. From this type of structure, 127-W laser power is obtained.

  4. Properties of InGaAs quantum dot saturable absorbers in monolithic mode-locked lasers

    DEFF Research Database (Denmark)

    Thompson, M.G.; Marinelli, C.; Chu, Y.

    Saturable absorbers properties are characterised in monolithic mode-locked InGaAs quantum dot lasers. We analyse the impact of weak quantum confined Stark effect, fast absorber recovery time and low absorber saturation power on the mode-locking performance.......Saturable absorbers properties are characterised in monolithic mode-locked InGaAs quantum dot lasers. We analyse the impact of weak quantum confined Stark effect, fast absorber recovery time and low absorber saturation power on the mode-locking performance....

  5. Continuous wave channel waveguide lasers in Nd:LuVO4 fabricated by direct femtosecond laser writing.

    Science.gov (United States)

    Ren, Yingying; Dong, Ningning; Macdonald, John; Chen, Feng; Zhang, Huaijin; Kar, Ajoy K

    2012-01-30

    Buried channel waveguides in Nd:LuVOlaser writing with the double-line technique. The photoluminescence properties of the bulk materials were found to be well preserved within the waveguide core region. Continuous-wave laser oscillation at 1066.4 nm was observed from the waveguide under ~809 nm optical excitation, with the absorbed pump power at threshold and laser slope efficiency of 98 mW and 14%, respectively.

  6. Mathematical modelling of gain-switched RF-excited CO2 waveguide laser

    Institute of Scientific and Technical Information of China (English)

    Hussain Badran; Tian Zhao-Shuo; Wang Qi

    2004-01-01

    The detailed mathematical models for the evolution of light pulses in RF-excited CO2 waveguide lasers are derived.Explicit expressions for the pulse characteristics in RF-excited CO2 waveguide lasers are obtained. The effects of losses and unsaturated gain on output power are calculated.

  7. Efficient 2.9 μm fluorozirconate glass waveguide chip laser.

    Science.gov (United States)

    Lancaster, David G; Gross, Simon; Ebendorff-Heidepriem, Heike; Withford, Michael J; Monro, Tanya M; Jackson, Stuart D

    2013-07-15

    We report a large mode-area holmium-doped ZBLAN waveguide laser operating at 2.9 μm, which was pumped by a 1150 nm diode laser. The laser is based on ultrafast laser inscribed depressed cladding waveguides fabricated in uniformly rare-earth-doped bulk glass. It has a threshold of 28 mW and produced up to 27 mW of output power at an internal slope efficiency of approximately 20%.

  8. Ion-exchanged waveguide lasers in Er3+/Yb3+ codoped silicate glass.

    Science.gov (United States)

    Peters, P M; Funk, D S; Peskin, A P; Veasey, D L; Sanford, N A; Houde-Walter, S N; Hayden, J S

    1999-11-20

    We investigated an Er(3+)/Yb(3+) codoped silicate glass as a host material for waveguide lasers operating near 1.5 microm. Spectroscopic properties of the glass are reported. Waveguide lasers were fabricated by K(+)-ion exchange from a nitrate melt. The waveguides support a single transverse mode at 1.5 microm. An investigation of the laser performance as a function of the Yb:Er ratio was performed, indicating an optimal ratio of approximately 5:1. Slope efficiencies of as great as 6.5% and output powers as high as 19.6 mW at 1.54 microm were realized. The experimental results are compared with a waveguide laser model that is used to extract the Er(3+) upconversion coefficients and the Yb(3+)-Er(3+) cross-relaxation coefficients. The results indicate the possibility of obtaining high-performance waveguide lasers from a durable silicate host glass.

  9. Electrically Injected Single Transverse-Mode Coupled Waveguide Lasers by Parity-time (PT) Symmetry

    CERN Document Server

    Yao, Ruizhe; Podolskiy, Viktor; Guo, Wei

    2016-01-01

    In this report, we demonstrate the single transverse-mode operation of InAs quantum dot (QD) broad-area coupled waveguide lasers by parity-time (PT) symmetry. A novel waveguide design is adopted by adding gain and loss in the electrically injected coupled waveguide laser cavity. In such counterintuitive waveguide design, the single mode operation is achieved by harnessing notions from PT symmetry breaking and mode selections. By further varying the loss in the coupled waveguides, the coupled waveguide operation in different PT symmetry regions is experimentally demonstrated and agrees well with the numerical models. The demonstration of an electrically pumped single transverse-mode based on PT symmetry breaking paves a way to the next-generation optoelectronic devices and advanced laser science.

  10. Fabrication and Characterisation of Low-noise Monolithic Mode-locked Lasers

    DEFF Research Database (Denmark)

    Larsson, David

    2007-01-01

    This thesis deals with the fabrication and characterisation of monolithic semiconductor mode-locked lasers for use in optical communication systems. Other foreseeable applications may be as sources in microwave photonics and optical sampling. The thesis also deals with the design and fabrication...... of intracavity monolithically integrated filters. The common dnominator among the diffrent parts of the thesis is how to achieve and measure the lowest possible noise. Achieving low noise has been pinpointed as one of the most important and difficult challenges for semiconductor mode-locked lasers. The main...... result of this thesis are a fabrication process of a monolithic and deeply etched distributed Bragg reflector and a characterisation system for measurement of quantum limitid timing noise at high repetition rates. The Bragg reflector is a key component in achieving transform limited pulses with low noise...

  11. Rare-earth-ion-doped waveguide lasers on a silicon chip

    Science.gov (United States)

    Pollnau, Markus

    2015-03-01

    Rare-earth-ion-doped materials are of high interest as amplifiers and lasers in integrated optics. Their longer excited-state lifetimes and the weaker refractive-index change accompanied with rare-earth-ion excitation compared to electron-hole pairs in III-V semiconductors provide spatially and temporally stable optical gain, allowing for high-speed amplification and narrow-linewidth lasers. Amorphous Al2O3 deposited onto thermally oxidized silicon wafers offers the advantage of integration with silicon photonics and electronics. Layer deposition by RF reactive co-sputtering and micro-structuring by chlorine-based reactive-ion etching provide low-loss channel waveguides. With erbium doping, we improved the gain to 2 dB/cm at 1533 nm and a gain bandwidth of 80 nm. The gain is limited by migration-accelerated energy-transfer upconversion and a fast quenching process. Since stimulated emission is even faster than this quenching process, lasers are only affected in terms of their threshold, allowing us to demonstrate diode-pumped micro-ring, distributed-feedback (DFB), and distributed-Bragg-reflector (DBR) lasers in Al2O3:Er3+ and Al2O3:Yb3+ on a silicon chip. Surface-relief Bragg gratings were patterned by laser-interference lithography. Monolithic DFB and DBR cavities with Q-factors of 1.35×106 were realized. In an Er-doped DFB laser, single-longitudinal-mode operation at 1545 nm was achieved with a linewidth of 1.7 kHz, corresponding to a laser Q-factor of 1.14×1011. Yb-doped DFB and DBR lasers were demonstrated at 1020 nm with output powers of 55 mW and a slope efficiency of 67% versus launched pump power. A dual-phaseshift, dual-wavelength laser was achieved and a stable microwave signal at ~15 GHz was created via the heterodyne photo-detection of the two laser wavelengths.

  12. Monolithic Multi-Colour 40 GHz Mode-Locked Laser Array

    OpenAIRE

    Hou, Lianping; Eddie, Iain; Marsh, John

    2016-01-01

    The monolithic integration of four 40 GHz multi-colored mode-locked lasers with a 4×1 MMI, four electroabsorption modulators and an SOA has been demonstrated. The shortest pulse widths are between 2.63 and 2.85 ps.

  13. Monolithic integration of electroabsorption modulators and tunnel injection distributed feedback lasers using quantum well intermixing

    Science.gov (United States)

    Wang, Yang; Pan, Jiao-Qing; Zhao, Ling-Juan; Zhu, Hong-Liang; Wang, Wei

    2010-12-01

    Electroabsorption modulators combining Franz-Keldysh effect and quantum confined Stark effect have been monolithically integrated with tunnel-injection quantum-well distributed feedback lasers using a quantum well intermixing method. Superior characteristics such as extinction ratio and temperature insensitivity have been demonstrated at wide temperature ranges.

  14. A monolithic relativistic electron beam source based on a dielectric laser accelerator structure

    Energy Technology Data Exchange (ETDEWEB)

    McNeur, Josh; Carranza, Nestor; Travish, Gil; Yin Hairong; Yoder, Rodney [UCLA Dept. of Physics and Astronomy, Los Angeles, CA 90095 (United States); College of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054 (China); Manhattanville College, Physics Dept., 2900 Purchase St., Purchase, NY 10577 (United States)

    2012-12-21

    Work towards a monolithic device capable of producing relativistic particle beams within a cubic-centimeter is detailed. We will discuss the Micro-Accelerator Platform (MAP), an optical laser powered dielectric accelerator as the main building block of this chip-scale source along with a field enhanced emitter and a region for sub-relativistic acceleration.

  15. Internal defect localization in 980 nm ridge waveguide lasers

    Science.gov (United States)

    Díaz, L.; Eichler, H. J.; Weich, K.; Klehr, A.; Zeimer, U.

    2006-04-01

    High power lasers emitting at 980 nm are essential for pumping sources of erbium-doped fiber amplifiers (EDFAs). These are used in longer distance telecommunications. Stability and reliability of the modules are two key characteristics. The present paper investigates 'sudden random failures' of double quantum-well 980 nm high power ridge waveguide lasers implemented in EDFAs. For the inspection of the external and internal status of the device we used optical spectrum modulation experiments, electroluminescence measurements, scanning electron microscopy and cathodoluminescence investigations. The localization of internal defects is the main point of this work. Two different 'sudden random failures' were found: catastrophical optical mirror damage (COMD) and internal dark line defect (DLD) formation.

  16. Effect of absorbed pump power on the quality of output beam from monolithic microchip lasers

    Indian Academy of Sciences (India)

    Pranab K Mukhopadhyay; K Ranganathan; Jogy George; S K Sharma; T P S Nathan

    2002-04-01

    The dependence of the beam propagation factor (2 parameter) with the absorbed pump power in the case of monolithic microchip laser under face-cooled configuration is extensively studied. Our investigations show that the 2 parameter is related to the absorbed pump power through two parameters ( and ) whose values depend on the laser material properties and laser configuration. We have shown that one parameter arises due to the oscillation of higher order modes in the microchip cavity and the other parameter accounts for the spherical aberration associated with the thermal lens induced by the pump beam. Such dependency of 2 parameter with the absorbed pump power is experimentally verified for a face-cooled monolithic microchip laser based on Nd3+ - doped GdVO4 crystal and the values of and parameters were estimated from the experimentally measured data points.

  17. Optically pumped planar waveguide lasers: Part II: Gain media, laser systems, and applications

    Science.gov (United States)

    Grivas, Christos

    2016-01-01

    The field of optically pumped planar waveguide lasers has seen a rapid development over the last two decades driven by the requirements of a range of applications. This sustained research effort has led to the demonstration of a large variety of miniature highly efficient laser sources by combining different gain media and resonator geometries. One of the most attractive features of waveguide lasers is the broad range of regimes that they can operate, spanning from continuous wave and single frequency through to the generation of femtosecond pulses. Furthermore, their technology has experienced considerable advances to provide increased output power levels, deriving benefits from the relative immunity from the heat generated in the gain medium during laser operation and the use of cladding-pumped architectures. This second part of the review on optically pumped planar waveguide lasers provides a snapshot of the state-of-the-art research in this field in terms of gain materials, laser system designs, and as well as a perspective on the status of their application as real devices in various research areas.

  18. Ceramic planar waveguide laser of non-aqueous tape casting fabricated YAG/Yb:YAG/YAG.

    Science.gov (United States)

    Wang, Chao; Li, Wenxue; Yang, Chao; Bai, Dongbi; Li, Jiang; Ge, Lin; Pan, Yubai; Zeng, Heping

    2016-08-18

    Ceramic YAG/Yb:YAG/YAG planar waveguide lasers were realized on continuous-wave and mode-locked operations. The straight waveguide, fabricated by non-aqueous tape casting and solid state reactive sintering, enabled highly efficient diode-pumped waveguide continuous-wave laser with the slope efficiency of 66% and average output power of more than 3 W. The influence of the waveguide structure on the wavelength tunability was also experimentally investiccgated with a dispersive prism. Passively mode-locked operation of the ceramic waveguide laser was achieved by using a semiconductor saturable absorber mirror (SESAM), output 2.95 ps pulses with maximum power of 385 mW at the central wavelength of 1030 nm.

  19. Low loss depressed cladding waveguide inscribed in YAG:Nd single crystal by femtosecond laser pulses.

    Science.gov (United States)

    Okhrimchuk, Andrey; Mezentsev, Vladimir; Shestakov, Alexander; Bennion, Ian

    2012-02-13

    A depressed cladding waveguide with record low loss of 0.12 dB/cm is inscribed in YAG:Nd(0.3at.%) crystal by femtosecond laser pulses with an elliptical beam waist. The waveguide is formed by a set of parallel tracks which constitute the depressed cladding. It is a key element for compact and efficient CW waveguide laser operating at 1064 nm and pumped by a multimode laser diode. Special attention is paid to mechanical stress resulting from the inscription process. Numerical calculation of mode distribution and propagation loss with the elasto-optical effect taken into account leads to the conclusion that the depressed cladding is a dominating factor in waveguide mode formation, while the mechanical stress only slightly distorts waveguide modes.

  20. Parameter study of RF excited diffusively cooled all-metal slab waveguide CO2 laser

    Institute of Scientific and Technical Information of China (English)

    Ning Su; Shuna Yao; Yanhong Zhong; Jianguo Xin

    2005-01-01

    @@ In this paper, we have investigated some parameters of a radio frequency (RF) excited diffusively cooled all-metal slab waveguide CO2 laser based on the modified Rigrod theory by introducing a waveguide coupling efficiency which designates the coupling between the waveguide and the resonator mirrors. The parameters of the laser small signal gain go, saturation intensity Is, and waveguide coupling efficiency η are studied theoretically and experimentally. In the experiments, three sets of output coupling flat mirrors with the different transitivities were used, and a maximum laser power output of 150 W was obtained from a gas discharge region of 2-mm height, 20-mm width, and 386-mm length coupled with a CASE-I optical waveguide resonator.

  1. Fabricating fluorinated polyimide optical waveguide by CO2 laser direct-writing

    Science.gov (United States)

    Jin, Xi; Zhu, Daqing; Zeng, Xiaoyan

    2008-12-01

    Fluorinated polyimide waveguides were fabricated by CO2 laser direct-writing. The poly(amic acid) micro-region exposed by CO2 laser beam was measured with FT-IR micro-spectroscopy. The FT-IR spectra indicated that the laser imidized polyimide was semicrystalline, and the imidization degree of scanned micro-region increased with the rising of output laser power. The increased aspect ratio of waveguide and smoothness of surface can be achieved by increasing the pre-cured temperature (below 120 °C) and writing rate, and optimizing laser power and the distance between the lens and the annular aperture. The guided light was clearly confined to the core of the fabricated waveguide, which means this technique can be used for fluorinated polyimide waveguide fabrication.

  2. On-chip integration of InGaAs/GaAs quantum dot lasers with waveguides and modulators on silicon

    Science.gov (United States)

    Yang, Jun; Bhattacharya, Pallab; Qin, Guoxuan; Ma, Zhenqiang

    2008-02-01

    Compound-semiconductor-based photonic devices, including lasers and modulators, directly grown and on-chip integrated on Si substrates provide a promising approach for the realization of optical interconnects with CMOS compatibility. Utilizing quantum dots as efficient dislocation filters near the GaAs-Si interface, for the first time, we demonstrated high-performance InGaAs/GaAs quantum dot (QD) lasers on silicon with a relatively low threshold current (J th = 900 A/cm2), large small-signal modulation bandwidth of 5.5 GHz, and a high characteristic temperature (T 0 = 278 K). The integrated InGaAs QD lasers with quantum well (QW) electroabsorption modulators, achieved through molecular beam epitaxy (MBE) growth and regrowth, exhibit a coupling coefficient greater than 20% and a modulation depth ~100% at 5 V reverse bias. We achieved the monolithic integration of amorphous and crystalline silicon waveguides with quantum dot lasers by using plasma-enhanced-chemical-vapor-deposition (PECVD) and membrane transfer, respectively. Finally, preliminary results on the integration of QD lasers with Si CMOS transistors are presented.

  3. Study on the characteristics of erbium-doped waveguide ring laser

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A theoretical model of the erbium-doped waveguide ring laser is established according to the theory of erbium-doped waveguide amplifier and the transmission matrix of waveguide directional coupler. The influence of bend radius, coupling coefficient and doped erbium ion concentration on the characteristics of waveguide ring laser is investigated. It is shown that due to the co-action of waveguide bend loss and other relevant loss there is an optimal bend radius which can provide simultaneously low threshold pumping power and high laser light output power. As one part of the resonator’s loss, the laser light coupling coefficient of directional coupler has an impact on the laser property. The analysis indicates that the laser achieves the high output power when the coupling coefficient is about 0.2. The threshold pumping power is the minimum when the doped erbium ion concentration is 0.85×1026 m-3. Increasing the concentration of doped erbium ions will enhance the output power of laser light as long as the concentration doesn’t introduce remarkable up-conversion effect. The results give a good theoretical basis for the design and fabrication of erbium-doped waveguide ring laser devices.

  4. Laser-assisted microstructuring for Ti:sapphire channel-waveguide fabrication

    NARCIS (Netherlands)

    Crunteanu, A.; Pollnau, Markus; Jänchen, G.; Hibert, C.; Hoffmann, P.; Salathé, R.P.; Eason, R.W.; Shepherd, D.P.

    We report on the fabrication of Ti:sapphire channel waveguides. Such channel waveguides are of interest, e.g., as low-threshold tunable lasers. We investigated several structuring methods including ion beam implantation followed by wet chemical etching strip loading by polyimide spin coating and

  5. Narrow-Linewidth Distributed Feedback Channel Waveguide Laser in Al$_2$O$_3$:Er$^{3+}$

    NARCIS (Netherlands)

    Bernhardi, E.H.; Agazzi, L.; Wörhoff, K.; Ridder, de R.M.; Pollnau, M.; Pozo, J.; Mortensen, M.; Urbach, P.; Leijtens, X.; Yousefi, M.

    2010-01-01

    We report on the fabrication and characterization of a distributed feedback channel waveguide laser in erbium-doped aluminium oxide on a standard thermally oxidized silicon substrate. Holographically-written surface-relief Bragg gratings have been integrated with the aluminium oxide waveguides via r

  6. Light propagation studies on laser modified waveguides using scanning near-field optical microscopy

    DEFF Research Database (Denmark)

    Borrise, X.; Berini, Abadal Gabriel; Jimenez, D.

    2001-01-01

    By means of direct laser writing on Al, a new method to locally modify optical waveguides is proposed. This technique has been applied to silicon nitride waveguides, allowing modifications of the optical propagation along the guide. To study the formed structures, a scanning near-held optical...

  7. Misalignment effects in a CO sub 2 waveguide laser

    Energy Technology Data Exchange (ETDEWEB)

    Hill, C.A. (Laser Sensing and Quantum Optics Div., Royal Signals and Radar Establishment, Malvern (GB)); Colley, A.D. (Optoelectrics and Laser Engineering Group, Dept. of Physics, Heriot-Watt Univ., Edinburgh (GB))

    1990-02-01

    The authors have studied a CO{sub 2} waveguide resonator with a square bore and plane mirrors, reporting the theoretical and experimental effects of changing the mirror-guide distance and of titling the mirror. It can be misleading to neglect typical mirror-guide distances {ital z} {approx equal} 2--4 mm in favor of extreme-near-field ( Case 1'') simplifications. The authors' results from a small ({approx equal}20 cm {times} 1.3 mm {times} 1.3 mm) RF-excited laser agree well with predictions (from an improved multimode matrix model) of output power, line-tuning behavior, and CW beat frequency.

  8. Generation of heralded single photons beyond 1100 nm by spontaneous four-wave mixing in a side-stressed femtosecond laser-written waveguide

    CERN Document Server

    Yan, Zhizhong; Helt, L G; Ams, Martin; Withford, Michael J; Steel, M J

    2015-01-01

    We demonstrate a monolithically integrable heralded photon source in a femtosecond laser direct written glass waveguide. The generation of photon pairs with a wide wavelength separation requires a concomitant large birefringence in the normal dispersion regime. Here, by incorporation of side-stress tracks, we produce a waveguide with a birefringence of $1.64\\times~10^{-4}$ and propagation loss as low as 0.21 dB/cm near 980~nm. We measure photon pairs with 300~nm wavelength separation at an internal generation rate exceeding $5.05\\times10^6$/s. The second order correlations indicate that the generated photon pairs are in a strongly non-classical regime.

  9. Widely tunable short-infrared thulium and holmium doped fluorozirconate waveguide chip lasers.

    Science.gov (United States)

    Lancaster, D G; Gross, S; Withford, M J; Monro, T M

    2014-10-20

    We report widely tunable (≈ 260 nm) Tm(3+) and Ho(3+) doped fluorozirconate (ZBLAN) glass waveguide extended cavity lasers with close to diffraction limited beam quality (M(2) ≈ 1.3). The waveguides are based on ultrafast laser inscribed depressed claddings. A Ti:sapphire laser pumped Tm(3+)-doped chip laser continuously tunes from 1725 nm to 1975 nm, and a Tm(3+)-sensitized Tm(3+):Ho(3+) chip laser displays tuning across both ions evidenced by a red enhanced tuning range of 1810 to 2053 nm. We also demonstrate a compact 790 nm diode laser pumped Tm(3+)-doped chip laser which tunes from 1750 nm to 1998 nm at a 14% incident slope efficiency, and a beam quality of M(2) ≈ 1.2 for a large mode-area waveguide with 70 µm core diameter.

  10. Patterning of graphene on silicon-on-insulator waveguides through laser ablation and plasma etching

    Science.gov (United States)

    Van Erps, Jürgen; Ciuk, Tymoteusz; Pasternak, Iwona; Krajewska, Aleksandra; Strupinski, Wlodek; Van Put, Steven; Van Steenberge, Geert; Baert, Kitty; Terryn, Herman; Thienpont, Hugo; Vermeulen, Nathalie

    2016-05-01

    We present the use of femtosecond laser ablation for the removal of monolayer graphene from silicon-on-insulator (SOI) waveguides, and the use of oxygen plasma etching through a metal mask to peel off graphene from the grating couplers attached to the waveguides. Through Raman spectroscopy and atomic force microscopy, we show that the removal of graphene is successful with minimal damage to the underlying SOI waveguides. Finally, we employ both removal techniques to measure the contribution of graphene to the loss of grating-coupled graphene-covered SOI waveguides using the cut-back method. This loss contribution is measured to be 0.132 dB/μm.

  11. Integrated Broadband Quantum Cascade Laser

    Science.gov (United States)

    Mansour, Kamjou (Inventor); Soibel, Alexander (Inventor)

    2016-01-01

    A broadband, integrated quantum cascade laser is disclosed, comprising ridge waveguide quantum cascade lasers formed by applying standard semiconductor process techniques to a monolithic structure of alternating layers of claddings and active region layers. The resulting ridge waveguide quantum cascade lasers may be individually controlled by independent voltage potentials, resulting in control of the overall spectrum of the integrated quantum cascade laser source. Other embodiments are described and claimed.

  12. Monolithic strained-InGaAsP multiple-quantum-well lasers with integrated electroabsorption modulators for active mode locking

    Science.gov (United States)

    Sato, Kenji; Wakita, Koichi; Kotaka, Isamu; Kondo, Yasuhiro; Yamamoto, Mitsuo; Takada, Atsushi

    1994-07-01

    Active mode locking by monolithic lasers with integrated electroabsorption modulators using strained-InGaAsP multiple quantum wells is described. The electroabsorption modulator acts as a short optical gate when a sinusoidal voltage is driven at a deep bias point. Pulse widths as short as 2 ps have been obtained at a repetition rate of 16.3 GHz for a 2.5-mm-long monolithic laser.

  13. Mid-IR laser oscillation in Cr2+:ZnSe planar waveguide.

    Science.gov (United States)

    Williams, J E; Fedorov, V V; Martyshkin, D V; Moskalev, I S; Camata, R P; Mirov, S B

    2010-12-06

    We demonstrate 2.6 µm mid-infrared lasing at room temperature in a planar waveguide structure. Planar waveguides were fabricated using pulsed laser deposition (PLD) by depositing chromium doped zinc selenide thin films on sapphire substrate (Cr2+:ZnSe/sapphire). Highly doped Cr2+:ZnSe/Sapphire thin film sample was also used to demonstrate passive Q-switching of Er:YAG laser operating at 1.645 µm.

  14. Q-switched pulse laser generation from double-cladding Nd:YAG ceramics waveguides.

    Science.gov (United States)

    Tan, Yang; Luan, Qingfang; Liu, Fengqin; Chen, Feng; Vázquez de Aldana, Javier Rodríguez

    2013-08-12

    This work reports on the Q-switched pulsed laser generation from double-cladding Nd:YAG ceramic waveguides. Double-cladding waveguides with different combination of diameters were inscribed into a sample of Nd:YAG ceramic. With an additional semiconductor saturable absorber, stable pulsed laser emission at the wavelength of 1064 nm was achieved with pulses of 21 ns temporal duration and ~14 μJ pulse energy at a repetition rate of 3.65 MHz.

  15. Monolithic Rare Earth Doped PTR Glass Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of airborne and spaceborne laser systems dictates a number of extremely challenging requirements for such fine optical devices. These requirements...

  16. Spectral performance of monolithic holmium and thulium lasers

    Science.gov (United States)

    Storm, Mark E.

    1991-01-01

    Fabry-Perot resonators have been used to demonstrate single-mode lasing of holmium and neodymium YAG. The previous demonstration in the holmium laser required TE cooling the crystal to -15 C in order to achieve threshold. The present study extends that result, demonstrating +25 C operation in a 1-mm thick plano/plano resonator. The experimental configuration of lasing both the holmium and thulium lasers used a 500-mW diode laser which was collimated, circularized, and focused into a beam radius of 60 microns. The single-frequency lasing spectrum of the holmium laser is shown. By adjusting the mirror reflectivity, the ability to control the laser's wavelength is demonstrated. This laser operated with 11 mW of optical power, a 57-percent slope efficiency, and 120-mW threshold vs absorbed diode power laser for the 60-micron beam radius. The thulium laser operated very efficiently at room temperature, but on seven longitudinal modes. The Tm:TAG laser exhibits typical characteristics of spatial hole burning not seen in the Ho:Tm:YAG for flat/flat resonators.

  17. InGaAsP Buried Channel Waveguide For Electroabsorption Modulation

    Science.gov (United States)

    Lin, S. C.; Chin, M. K.; Jing, X. L.; Walpita, L. M.; Yu, P. K. L.; Chang, W. S.

    1987-11-01

    External modulation of 1.3 μm laser light with LPE grown InGaAsP/InP buried channel waveguides is presented. The waveguide is compatible with single mode fiber and the planar structure has potential for monolithic integration. In this paper, a numerical analysis of electroabsorption (EA) modulation for the waveguide modulator shows interesting results which may help the design of this device.

  18. Analysis of directional emission in square resonator lasers with an output waveguide

    Institute of Scientific and Technical Information of China (English)

    Wei Zhao; Yongzhen Huang

    2007-01-01

    Square microcavity laser with an output waveguide is proposed and analyzed by the finite-difference time-domain (FDTD) technique. For a square resonator with refractive index of 3.2, side length of 4 μm, and output waveguide of 0.4-μm width, we have got the quality factors (Q factors) of 6.7 × 102 and 7.3 × 103 for the fundamental and first-order transverse magnetic (TM) mode near the wavelength of 1.5 μm, respectively. The simulated intensity distribution for the first-order TM mode shows that the coupling efficiency in the waveguide reaches 53%. The numerical simulation shows that the first-order transverse modes have fairly high Q factor and high coupling efficiency to the output waveguide. Therefore the square resonator with an output waveguide is a promising candidate to realize single-mode directional emission microcavity lasers.

  19. Monolithic Laser Scribed Graphene Scaffold with Atomic Layer Deposited Platinum for Hydrogen Evolution Reaction

    KAUST Repository

    Nayak, Pranati

    2017-09-01

    The use of three-dimensional (3D) electrode architectures as scaffolds for conformal deposition of catalysts is an emerging research area with significant potential for electrocatalytic applications. In this study, we report the fabrication of monolithic, self-standing, 3D graphitic carbon scaffold with conformally deposited Pt by atomic layer deposition (ALD) as a hydrogen evolution reaction catalyst. Laser scribing is employed to transform polyimide into 3D porous graphitic carbon, which possesses good electronic conductivity and numerous edge plane sites. This laser scribed graphene (LSG) architecture makes it possible to fabricate monolithic electrocatalyst support without any binders or conductive additives. The synergistic effect between ALD of Pt on 3D network of LSG provides an avenue for minimal yet effective Pt usage, leading to an enhanced HER activity. This strategy establish a general approach for inexpensive and large scale HER device fabrication with minimum catalyst cost.

  20. Myocardium tissue ablation with hollow-waveguide-delivered near-infrared nanosecond laser pulses

    Science.gov (United States)

    Sato, Shunichi; Arai, Tsunenori; Shi, Yi-Wei; Matsuura, Yuji; Miyagi, Mitsunobu; Ashida, Hiroshi

    2001-06-01

    With 1064-nm, nanosecond laser pulses delivered from hollow waveguide, ablation characteristics of porcine myocardium tissue have been investigated in vitro. For the hollow waveguide a vacuum-cored scheme was introduced to suppress the laser-induced air breakdown that limited the available transmitted laser energy/power. The delivered laser pulse beam was focused with a collimation lens and a focusing lens, and it was shown that higher efficiency ablation was obtained when a focusing lens with a shorter focal length was used. Waveguide bending (bending angle 90 degree(s)C, bending radius approximately 50 cm) caused no deteriorating effect on the ablation characteristics for ablation energies up to approximately 60 mJ/pulse. It was demonstrated that deep and sharp ablated holes with aspect ratios > 8 was obtained with the hollow-waveguide-delivered laser pulses. It may be a realistic option to aim at using the present hollow waveguide system for trocar-based applications or replacing articulated mirror-based laser delivery systems. It is an important part of the future works to downsize the waveguide output unit for catheter-based applications.

  1. Low-loss waveguides fabricated in BK7 glass by high repetition rate femtosecond fiber laser.

    Science.gov (United States)

    Eaton, Shane M; Ng, Mi Li; Bonse, Jörn; Mermillod-Blondin, Alexandre; Zhang, Haibin; Rosenfeld, Arkadi; Herman, Peter R

    2008-04-20

    For the first time femtosecond-laser writing has inscribed low-loss optical waveguides in Schott BK7 glass, a commercially important type of borosilicate widely used in optical applications. The use of a variable repetition rate laser enabled the identification of a narrow processing window at 1 MHz repetition rate with optimal waveguides exhibiting propagation losses of 0.3 dB/cm and efficient mode matching to standard optical fibers at a 1550 nm wavelength. The waveguides were characterized by complementary phase contrast and optical transmission microscopy, identifying a micrometer-sized guiding region within a larger complex structure of both positive and negative refractive index variations.

  2. Analysis of Semi-conductor Laser Diode with Two-dimension Nonlinearly Tapered Waveguide

    Institute of Scientific and Technical Information of China (English)

    LI Hong; HAUNG Dexiu

    2001-01-01

    A novel semiconductor laser diode with a two-dimension nonlinearly tapered waveguide is proposed and its property is studied by Fourier expanding method. It is shown that coupling loss between the semiconductor laser diode and a single mode fiber is reduced effectively, the reduction role of the nonlinearly tapered waveguide is more apparent than that of a linearly tapered waveguide , the minimum coupling loss is 0.36 dB, and the far field divergence is decreased. The reduction mechanism is discussed.

  3. Monolithically integrated interferometer for optical displacement measurement

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1996-01-01

    We discuss the fabrication of a monolithically integrated optical displacement sensors using III-V semiconductor technology. The device is configured as a Michelson interferometer and consists of a distributed Bragg reflector laser, a photodetector and waveguides forming a directional coupler. Using this interferometer, displacements in the 100 nm range could be measured at distances of up to 45 cm. We present fabrication, device results and characterization of the completed interferometer, problems, limitations and future applications will also be discussed.

  4. Completely monolithic linearly polarized high-power fiber laser oscillator

    Science.gov (United States)

    Belke, Steffen; Becker, Frank; Neumann, Benjamin; Ruppik, Stefan; Hefter, Ulrich

    2014-03-01

    We have demonstrated a linearly polarized cw all-in-fiber oscillator providing 1 kW of output power and a polarization extinction ratio (PER) of up to 21.7 dB. The design of the laser oscillator is simple and consists of an Ytterbium-doped polarization maintaining large mode area (PLMA) fiber and suitable fiber Bragg gratings (FBG) in matching PLMA fibers. The oscillator has nearly diffraction-limited beam quality (M² high power 6+1:1 pump coupler. The slope efficiency of the laser is 75 %. The electro/optical efficiency of the complete laser system is ~30 % and hence in the range of Rofin's cw non-polarized fiber lasers. Choosing an adequate bending diameter for the Yb-doped PLMA fiber, one polarization mode as well as higher order modes are sufficiently supressed1. Resulting in a compact and robust linearly polarized high power single mode laser without external polarizing components. Linearly polarized lasers are well established for one dimensional cutting or welding applications. Using beam shaping optics radially polarized laser light can be generated to be independent from the angle of incident to the processing surface. Furthermore, high power linearly polarized laser light is fundamental for nonlinear frequency conversion of nonlinear materials.

  5. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    OpenAIRE

    Longqing Yi; Alexander Pukhov; Baifei Shen

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO$_{2}$ laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energ...

  6. Optical 40 GHz pulse source module based on a monolithically integrated mode locked DBR laser

    Science.gov (United States)

    Huettl, B.; Kaiser, R.; Kroh, M.; Schubert, C.; Jacumeit, G.; Heidrich, H.

    2005-11-01

    In this paper the performance characteristics of compact optical 40 GHz pulse laser modules consisting of a monolithic mode-locked MQW DBR laser on GaInAsP/InP are reported. The monolithic devices were fabricated as tunable multi-section buried heterostructure lasers. A DBR grating is integrated at the output port of an extended cavity in order to meet the standardized ITU wavelength channels allocated in the spectral window around 1.55 μm in optical high speed communication networks. The fabricated 40 GHz lasers modules not only emit short optical pulses (< 1.5 ps) with very low amplitude noise (<1.5 %) and phase noise levels (timing jitter: 50 fs) but also enable good pulse-to-pulse phase and long-term stability. A wavelength tuning range of 6 nm is possible and large locking bandwidths between 100 ... 260 MHz are observed. All data have been achieved by operating the lasers in a hybrid mode-locking scheme with a required minimum micro-wave power of only 12 dBm for pulse synchronization. Details on laser chip architecture and module performance are summarized and the results of a stable and error free module performance in first 160 Gb/s (4 x 40 Gb/s OTDM) RZ-DPSK transmission experiments are presented.

  7. 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

    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...... 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....

  8. Heat accumulation during high repetition rate ultrafast laser interaction: Waveguide writing in borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haibin; Eaton, Shane M; Li, Jianzhao; Herman, Peter R [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, ON, M5S 3G4 (Canada)

    2007-04-15

    During high repetition rate (>200 kHz) ultrafast laser waveguide writing, visible heat modified zones surrounding the formed waveguide occur as a result of heat accumulation. The radii of the heat-modified zones increase with the laser net fluence, and were found to correlate with the formation of low-loss and cylindrically symmetric optical waveguides. A numerical thermal model based on the finite difference method is applied here to account for cumulative heating and diffusion effects. The model successfully shows that heat propagation and accumulation accurately predict the radius of the 'heat modified' zones observed in borosilicate glass waveguides formed across a wide range of laser exposure conditions. Such modelling promises better control of thermal effects for optimizing the fabrication and performance of three-dimensional optical devices in transparent materials.

  9. Near- infrared, mode-locked waveguide lasers with multi-GHz repetition rates

    Science.gov (United States)

    Choudhary, A.; Lagatsky, A. A.; Zhang, Z. Y.; Zhou, K. J.; Wang, Q.; Hogg, R. A.; Pradeesh, K.; Rafailov, E. U.; Resan, B.; Oehler, A. E. H.; Weingarten, K. J.; Sibbett, W.; Brown, C. T. A.; Shepherd, D. P.

    2014-02-01

    In this work, we discuss mode-locking results obtained with low-loss, ion-exchanged waveguide lasers. With Yb3+-doped phosphate glass waveguide lasers, a repetition rate of up to 15.2 GHz was achieved at a wavelength of 1047 nm with an average power of 27 mW and pulse duration of 811 fs. The gap between the waveguide and the SESAM introduced negative group velocity dispersion via the Gires Tournois Interferometer (GTI) effect which allowed the soliton mode-locking of the device. A novel quantum dot SESAM was used to mode-lock Er3+, Yb3+-doped phosphate glass waveguide lasers around 1500 nm. Picosecond pulses were achieved at a maximum repetition rate of 6.8 GHz and an average output power of 30 mW. The repetition rate was tuned by more than 1 MHz by varying the pump power.

  10. Chirp of monolithic colliding pulse mode-locked diode lasers

    DEFF Research Database (Denmark)

    Hofmann, M.; Bischoff, S.; Franck, Thorkild

    1997-01-01

    Spectrally resolved streak camera measurements of picosecond pulses emitted by hybridly colliding pulse mode-locked (CPM) laser diodes are presented in this letter. Depending on the modulation frequency both blue-chirped (upchirped) and red-chirped (downchirped) pulses can be observed. The two...... different regimes and the transition between them are characterized experimentally and the behavior is explained on the basis of our model for the CPM laser dynamics. (C) 1997 American Institute of Physics....

  11. Transverse writing of three-dimensional tubular optical waveguides in glass with slit-shaped femtosecond laser beams

    CERN Document Server

    Liao, Yang; Wang, Peng; Chu, Wei; Wang, Zhaohui; Qiao, Lingling; Cheng, Ya

    2016-01-01

    We report on fabrication of tubular optical waveguides buried in ZBLAN glass based on transverse femtosecond laser direct writing. Irradiation in ZBLAN with focused femtosecond laser pulses leads to decrease of refractive index in the modified region. Tubular optical waveguides of variable mode areas are fabricated by forming the four sides of the cladding with slit-shaped femtosecond laser pulses, ensuring single mode waveguiding with a mode field dimension compatible with direct coupling to single-mode optical fibers.

  12. Transverse writing of three-dimensional tubular optical waveguides in glass with slit-shaped femtosecond laser beams

    OpenAIRE

    Liao, Yang; Qi, Jia; Wang, Peng; Chu, Wei; Wang, Zhaohui; Qiao, Lingling; Cheng, Ya

    2016-01-01

    We report on fabrication of tubular optical waveguides buried in ZBLAN glass based on transverse femtosecond laser direct writing. Irradiation in ZBLAN with focused femtosecond laser pulses leads to decrease of refractive index in the modified region. Tubular optical waveguides of variable mode areas are fabricated by forming the four sides of the cladding with slit-shaped femtosecond laser pulses, ensuring single mode waveguiding with a mode field dimension as small as ~ 4 {\\mu}m.

  13. Transverse writing of three-dimensional tubular optical waveguides in glass with a slit-shaped femtosecond laser beam

    Science.gov (United States)

    Liao, Yang; Qi, Jia; Wang, Peng; Chu, Wei; Wang, Zhaohui; Qiao, Lingling; Cheng, Ya

    2016-06-01

    We report on fabrication of tubular optical waveguides buried in ZBLAN glass based on transverse femtosecond laser direct writing. Irradiation in ZBLAN with focused femtosecond laser pulses leads to decrease of refractive index in the modified region. Tubular optical waveguides of variable mode areas are fabricated by forming the four sides of the cladding with slit-shaped femtosecond laser pulses, ensuring single mode waveguiding with a mode field dimension as small as ~4 μm.

  14. Transverse writing of three-dimensional tubular optical waveguides in glass with a slit-shaped femtosecond laser beam

    OpenAIRE

    Yang Liao; Jia Qi; Peng Wang; Wei Chu; Zhaohui Wang; Lingling Qiao; Ya Cheng

    2016-01-01

    We report on fabrication of tubular optical waveguides buried in ZBLAN glass based on transverse femtosecond laser direct writing. Irradiation in ZBLAN with focused femtosecond laser pulses leads to decrease of refractive index in the modified region. Tubular optical waveguides of variable mode areas are fabricated by forming the four sides of the cladding with slit-shaped femtosecond laser pulses, ensuring single mode waveguiding with a mode field dimension as small as ~4 μm.

  15. Design of a monolithic tunable laser based on equivalent-chirp grating reflectors.

    Science.gov (United States)

    Dai, Yitang; Xu, Kun; Wu, Jian; Li, Yan; Hong, Xiaobin; Guo, Hongxiang; Lin, Jintong

    2010-12-01

    A Vernier-tuned distributed Bragg reflector (DBR) semiconductor laser is an effective monolithic approach for wide wavelength tunability, at the expense, however, of costly electron-beam lithography during fabrication. In this Letter, a tunable laser design with equivalent-chirp based, flat-top envelope grating reflectors is proposed that can be implemented easily by conventional two-beam interference lithography. The principle is described, and a detailed design shows uniform output power (0.08 dB variation) and excellent side-mode suppression ratio (47 dB minimum) within a wide tuning range (>32 nm) through numerical simulation.

  16. Widely Tunable Monolithic Mid-Infrared Quantum Cascade Lasers Using Super-Structure Grating Reflectors

    OpenAIRE

    Dingkai Guo; Jiun-Yun Li; Liwei Cheng; Xing Chen; Terry Worchesky; Fow-Sen Choa

    2016-01-01

    A monolithic, three-section, and widely tunable mid-infrared (mid-IR) quantum cascade laser (QCL) is demonstrated. This electrically tuned laser consists of a gain section placed between two super structure grating (SSG) distributed Bragg reflectors (DBRs). By varying the injection currents to the two grating sections of this device, its emission wavelength can be tuned from 4.58 μm to 4.77 μm (90 cm−1) with a supermode spacing of 30 nm. This type of SSG-DBR QCLs can be a compact replacement ...

  17. Graphene Q-switched Tm:KY(WO4)2 waveguide laser

    Science.gov (United States)

    Kifle, E.; Mateos, X.; Loiko, P.; Yumashev, K.; Yasukevich, A.; Petrov, V.; Griebner, U.; Aguiló, M.; Díaz, F.

    2017-04-01

    We report on the first Tm3+-doped double tungstate waveguide laser passively Q-switched by a graphene saturable absorber using a 12.4 µm-thick 3 at.% Tm:KY0.58Gd0.22Lu0.17(WO4)2 epitaxial layer grown on a (0 1 0)-oriented pure KY(WO4)2 substrate. This laser generated 5.8 nJ/195 ns pulses at 1831.8 nm corresponding to a pulse repetition frequency of 1.13 MHz. These are the shortest pulses achieved in passively Q-switched Tm waveguide lasers. The laser slope efficiency was 9% and the Q-switching conversion efficiency reached 45%. Graphene is promising for the generation of ns pulses at ~2 µm in Tm3+-doped double tungstate waveguide lasers operating in the MHz-range.

  18. Optical lattice-like cladding waveguides by direct laser writing: fabrication, luminescence, and lasing.

    Science.gov (United States)

    Nie, Weijie; He, Ruiyun; Cheng, Chen; Rocha, Uéslen; Rodríguez Vázquez de Aldana, Javier; Jaque, Daniel; Chen, Feng

    2016-05-15

    We report on the fabrication of optical lattice-like waveguide structures in an Nd:YAP laser crystal by using direct femtosecond laser writing. With periodically arrayed laser-induced tracks, the waveguiding cores can be located in either the regions between the neighbored tracks or the central zone surrounded by a number of tracks as outer cladding. The polarization of the femtosecond laser pulses for the inscription has been found to play a critical role in the anisotropic guiding behaviors of the structures. The confocal photoluminescence investigations reveal different stress-induced modifications of the structures inscribed by different polarization of the femtosecond laser beam, which are considered to be responsible for the refractive index changes of the structures. Under optical pump at 808 nm, efficient waveguide lasing at ∼1  μm wavelength has been realized from the optical lattice-like structure, which exhibits potential applications as novel miniature light sources.

  19. Theoretical study of a waveguide THz free electron laser and comparisons with simulations

    Science.gov (United States)

    Shobuda, Yoshihiro; Chin, Yong Ho

    2016-09-01

    In a so-called waveguide free electron laser (FEL) for THz radiations, an extremely small aperture (˜mm ) waveguide is used to confine angularly wide spread radiation fields from a low energy electron beam into a small area. This confinement increases the interaction between the electron beam and the radiation fields to achieve a much higher FEL gain. The radiation fields propagate inside the waveguide as waveguide modes, not like a light flux in a free space FEL. This characteristic behavior of the radiation fields makes intuitive understanding of the waveguide FEL difficult. We developed a three-dimensional waveguide FEL theory to calculate a gain of THz waveguide FEL including the effects of the energy spread, the beam size and the betatron oscillations of an electron beam, and effects of a rectangular waveguide. The FEL gain can be calculated as a function of frequency by solving the dispersion relation. Theoretical gains are compared with simulation results for a waveguide FEL with a planar undulator similar to the KAERI one. Good agreements are obtained.

  20. Theoretical study of a waveguide THz free electron laser and comparisons with simulations

    Directory of Open Access Journals (Sweden)

    Yoshihiro Shobuda

    2016-09-01

    Full Text Available In a so-called waveguide free electron laser (FEL for THz radiations, an extremely small aperture (∼mm waveguide is used to confine angularly wide spread radiation fields from a low energy electron beam into a small area. This confinement increases the interaction between the electron beam and the radiation fields to achieve a much higher FEL gain. The radiation fields propagate inside the waveguide as waveguide modes, not like a light flux in a free space FEL. This characteristic behavior of the radiation fields makes intuitive understanding of the waveguide FEL difficult. We developed a three-dimensional waveguide FEL theory to calculate a gain of THz waveguide FEL including the effects of the energy spread, the beam size and the betatron oscillations of an electron beam, and effects of a rectangular waveguide. The FEL gain can be calculated as a function of frequency by solving the dispersion relation. Theoretical gains are compared with simulation results for a waveguide FEL with a planar undulator similar to the KAERI one. Good agreements are obtained.

  1. Ultrafast laser fabrication of low-loss waveguides in chalcogenide glass with 0.65 dB/cm loss.

    Science.gov (United States)

    McMillen, Ben; Zhang, Botao; Chen, Kevin P; Benayas, Antonio; Jaque, Daniel

    2012-05-01

    This Letter reports on the fabrication of low-loss waveguides in gallium-lanthanum-sulfide chalcogenide glasses using an ultrafast laser. Spatial beam shaping and temporal pulse width tuning were used to optimize the guided mode profiles and optical loss of laser-written waveguides. Highly symmetric single-mode waveguides guiding at 1560 nm with a loss of 0.65  dB/cm were fabricated using 1.5 ps laser pulses. This Letter suggests a pathway to produce high quality optical waveguides in substrates with strong nonlinearity using the ultrafast laser direct writing technique.

  2. Femtosecond laser fabrication of monolithically integrated microfluidic sensors in glass.

    Science.gov (United States)

    He, Fei; Liao, Yang; Lin, Jintian; Song, Jiangxin; Qiao, Lingling; Cheng, Ya; Sugioka, Koji

    2014-10-17

    Femtosecond lasers have revolutionized the processing of materials, since their ultrashort pulse width and extremely high peak intensity allows high-quality micro- and nanofabrication of three-dimensional (3D) structures. This unique capability opens up a new route for fabrication of microfluidic sensors for biochemical applications. The present paper presents a comprehensive review of recent advancements in femtosecond laser processing of glass for a variety of microfluidic sensor applications. These include 3D integration of micro-/nanofluidic, optofluidic, electrofluidic, surface-enhanced Raman-scattering devices, in addition to fabrication of devices for microfluidic bioassays and lab-on-fiber sensors. This paper describes the unique characteristics of femtosecond laser processing and the basic concepts involved in femtosecond laser direct writing. Advanced spatiotemporal beam shaping methods are also discussed. Typical examples of microfluidic sensors fabricated using femtosecond lasers are then highlighted, and their applications in chemical and biological sensing are described. Finally, a summary of the technology is given and the outlook for further developments in this field is considered.

  3. Femtosecond Laser Fabrication of Monolithically Integrated Microfluidic Sensors in Glass

    Directory of Open Access Journals (Sweden)

    Fei He

    2014-10-01

    Full Text Available Femtosecond lasers have revolutionized the processing of materials, since their ultrashort pulse width and extremely high peak intensity allows high-quality micro- and nanofabrication of three-dimensional (3D structures. This unique capability opens up a new route for fabrication of microfluidic sensors for biochemical applications. The present paper presents a comprehensive review of recent advancements in femtosecond laser processing of glass for a variety of microfluidic sensor applications. These include 3D integration of micro-/nanofluidic, optofluidic, electrofluidic, surface-enhanced Raman-scattering devices, in addition to fabrication of devices for microfluidic bioassays and lab-on-fiber sensors. This paper describes the unique characteristics of femtosecond laser processing and the basic concepts involved in femtosecond laser direct writing. Advanced spatiotemporal beam shaping methods are also discussed. Typical examples of microfluidic sensors fabricated using femtosecond lasers are then highlighted, and their applications in chemical and biological sensing are described. Finally, a summary of the technology is given and the outlook for further developments in this field is considered.

  4. Monolithic Ge-on-Si lasers for large-scale electronic-photonic integration

    Science.gov (United States)

    Liu, Jifeng; Kimerling, Lionel C.; Michel, Jurgen

    2012-09-01

    A silicon-based monolithic laser source has long been envisioned as a key enabling component for large-scale electronic-photonic integration in future generations of high-performance computation and communication systems. In this paper we present a comprehensive review on the development of monolithic Ge-on-Si lasers for this application. Starting with a historical review of light emission from the direct gap transition of Ge dating back to the 1960s, we focus on the rapid progress in band-engineered Ge-on-Si lasers in the past five years after a nearly 30-year gap in this research field. Ge has become an interesting candidate for active devices in Si photonics in the past decade due to its pseudo-direct gap behavior and compatibility with Si complementary metal oxide semiconductor (CMOS) processing. In 2007, we proposed combing tensile strain with n-type doping to compensate the energy difference between the direct and indirect band gap of Ge, thereby achieving net optical gain for CMOS-compatible diode lasers. Here we systematically present theoretical modeling, material growth methods, spontaneous emission, optical gain, and lasing under optical and electrical pumping from band-engineered Ge-on-Si, culminated by recently demonstrated electrically pumped Ge-on-Si lasers with >1 mW output in the communication wavelength window of 1500-1700 nm. The broad gain spectrum enables on-chip wavelength division multiplexing. A unique feature of band-engineered pseudo-direct gap Ge light emitters is that the emission intensity increases with temperature, exactly opposite to conventional direct gap semiconductor light-emitting devices. This extraordinary thermal anti-quenching behavior greatly facilitates monolithic integration on Si microchips where temperatures can reach up to 80 °C during operation. The same band-engineering approach can be extended to other pseudo-direct gap semiconductors, allowing us to achieve efficient light emission at wavelengths previously

  5. Transverse mode selection in a monolithic microchip laser

    CSIR Research Space (South Africa)

    Naidoo, Darryl

    2011-11-01

    Full Text Available The article outlines an approach to mode selection in a microchip laser through judicious shaping of the pump light to create a high modal overlap with the desired mode. The authors demonstrate the principle by creating a donut-shaped pump profile...

  6. Systematic control of optical features in aluminosilicate glass waveguides using direct femtosecond laser writing

    Science.gov (United States)

    Babu, B. Hari; Niu, Mengsi; Yang, Xiaoyu; Wang, Yanbo; Feng, Lin; Qin, Wei; Hao, Xiao-Tao

    2017-10-01

    Low loss optical waveguides inside aluminosilicate glasses have been successfully fabricated using direct femtosecond laser writing. To establish the influence of pulse energy and host variations on the optical waveguides have been tentatively explored and systematically studied with the help of different spectroscopic techniques. Isochronal annealing treatment effectively reduces the insertion losses to 1.01 ± 0.28 dB at 632.8 nm. A red shift of the Raman band has been observed with increasing Al2O3 content due to the bond angle variations. The point defects such as non-bridging oxygen hole centers have been corroborated by the photoluminescence studies and significant red-shift has also been documented with increasing Al2O3 content. In addition, there is no NBOHC defects perceived after isochronal annealing treatment inside the glass waveguides. Our results envisage that the present glass waveguides should be promising and potential for applications in passive waveguides and integrated photonic devices.

  7. On-chip optical phase locking of single growth monolithically integrated Slotted Fabry Perot lasers.

    Science.gov (United States)

    Morrissey, P E; Cotter, W; Goulding, D; Kelleher, B; Osborne, S; Yang, H; O'Callaghan, J; Roycroft, B; Corbett, B; Peters, F H

    2013-07-15

    This work investigates the optical phase locking performance of Slotted Fabry Perot (SFP) lasers and develops an integrated variable phase locked system on chip for the first time to our knowledge using these lasers. Stable phase locking is demonstrated between two SFP lasers coupled on chip via a variable gain waveguide section. The two lasers are biased differently, one just above the threshold current of the device with the other at three times this value. The coupling between the lasers can be controlled using the variable gain section which can act as a variable optical attenuator or amplifier depending on bias. Using this, the width of the stable phase locking region on chip is shown to be variable.

  8. Direct mapping of local redox current density on a monolith electrode by laser scanning.

    Science.gov (United States)

    Lee, Seung-Woo; Lopez, Jeffrey; Saraf, Ravi F

    2013-09-15

    An optical method of mapping local redox reaction over a monolith electrode using simple laser scanning is described. As the optical signal is linearly proportional to the maximum redox current that is measured concomitantly by voltammetry, the optical signal quantitatively maps the local redox current density distribution. The method is demonstrated on two types of reactions: (1) a reversible reaction where the redox moieties are ionic, and (2) an irreversible reaction on two different types of enzymes immobilized on the electrode where the reaction moieties are nonionic. To demonstrate the scanning capability, the local redox behavior on a "V-shaped" electrode is studied where the local length scale and, hence, the local current density, is nonuniform. The ability to measure the current density distribution by this method will pave the way for multianalyte analysis on a monolith electrode using a standard three-electrode configuration. The method is called Scanning Electrometer for Electrical Double-layer (SEED).

  9. Femtosecond-laser inscribed double-cladding waveguides in Nd:YAG crystal: a promising prototype for integrated lasers.

    Science.gov (United States)

    Liu, Hongliang; Chen, Feng; Vázquez de Aldana, Javier R; Jaque, D

    2013-09-01

    We report on the design and implementation of a prototype of optical waveguides fabricated in Nd:YAG crystals by using femtosecond-laser irradiation. In this prototype, two concentric tubular structures with nearly circular cross sections of different diameters have been inscribed in the Nd:YAG crystals, generating double-cladding waveguides. Under 808 nm optical pumping, waveguide lasers have been realized in the double-cladding structures. Compared with single-cladding waveguides, the concentric tubular structures, benefiting from the large pump area of the outermost cladding, possess both superior laser performance and nearly single-mode beam profile in the inner cladding. Double-cladding waveguides of the same size were fabricated and coated by a thin optical film, and a maximum output power of 384 mW and a slope efficiency of 46.1% were obtained. Since the large diameters of the outer claddings are comparable with those of the optical fibers, this prototype paves a way to construct an integrated single-mode laser system with a direct fiber-waveguide configuration.

  10. Vertical coupling of laser glass microspheres to buried silicon nitride ellipses and waveguides

    CERN Document Server

    Navarro-Urrios, Daniel; Capuj, Nestor E; Berencen, Yonder; Garrido, Blas; Tredicucci, Alessandro

    2015-01-01

    We demonstrate the integration of Nd3+ doped Barium-Titanium-Silicate microsphere lasers with a Silicon Nitride photonic platform. Devices with two different geometrical configurations for extracting the laser light to buried waveguides have been fabricated and characterized. The first configuration relies on a standard coupling scheme, where the microspheres are placed over strip waveguides. The second is based on a buried elliptical geometry whose working principle is that of an elliptical mirror. In the latter case, the input of a strip waveguide is placed on one focus of the ellipse, while a lasing microsphere is placed on top of the other focus. The fabricated elliptical geometry (ellipticity=0.9) presents a light collecting capacity that is 50% greater than that of the standard waveguide coupling configuration and could be further improved by increasing the ellipticity. Moreover, since the dimensions of the spheres are much smaller than those of the ellipses, surface planarization is not required. On th...

  11. Ion-exchanged tapered-waveguide laser in neodymium-doped BK7 glass.

    Science.gov (United States)

    Hettrick, S J; Mackenzie, J I; Harris, R D; Wilkinson, J S; Shepherd, D P; Tropper, A C

    2000-10-01

    We report what is to our knowledge the first operation of a planar dielectric tapered-waveguide laser. The waveguide laser is fabricated by potassium-ion exchange in Nd(3+) -doped BK7 glass and consists of a single-mode channel waveguide of a few micrometers' width followed by a linear taper up to a broad region with a width of ~180microm . A slope efficiency of 42% is found both in the tapers and in standard channel waveguides fabricated upon the same substrate, indicating that the tapers and the channels have similar internal losses; hence the low-loss nature of the tapered beam expansion. The output from either end of the tapered structure is found to be nearly diffraction limited.

  12. Low threshold monocrystalline Nd:(Gd,Lu)2O3 channel waveguide laser

    NARCIS (Netherlands)

    Kahn, Andreas; Heinrich, Sebastian; Kühn, Henning; Petermann, Klaus; Bradley, J.; Worhoff, Kerstin; Pollnau, Markus; Huber, Günther

    2009-01-01

    We report the first waveguide laser based on a rare-earth-doped sesquioxide. A 2 μm thick lattice matched Nd(0.5%):${(Gd, Lu)_2O_3}$ film with a nearly atomically flat surface has been epitaxially grown on a $Y_2O_3$ substrate, using pulsed laser deposition. The film has been structured with reactiv

  13. Modeling of mode-locked coupled-resonator optical waveguide lasers

    DEFF Research Database (Denmark)

    Agger, Christian; Skovgård, Troels Suhr; Gregersen, Niels;

    2010-01-01

    Coupled-resonator optical waveguides made from coupled high-Q photonic crystal nanocavities are investigated for use as cavities in mode-locked lasers. Such devices show great potential in slowing down light and can serve to reduce the cavity length of a mode-locked laser. An explicit expression...

  14. Wide-band residual phase-noise measurements on 40-GHz monolithic mode-locked lasers

    DEFF Research Database (Denmark)

    Larsson, David; Hvam, Jørn Märcher

    2005-01-01

    We have performed wide-band residual phase-noise measurements on semiconductor 40-GHz mode-locked lasers by employing electrical waveguide components for the radio-frequency circuit. The intrinsic timing jitters of lasers with one, two, and three quantum wells (QW) are compared and our design...... prediction, concerning noise versus number of QWs, for the first time corroborated by experiments. A minimum jitter of 44 fs is found, by extrapolating to the Nyquist frequency, for the one-QW device having nearly transform-limited pulses of 1.2 ps. This jitter is nearly three times lower than for a three...

  15. Optical characterization of femtosecond laser induced active channel waveguides in lithium fluoride crystals

    Energy Technology Data Exchange (ETDEWEB)

    Chiamenti, I.; Kalinowski, H. J., E-mail: hjkalin@utfpr.edu.br [Federal University of Technology–Paraná, Photonics Laboratory, 80230-901 Curitiba (Brazil); Bonfigli, F.; Montereali, R. M. [ENEA C.R. Frascati, Photonics Micro and Nanostructures Laboratory, V. E. Fermi, 45, 00044 Frascati (RM) (Italy); Gomes, A. S. L. [Universidade Federal de Pernambuco, Department of Physics, 50740-560 Recife (Brazil); Michelotti, F. [Universitá degli Studi di Roma “La Sapienza,” Dipartimento di Scienze di Base e Applicate per l' Ingegneria, Via A. Scarpa, 16, 00161, Rome (Italy)

    2014-01-14

    We successfully realized broad-band light-emitting color center waveguides buried in LiF crystals by using femtosecond laser pulses. The characterization of the waveguides was performed by optical microscopy, photoluminescence spectra, loss measurements and near-field profiling. The experimental results show that the direct-writing fabrication process induces low-index contrast active channel waveguides: their wavelength-dependent refractive index changes, estimated from 10{sup −3} to 10{sup −4} depending on the writing conditions, allow supporting few modes at visible and near-infrared wavelengths.

  16. Optical characterization of femtosecond laser induced active channel waveguides in lithium fluoride crystals

    Science.gov (United States)

    Chiamenti, I.; Bonfigli, F.; Gomes, A. S. L.; Michelotti, F.; Montereali, R. M.; Kalinowski, H. J.

    2014-01-01

    We successfully realized broad-band light-emitting color center waveguides buried in LiF crystals by using femtosecond laser pulses. The characterization of the waveguides was performed by optical microscopy, photoluminescence spectra, loss measurements and near-field profiling. The experimental results show that the direct-writing fabrication process induces low-index contrast active channel waveguides: their wavelength-dependent refractive index changes, estimated from 10-3 to 10-4 depending on the writing conditions, allow supporting few modes at visible and near-infrared wavelengths.

  17. Femtosecond laser fabrication of tubular waveguides in poly(methyl methacrylate).

    Science.gov (United States)

    Zoubir, Arnaud; Lopez, Cedric; Richardson, Martin; Richardson, Kathleen

    2004-08-15

    Femtosecond laser direct writing is employed for the fabrication of buried tubular waveguides in bulk poly(methyl methacrylate). A novel technique using selective chemical etching is presented to resolve the two-dimensional refractive-index profile of the fabrication structures. End-to-end coupling in the waveguides reveals a near-field intensity distribution that results from the superimposition of several propagating modes with different azimuthal symmetries. Mode analysis of the tubular waveguides is performed using the finite-difference method, and the possible propagating mode profiles are compared with the experimental data.

  18. Integration of a terahertz quantum cascade laser with a hollow waveguide

    Science.gov (United States)

    Wanke, Michael C [Albuquerque, NM; Nordquist, Christopher D [Albuquerque, NM

    2012-07-03

    The present invention is directed to the integration of a quantum cascade laser with a hollow waveguide on a chip to improve both the beam pattern and manufacturability. By coupling the QCL output into a single-mode rectangular waveguide the radiation mode structure can be known and the propagation, manipulation, and broadcast of the QCL radiation can then be entirely controlled by well-established rectangular waveguide techniques. By controlling the impedance of the interface, enhanced functions, such as creating amplifiers, efficient coupling to external cavities, and increasing power output from metal-metal THz QCLs, are also enabled.

  19. Optical Cladding Waveguides in Dielectric Crystals Produced by Femtosecond Laser Inscription

    Directory of Open Access Journals (Sweden)

    Chen Feng

    2013-11-01

    Full Text Available In this work, the recent progress of our research on optical cladding waveguides in dielectric crystals produced by femtosecond laser inscription has been overviewed. With different scales at cross sections, the cladding waveguides support guidance from single mode to highly multi-modes, and work for wavelength till mid-infrared regimes. Applications of the fabricated cladding structures as new integrated light sources are introduced.

  20. A DC excited waveguide multibeam CO2 laser using high frequency pre-ionization technique

    Indian Academy of Sciences (India)

    S V Deshmukh; C Rajagopalan

    2003-12-01

    High power industrial multibeam CO2 lasers consist of a large number of closely packed parallel glass discharge tubes sharing a common plane parallel resonator. Every discharge tube forms an independent resonator. When discharge tubes of smaller diameter are used and the Fresnel number $ \\ll 1$ for all resonators, they operate in waveguide mode. Waveguide modes have excellent discrimination of higher order modes. A DC excited waveguide multibeam CO2 laser is reported having six glass discharge tubes. Simultaneous excitation of DC discharge in all sections is achieved by producing pre-ionization using an auxiliary high frequency pulsed discharge along with its other advantages. Maximum 170 W output power is obtained with all beams operating in EH11 waveguide mode. The specific power of 28 W/m is much higher as compared to similar AC excited waveguide multibeam CO2 lasers. Theoretical analysis shows that all resonators of this laser will support only EH11 mode. This laser is successfully used for woodcutting.

  1. Microchip laser based on Yb:YAG/V:YAG monolith crystal

    Science.gov (United States)

    Nejezchleb, Karel; Šulc, Jan; Jelínková, Helena; Škoda, Václav

    2016-03-01

    V:YAG crystal was investigated as a passive Q-switch of longitudinally diode-pumped microchip laser, emitting radiation at wavelength 1030.5 nm. This laser was based on diffusion bonded monolith crystal (diameter 3 mm) which combines in one piece an active laser part (Yb:YAG crystal, 10 at.% Yb/Y, 3 mm long) and saturable absorber (V:YAG crystal, 2 mm long, initial transmission 86 % @ 1031 nm). The microchip resonator consisted of dielectric mirrors directly deposited on the monolith surfaces (pump mirror HT @ 968 nm and HR @ 1031 nm on Yb:YAG part, output coupler with reflection 55 % @ 1031 nm on the V:YAG part). For longitudinal CW pumping of Yb:YAG part, a fibre coupled (core diameter 100 μm, NA = 0.22, emission @ 968 nm) laser diode was used. The laser threshold was 3.8W. The laser slope efficiency for output mean in respect to incident pumping was 16 %. The linearly polarized generated transversal intensity beam profile was close to the fundamental Gaussian mode. The generated pulse length, stable and mostly independent on pumping power, was equal to 1.3 ns (FWHM). The single pulse energy was increasing with the pumping power and for the maximum pumping 9.7W it was 78 μJ which corresponds to the pulse peak-power 56 kW. The maximum Yb:YAG/V:YAG microchip laser mean output power of 1W was reached without observable thermal roll-over. The corresponding Q-switched pulses repetition rate was 13.1 kHz.

  2. UV-exposed Bragg gratings for laser applications in silver-sodium ion-exchanged phosphate glass waveguides.

    Science.gov (United States)

    Yliniemi, Sanna; Albert, Jacques; Wang, Qing; Honkanen, Seppo

    2006-04-03

    High reflectivity Bragg gratings have been written by ArF excimer laser through a phase mask into IOG-1 hybrid phosphate glass. After grating exposure, a waveguide was fabricated by silver-sodium ion-exchange. Reflectivities around 80% at a wavelength of ~ 1535 nm were measured from the waveguide for both quasi-TE and -TM polarizations. Waveguide laser operation with the photowritten waveguide grating as another mirror was demonstrated. Output power of 3.8 mW with a pump power of 199 mW could be extracted from the laser configuration.

  3. Monolithic electrically injected nanowire array edge-emitting laser on (001) silicon

    KAUST Repository

    Frost, Thomas

    2014-08-13

    A silicon-based laser, preferably electrically pumped, has long been a scientific and engineering goal. We demonstrate here, for the first time, an edge-emitting InGaN/GaN disk-in-nanowire array electrically pumped laser emitting in the green (λ = 533 nm) on (001) silicon substrate. The devices display excellent dc and dynamic characteristics with values of threshold current density, differential gain, T0 and small signal modulation bandwidth equal to 1.76 kA/cm2, 3 × 10-17 cm2, 232 K, and 5.8 GHz respectively under continuous wave operation. Preliminary reliability measurements indicate a lifetime of 7000 h. The emission wavelength can be tuned by varying the alloy composition in the quantum disks. The monolithic nanowire laser on (001)Si can therefore address wide-ranging applications such as solid state lighting, displays, plastic fiber communication, medical diagnostics, and silicon photonics. © 2014 American Chemical Society.

  4. A 1.55-μm laser array monolithically integrated with an MMI combiner

    Institute of Scientific and Technical Information of China (English)

    Ma Li; Zhu Hongliang; Liang Song; Wang Baojun; Zhang Can; Zhao Lingjuan; Bian Jing

    2013-01-01

    The monolithic integration of four 1.55-μm range InGaAsP/InP distributed feedback lasers with a 4 × 1multimode-interference (MMI) optical combiner using the varied width ridge method is proposed and demonstrated.The average output power is 1.5 mW when the current of LD is 100 mA and the threshold current is 30-35 mA at 25 ℃.The lasing wavelength is 1.55-μm range and 40 dB sidemode suppression ratio is obtained.The four channels can operate separately or simultaneously.

  5. Progress in fabrication of waveguide spatial light modulators via femtosecond laser micromachining

    Science.gov (United States)

    Savidis, Nickolaos; Jolly, Sundeep; Datta, Bianca; Moebius, Michael; Karydis, Thrasyvoulos; Mazur, Eric; Gershenfeld, Neil; Bove, V. Michael

    2017-02-01

    We have previously introduced a femtosecond laser micromachining-based scheme for the fabrication of anisotropic waveguides in lithium niobate for use in a guided-wave acousto-optic spatial light modulator. This spatial light modulation scheme is extensible to off-plane waveguide holography via the integration of a Bragg reflection grating. In this paper, we present femtosecond laser-based direct-write approaches for the fabrication of (1) waveguide in-coupling gratings and (2) volume Bragg reflection gratings via permanent refractive index changes within the lithium niobate substrate. In combination with metal surface-acoustic-wave transducers, these direct-write approaches allow for complete fabrication of a functional spatial light modulator via femtosecond laser direct writing.

  6. Specific features of waveguide recombination in laser structures with asymmetric barrier layers

    DEFF Research Database (Denmark)

    Polubavkina, Yu; Zubov, F. I.; Moiseev, E.

    2017-01-01

    The spatial distribution of the intensity of the emission caused by recombination appearing at a high injection level (up to 30 kA/cm2) in the waveguide layer of a GaAs/AlGaAs laser structure with GaInP and AlGaInAs asymmetric barrier layers is studied by means of near-field scanning optical...... microscopy. It is found that the waveguide luminescence in such a laser, which is on the whole less intense as compared to that observed in a similar laser without asymmetric barriers, is non-uniformly distributed in the waveguide, so that the distribution maximum is shifted closer to the p-type cladding...... layer. This can be attributed to the ability of the GaInP barrier adjoining the quantum well on the side of the n-type cladding layer to suppress the hole transport....

  7. Coherent beam combination of fiber lasers with a strongly confined waveguide: numerical model.

    Science.gov (United States)

    Tao, Rumao; Si, Lei; Ma, Yanxing; Zhou, Pu; Liu, Zejin

    2012-08-20

    Self-imaging properties of fiber lasers in a strongly confined waveguide (SCW) and their application in coherent beam combination (CBC) are studied theoretically. Analytical formulas are derived for the positions, amplitudes, and phases of the N images at the end of an SCW, which is important for quantitative analysis of waveguide CBC. The formulas are verified with experimental results and numerical simulation of a finite difference beam propagation method (BPM). The error of our analytical formulas is less than 6%, which can be reduced to less than 1.5% with Goos-Hahnchen penetration depth considered. Based on the theoretical model and BPM, we studied the combination of two laser beams based on an SCW. The effects of the waveguide refractive index and Gaussian beam waist are studied. We also simulated the CBC of nine and 16 fiber lasers, and a single beam without side lobes was achieved.

  8. Propagation of a laser beam in a time-varying waveguide. [plasma heating for controlled fusion

    Science.gov (United States)

    Chapman, J. M.; Kevorkian, J.

    1978-01-01

    The propagation of an axisymmetric laser beam in a plasma column having a radially parabolic electron density distribution is reported. For the case of an axially uniform waveguide it is found that the basic characteristics of alternating focusing and defocusing beams are maintained. However, the intensity distribution is changed at the foci and outer-beam regions. The features of paraxial beam propagation are discussed with reference to axially varying waveguides. Laser plasma coupling is considered noting the case where laser heating produces a density distribution radially parabolic near the axis and the energy absorbed over the focal length of the plasma is small. It is found that: (1) beam-propagation stability is governed by the relative magnitude of the density fluctuations existing in the axial variation of the waveguides due to laser heating, and (2) for beam propagation in a time-varying waveguide, the global instability of the propagation is a function of the initial fluctuation growth rate as compared to the initial time rate of change in the radial curvature of the waveguide.

  9. Planar waveguide amplifiers and laser in erbium doped silica

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas; Kristensen, Martin

    1999-01-01

    The objective of this work was to develop optically amplifying planar waveguides, using erbium-doped germano-silicate glass films deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition). The waveguides should exhibit enough gain to be useful as optical amplifiers in integrated planar...... fluorescence level. In addition the first measurement of the diffusion coefficient of erbim in silica is presented and it is shown that erbium rich precipitates are formed in areas of high erbium concentration. The manufacturing of planar waveguide structures using RIE (Reactive Ion Etching) is described...... and it is shown that sidewall roughness resulting from micro masking by non-volatile reaction products can be minimised through a careful choice of etching parameters. This results in low propagation loss for the fabricated waveguides. It is shown that the achievable population inversion depends on the eribum...

  10. Monolithic translucent BaMgAl10O17:Eu2+ phosphors for laser-driven solid state lighting

    Directory of Open Access Journals (Sweden)

    Clayton Cozzan

    2016-10-01

    Full Text Available With high power light emitting diodes and laser diodes being explored for white light generation and visible light communication, thermally robust encapsulation schemes for color-converting inorganic phosphors are essential. In the current work, the canonical blue-emitting phosphor, high purity Eu-doped BaMgAl10O17, has been prepared using microwave-assisted heating (25 min and densified into translucent ceramic phosphor monoliths using spark plasma sintering (30 min. The resulting translucent ceramic monoliths convert UV laser light to blue light with the same efficiency as the starting powder and provide superior thermal management in comparison with silicone encapsulation.

  11. 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....

  12. Monolithic translucent BaMgAl10O17:Eu2+ phosphors for laser-driven solid state lighting

    Science.gov (United States)

    Cozzan, Clayton; Brady, Michael J.; O'Dea, Nicholas; Levin, Emily E.; Nakamura, Shuji; DenBaars, Steven P.; Seshadri, Ram

    2016-10-01

    With high power light emitting diodes and laser diodes being explored for white light generation and visible light communication, thermally robust encapsulation schemes for color-converting inorganic phosphors are essential. In the current work, the canonical blue-emitting phosphor, high purity Eu-doped BaMgAl10O17, has been prepared using microwave-assisted heating (25 min) and densified into translucent ceramic phosphor monoliths using spark plasma sintering (30 min). The resulting translucent ceramic monoliths convert UV laser light to blue light with the same efficiency as the starting powder and provide superior thermal management in comparison with silicone encapsulation.

  13. Low-Loss Hollow Waveguide Fibers for Mid-Infrared Quantum Cascade Laser Sensing Applications

    Directory of Open Access Journals (Sweden)

    James A. Harrington

    2013-01-01

    Full Text Available We report on single mode optical transmission of hollow core glass waveguides (HWG coupled with an external cavity mid-IR quantum cascade lasers (QCLs. The QCL mode results perfectly matched to the hybrid HE11 waveguide mode and the higher losses TE-like modes have efficiently suppressed by the deposited inner dielectric coating. Optical losses down to 0.44 dB/m and output beam divergence of ~5 mrad were measured. Using a HGW fiber with internal core size of 300 µm we obtained single mode laser transmission at 10.54 µm and successful employed it in a quartz enhanced photoacoustic gas sensor setup.

  14. Low-loss hollow waveguide fibers for mid-infrared quantum cascade laser sensing applications.

    Science.gov (United States)

    Patimisco, Pietro; Spagnolo, Vincenzo; Vitiello, Miriam S; Scamarcio, Gaetano; Bledt, Carlos M; Harrington, James A

    2013-01-21

    We report on single mode optical transmission of hollow core glass waveguides (HWG) coupled with an external cavity mid-IR quantum cascade lasers (QCLs). The QCL mode results perfectly matched to the hybrid HE(11) waveguide mode and the higher losses TE-like modes have efficiently suppressed by the deposited inner dielectric coating. Optical losses down to 0.44 dB/m and output beam divergence of ~5 mrad were measured. Using a HGW fiber with internal core size of 300 µm we obtained single mode laser transmission at 10.54 µm and successful employed it in a quartz enhanced photoacoustic gas sensor setup.

  15. Laser ablation- and plasma etching-based patterning of graphene on silicon-on-insulator waveguides.

    Science.gov (United States)

    Van Erps, Jürgen; Ciuk, Tymoteusz; Pasternak, Iwona; Krajewska, Aleksandra; Strupinski, Wlodek; Van Put, Steven; Van Steenberge, Geert; Baert, Kitty; Terryn, Herman; Thienpont, Hugo; Vermeulen, Nathalie

    2015-10-05

    We present a new approach to remove monolayer graphene transferred on top of a silicon-on-insulator (SOI) photonic integrated chip. Femtosecond laser ablation is used for the first time to remove graphene from SOI waveguides, whereas oxygen plasma etching through a metal mask is employed to peel off graphene from the grating couplers attached to the waveguides. We show by means of Raman spectroscopy and atomic force microscopy that the removal of graphene is successful with minimal damage to the underlying SOI waveguides. Finally, we employ both removal techniques to measure the contribution of graphene to the loss of grating-coupled graphene-covered SOI waveguides using the cut-back method.

  16. Low-repetition rate femtosecond laser writing of optical waveguides in water-white glass slides.

    Science.gov (United States)

    Lazcano, H E; Vázquez, G V

    2016-04-20

    Energy dose ranges for fabrication of subsurface and ablated ridge waveguides were defined using a low repetition rate femtosecond laser. The waveguides were written along the width of water-white glass slides. The buried waveguides written between 0.23 and 0.62  μJ/μm3 energy dose show strong guidance at 633 nm, reaching in the best cases propagation losses of 0.7 dB/cm. Meanwhile, the ridge waveguides were fabricated between 2.04 and 31.9  μJ/μm3, with a best case of 3.1 dB/cm. Outcomes of this study are promising for use in the manufacturing of sensing devices.

  17. Characterization and estimation of refractive index profile of laser-written photopolymer optical waveguides

    Science.gov (United States)

    Dinleyici, Mehmet Salih; Sümer, Can

    2011-10-01

    In this study, channel waveguides fabricated in photopolymer films by direct-writing using a low-power CW laser, are used as phase objects in a simple plane-wave diffraction setup, and the refractive index modulation profiles of the waveguides are characterized using the recorded diffraction patterns. Index profiles are modeled by piece-wisely combining two Gaussian functions representing the central and the tail regions. Measured diffraction patterns are matched with patterns generated using the model. This simple model makes it possible to design various channel waveguides embedded into polymer substrates. The proposed model is tested on three distinctive waveguide profiles written on the same Acrylamide/Polyvinyl Alcohol based photopolymer with different exposures.

  18. Laser Scanning of a Monolithic Column during Processing in Middle Egypt

    Science.gov (United States)

    Ajioka, O.; Hori, Y.

    2011-09-01

    From ancient quarries around Akoris in Middle Egypt, which belong to the Ptolemaic and Roman periods, the stone blocks could be carried to the working area located in the outside of the city. Those blocks included a giant monolithic column measured approximately 14m in length, which had been cracked for reasons unknown and must have contributed to disuse of monolith. The first deal is a comparison of plans drawn by the point clouds by laser scanning with those coming from plane-tabling, which had been one of popular methods for measuring in the last century. This part shows how the laser scanning technology is useful in far better measuring and documentation of the site. The second discuss is about a detailed assessment of the procedure of processing through the observation of chisel marks and the detail analysis about the 3 dimensional data. In the result, we are succeed to show the restoration of the procedure of the proceedings using guidelines and a wooden curve since we concentrate attention on the point of abstracting the centre line and shaving the surface into the round shape.

  19. Multi-gigahertz repetition rate ultrafast waveguide lasers mode-locked with graphene saturable absorbers

    Science.gov (United States)

    Obraztsov, P. A.; Okhrimchuk, A. G.; Rybin, M. G.; Obraztsova, E. D.; Garnov, S. V.

    2016-08-01

    We report the development of an approach to build compact waveguide lasers that operate in the stable fundamental mode-locking regime with multigigahertz repetition rates. The approach is based on the use of depressed cladding multi- or single-mode waveguides fabricated directly in the active laser crystal using the femtosecond laser inscription method and a graphene saturable absorber. Using this approach we achieve the stable self-starting mode-locking operation of a diode-pumped waveguide Nd:YAG laser that delivers picosecond pulses at a repetition rate of up to 11.5 GHz with an average power of 12 mW at a central wavelength of 1064 nm. The saturable absorbers are formed through the chemical vapor deposition of single-layer graphene on the output coupler mirror or directly on the end facet of the laser crystal. The stable self-starting mode-locking operation is achieved by controlling the group delay dispersion in the laser cavity with an intracavity interferometer. The method developed for the creation of compact ultrashort pulse laser generators with gigahertz repetition rates can be extended further and applied for the development of compact high-repetition rate lasers that operate at a wide range of IR wavelengths.

  20. Multi-criteria optimization in CO2 laser ablation of multimode polymer waveguides

    Science.gov (United States)

    Tamrin, K. F.; Zakariyah, S. S.; Sheikh, N. A.

    2015-12-01

    High interconnection density associated with current electronics products poses certain challenges in designing circuit boards. Methods, including laser-assisted microvia drilling and surface mount technologies for example, are being used to minimize the impacts of the problems. However, the bottleneck is significantly pronounced at bit data rates above 10 Gbit/s where losses, especially those due to crosstalk, become high. One solution is optical interconnections (OI) based on polymer waveguides. Laser ablation of the optical waveguides is viewed as a very compatible technique with ultraviolet laser sources, such as excimer and UV Nd:YAG lasers, being used due to their photochemical nature and minimal thermal effect when they interact with optical materials. In this paper, the authors demonstrate the application of grey relational analysis to determine the optimized processing parameters concerning fabrication of multimode optical polymer waveguides by using infra-red 10.6 μm CO2 laser micromachining to etch acrylate-based photopolymer (Truemode™). CO2 laser micromachining offers a low cost and high speed fabrication route needed for high volume productions as the wavelength of CO2 lasers can couple well with a variety of polymer substrates. Based on the highest grey relational grade, the optimized processing parameters are determined at laser power of 3 W and scanning speed of 100 mm/s.

  1. Widely Tunable Monolithic Mid-Infrared Quantum Cascade Lasers Using Super-Structure Grating Reflectors

    Directory of Open Access Journals (Sweden)

    Dingkai Guo

    2016-05-01

    Full Text Available A monolithic, three-section, and widely tunable mid-infrared (mid-IR quantum cascade laser (QCL is demonstrated. This electrically tuned laser consists of a gain section placed between two super structure grating (SSG distributed Bragg reflectors (DBRs. By varying the injection currents to the two grating sections of this device, its emission wavelength can be tuned from 4.58 μm to 4.77 μm (90 cm−1 with a supermode spacing of 30 nm. This type of SSG-DBR QCLs can be a compact replacement for the external cavity QCL. It has great potential to achieve gap-free and even further tuning ranges for sensor applications.

  2. Diffraction coupled phase-locked arrays of quantum cascade lasers with monolithically integrated Talbot cavities

    CERN Document Server

    Wang, Lei; Jia, Zhi-Wei; Zhao, Yue; Liu, Chuan-Wei; Liu, Ying-Hui; Zhai, Shen-Qiang; Zhuo, Ning; Liu, Feng-Qi; Xu, Xian-Gang

    2016-01-01

    Diffraction coupled arrays of quantum cascade laser are presented. The phase-locked behavior is achieved through monolithic integration of a Talbot cavity at one side of the laser array. The principle is based on fractional Talbot effect. By controlling length of Talbot cavity to be a quarter of Talbot distance (Zt/4), in-phase mode operation is selected. Measured far-field radiation patterns reflect stable in-phase mode operation under different injection currents, from threshold current to full power current. Diffraction-limited performance is shown from the lateral far-field, where three peaks can be obtained and main peak and side peak interval is 10.5{\\deg}. The phase-locked arrays with in-phase mode operation may be a feasible solution to get higher output power and maintain well beam quality meanwhile.

  3. 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

    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......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...... 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...

  4. Optically amplifying planar glass waveguides: Laser on a chip

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas

    The objective of this work was to devlop optically amplifying planar wavguides, using erbium-doped germano-silicate glass films deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition). The waveguides should exhibit enough gain to be useful as optical amplifiers in integrated planar...... fluoresence level. In addition the first measurement of the diffusion coefficient of erbium in silica is presented and it is shown that eribum rich precipitaties are formed in areas of high erbium concentration. The manufacturing of planar waveguide structures using RIE (Reactive Ion Etching) is described...... and it is shown that sidewall roughness resulting from micro masking by non-volatile reaction products can be minimised through a carful choice of etching parameters. This results in low propagation loss for the fabricated waveguides. It is shown that the achivable population inversion depends on the erbium...

  5. Development of monolith Nd:YAG /Cr+4:YAG passively Q-switched microchip laser

    Science.gov (United States)

    Izhnin, Ihor; Vakiv, Mykola; Izhnin, Aleksandr; Syvorotka, Igor; Ubizskii, Sergii; Syvorotka, Ihor, Jr.

    2005-09-01

    The main features of passively Q-switched microchip lasers development are considered. The active medium of laser is an epitaxial structure combining an epitaxial layer of saturable absorber Cr4+:Y3Al5O12 (Cr:YAG) grown on substrate of generating crystal Nd:YAG by liquid phase epitaxy. The modulator layer has an initial optical absorption of 36 cm-1 at wavelength of lasing (1064 nm). The epitaxial layer grown on unworking side was mechanically removed and this substrate side was optically polished. The other one was processed precisely to needed thickness. The cavity's mirrors were deposited by electron beam technique directly on each side of the structure to form a rugged, monolithic resonator. Diode laser Model ATC-C4000 with lasing wavelength 808 nm provided the CW end pumping. The output pulses parameters were investigated by means of test bench consisting of photoelectric transducer FEK-15 and Digital Phosphor Oscilloscope TDS 5052B. The obtained laser parameter are as follows: pulse width (FWHM) about 1.3 ns, repetition rate 5.5 kHz, average output power about 10 mW, pulse energy 1.0 μJ, pick power 1.2 kW. The possible solutions for laser parameter improving and optimization are discussed.

  6. Analog characterization of a Franz-Keldysh electroabsorption modulator monolithically integrated with a DFB laser

    Science.gov (United States)

    Oennegren, Jan; Svedin, Jan; Sahlen, Olof; Jansson, Mats; Alping, Arne G.

    1995-10-01

    Electroabsorption modulators (EA) are attractive components for very high speed digital links (up to 40 Gbit/s). The objective of the present work has been to evaluate the analog performance and use of a Franz Keldysh modulator (FK) monolithically integrated with a DFB laser (DFB/FK-modulator) operating at 1550 nm. This DFB/FK-modulator is a combination of a directly modulated laser diode and an external modulator in one chip. The analog performance is therefore depending on both the modulator bias voltage and DFB-laser bias current. The normal optical output characteristic from an EA-modulator has a strongly nonlinear behavior. The modulator described in this paper shows for low bias voltage and/or high laser current a linear bahavior. This linear behavior is mainly due to the hole pile-up effect at the p/i-interface of the modulator. In digital transmission system this hole pile-up effect is a disadvantage, but in an analog transmission system it can be used to achieve better analog performance. Measurements (and simulations) on the DFB/FK-modulator show that its analog performance competes well with direct modulated FP and DFB lasers, especially if the modulator is biased for optimum analog performance.

  7. Ultrafast Laser Pulses for Structuring Materials at Micro/Nano Scale: From Waveguides to Superhydrophobic Surfaces

    Directory of Open Access Journals (Sweden)

    Daniel S. Correa

    2017-01-01

    Full Text Available The current demand for fabricating optical and photonic devices displaying high performance, using low-cost and time-saving methods, prompts femtosecond (fs-laser processing as a promising methodology. High and low repetition femtosecond lasers enable surface and/or bulk modification of distinct materials, which can be used for applications ranging from optical waveguides to superhydrophobic surfaces. Herein, some fundamental aspects of fs-laser processing of materials, as well as the basics of their most common experimental apparatuses, are introduced. A survey of results on polymer fs-laser processing, resulting in 3D waveguides, electroluminescent structures and active hybrid-microstructures for luminescence or biological microenvironments is presented. Similarly, results of fs-laser processing on glasses, gold and silicon to produce waveguides containing metallic nanoparticles, analytical chemical sensors and surface with modified features, respectively, are also described. The complexity of fs-laser micromachining involves precise control of material properties, pushing ultrafast laser processing as an advanced technique for micro/nano devices.

  8. Monolithically integrated multi-wavelength MQW-DBR laser diodes fabricated by selective metalorganic vapor phase epitaxy

    Science.gov (United States)

    Sasaki, Tatsuya; Yamaguchi, Masayuki; Kitamura, Mitsuhiro

    1994-12-01

    Selective metalorganic vapor phase epitaxy (MOVPE) was used to grow InGaAsP/InP layers for fabricating multi-wavelength laser diodes. Multiple quantum well (MQW) active and passive waveguides were simultaneously grown by one step selective growth. The selectively grown layer thickness increases with the mask stripe width. This growth enhancement can be used to control the lasing wavelength of distributed Bragg reflector (DBR) laser diodes, because the effective refractive index of the MQW passive waveguide at the DBR region can be controlled by the mask stripe width. This simple technique was used to fabricate multi-wavelength MQW-DBR laser diodes. In the selective growth, the MQW structure was grown under 150 Torr to obtain large bandgap energy shift for the MQW passive waveguides compared to the active waveguide, which was effective for wide wavelength tuning range. On the contrary, a bulk InGaAsP guide layer was grown under 35 Torr to prevent too much composition shift and maintain high crystalline quality of the MQW passive waveguide. For 10 consecutive laser diodes, a wavelength span of over 20 nm with accurate wavelength control was achieved.

  9. Life problems of dc and RF-excited low-power CW CO2 waveguide lasers

    Science.gov (United States)

    Hochuli, U. E.; Haldemann, P. R.

    1986-01-01

    A number of different, RF-excited 3-W CW CO2 waveguide lasers have been built. Four of these lasers, after continuously working for 15,000-30,000 h, still yield about 70 percent of their original power output. The design variations cover N2and CO-bearing gas mixtures, as well as internal- and external-capacitively coupled excitation electrodes. A similar laser survived 50,000 5-min-ON/5-min-OFF cycles without significant mirror damage. It was not possible to find suitable cold cathodes that allow the building of longitudinally dc-excited CW CO2 waveguide lasers that work for such extended periods of time.

  10. High-power single-transverse-mode ridge optical waveguide semiconductor lasers

    NARCIS (Netherlands)

    Popovichev, VV; Davydova, EI; Marmalyuk, AA; Simakov, A; Uspenskii, MB; Chel'nyi, AA; Bogatov, AP; Drakin, AE; Plisyuk, SA; Sratonnikov, AA

    2002-01-01

    More than 200 mW of a single-transverse-mode cw output power is obtained from a semiconductor heterolaser by optimising the waveguide properties of its ridge structure. e laser-beam divergence is close to the diffraction limit and its brightness exceeds 5 x 10(7) W cm(-2) sr(-1). The calculated and

  11. Rare-earth activated potassium double tungstate waveguide amplifiers and lasers

    NARCIS (Netherlands)

    García Blanco, Sonia Maria; Geskus, D.; van Dalfsen, Koop; Aravazhi, S.; Pollnau, Markus

    Several fields, including optical communications, bio-sensing, health, and safety, will greatly benefit from on-chip high-gain amplifiers and high-power, compact, efficient, tunable or short-pulse lasers in channel waveguide geometry. The rare-earth (RE) doped potassium double tungstates KY(WO4)2,

  12. THEORETICAL STUDIES ON HIGH POWERED RADIO-FREQUENCY TRANSVERSE-EXCITED WAVEGUIDE ATOMIC GAS LASERS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    @@ By solving the extended Boltzmann equation and the electron number balance equation,we obtained the electron energy distribution functions(EEDFs)and the electronic excitation rates in the discharge of the radio-frequency(RF)transverse-excited intermediate pressure waveguide heliumneon laser.

  13. Efficient channel waveguide lasers in monoclinic double tungstates: towards further integration with on-chip mirrors

    NARCIS (Netherlands)

    van Dalfsen, Koop; van Wolferen, Hendricus A.G.M.; Dijkstra, Mindert; Aravazhi, S.; Bernhardi, Edward; García Blanco, Sonia Maria; Pollnau, Markus

    2012-01-01

    By varying the thulium concentration in the range of 1.5 – 8.0 at.% in thulium- gadolinium-lutetium-yttrium-co-doped monoclinic double tungstate channel waveguides, a maximum laser slope efficiency of 70% with respect to the absorbed pump power was obtained. Further integration of these channel

  14. Pulse width tunable subpicosecond pulse generation from an actively modelocked monolithic MQW laser/MQW electroabsorption modulator

    Science.gov (United States)

    Takada, A.; Sato, K.; Saruwatari, M.; Yamamoto, M.

    1994-05-01

    Actively modelocked pulses are generated from a 1.59 micron MQW laser integrated with an MQW electroabsorption modulator driven at the monolithic cavity frequency. The pulse width is controlled from 39 ps to 0.55 ps by changing the inverse bias voltage applied to the electroabsorption modulator and by linear pulse compression using a fiber.

  15. ytterbium- & erbium-doped silica for planar waveguide lasers & amplifiers

    DEFF Research Database (Denmark)

    Dyndgaard, Morten Glarborg

    2001-01-01

    fabricated using plasma enhanced chemical vapor deposition (PECVD) and reactive ion etching (RIE). These processes and the control of the film composition is discussed. Ytterbium doped planar waveguides are demonstrated, and it is shown that codoping with aluminium has a positive influence...

  16. 3.1 kW monolithic MOPA configuration fibre laser bidirectionally pumped by non-wavelength-stabilized laser diodes

    Science.gov (United States)

    Yan, Ping; Huang, Yusheng; Sun, Junyi; Li, Dan; Wang, Xuejiao; Gong, Mali; Xiao, Qirong

    2017-08-01

    We report an all-fibre monolithic master oscillator power amplifier configuration fibre laser bidirectionally pumped by non-wavelength-stabilized laser diodes. The Raman Effect and thermal problems can be effectively suppressed by the bidirectional pumping configuration. A small core diameter double-clad ytterbium-doped fibre is utilized in the amplifier for a refined beam quality control. As a result, a maximum output power of 3122 W and an optical-to-optical efficiency of 81.4% are achieved with near-diffraction-limitation beam quality. No mode instability was detected via a photodiode. Also, the output power instability was measured to be less than 0.6% during a continuous operation of 2 h.

  17. Fabrication of polarization-independent single-mode waveguides in lithium niobate crystal with femtosecond laser pulses

    CERN Document Server

    Qi, Jia; Liao, Yang; Chu, Wei; Liu, Zhengming; Wang, Zhaohui; Qiao, Lingling; Cheng, Ya

    2016-01-01

    We report on fabrication of depressed cladding optical waveguides buried in lithium niobate crystal with shaped femtosecond laser pulses. Depressed cladding waveguides of variable mode-field sizes are fabricated by forming the four sides of the cladding using a slit-beam shaping technique. We show that the waveguides fabricated by our technique allows single-mode propagation of the light polarized in both vertical and horizontal directions.

  18. Optical spectroscopy in channel waveguides made in Nd:YAG crystals by femtosecond laser writing

    Energy Technology Data Exchange (ETDEWEB)

    Torchia, G.A. [Grupo de Optica, Departamento de Fisica Aplicada, Universidad de Salamanca, Plaza de la Merced s/n, 37008 Salamanca (Spain); Centro de Investigaciones Opticas (CIOp), CIC-Conicet, CC 124 La Plata (1900) (Argentina)], E-mail: gtorchia@usal.es; Mendez, C.; Roso, L. [Grupo de Optica, Departamento de Fisica Aplicada, Universidad de Salamanca, Plaza de la Merced s/n, 37008 Salamanca (Spain); Tocho, J.O. [Centro de Investigaciones Opticas (CIOp), CIC-Conicet, CC 124 La Plata (1900) (Argentina)

    2008-05-15

    In this work, we present an optical characterization of channel waveguides fabricated by means of femtosecond laser writing on Nd:YAG substrates. These guiding structures show a refractive index increment of about 1x10{sup -3} which allows TE propagation. By pumping with a CW solid-state laser at 532 nm reaching the {sup 2}G{sub 9/2} and {sup 4}G{sub 7/2} manifolds of Nd{sup 3+} ions, we have explored the emission band corresponding to {sup 4}F{sub 3/2}{yields}{sup 4}I{sub 9/2} optical transitions (peaked at 890 nm). From data, we have found that emission showed similar characteristics for waveguide and bulk. On the other hand, the lifetime corresponding to the {sup 4}F{sub 3/2} metaestable level was determined to be 240 {mu}s for bulk and waveguide. Summarizing, we have made suitable channel waveguides in Nd:YAG crystals, by fs interaction, with similar spectroscopic properties to those of the bulk, a fact that boosters the photonics application of these devices. For the first time to our knowledge, a direct index increment waveguide made by interaction with ultra-short intense pulses in YAG crystals has been performed. This fabrication procedure can be an efficient tool to make several optical circuits in active materials by means of the one-step, fast and low-cost processing.

  19. Red emitting monolithic dual wavelength DBR diode lasers for shifted excitation Raman difference spectroscopy

    Science.gov (United States)

    Sumpf, B.; Maiwald, M.; Müller, A.; Bugge, F.; Fricke, J.; Ressel, P.; Pohl, J.; Erbert, G.; Tränkle, G.

    2014-02-01

    Raman lines are often obscured by background light or fluorescence especially when investigating biological samples or samples containing impurities. Shifted excitation Raman difference spectroscopy (SERDS) is a technique to overcome this. By exciting the sample with two slightly shifted wavelengths, it is possible to separate the Raman lines and distortions. In this paper, monolithic dual wavelength DBR diode lasers meeting the demands of Raman spectroscopy and SERDS will be presented. The wavelengths are stabilized and selected by using deeply-etched 10th order surface gratings with different periods manufactured using i-line wafer stepper lithography. Two possible resonator concepts, i.e. a mini-array of two parallel DBR RW-lasers and a Y-branch DBR laser, will be compared. Established excitation wavelengths for Raman spectroscopy at 671 nm and 785 nm are chosen. The total laser length is 3 mm; the ridge width is 2.2 μm for the 785 nm devices and 5 μm for the 671 nm lasers. The length of the DBR gratings is 500 μm. The devices at 671 nm reach output powers up to 100 mW having an emission width smaller than 12 pm (FWHM). The 785 nm lasers show output powers up to 200 mW and a narrow emission below 22 pm. For the dual wavelength lasers the spectral distance between the two excitation lines is about 0.5 nm as targeted. The power consumption at both wavelengths is below 1 W. These data proof that the devices are well suited for their application in portable Raman measurement systems such as handheld devices using SERDS.

  20. Fifty percent internal slope efficiency femtosecond direct-written Tm³⁺:ZBLAN waveguide laser.

    Science.gov (United States)

    Lancaster, D G; Gross, S; Ebendorff-Heidepriem, H; Kuan, K; Monro, T M; Ams, M; Fuerbach, A; Withford, M J

    2011-05-01

    We report a 790 nm pumped, Tm³⁺ doped ZBLAN glass buried waveguide laser that produces 47 mW at 1880 nm, with a 50% internal slope efficiency and an M² of 1.7. The waveguide cladding is defined by two overlapping rings created by femtosecond direct-writing of the glass, which results in the formation of a tubular depressed-index-cladding structure, and the laser resonator is defined by external dielectric mirrors. This is, to the best of our knowledge, the most efficient laser created in a glass host via femtosecond waveguide writing.

  1. Q-switched waveguide laser based on two-dimensional semiconducting materials: tungsten disulfide and black phosphorous.

    Science.gov (United States)

    Tan, Yang; Guo, Zhinan; Ma, Linan; Zhang, Han; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng

    2016-02-01

    Owing to their unique properties, graphene-like two dimensional semiconducting materials, including Tungsten Disulfide (WS2) and Black Phosphorous (BP), have attracted increasing interest from basic research to practical applications. Herein, we demonstrated the ultrafast nonlinear saturable absorption response of WS2 and BP films in the waveguide structure. Through fabricating WS2 and BP films by evaporating the solutions on glass wafers. Saturable absorber films were attached onto the end-facet of the waveguide, which therefore constitutes a resonant cavity for the waveguide laser. Under a pump laser at 810 nm, we could obtain a stable Q-switched operation in the waveguide structure. This work indicated the significant potential of WS2 and BP for the ultrafast waveguide laser.

  2. Efficient second harmonic generation of a diode-laser-pumped CW Nd:YAG laser using monolithic MgO:LiNbO3 external resonant cavities

    Science.gov (United States)

    Kozlovsky, William J.; Nabors, C. D.; Byer, Robert L.

    1988-01-01

    56-percent efficient external-cavity-resonant second-harmonic generation of a diode-laser pumped, CW single-axial-mode Nd:YAG laser is reported. A theory of external doubling with a resonant fundamental is presented and compared to experimental results for three monolithic cavities of nonlinear MgO:LiNbO3. The best conversion efficiency was obtained with a 12.5-mm-long monolithic ring cavity doubler, which produced 29.7 mW of CW, single-axial model 532-nm radiation from an input of 52.5 mW.

  3. Planar Bragg gratings made by excimer-laser modification of ion-exchanged waveguides.

    Science.gov (United States)

    Montero, C; Gomez-Reino, C; Brebner, J L

    1999-11-01

    The refractive indices of planar silver-ion-exchanged waveguides have been modified by UV excimer laser irradiation (lambda=193 nm) . The effective index changes of the fundamental modes of the waveguides after exposition are as large as 2x10(-2) . The procedure permits the fabrication of integrated optical components in a direct way, with neither the use of standard lithography nor previous sensitizing of the substrate. Optical characterization of the irradiated samples is presented. By the use of appropriate masks, we have fabricated planar Bragg gratings.

  4. Femtosecond laser fabrication of phase-shifted Bragg grating waveguides in fused silica.

    Science.gov (United States)

    Grenier, Jason R; Fernandes, Luís A; Aitchison, J Stewart; Marques, Paulo V S; Herman, Peter R

    2012-06-15

    Phase-shifted Bragg grating waveguides (PSBGWs) were formed in bulk fused silica glass by femtosecond laser direct writing to produce narrowband (22±3)  pm filters at 1550 nm. Tunable π and other phase shifts generated narrow passbands in controlled positions of the Bragg stopband, while the accurate placement of multiple cascaded phase-shift regions yielded a rectangular-shaped bandpass filter. A waveguide birefringence of (7.5±0.3)×10(-5) is inferred from the polarization-induced spectral shifting of the PSBGW narrowband filters.

  5. Passively mode-locked fiber laser based on polarization rotation in a multiple-quantum-well waveguide.

    Science.gov (United States)

    Okhotnikov, O G; Salcedo, J R

    1995-01-01

    We give experimental evidence for a new type of mode-locking mechanism for Er-doped fiber lasers based on polarization evolution in an intracavity multiple-quantum-well waveguide. Experiments indicate that anisotropic properties of waveguides can continuously start the mode-locking process.

  6. Broadband single-transverse-mode fluorescence sources based on ribs fabricated in pulsed laser deposited Ti: sapphire waveguides

    NARCIS (Netherlands)

    Grivas, C.; May-Smith, T.C.; Shepherd, D.P.; Eason, R.W.; Pollnau, M.; Jelinek, M.

    2004-01-01

    Active rib waveguides with depths and widths varying from 3 to 5 μm and from 9 to 24 μm, respectively, have been structured by $Ar^{+}$-beam etching in pulsed laser deposited Ti:sapphire layers. Losses in the channel structures were essentially at the same levels as the unstructured planar waveguide

  7. Passively Q-switched waveguide lasers based on two-dimensional transition metal diselenide.

    Science.gov (United States)

    Cheng, Chen; Liu, Hongliang; Tan, Yang; Vázquez de Aldana, Javier R; Chen, Feng

    2016-05-16

    We reported on the passively Q-switched waveguide lasers based on few-layer transition metal diselenide, including molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2), as saturable absorbers. The MoSe2 and WSe2 membranes were covered on silica wafers by chemical vapor deposition (CVD). A low-loss depressed cladding waveguide was produced by femtosecond laser writing in a Nd:YAG crystal. Under optical pump at 808 nm, the passive Q-switching of the Nd:YAG waveguide lasing at 1064 nm was achieved, reaching maximum average output power of 115 mW (MoSe2) and 45 mW (WSe2), respectively, which are corresponding to single-pulse energy of 36 nJ and 19 nJ. The repetition rate of the Q-switched waveguide lasers was tunable from 0.995 to 3.334 MHz (MoSe2) and 0.781 to 2.938 MHz (WSe2), and the obtained minimum pulse duration was 80ns (MoSe2) and 52 ns (WSe2), respectively.

  8. Radiation from laser-microplasma-waveguide interactions in the ultra-intense regime

    Science.gov (United States)

    Yi, Longqing; Pukhov, Alexander; Shen, Baifei

    2016-07-01

    When a high-contrast ultra-relativistic (>1020 W/cm2) laser beam enters a micro-sized plasma waveguide, the pulse energy is coupled into waveguide modes, which significantly modifies the interaction between the electrons and electromagnetic wave. Electrons pulled out from the walls of the waveguide form a dense helical bunch inside the channel and are efficiently accelerated by the transverse magnetic modes to hundreds of MeV. The asymmetry in the transverse electric and magnetic fields drives strong oscillations, which lead to the emission of bright, well-collimated, hard X-rays. In this paper, we present our study on the underlying physics in the aforementioned process using 3D particle-in-cell simulations. The mechanism of electron acceleration and the dependence of radiation properties on different laser plasma parameters are addressed. An analytic model and basic scalings for X-ray emission are also presented by considering the lowest optical modes in the waveguide, which is adequate to describe the basic phenomenon. In addition, the effects of high-order modes as well as laser polarization are also qualitatively discussed. The considered X-ray source has promising features, potentially making it a competitive candidate for a future tabletop synchrotron source.

  9. Monolithic polymer microcavity lasers with on-top evaporated dielectric mirrors

    Science.gov (United States)

    Persano, Luana; Carro, Pompilio Del; Mele, Elisa; Cingolani, Roberto; Pisignano, Dario; Zavelani-Rossi, Margherita; Longhi, Stefano; Lanzani, Guglielmo

    2006-03-01

    We report on a monolithic polymeric microcavity laser with all dielectric mirrors realized by low-temperature electron-beam evaporation. The vertical heterostructure was realized by 9.5 TiOx/SiOx pairs evaporated onto an active conjugated polymer, that was previously spincast onto the bottom distributed Bragg reflector (DBR). The cavity supports single-mode lasing at 509nm, with a linewidth of 1.8nm, and a lasing threshold of 84μJ/cm2. We also report on the emission properties of the polymer we used, investigated by a pump-probe technique. These results show that low-temperature electron-beam evaporation is a powerful and straightforward fabrication technique for molecular-based fully integrable microcavity resonators.

  10. Green monolithic II-VI vertical-cavity surface-emitting laser operating at room temperature

    Science.gov (United States)

    Kruse, C.; Ulrich, S. M.; Alexe, G.; Roventa, E.; Kröger, R.; Brendemühl, B.; Michler, P.; Gutowski, J.; Hommel, D.

    2004-02-01

    The realization of a monolithic all II-VI-based vertical cavity surface emitting laser (VCSEL) for the green spectral region is reported. Optically pumped lasing operation was achieved up to room temperature using a planar VCSEL structure. Taking advantage of distributed Bragg-reflectors based on MgS/Zn(Cd)Se superlattices as the low-refractive index material and ZnS0.06Se0.94 layers as the high-index material with a refractive index contrast of n = 0.6, a quality factor exceeding Q = 2000 is reached by using only 18 Bragg periods for the bottom DBR and 15 Bragg periods for the top DBR. The threshold power density is 0.32 MW/cm2 at a temperature of 10 K (emission wavelength 498.5 nm) and 1.9 MW/cm2 at room temperature (emission wavelength 502.3 nm).

  11. Monolithic integration of electroabsorption modulator and DFB laser for 10-Gb/s transmission

    Science.gov (United States)

    Zhao, Q.; Pan, J. Q.; Zhang, J.; Li, B. X.; Zhou, F.; Wang, B. J.; Wang, L. F.; Bian, J.; Zhao, L. J.; Wang, W.

    2006-04-01

    A strained InGaAsP-InP multiple-quantum-well DFB laser monolithically integrated with electroabsorption modulator by ultra-low-pressure (22 mbar) selective-area-growth is presented. The integrated chip exhibits superior characteristics, such as low threshold current of 19 mA, single-mode operation around 1550 nm range with side-mode suppression ratio over 40 dB, and larger than 16 dB extinction ratio when coupled into a single-mode fiber. More than 10 GHz modulation bandwidth is also achieved. After packaged in a compact module, the device successfully performs 10-Gb/s NRZ transmission experiments through 53.3 km of standard fiber with 8.7 dB dynamic extinction ratio. A receiver sensitivity of -18.9 dBm at bit-error-rate of 10-10 is confirmed.

  12. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO 2 laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread (~1%) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO2 laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  13. Direct acceleration of electrons by a CO$_{2}$ laser in a curved plasma waveguide

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO$_{2}$ laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread ($\\sim1\\%$) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO$_{2}$ laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  14. NONLINEAR OPTICS: Coherent laser spectroscopy of matter utilizing waveguide structures

    Science.gov (United States)

    Chaus, A. I.; Yashkir, Yu N.

    1990-07-01

    Some features of CARS spectroscopy in waveguide structures are investigated theoretically taking into account stimulated Raman amplification of a weak pump wave in the field of a strong wave and allowing for the phase matching. A four-photon intermode coupling which occurs under amplification conditions results in energy diffusion between different modes. General expressions for the intensities of the pump waves undergoing stimulated amplification and for the anti-Stokes signal are derived and analyzed.

  15. Structural, mechanical and optical studies on ultrafast laser inscribed chalcogenide glass waveguide

    Science.gov (United States)

    Ayiriveetil, Arunbabu; Varma, G. Sreevidya; Chaturvedi, Abhishek; Sabapathy, Tamilarasan; Ramamurty, Upadrasta; Asokan, Sundarrajan

    2017-04-01

    Multi-scan waveguides have been inscribed in GeS2 glass sample with different pulse energies and translation speeds. Mechanical and structural changes on GeS2 binary glass in response to irradiation to 1047 nm femto-second laser pulses have been investigated. The optical characterization of these waveguides has been done at 1550 nm of laser wavelength and the material response to laser exposure is characterized by both nanoindentation studies and micro-Raman spectroscopy. Nanoindentation investigations show a decrease in hardness (H) and elastic modulus (E) upon laser irradiation. The change in E and H are found to be varying with the translational speed, pulse energy and hence the net-fluence at the sample. These changes are correlated with variations in the Raman response of photo-exposed glass which is interpreted in terms of structural modifications made by the laser inscriptions to the glassy network. The mechanical behavior and local structural changes on waveguide writing is found to be dependent on net-fluence and it is correlated with the preparation conditions like melt temperature and cooling rate.

  16. Heuristic modelling of laser written mid-infrared LiNbO3 stressed-cladding waveguides.

    Science.gov (United States)

    Nguyen, Huu-Dat; Ródenas, Airán; Vázquez de Aldana, Javier R; Martínez, Javier; Chen, Feng; Aguiló, Magdalena; Pujol, Maria Cinta; Díaz, Francesc

    2016-04-04

    Mid-infrared lithium niobate cladding waveguides have great potential in low-loss on-chip non-linear optical instruments such as mid-infrared spectrometers and frequency converters, but their three-dimensional femtosecond-laser fabrication is currently not well understood due to the complex interplay between achievable depressed index values and the stress-optic refractive index changes arising as a function of both laser fabrication parameters, and cladding arrangement. Moreover, both the stress-field anisotropy and the asymmetric shape of low-index tracks yield highly birefringent waveguides not useful for most applications where controlling and manipulating the polarization state of a light beam is crucial. To achieve true high performance devices a fundamental understanding on how these waveguides behave and how they can be ultimately optimized is required. In this work we employ a heuristic modelling approach based on the use of standard optical characterization data along with standard computational numerical methods to obtain a satisfactory approximate solution to the problem of designing realistic laser-written circuit building-blocks, such as straight waveguides, bends and evanescent splitters. We infer basic waveguide design parameters such as the complex index of refraction of laser-written tracks at 3.68 µm mid-infrared wavelengths, as well as the cross-sectional stress-optic index maps, obtaining an overall waveguide simulation that closely matches the measured mid-infrared waveguide properties in terms of anisotropy, mode field distributions and propagation losses. We then explore experimentally feasible waveguide designs in the search of a single-mode low-loss behaviour for both ordinary and extraordinary polarizations. We evaluate the overall losses of s-bend components unveiling the expected radiation bend losses of this type of waveguides, and finally showcase a prototype design of a low-loss evanescent splitter. Developing a realistic waveguide

  17. Delivery of 3-5 μm laser radiation by a hollow waveguide

    Science.gov (United States)

    Němec, M.; Jelínková, H.; Miyagi, M.; Iwai, K.; Doroshenko, M.

    2014-04-01

    Radiation delivery is required for various applications—mainly in medicine or industry. Due to the necessity of delivering IR, UV or powerful radiation, its transfer by hollow waveguides was investigated because standard glass fibers cause serious losses. Our special waveguide was based on a fused silica glass capillary tube with an inner silver layer and dielectric film (cyclic olefin polymer (COP)). Three lasers were designed and constructed as mid-infrared sources, namely Er:YAG (2.94 μm), Dy: PbGa2S4 (4.3 μm) and Fe:ZnSe (4.45 μm). The delivered spatial beam profile and transfer capability of 3-5 μm radiation by the COP/Ag hollow glass waveguide were characterized.

  18. Waveguide and articulated arm for Er:YAG laser system: shape and depth of laser cavity in hard dental tissues

    Science.gov (United States)

    Jelinkova, Helena; Dostalova, Tatjana; Miyagi, Mitsunobu; Wang, You; Shi, Yi-Wei; Dolezalova, Libuse; Hamal, Karel; Krejsa, Otakar; Kubelka, Jiri; Prochazka, Stanislav

    1998-04-01

    The aim of our study was to verify the efficiency of delivery systems for Er:YAG laser radiation which could be used in dentistry. The influence of increasing energy and number of pulses on a profile and depth of drilled holes was investigated. Er:YAG laser was operating in a free-running mode, generating a length of pulses 200 microsecond with a maximum energy of 500 mJ. The delivery systems investigated were an articulated arm and a fluorocarbon polymer-coated silver hollow glass waveguide. The prepared hard tissues were a sliced part of enamel, dentine and ivory. The laser radiation was directed on them by focusing optics (CaF2 lens) together with the cooling water to ensure that the tissues will not be burned. For the evaluation of shapes, depth and profiles of the prepared cavities the metallographic microscope, x-ray microtomograph and scanning electron microscope were used. From the results it was observed that the profile and depth of the cavities prepared by the laser radiation delivered by the various systems (waveguide or articulated arm) are not the same. The laser radiation delivered by waveguide produces a larger diameter cavity with a lower depth. The holes are smoother and without side effects.

  19. Monolithic PM Raman fiber laser at 1679 nm for Raman amplification at 1810 nm

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    2013-01-01

    Stimulated Raman scattering (SRS) has been subject to much attention within the field of fiber lasers and amplifiers as it provides an extended wavelength coverage in comparison to rare-earth based devices. Motivated by the projected capacity crunch [1], different approaches are being explored...... demonstrate a monolithic RM Raman fiber laser (RFL), which acts as a pump for a Raman amplifier (RA) at 1810 nm. The lasing wavelength of a RFL, thus also for a RA, can in principle be designed arbitrarily within the entire wavelength range from the Erbium band up to the Thulium/Holmium band...... of OFS PM Raman fiber, with an estimated propagation loss of 0.42/0.46/1.3 dB/km at 1564/1679/1810 nm. The Raman gain coefficient was measured to be gR=2.66/2.35 W-1km-1 at 1679/1810 nm. The laser curve of the RFL is depicted in Fig. 1b, with a slope efficiency of 67 %. The high slope efficiency...

  20. Structured plasma waveguides and deep EUV generation enabled by intense laser-cluster interactions

    Science.gov (United States)

    Layer, Brian David

    Using the unique properties of the interaction between intense, short-pulse lasers and nanometer scale van-der-Waals bonded aggregates (or 'clusters'), modulated waveguides in hydrogen, argon and nitrogen plasmas were produced and extreme ultraviolet (EUV) light was generated in deeply ionized nitrogen plasmas. A jet of clusters behaves as an array of mass-limited, solid-density targets with the average density of a gas. Two highly versatile experimental techniques are demonstrated for making preformed plasma waveguides with periodic structure within a laser-ionized cluster jet. The propagation of ultra-intense femtosecond laser pulses with intensities up to 2 x1017 W/cm2 has been experimentally demonstrated in waveguides generated using both methods, limited by available laser energy. The first uses a 'ring grating' to impose radial intensity modulations on the channel-generating laser pulse, which leads to axial intensity modulations at the laser focus within the cluster jet target. This creates a waveguide with axial modulations in diameter with a period between 35 mum and 2 mm, determined by the choice of ring grating. The second method creates modulated waveguides by focusing a uniform laser pulse within a jet of clusters with ow that has been modulated by periodically spaced wire obstructions. These wires make sharp, stable voids as short as 50 mum with a period as small as 200 mum within waveguides of hydrogen, nitrogen, and argon plasma. The gaps persist as the plasma expands for the full lifetime of the waveguide. This technique is useful for quasi-phase matching applications where index-modulated guides are superior to diameter modulated guides. Simulations show that these 'slow wave' guiding structures could allow direct laser acceleration of electrons, achieving gradients of 80 MV/cm and 10 MV/cm for laser pulse powers of 1.9 TW and 30 GW, respectively. Results are also presented from experiments in which a nitrogen cluster jet from a cryogenically

  1. High-index-contrast multilayer hollow waveguides for mid-IR laser delivery

    Science.gov (United States)

    Melzer, Jeffrey E.; Kendall, Wesley Y.; Harrington, James A.

    2016-03-01

    Hollow glass waveguides (HGWs) have been researched extensively for the efficient transmission of radiation over a broad spectral range spanning from the visible region to the far-IR. One such HGW film structure consists of a metallic substrate with overlaying multilayer dielectric thin film stack of alternating high and low refractive index films. The optical properties of such multilayer thin film stacks are well established and provide a method for developing photonic bandgap fibers with exceptionally low attenuation losses at a desired wavelength. Transmission losses can be minimized in multilayer waveguides through two main approaches; either maximizing the number of alternating layer pairs or maximizing the index contrast between adjacent films. In practice, it has been shown that for liquid-phase deposition-based procedures, the former approach leads to compounding surface and interface roughness, negating the low-loss advantage of a multilayer waveguide. Thus, this research focuses on maximizing index contrast between adjacent dielectrics in an attempt to minimize the number of films required to achieve acceptable transmission characteristics both in theory and in practice. In this study, multilayer waveguides are fabricated using three dielectric materials: silver iodide, lead sulfide, and cyclic olefin copolymer. Through exploitation of their high index contrast, these materials are used to develop low-film-count multilayer waveguides designed for enhanced transmission at both Er:YAG and CO2 laser wavelengths.

  2. Investigation of single lateral mode for 852nm diode lasers with ridge waveguide design

    Science.gov (United States)

    Liu, Chu; Guan, Baolu; Mi, Guoxin; Liao, Yiru; Liu, Zhenyang; Li, Jianjun; Xu, Chen

    2016-11-01

    852nm Narrow linewidth lasers can be widely used in the field of ultra-fine spectrum measurement, Cs atomic clock control, satellite and optical fiber communication and so on. Furthermore, the stability of the single lateral mode is a very important condition to guarantee the narrow linewidth lasers. Here we investigate experimentally the influence of the narrow ridge structure and asymmetrical waveguide design on the stability single lateral mode of an 852nm diode laser. According to the waveguide theoretical analysis, ridge mesa etch depth (Δη , related to the refractive index difference of parallel to the junction) and ridge mesa width (the narrower the more control force to low order mode) are the main elements for lateral modes. In this paper, we designed different structures to investigate and verify major factors for lateral mode by experiment, and to confirm our thought. Finally, the 5μm mesa ridge laser, 800nm etch depth, with groove structure obtains excellent steady single lateral mode output by 150mA operating current and 30°C temperature. The optical spectrum FWHM is 0.5nm and side mode suppression ratio is 27dBm with uncoated. The laser with 1mm cavity length showed the threshold current of 50mA, a lasing wavelength of λ = 852.6nm, slope efficiency of above 0.7mW/mA. We accomplished single lateral mode of ridge waveguide edge-emitting lasers which can also be used as a laser source in the ultra-narrow linewidth external cavity laser system.

  3. Fabrication of polarization-independent waveguides deeply buried in lithium niobate crystal using aberration-corrected femtosecond laser direct writing

    Science.gov (United States)

    Wang, Peng; Qi, Jia; Liu, Zhengming; Liao, Yang; Chu, Wei; Cheng, Ya

    2017-01-01

    Writing optical waveguides with femtosecond laser pulses provides the capability of forming three-dimensional photonic circuits for manipulating light fields in both linear and nonlinear manners. To fully explore this potential, large depths of the buried waveguides in transparent substrates are often desirable to facilitate achieving vertical integration of waveguides in a multi-layer configuration, which, however, is hampered by rapidly degraded axial resolution caused by optical aberration. Here, we show that with the correction of the spherical aberration, polarization-independent waveguides can be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up to 1400 μm, which is more than one order of magnitude deeper than the waveguides written with aberration uncorrected femtosecond laser pulses. Our technique is beneficial for applications ranging from miniaturized nonlinear light sources to quantum information processing. PMID:28112246

  4. Fabrication of polarization-independent waveguides deeply buried in crystal using aberration-corrected femtosecond laser direct writing

    CERN Document Server

    Wang, Peng; Liu, Zhengming; Liao, Yang; Chu, Wei; Cheng, Ya

    2016-01-01

    Writing optical waveguides with femtosecond laser pulses provides the capability of forming three-dimensional photonic circuits for manipulating light fields in both linear and nonlinear manners. To fully explore this potential, large depths of the buried waveguides in transparent substrates are often desirable to facilitate achieving vertical integration of waveguides in a multi-layer configuration, which, however, is hampered by rapidly degraded axial resolution caused by optical aberration. Here, we show that with the correction of the spherical aberration, polarization-independent waveguides can be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up to 1.4 mm, which is more than one order of magnitude deeper than the waveguides written with aberration uncorrected femtosecond laser pulses. Our technique is beneficial for applications ranging from miniaturized nonlinear light sources to quantum information processing.

  5. Direct laser writing of a new type of waveguides in silver containing glasses.

    Science.gov (United States)

    Abou Khalil, Alain; Bérubé, Jean-Philippe; Danto, Sylvain; Desmoulin, Jean-Charles; Cardinal, Thierry; Petit, Yannick; Vallée, Réal; Canioni, Lionel

    2017-09-11

    Direct laser writing in glasses is a growing field of research in photonics since it provides a robust and efficient way to directly address 3D material structuring. Generally, direct laser writing in glasses induces physical modifications such as refractive index changes that have been classified under three different types (Type I, II & III). In a silver-containing zinc phosphate glass, direct laser writing additionally proceeds via the formation of silver clusters at the periphery of the interaction voxel. In this paper, we introduce a novel type of refractive index modification based on the creation of the photo-induced silver clusters allowing the inscription of a new type of optical waveguides. Various waveguides as well as a 50-50 beam splitter were written inside bulk glasses and characterized. The waveguiding properties observed in the bulk of such silver-containing glass samples were further transposed to ribbon shaped fibers made of the same material. Our results pave the way for the fabrication of 3D integrated circuits and fiber sensors with original fluorescent, nonlinear optical and plasmonic properties. The universality of these new findings should further extend in any silver-containing glasses that show similar laser-induced behavior in terms of silver cluster production.

  6. Femtosecond laser writing of Bragg grating waveguide bundles in bulk glass.

    Science.gov (United States)

    Thiel, Markus; Flachenecker, Günter; Schade, Wolfgang

    2015-04-01

    Waveguide bundles in bulk glass materials, consisting of several parallel scans of refractive index modifications, have been generated with a low-repetition femtosecond laser. Additionally, Bragg grating (BG) structures for 840 and 1550 nm have been introduced by segmentation of the central scan. A spectral loss in the transmission signal of >36  dB was achieved at 1550 nm with a second-order Bragg grating waveguide (BGW) in fused silica, which corresponds to an intrinsic grating efficiency of >16  dB/cm. This is to our knowledge the strongest BG structure realized in glass with a femtosecond laser. The BGW were proven to be stable up to a temperature of 250°C in fused silica. The diameter of the waveguide bundles can be adapted very easily for a broad range of wavelengths and have been demonstrated for diameters between 1 and 50 μm. The transmission properties of the waveguide bundles are affected minorly by the insertion of BG structures, which opens the ability for adjusting the BGW for a broad range of wavelength in single-mode or multimode optical circuits. BGW have been realized successfully in fused silica, borosilicate glass (BOROFLOAT 33), and AF 32 eco Thin Glass from Schott.

  7. Vertical coupling of laser glass microspheres to buried silicon nitride ellipses and waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Navarro-Urrios, D., E-mail: daniel.navarrourrios@nano.cnr.it [NEST, Istituto Nanoscienze—CNR and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa I-56127 (Italy); Ramírez, J. M.; Berencén, Y.; Garrido, B. [Departament d' Electrònica, Universitat de Barcelona, Barcelona 08028 (Spain); Capuj, N. E. [Depto. Física, Universidad de la Laguna, 38206, La Laguna (Spain); Tredicucci, A. [NEST, Istituto Nanoscienze and Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, Pisa I-56127 (Italy)

    2015-09-07

    We demonstrate the integration of Nd{sup 3+} doped barium-titanium-silicate microsphere lasers with a silicon nitride photonic platform. Devices with two different geometrical configurations for extracting the laser light to buried waveguides have been fabricated and characterized. The first configuration relies on a standard coupling scheme, where the microspheres are placed over strip waveguides. The second is based on a buried elliptical geometry whose working principle is that of an elliptical mirror. In the latter case, the input of a strip waveguide is placed on one focus of the ellipse, while a lasing microsphere is placed on top of the other focus. The fabricated elliptical geometry (ellipticity = 0.9) presents a light collecting capacity that is 50% greater than that of the standard waveguide coupling configuration and could be further improved by increasing the ellipticity. Moreover, since the dimensions of the spheres are much smaller than those of the ellipses, surface planarization is not required. On the contrary, we show that the absence of a planarization step strongly damages the microsphere lasing performance in the standard configuration.

  8. Transmission properties of fluorocarbon polymer-coated silver hollow glass waveguide with tapered section for Er:YAG laser light

    Science.gov (United States)

    Wang, You; Hiraga, Hajime; Miura, Daisuke; Kato, Yuji; Miyagi, Mitsunobu

    1996-11-01

    We have succeeded in fabricating low-loss fluorocarbon polymer (FCP)-coated silver hollow glass waveguides by using a liquid-flow coating method. The thickness of a FCP film is strongly dependent on the flow speed and the concentration of FCP solution. It is shown that the optimum condition exists for depositing the polymer to reduce the roughness of layer. The transmission loss of the fabricated waveguide with inner diameter of 700 micrometers is about 0.2 dB/m for Er:YAG laser light. An efficient tapered coupler with a lens is also investigated to couple the laser beam with large diameter to small-bore waveguides.

  9. A Ka-band monolithic low phase noise coplanar waveguide oscillator using InAlAs/InGaAs HBT

    Science.gov (United States)

    Cui, Delong; Hsu, Shawn; Pavlidis, Dimitris; Chin, Patrick; Block, Tom

    2002-02-01

    A Ka-band oscillator has been designed, fabricated and tested using InAlAs/InGaAs HBTs. Coplanar waveguide technology has been employed to improve the Q-factor of the circuit. An output power of 2.6 dBm with DC to RF conversion efficiency of 7.8% was measured at 31.7 GHz. Low phase noise of -87 and -112 dBc/Hz were achieved at an offset frequency of 100 kHz and 1 MHz respectively. These low phase noise values can be attributed to the low 1/ f noise of the InAlAs/InGaAs HBT devices and the coplanar design used for the circuit.

  10. Gratings, photosensitivity, and poling in silica optical waveguides with 157-nm fluorine laser radiation

    Science.gov (United States)

    Chen, Peng (Kevin)

    2002-08-01

    The energetic 7.9-eV photons of the F2 laser directly access bandgap states in germanosilicate glasses to drive one-photon processes for inducing strong refractive index changes in silica optical waveguides. In this thesis, the author carried out the first comprehensive F2-laser photosensitivity studies with an aim to assess prospects for shaping useful photonic structures directly inside the germanosilicate waveguides. Both planar waveguides and standard telecommunication fibers were examined. Large effective index change (>10-3) was induced in both fibers and planar waveguides without any enhancement technique. With the use of hydrogen loading enhancement, asymmetric refractive index profiles were noted by atomic force microscopy and microreflection microscopy, having a peak index change of larger than 0.01 in the fiber core. The 157-nm laser radiation is effective in rapidly forming long-period gratings in standard fibers. Grating formation is over 250 times faster than that with the 248-nm KrF laser constituting the fastest photosensitivity response ever reported. For planar lightwave circuits (PLCs), the 157-nm laser exposure generate narrow profiles of large index changes (Deltan ˜ 10 -2) that is useful in trimming phase errors and controlling birefringence in frequency domain modulators (FDMs) and interleavers. The large vacuum-ultraviolet-induced birefringence was used to completely compensate the intrinsic birefringence of Deltan ˜ 10-4 in typical PLCs. With hydrogen soaking, modest 157-nm pre-irradiation (accumulated fluence >3 J/cm2) was found to 'lock-in' a permanent photosensitivity enhancement in the germanosilica, permitting the formation of strong (40 dB) and stable fiber Bragg gratings with 248-nm-KrF laser light. The F2-laser photosensitivity locking was 300-time more effective than with KrF-laser pretreatment. The practical trimming applications in PLCs were demonstrated in PLC interleavers and FDMs. The 157-nm laser pre-radiation was found to

  11. Laser Soldering and Thermal Cycling Tests of Monolithic Silicon Pixel Chips

    CERN Document Server

    Strand, Frode Sneve

    2015-01-01

    An ALPIDE-1 monolithic silicon pixel sensor prototype has been laser soldered to a flex printed circuit using a novel interconnection technique using lasers. This technique is to be optimised to ensure stable, good quality connections between the sensor chips and the FPCs. To test the long-term stability of the connections, as well as study the effects on hit thresholds and noise in the sensor, it was thermally cycled in a climate chamber 1200 times. The soldered connections showed good qualities like even melting and good adhesion on pad/flex surfaces, and the chip remained in working condition for 1080 cycles. After this, a few connections failed, having cracks in the soldering tin, rendering the chip unusable. Threshold and noise characteristics seemed stable, except for the noise levels of sector 2 in the chip, for 1000 cycles in a temperature interval of "10^{\\circ}" and "50^{\\circ}" C. Still, further testing with wider temperature ranges and more cycles is needed to test the limitations of the chi...

  12. Monolithic Y-Ba-Cu-O structures fabricated using the laser-writing patterning technique

    Energy Technology Data Exchange (ETDEWEB)

    Sobolewski, R.; Xiong, W.; Kula, W.; Maung, W.N.; Butler, D.P. [Dept. of Electr. Eng., Rochester Univ., NY (United States)

    1994-05-01

    We report our progress in fabrication of thin-film YBa{sub 2}Cu{sub 3}O{sub x} (YBCO) superconducting electronic devices, using a recently developed, laser-writing patterning technique. Laser writing allows one to form in the same YBCO film planar patterns that consist of both the oxygen-rich (superconducting) and the oxygen-poor (semiconducting) phases. The patterns are highly uniform with very sharp (less than 1 mu m wide) superconductor-semiconductor interfaces. The oxygen-rich regions possess excellent superconducting properties with critical temperatures as high as those of the best epitaxial films, and critical current densities above 2x10{sup 6} A cm{sup -2} at 77 K. Simultaneously, the oxygen-poor regions exhibit a disordered-semiconductor-like, thermally activated transport. Below 100 K, they are almost insulating and characterized by relatively low (below 20) dielectric constant and low microwave loss. A number of test structures, consisting of oxygen-rich and oxygen-poor microbridges and coplanar microwave transmission lines and resonators, was fabricated and tested. All these devices are completely monolithic and were used to study DC and microwave transport properties of the oxygen-rich and oxygen-poor YBCO phases. (author)

  13. High-power 850-870-nm pulsed lasers based on heterostructures with narrow and wide waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Ladugin, M A; Koval' , Yu P; Marmalyuk, Aleksandr A; Petrovskii, V A; Bagaev, T A; Andreev, A Yu; Padalitsa, A A; Simakov, V A [Open Joint-Stock Company ' M.F. Stel' makh Polyus Research and Development Institute' , Moscow (Russian Federation)

    2013-05-31

    The power and spectral characteristics of pulsed laser diode arrays operating in the spectral range of 850-870 nm and based on heterostructures of two different types (with narrow and wide waveguides) are studied. It is found that the power-current characteristics of the laser arrays of both types are linear within the pump current range of 10-50 A and that the steepness of these characteristics decreases at currents exceeding 80 A. The decrease in the slope efficiency is more noticeable for laser arrays based on heterostructures with wide waveguides. (semiconductor lasers. physics and technology)

  14. Waveguide design for mid- and far-infrared p-Si/SiGe quantum cascade lasers

    Science.gov (United States)

    Ikonic, Z.; Kelsall, R. W.; Harrison, P.

    2004-01-01

    Design considerations are presented for waveguides to be used in p-Si/SiGe based quantum cascade lasers operating in the mid- and far-infrared wavelength ranges. Modal losses and confinement factors are calculated for both TM and TE modes in conventional double metal clad structures, metal-highly doped semiconductor layer structures and also in novel metal-metal silicide structures. Guidelines for choosing the confinement and contact layer parameters are given.

  15. A medium-power small-scale slotted CO2 waveguide laser with HF excitation

    Science.gov (United States)

    Vitruk, P. P.; Iatsenko, N. A.

    1989-03-01

    Experimental results are reported on the high-frequency capacitive discharge (HFCD) regime of a medium-power small-scale slotted waveguide CO2 laser. An output power of 100-200 W at an electrooptical efficiency of 5-6 percent was obtained using a CO2:N2:He = 1:1:3 mixture at a pressure of 8-12 torr at a low gas flowrate (0.2 liter/min).

  16. Cascaded-focus laser writing of low-loss waveguides in polymers.

    Science.gov (United States)

    Pätzold, Welm M; Reinhardt, Carsten; Demircan, Ayhan; Morgner, Uwe

    2016-03-15

    Waveguide writing in poly (methyl methacrylate) (PMMA) with femtosecond laser radiation is presented. An adequate refractive index change is induced in the border area below the irradiated focal volume. It supports an almost symmetric fundamental mode with propagation losses down to 0.5  dB/cm, the lowest losses observed so far in this class of materials. The writing process with a cascaded focus is demonstrated to be highly reliable over a large parameter range.

  17. Multilayer Slab Waveguide Distributed Feedback Dye Laser Sensors

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Smith, Cameron; Leung, M.

    2013-01-01

    Organic dye-based distributed feedback (DFB) lasers are widely tunable laser light sources in the visible wavelength range and exhibit low-cost, simple fabrication, low threshold and single-mode emission [1]. Precise emission wavelength modeling is essential for understanding and optimization of ...

  18. A monolithically integrated dual-mode laser for photonic microwave generation and all-optical clock recovery

    Science.gov (United States)

    Yu, Liqiang; Zhou, Daibing; Zhao, Lingjuan

    2014-09-01

    We demonstrate a monolithically integrated dual-mode laser (DML) with narrow-beat-linewidth and wide-beat-tunability. Using a monolithic DFB laser subjected to amplified feedback, photonic microwave generation of up to 45 GHz is obtained with higher than 15 GHz beat frequency tunability. Thanks to the high phase correlation of the two modes and the narrow mode linewidth, a RF linewidth of lower than 50 kHz is measured. Simulations are also carried out to illustrate the dual-mode beat characteristic. Furthermore, using the DML, an all-optical clock recovery for 40  Gbaud NRZ-QPSK signals is demonstrated. Timing jitter of lower than 363 fs (integrated within a frequency range from 100 Hz to 1 GHz) is obtained.

  19. Integration of multimode waveguides and micromirror couplers in printed circuit boards using laser ablation

    Science.gov (United States)

    Van Steenberge, Geert; Geerinck, Peter; Van Put, Steven; Van Daele, Peter

    2004-09-01

    Integration of optical interconnections on a Printed Circuit Board (PCB) is very challenging, as it should remain compatible with existing PCB manufacturing technology based on laminated FR4-substrates and making use of solder-reflow and well-known placement and assembly techniques. In this paper we will describe different technologies being used for integration of such optical interconnections in PCB's. As we will demonstrate, the use of laser ablation, already used in PCB manufacturing for microvia's, is a suitable technique for the fabrication of multimode waveguides and micromirrors to provide optical coupling. Laser ablation is a very flexible technology that is particularly well suited for structuring of polymers because of their excellent UV-absorption properties and highly non-thermal ablation behavior. One of the most critical problems on the integration of optical interconnections in PCB's is coupling the light in and out of the optical plane. Because in our set-up the excimer laser beam can be tilted, the 45 degrees micromirrors can be easily fabricated using laser ablation. The focus is on ablation of waveguides using a frequency tripled Nd-YAG laser and on ablation of 45 degrees facets using a KrF excimer laser. It is shown that these structures can be defined in one single processing step, resulting in a very accurate alignment.

  20. EML Array fabricated by SAG technique monolithically integrated with a buried ridge AWG multiplexer

    Science.gov (United States)

    Xu, Junjie; Liang, Song; Zhang, Zhike; An, Junming; Zhu, Hongliang; Wang, Wei

    2017-06-01

    We report the fabrication of a ten channel electroabsorption modulated DFB laser (EML) array. Different emission wavelengths of the laser array are obtained by selective area growth (SAG) technique, which is also used for the integration of electroabsorption modulators (EAM) with the lasers. An arrayed waveguide grating (AWG) combiner is integrated monolithically with the laser array by butt-joint regrowth (BJR) technique. A buried ridge waveguide structure is adopted for the AWG combiner. A self aligned fabrication procedure is adopted for the fabrication of the waveguide structure of the device to eliminate the misalignment between the laser active waveguide and the passive waveguide. A Ti thin film heater is integrated for each laser in the array. With the help of the heaters, ten laser emissions with 1.8 nm channel spacing are obtained. The integrated EAM has a larger than 11 dB static extinction ratios and larger than 8 GHz small signal modulation bandwidths. The light power collected in the output waveguide of the AWG is larger than -13 dBm for each wavelength.

  1. Fabrication of Tunable Sampled Grating DBR Laser Integrated Monolithically with Optical Semiconductor Amplifier Using Planar Buried Heterostructure

    Science.gov (United States)

    Oh, Su Hwan; Lee, Ji-Myon; Kim, Soo; Ko, Hyunsung; Lee, Chul-Wook; Park, Sahnggi; Park, Moon-Ho

    2004-10-01

    We have demonstrated a high-power widely tunable sampled grating (SG) DBR laser integrated monolithically with optical semiconductor amplifier (SOA), using planar buried heterostructure (PBH). The measured threshold current was 5 mA on average with 60 chips randomly selected which is lowest among the typical average values. Fiber-coupled output power was 12.4 dBm and the output power variation was ˜1 dB for the whole tuning range.

  2. Monolithic translucent BaMgAl10O17:Eu2+ phosphors for laser-driven solid state lighting

    OpenAIRE

    Clayton Cozzan; Brady, Michael J.; Nicholas O’Dea; Emily E. Levin; Shuji Nakamura; Steven P. DenBaars; Ram Seshadri

    2016-01-01

    With high power light emitting diodes and laser diodes being explored for white light generation and visible light communication, thermally robust encapsulation schemes for color-converting inorganic phosphors are essential. In the current work, the canonical blue-emitting phosphor, high purity Eu-doped BaMgAl10O17, has been prepared using microwave-assisted heating (25 min) and densified into translucent ceramic phosphor monoliths using spark plasma sintering (30 min). The resulting transluc...

  3. Lasering in a Waveguide with Scatterers in Diameter 20 nm

    Institute of Scientific and Technical Information of China (English)

    LIU Chun-Xu; LIU Jun-Ye; ZHANG Jia-Hua; DOU Kai

    2004-01-01

    We report random lasing achieved in a MEH-PPV/glass waveguide with the TiO2 scatterers in diameter 20nm that is significantly smaller than submicrometre of TiO2 scatterers in the films or suspensions previously reported on random lasing. The spectral lines are dramatically narrowed by almost two orders of magnitude compared with those excited by a xenon lamp. The amplified spontaneous emission is identified as the dominant mechanism in our system. Light localization might be achieved in a broad class of random materials based on the features of the mean free path l* = 5.4 × 105 nm, kl* > 1 and the Thouless number 6.73 × 10-5 with k being the wave number.

  4. High Power 940 nm Al-free Active Region Laser Diodes and Bars with a Broad Waveguide

    Institute of Scientific and Technical Information of China (English)

    FANG Gaozhan; XIAO Jianwei; MA Xiaoyu; XU Zuntu; ZHANG Jinming; TAN Manqing; LIU Zongshun; LIU Suping; FENG Xiaoming

    2002-01-01

    The 940 nm Al-free active region laser diodes and bars with a broad waveguide were designed and fabricated. The stuctures were grown by metal organic chemical vapour deposition. The devices show excellent performances. The maximum output power of 6.7 W in the 100 μm broad-area laser diodes has been measured, and is 2.5 times higher than that in the Al-containing active region laser diodes with a narrow waveguide and 1.7 times higher than that in Al-free active region laser diodes with a narrow waveguide. The 19% fill-factor laser diode bars emit 33 W, and they can operate at 15W with low degradation rates.

  5. Power delivery of free electron laser light by hollow glass waveguides.

    Science.gov (United States)

    Matsuura, Y; Matsuura, K; Harrington, J A

    1996-09-20

    Hollow glass waveguides are used to deliver free electron laser (FEL) energy for applications in medicine and laser surgery. The hollow guides, optimized for the delivery of 6.45-μm FEL radiation, exhibited losses for the 1000-μm bore as low as 0.39 dB/m when the guide was straight and 1.75 dB/m when bent to a radius of 25 cm. Hollow glass guides are flexible, and their broadband capability provides an ideal fiber optic for the tunable FEL.

  6. ZnSe-based laser structures for electron-beam pumping with graded index waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Sorokin, S.V.; Sedova, I.V.; Ivanov, S.V. [Ioffe Physico-Technical Institute, Polytekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Zdanova, E.V.; Zverev, M.M. [Moscow State Institute of Radio Engineering, Electronics and Automations, Moscow 117454 (Russian Federation); Gronin, S.V.

    2010-06-15

    Electron beam pumped (EBP) laser heterostructures with graded index waveguide (GIW) have been grown by molecular beam epitaxy and studied in detail. The maximum achieved output pulse power per facet is as high as 8.5 W at an electron beam energy of 16 kV. No saturation of output power with the increase of electron beam current as well as no suitable degradation of GIW EBP laser structures have been observed. The ways for further optimizations of GIW heterostructures are discussed. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

    Energy Technology Data Exchange (ETDEWEB)

    Molpeceres, C. [Centro Laser UPM, Univ. Politecnica de Madrid, Crta. de Valencia Km 7.3, 28031 Madrid (Spain)], E-mail: carlos.molpeceres@upm.es; Lauzurica, S.; Garcia-Ballesteros, J.J.; Morales, M.; Guadano, G.; Ocana, J.L. [Centro Laser UPM, Univ. Politecnica de Madrid, Crta. de Valencia Km 7.3, 28031 Madrid (Spain); Fernandez, S.; Gandia, J.J. [Dept. de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Villar, F.; Nos, O.; Bertomeu, J. [CeRMAE Dept. Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona (Spain)

    2009-03-15

    Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication.

  8. High-Power and Low-Noise 10-GHz All-Active Monolithic Mode-Locked Lasers with Surface Etched Bragg Grating

    DEFF Research Database (Denmark)

    Larsson, David; Yvind, Kresten; Hvam, Jørn Märcher

    2007-01-01

    We have fabricated 4.4 mm long monolithic InAlGaAsP/InP mode-locked lasers with integrated deeply surface etched DBR-mirrors. The lasers produce 3.7 ps transform-limited Gaussian pulses with 10 mW average power and 250 fs timing jitter.......We have fabricated 4.4 mm long monolithic InAlGaAsP/InP mode-locked lasers with integrated deeply surface etched DBR-mirrors. The lasers produce 3.7 ps transform-limited Gaussian pulses with 10 mW average power and 250 fs timing jitter....

  9. A Helical Undulator Wave-guide Inverse Free-Electron Laser

    Science.gov (United States)

    Rosenzweig, J.; Bodzin, N.; Frigola, P.; Joshi, C.; Musumeci, P.; Pellegrini, C.; Tochitsky, S.; Travish, G.

    2004-12-01

    With recent success in high gradient, high-energy gain IFEL experiments at the UCLA Neptune Laboratory, future experiments are now being contemplated. The Neptune IFEL was designed to use a tightly focused, highly diffracting, near-TW peak power 10 micron laser. This choice of laser focusing, driven by power-handling limitations of the optics near the interaction region, led to design and use of a very complex undulator, and to sensitivity to both laser misalignment and focusing errors. As these effects limited the performance of the IFEL experiment, a next generation experiment at Neptune has been studied which avoids the use of a highly diffractive laser beam through use of a waveguide. We discuss here the choice of low-loss waveguide, guided mode characteristics and likely power limitations. We also examine a preferred undulator design, which is chosen to be helical in order to maximize the acceleration achieved for a given power. With the limitations of these laser and undulator choices in mind, we show the expected performance of the IFEL using 1D simulations. Three-dimensional effects are examined, in the context of use of a solenoid for focusing and acceleration enhancement.

  10. Calculation of focal positions in an optical head for parallel data processing with a monolithic four-beam laser diode.

    Science.gov (United States)

    Shinoda, M

    2001-03-01

    A method for calculating focal positions in a multibeam optical head by use of a multibeam laser diode, in which conditions for misalignment of the light source are taken into consideration, is introduced. One calculates the focal positions by using the practical characteristics of a monolithic four-beam laser diode and the practical specifications of the optics in an optical head. The results show that each focal position is defocused mainly as a result of curvature of the fields of the lenses. The adaptability of focal positions for various calculated conditions is discussed from the standpoint of depth of focus.

  11. High performance highly strained InGaAs quantum-well ridge waveguide lasers

    Institute of Scientific and Technical Information of China (English)

    QU Yi; J. X. Zhang; A. Uddin; S. M. Wang; M. Sadeghi; A. Larsson; BO Baoxue; LIU Guojun; JIANG Huilin

    2005-01-01

    Highly strained InGaAs ridge waveguide lasers were fabricated with pulsed anodic oxidation. The laser structure was grown by molecular beam epitaxy (MBE) system. The output powers up to 50 mW per facet in CW mode were reached at room temperature for the 4 μm stripe lasers. The threshold current density of 300 A/cm2 was achieved with 600 μm cavity length. The emission wavelength at 100 mA was 1.19 μm. The slope efficiency was 0.45 W/A in linear output region of light-current characteristics. The laser characteristic temperature was 129 K (20℃―100℃).

  12. Fiber-Type Random Laser Based on a Cylindrical Waveguide with a Disordered Cladding Layer

    Science.gov (United States)

    Zhang, Wei Li; Zheng, Meng Ya; Ma, Rui; Gong, Chao Yang; Yang, Zhao Ji; Peng, Gang Ding; Rao, Yun Jiang

    2016-05-01

    This letter reports a fiber-type random laser (RL) which is made from a capillary coated with a disordered layer at its internal surface and filled with a gain (laser dye) solution in the core region. This fiber-type optical structure, with the disordered layer providing randomly scattered light into the gain region and the cylindrical waveguide providing confinement of light, assists the formation of random lasing modes and enables a flexible and efficient way of making random lasers. We found that the RL is sensitive to laser dye concentration in the core region and there exists a fine exponential relationship between the lasing intensity and particle concentration in the gain solution. The proposed structure could be a fine platform of realizing random lasing and random lasing based sensing.

  13. Ultrafast pulse generation in a mode-locked Erbium chip waveguide laser

    CERN Document Server

    Khurmi, Champak; Zhang, Wen Qi; V., Shahraam Afshar; Chen, George; Genest, Jérôme; Monro, Tanya M; Lancaster, David G

    2016-01-01

    We report mode-locked ~1550 nm output of transform-limited ~180 fs pulses from a large mode-area (diameter ~ 50 {\\mu}m) guided-wave erbium fluorozirconate glass laser. The passively mode-locked oscillator generates pulses with 25 nm bandwidth at 156 MHz repetition rate and peak-power of 260 W. Scalability to higher repetition rate is demonstrated by transform-limited 410 fs pulse output at 1.3 GHz. To understand the origins of the broad spectral output, the laser cavity is simulated by using a numerical solution to the Ginzburg-Landau equation. This paper reports the widest bandwidth and shortest pulses achieved from an ultra-fast laser inscribed waveguide laser.

  14. Writing waveguides in glass with a femtosecond laser.

    Science.gov (United States)

    Davis, K M; Miura, K; Sugimoto, N; Hirao, K

    1996-11-01

    With the goal of being able to create optical devices for the telecommunications industry, we investigated the effects of 810-nm, femtosecond laser radiation on various glasses. By focusing the laser beam through a microscope objective, we successfully wrote transparent, but visible, round-elliptical damage lines inside highsilica, borate, soda lime silicate, and f luorozirconate (ZBLAN) bulk glasses. Microellipsometer measurements of the damaged region in the pure and Ge-doped silica glasses showed a 0.01-0.035 refractive-index increase, depending on the radiation dose. The formation of several defects, including Si E' or Ge E' centers, nonbridging oxygen hole centers, and peroxy radicals, was also detected. These results suggest that multiphoton interactions occur in the glasses and that it may be possible to write three-dimensional optical circuits in bulk glasses with such a focused laser beam technique.

  15. Monolithic crystalline cladding microstructures for efficient light guiding and beam manipulation in passive and active regimes

    Science.gov (United States)

    Jia, Yuechen; Cheng, Chen; Vázquez de Aldana, Javier R.; Castillo, Gabriel R.; Rabes, Blanca del Rosal; Tan, Yang; Jaque, Daniel; Chen, Feng

    2014-01-01

    Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump of miniaturized waveguiding active structures offers a low-cost but intriguing solution for compact light-emitting devices. In this work, we demonstrate a novel family of three dimensional (3D) photonic microstructures monolithically integrated in a Nd:YAG laser crystal wafer. They are produced by the femtosecond laser writing, capable of simultaneous light waveguiding and beam manipulation. In these guiding systems, tailoring of laser modes by both passive/active beam splitting and ring-shaped transformation are achieved by an appropriate design of refractive index patterns. Integration of graphene thin-layer as saturable absorber in the 3D laser structures allows for efficient passive Q-switching of tailored laser radiations which may enable miniature waveguiding lasers for broader applications. Our results pave a way to construct complex integrated passive and active laser circuits in dielectric crystals by using femtosecond laser written monolithic photonic chips. PMID:25100561

  16. Radiation from laser-microplasma-waveguide interactions in the ultra-intense regime

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    When a high-contrast ultra-relativistic laser beam enters a micro-sized plasma waveguide, the pulse energy is coupled into waveguide modes, which remarkably modifies the interaction of electrons and electromagnetic wave. The electrons that pulled out of walls form a dense helical bunch inside the channel are efficiently accelerated by the transverse magnetic modes to hundreds of MeVs. In the mean time, the asymmetry in the transverse electric and magnetic fields provides significant wiggling that leads to a bright, well-collimated emission of hard X-rays. In this paper, we present our study on the underlying physics in the aforementioned process using 3D particle-in-cell simulations. The mechanism of electron acceleration and the dependence of radiation properties on different laser plasma parameters are addressed. A theoretical analysis model and basic scalings for X-ray emission are also presented by considering the lowest optical modes in the waveguide, which is adequate to describe the basic observed phen...

  17. Control of waveguide properties by tuning femtosecond laser induced compositional changes

    Energy Technology Data Exchange (ETDEWEB)

    Hoyo, Jesús; Fernandez, Toney Teddy del; Siegel, Jan; Solis, Javier, E-mail: j.solis@io.cfmac.csic.es [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, 28006 Madrid (Spain); Vazquez, Rebeca Martinez; Osellame, Roberto [Instituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Sotillo, Belén; Fernández, Paloma [Depto. de Física de Materiales, Facultad de Físicas, Univ. Complutense, 28040 Madrid (Spain)

    2014-09-29

    Local compositional changes induced by high repetition rate fs-laser irradiation can be used to produce high performance optical waveguides in phosphate-based glasses. The waveguide refractive index contrast is determined by the local concentration of La, which can be changed by the action of the writing laser pulses. In this work, we have investigated the degree of control that can be exerted using this waveguide writing mechanism over the cross-section of the guiding region, and the local refractive index and compositional changes induced. These variables can be smoothly controlled via processing parameters using the slit shaping technique with moderate Numerical Aperture (NA 0.68) writing optics. The combined use of X-ray microanalysis and near field refractive index profilometry evidences a neat linear correlation between local La content and refractive index increase over a broad Δn interval (>3 × 10{sup −2}). This result further confirms the feasibility of generating efficient, integrated optics elements via spatially selective modification of the glass composition.

  18. Second harmonic generation via femtosecond laser fabrication of poled, quasi-phase-matched waveguides in fused silica.

    Science.gov (United States)

    Ng, Jason C; Herman, Peter R; Qian, Li

    2017-01-15

    Second harmonic generation (SHG) is demonstrated in femtosecond laser written waveguides in fused silica through a combination of thermal poling and laser-based quasi-phase-matching (QPM) techniques. Quasi-phase-matching was controlled by the periodic erasure of induced nonlinearity through femtosecond laser erasure. A maximum SHG conversion efficiency of 6.6±0.5×10-5%/W is reported for the fundamental wavelength of 1552.8 nm with a phase-matching bandwidth of 4.4 nm for a 10.0 mm long waveguide. For a shorter sample, an effective second-order nonlinearity of χ(2)=0.012±0.001  pm/V was measured. Chirped QPM structures for wider SHG bandwidths also were demonstrated. Such periodically poled waveguides are promising for introducing nonlinear optical components within the 3D passive optical circuits that can be flexibly formed in fused silica by femtosecond laser writing.

  19. Laser Doppler velocimetry in Microchannels using integrated optical waveguides.

    NARCIS (Netherlands)

    Pandraud, G.; van den Berg, Albert; Semenov, S.N.

    2000-01-01

    The possibility of laser Doppler velocimetry (LDV) in microchannels, where particles are suspended in a liquid, and where oscillating or evanescent guided coherent light wave is present, is examined theoretically. The conditions for the observation of the transverse and longitudinal collective phore

  20. Spatially Modulated Gain Waveguide Electro-Optic Laser

    Science.gov (United States)

    2013-08-09

    tuning range and a large output power. Such applications include: coherent optical receiver, CWFM lidar , RF/Optical waveform generation, etc. However...reflected signal from the laser sample is first detected by a high speed photodetector , followed by an wideband RF amplifier. A vector network

  1. Room-temperature continuous-wave operation of Ti:sapphire buried channel-waveguide lasers fabricated via proton implantation

    NARCIS (Netherlands)

    Grivas, C.; Shepherd, D.P.; Eason, R.W.; Laversenne, L.; Moretti, P.; Borca, C.N.; Pollnau, M.

    2006-01-01

    Fabrication and laser operation of proton-implanted Ti:sapphire buried channel waveguides is reported for the first time to our knowledge. Without any postimplantation annealing of the structures, continuous laser operation near 780 nm was demonstrated at room temperature at an absorbed pump power t

  2. Planar waveguide Michelson interferometer fabricated by using 157nm mask laser micromachining

    Science.gov (United States)

    Bao, Haihong; Ran, Zengling; Wu, Xuezhong; Yang, Ke; Jiang, Yuan; Rao, Yunjiang

    2015-07-01

    A Michelson interferometer is fabricated on silica planar waveguide by using the one-step technology based on 157nm mask laser micromachining. The fabrication time for one device is ~10s. Experimental results show that such an interferometer has an excellent fringe contrast of >20dB. Its temperature and refractive index (RI) responses are tested by observing the wavelength shift of the interferometric fringes, which shows linear characteristics with a thermo-coefficient of ~9.5pm/°C and a RI-coefficient of ~36.7nm/RIU, respectively. The fabrication technology may pave a new way for direct writing of planar silica waveguide devices for sensing applications with high efficiency and quality.

  3. Photo-structurable polymer for interlayer single-mode waveguide fabrication by femtosecond laser writing

    Science.gov (United States)

    Nguyen, Ho Hoai Duc; Hollenbach, Uwe; Pfirrmann, Stefan; Ostrzinski, Ute; Pfeiffer, Karl; Hengsbach, Stefan; Mohr, Juergen

    2017-04-01

    We present the fabrication and characterization of inter-layer single-mode light-guiding structures in a newly developed photo-structurable polymer via femtosecond laser writing. A host-guest polymer system utilizing external diffusion induces permanent and high refractive index modulation. Analyzing the complete curing and the impact of external diffusion on refractive index profile helps optimize the fabrication process. The fabrications of 4 × 2 array interconnect and 3-waveguide core fan-out device involve only a single layer, and need no stacking or alignment effort. The resulting pitch size and crosstalk between single-mode waveguides are 25 μm and -34 dB, respectively. Adding sensitizer into the photopolymer to increase its sensitivity in two-photon polymerization at a writing wavelength of 390 nm reduces the surface roughness of written structures by a factor of seven.

  4. High-Power Tunable Laser Pulse Driven Terahertz Generation in Corrugated Plasma Waveguides

    Science.gov (United States)

    Miao, Chenlong; Palastro, John; Antonsen, Thomas

    2016-10-01

    Excitation of terahertz radiation by the interaction of an ultra-short laser pulse and the fields of a miniature, corrugated plasma waveguide is considered. Plasma structures of this type have been realized experimentally and they can support electromagnetic (EM) channel modes with properties that allow for radiation generation. In particular, the mode have subluminal field components, thus allowing phase matching between the generated THz modes and the ponderomotive potential of the laser pulse. Theoretical analysis and full format PIC simulations are conducted. We find THz generated by this slow wave phase matching mechanism is characterized by lateral emission and a coherent, narrow band, tunable spectrum with relatively high power and conversion efficiency. We investigated two different types of channels, and a range of realistic laser pulses and plasma profile parameters are considered with the goal of increasing the conversion of optical energy to THz radiation. We find high laser intensities strongly modify the THz spectrum by exciting higher order channel modes. Enhancement of a specific channel mode can be realized by using an optimum pulse duration and plasma density. As an example, a fixed drive pulse (0.55 J) with spot size of 15 µm and pulse duration of 15 fs excites 37.8 mJ of THz radiation in a 1.5 cm corrugated plasma waveguide with on axis average density of 1.4×1018cm-3, conversion efficiency exceeding 8% is achieved.

  5. Slit beam shaping method for femtosecond laser direct-write fabrication of symmetric waveguides in bulk glasses

    Science.gov (United States)

    Ams, Martin; Marshall, G. D.; Spence, D. J.; Withford, M. J.

    2005-07-01

    We report both theoretical and experimental results of a slit beam shaping configuration for fabricating photonic waveguides by use of femtosecond laser pulses. Most importantly we show the method supports focusing objectives with a long depth of field and allows the direct-writing of microstructures with circular cross-sections whilst employing a perpendicular writing scheme. We applied this technique to write low loss (0.39 dB/cm), single mode waveguides in phosphate glass.

  6. Passively Q-switched diode-pumped Cr4+:YAG/Nd3+:GdVO4 monolithic microchip laser

    CERN Document Server

    Forget, S; Balembois, F; Georges, P; Landru, N; Feve, J P; Lin, J; Weng, Z; Forget, Sebastien; Druon, Frederic; Balembois, Francois; Georges, Patrick; Landru, Nicolas; Feve, Jean Philippe; Lin, Jiali; Weng, Zhiming

    2006-01-01

    the realization of high repetition rate passively Q-switched monolithic microlaser is a challenge since a decade. To achieve this goal, we report here on the first passively Q-switched diode-pumped microchip laser based on the association of a Nd:GdVO4 crystal and a Cr4+:YAG saturable absorber. The monolithic design consists of 1 mm long 1% doped Nd:GdVO4 optically contacted on a 0.4 mm long Cr4+:YAG leading to a plano-plano cavity. A repetition rate as high as 85 kHz is achieved. The average output power is approximately 400 mW for 2.2 W of absorbed pump power and the pulse length is 1.1 ns.

  7. Waveguide embedded plasmon laser with multiplexing and electrical modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ren-min; Zhang, Xiang

    2017-08-29

    This disclosure provides systems, methods, and apparatus related to nanometer scale lasers. In one aspect, a device includes a substrate, a line of metal disposed on the substrate, an insulating material disposed on the line of metal, and a line of semiconductor material disposed on the substrate and the insulating material. The line of semiconductor material overlaying the line of metal, disposed on the insulating material, forms a plasmonic cavity.

  8. Fabrication of copper oxide-coated hollow waveguides for CO2 laser radiation.

    Science.gov (United States)

    Matsuura, Y; Miura, D; Miyagi, M

    1999-03-20

    Hollow fibers for transmitting CO(2) laser light were fabricated by the chemical vapor deposition (CVD) method. A dielectric film of copper oxide (Cu(2)O) was deposited upon the inside of a Ag-coated glass capillary by use of a metal acetylacetonate as the precursor. The waveguide, which was coated with Cu(2)O and had a bore diameter of 700 microm, showed a loss of 0.9 dB/m for CO(2) laser light. The Cu(2)O film deposited by CVD had high chemical and heat resistivity. Therefore a hollow fiber coated with copper oxide is suitable for high-power laser applications in a severe environment.

  9. Comparison of Monolithic Optical Frequency Comb Generators Based on Passively Mode-Locked Lasers for Continuous Wave mm-Wave and Sub-THz Generation

    DEFF Research Database (Denmark)

    Criado, A. R.; de Dios, C.; Acedo, P.;

    2012-01-01

    In this paper, two different Passive Mode-Locked Laser Diodes (PMLLD) structures, a Fabry–Perot cavity and a ring cavity laser are characterized and evaluated as monolithic Optical Frequency Comb Generators (OFCG) for CW sub-THz generation. An extensive characterization of the devices under study...

  10. High-Power and Low-Noise 10-GHz All-Active Monolithic Mode-Locked Lasers with Surface Etched Bragg Grating

    OpenAIRE

    Larsson, David; Yvind, Kresten; Hvam, Jørn Märcher

    2007-01-01

    We have fabricated 4.4 mm long monolithic InAlGaAsP/InP mode-locked lasers with integrated deeply surface etched DBR-mirrors. The lasers produce 3.7 ps transform-limited Gaussian pulses with 10 mW average power and 250 fs timing jitter.

  11. Monolithically integrated distributed Bragg reflector lasers for 1.5 μm operation with band gap shifted grating section

    Science.gov (United States)

    Ke, Maolong; Allan, B. D.; Liu, X. F.; Boyd, A.; Qiu, B. C.; Qian, Y. H.; Hamilton, C. J.; McDougall, S. D.; Kowalski, O. P.; Bryce, A. C.; De La Rue, R. M.; Marsh, J. H.

    2000-07-01

    The design and operation of long wavelength ridge waveguide distributed Bragg reflector lasers in both InGaAs-InGaAlAs and InGaAs-InGaAsP materials with deeply dry-etched surface gratings are presented. To our knowledge, quantum well intermixing was used for the first time in these systems to widen the band gap in the grating region, and significant improvement in performance is obtained from the distributed Bragg reflector (DBR) lasers with intermixed grating region.

  12. IEEE International Semiconductor Laser Conference (14th) Held in Maui, Hawaii on September 19-23, 1994

    Science.gov (United States)

    1994-09-23

    a Laser Diode with a Polymer -Based Waveguide for Photonic Integrated Circuits ....... 93 P7 Extremely Small Active Stripe Laser Diodes (EXSAS-LDs) For...600 800 1000 0 500 1000 1500 2000 Current I - Ith [mA] Cartier Reservoir Thickness Lrsv [nm] Fig. 3. Opticalifrequency shift at steady state Fig. 4...Monolithic Integration of a Laser Diode with a Polymer -Based Waveguide for Photonic Integrated Circuits. N.Bouadma, J.LUang, R.Pinsard-Levenson

  13. Yb3+ and Tm3+ doped KGdxLuyY1-x-y(WO4)2 channel waveguide lasers

    NARCIS (Netherlands)

    Geskus, D.; van Dalfsen, Koop; Aravazhi, S.; Worhoff, Kerstin; Pollnau, Markus

    Channel waveguides with high refractive-index contrast are fabricated in double tungstates. Yb3+ lasers with 71% slope efficiency and 418 mW output power are demonstrated. Tm3+ lasers at 1843 nm have also been demonstrated.

  14. Refractive index and dispersion control of ultrafast laser inscribed waveguides in gallium lanthanum sulphide for near and mid-infrared applications

    DEFF Research Database (Denmark)

    Demetriou, Giorgos; Berube, Jean-Philippe; Vallee, Real

    2016-01-01

    The powerful ultrafast laser inscription technique is used to fabricate optical waveguides in gallium lanthanum sulphide substrates. For the first time the refractive index profile and the dispersion of such ultrafast laser inscribed waveguides are experimentally measured. In addition the Zero Di...... in gallium lanthanum sulphide glasses for near and mid-IR applications. (C) 2016 Optical Society of America...

  15. Bright X-ray source from a laser-driven micro-plasma-waveguide

    CERN Document Server

    Yi, Longqing

    2016-01-01

    Bright tunable x-ray sources have a number of applications in basic science, medicine and industry. The most powerful sources are synchrotrons, where relativistic electrons are circling in giant storage rings. In parallel, compact laser-plasma x-ray sources are being developed. Owing to the rapid progress in laser technology, very high-contrast femtosecond laser pulses of relativistic intensities become available. These pulses allow for interaction with micro-structured solid-density plasma without destroying the structure by parasitic pre-pulses. The high-contrast laser pulses as well as the manufacturing of materials at micro- and nano-scales open a new realm of possibilities for laser interaction with photonic materials at the relativistic intensities. Here we demonstrate, via numerical simulations, that when coupling with a readily available 1.8 Joule laser, a micro-plasma-waveguide (MPW) may serve as a novel compact x-ray source. Electrons are extracted from the walls by the laser field and form a dense ...

  16. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    Science.gov (United States)

    Yi, Longqing; Pukhov, Alexander; Shen, Baifei

    2016-06-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO2 laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread (~1%) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO2 laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  17. Performance characteristics of a CO/sub 2/ waveguide laser

    Energy Technology Data Exchange (ETDEWEB)

    Lavigne, P.; Otis, G.; Vincent, D.

    1979-08-01

    A rugged CW CO2 2-mm-diameter laser tube has been developed and its performance analyzed. It has been found that the small-signal gain was optimum when the CO2 partial pressure in a CO2:Xe:He mixture amounted to about 15 torr with the peak value decreasing with the CO2 proportion. Replacement of part of the CO2 by CO resulted in a significant improvement of the laser efficiency. A power extraction of 0.18 W/cm has been achieved at 110 torr with a CO2:CO:Xe:He mixture of 10:20:4:66 in a 9.5-cm-long discharge. There are indications that a better extraction is possible in longer tubes. Use of a grating as one end mirror was sufficient to control the electric field orientation and led to a greater tuning range by limiting the number of oscillating lines. At the present stage, semi-sealed-off operation is possible with a filling period of about 300 hours.

  18. Gain enhancement in a two-frequency high-gain waveguide free-electron laser

    CERN Document Server

    Lefèvre, T; Rullier, J L; Gouard, P; Donohue, J T

    2002-01-01

    In a waveguide monomode free-electron laser (FEL), two resonant frequencies can be amplified by the electron beam. At the CEA/CESTA facility, single-pass high-gain FEL experiments have been performed over the last five years using relativistic electron beams provided by induction linacs. Most of the work was done in the amplifier regime (at the higher frequency) with the aim of producing a 35 GHz bunched beam. However, super-radiant measurements were also made and have shown that the FEL gain at the upper frequency is higher than in the amplifier regime and may be driven by the lower frequency FEL interaction.

  19. Compact optical displacement sensing by detection of microwave signals generated from a monolithic passively mode-locked laser under feedback

    Science.gov (United States)

    Simos, Christos; Simos, Hercules; Nikas, Thomas; Syvridis, Dimitris

    2015-05-01

    A monolithic passively mode-locked laser is proposed as a compact optical sensor for displacements and vibrations of a reflecting object. The sensing principle relies on the change of the laser repetition frequency that is induced by optical feedback from the object under measurement. It has been previously observed that, when a semiconductor passively mode locked laser receives a sufficient level of optical feedback from an external reflecting surface it exhibits a repetition frequency that is no more determined by the mode-locking rule of the free-running operation but is imposed by the length of the external cavity. Therefore measurement of the resulting laser repetition frequency under self-injection permits the accurate and straightforward determination of the relative position of the reflecting object. The system has an inherent wireless capability since the repetition rate of the laser can be wirelessly detected by means of a simple antenna which captures the microwave signal generated by the saturable absorber and is emitted through the wiring of the laser. The sensor setup is very simple as it requires few optical components besides the laser itself. Furthermore, the deduction of the relative position of the reflecting object is straightforward and does not require any processing of the detected signal. The proposed sensor has a theoretical sub-wavelength resolution and its performance depends on the RF linewidth of the laser and the resolution of the repetition frequency measurement. Other physical parameters that induce phase changes of the external cavity could also be quantified.

  20. Monolithic intracavity laser-modulator device fabrication using postgrowth processing of 1.55 μm heterostructures

    Science.gov (United States)

    Aimez, V.; Beauvais, J.; Beerens, J.; Ng, S. L.; Ooi, B. S.

    2001-11-01

    In this letter, we present the attractive characteristics of a fabrication method based on quantum-well intermixing induced by low energy ion implantation for the realization of photonic integrated circuits on GaInAsP-InP heterostructures. Intracavity electro-absorption modulators monolithically integrated with laser devices were fabricated, using this postgrowth technique. The modulator section of the integrated devices was blueshifted by 75 nm while keeping the laser section unshifted and preserving very low values of the lasing threshold current density. Modulation depths in excess of 10 dB/V at 1.55 μm were obtained on these integrated devices which incorporate both a modulator and a laser.

  1. Tunable, continuous-wave Ti:sapphire channel waveguide lasers written by femtosecond and picosecond laser pulses.

    Science.gov (United States)

    Grivas, Christos; Corbari, Costantino; Brambilla, Gilberto; Lagoudakis, Pavlos G

    2012-11-15

    Fabrication and cw lasing at 798.25 nm is reported for femtosecond (fs) and picosecond (ps) laser-inscribed channel waveguides in Ti:sapphire crystals. Lasing in channels written by fs (ps) pulses was obtained above a threshold of 84 mW (189 mW) with a maximum output power and a slope efficiency of 143 mW (45 mW) and 23.5% (7.1%), respectively. The emission wavelength was tuned over a 170 nm range by using a birefringent filter in an external cavity.

  2. 456-mW graphene Q-switched Yb:yttria waveguide laser by evanescent-field interaction.

    Science.gov (United States)

    Choudhary, Amol; Beecher, Stephen J; Dhingra, Shonali; D'Urso, Brian; Parsonage, Tina L; Grant-Jacob, James A; Hua, Ping; Mackenzie, Jacob I; Eason, Robert W; Shepherd, David P

    2015-05-01

    In this Letter, we present a passively Q-switched Yb:Y2O3 waveguide laser using evanescent-field interaction with an atmospheric-pressure-chemical-vapor-deposited graphene saturable absorber. The waveguide, pumped by a broad area diode laser, produced an average output power of 456 mW at an absorbed power of 4.1 W. The corresponding pulse energy and peak power were 330 nJ and 2 W, respectively. No graphene damage was observed, demonstrating the suitability of top-deposited graphene for high-power operation.

  3. Amplification Properties of Femtosecond Laser-Written Er3+/Yb3+ Doped Waveguides in a Tellurium-Zinc Glass

    Directory of Open Access Journals (Sweden)

    Massimo Olivero

    2013-01-01

    Full Text Available We report on the fabrication and characterization of active waveguides in a TeO2-ZnO glass sample doped with Er3+/Yb3+ fabricated by direct laser writing with a femtosecond laser delivering 150 fs pulses at 1 kHz repetition rate. The waveguides exhibit an internal gain of 0.6 dB/cm at 1535 nm, thus demonstrating the feasibility of active photonics lightwave circuits and lossless components in such a glass composition.

  4. Femtosecond-Laser-Inscribed BiB3O6 Nonlinear Cladding Waveguide for Second-Harmonic Generation

    Science.gov (United States)

    Jia, Yuechen; Vázquez de Aldana, Javier R.; Romero, Carolina; Ren, Yingying; Lu, Qingming; Chen, Feng

    2012-07-01

    We report on the fabrication of a nonlinear cladding waveguide in BiB3O6 crystal by using femtosecond laser inscription. The waveguide (with a nearly circular cross section of 150 µm diameter) shows good guiding properties in two transverse polarizations. The guided-wave second-harmonic generation (SHG) at 532 nm green light has been realized under CW and pulsed wave pump at 1064 nm, based on the Type I birefringent phase matching configuration. The conversion efficiencies for CW and pulsed green laser SHG are 0.083 and 25%, respectively.

  5. Progress on femtosecond laser-based system-materials: three-dimensional monolithic electrostatic micro-actuator for optomechanics

    Science.gov (United States)

    Yang, Tao; Bellouard, Yves

    2016-03-01

    Femtosecond laser-dielectric interaction in a three-dimensional (3D) manner defines a capable platform for integrated 3D micro-devices fabricated out of a single piece of system-material. Here, we add a new function to femtosecond laserbased single monolith in amorphous fused silica by demonstrating a transparent 3D micro-actuator using non-ablative femtosecond laser micromachining with subsequent chemical etching. The actuation principle is based on dielectrophoresis (DEP), defined as the unbalanced electrostatic action on dielectrics, due to an induced dipole moment under a non-uniform electric field. An analytical model of this actuation scheme is proposed, which is capable of performance prediction, design parameter optimization and motion instability analysis. Furthermore, the static and dynamic performances are experimentally characterized using optical measurement methods. An actuation range of 30 μm is well attainable; resonances and the settling time in transient responses are measured; the quality factor and the bandwidth for the primary vertical resonance are also evaluated. Experimental results are in good consistence with theoretical analyses. The proposed actuation principle suppresses the need for electrodes on the mobile, non-conductive component and is particularly interesting for moving transparent elements. Thanks to the flexibility of femtosecond laser manufacturing process, this actuation scheme can be integrated in other functionalities within monolithic transparent Micro-Electro-Mechanical Systems (MEMS) for applications like resonators, adaptive lenses and integrated photonics circuits.

  6. Monolithic III-V and hybrid polysilicon-III-V microelectromechanical tunable vertical-cavity surface-emitting lasers

    Science.gov (United States)

    Ochoa, Edward M.; Lott, James A.; Nelson, Thomas R., Jr.; Harvey, M. C.; Raley, J. A.; Stintz, Andreas; Malloy, Kevin J.

    2003-04-01

    We report our progress on the design and fabrication of electrostatically-actuated microelectromechanical (MEM) tunable wavelength filters and vertical cavity surface-emitting lasers (VCSELs). We investigate both an all-semiconductor monolithic approach and a hybrid approach based on the combination of conventional polysilicon microelectromechanical systems (MEMS) and III-V semiconductor thin-film distributed Bragg reflector (DBR) and VCSEL structures. In the tunable hybrid structures the III-V semiconductor layers are flip-bonded onto specially designed polysilicon foundry MEMS structures and separated from their lattice-matched parent substrates by a novel post-bonding lift-off process.

  7. Complex coupled distributed feedback laser monolithically integrated with electroabsorption modulator and semiconductor optical amplifier at 1.3-micrometer wavelength

    Science.gov (United States)

    Gerlach, Philipp; Peschke, Martin; Wenger, Thomas; Saravanan, Brem K.; Hanke, Christian; Lorch, Steffen; Michalzik, Rainer

    2006-04-01

    We report on the design and experimental results of monolithically integrated optoelectronic devices containing distributed feedback (DFB) laser, electroabsorption modulator (EAM), and semiconductor optical amplifier (SOA). Common InGaAlAs multiple quantum well (MQW) layers are used in all device sections. The incorporation of local lateral metal gratings in the DFB section enables device fabrication by single-step epitaxial growth. The emission wavelength is λ=1.3 micrometer. More than 2 mW single-mode fiber-coupled output power as well as 10 dB/2 V static extinction ratio have been achieved. Modulation experiments clearly show 10 Gbit/s capability.

  8. Femtosecond laser direct writing of gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass

    Energy Technology Data Exchange (ETDEWEB)

    Vishnubhatla, K C; Kumar, R Sai Santosh; Rao, D Narayana [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Rao, S Venugopal [ACRHEM, University of Hyderabad, Hyderabad 500046 (India); Osellame, R; Ramponi, R [IFN - CNR and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milano (Italy); Bhaktha, S N B; Mattarelli, M; Montagna, M [Dipartimento di Fisica, CSMFO Lab., Universita di Trento, 38050 Trento (Italy); Turrell, S [Universite des Sciences et Technologies de Lille, Laboratoire de Spectrochimie Infrarouge et Raman, Batiment C5 - UMR CNRS 8516, 59655 Villeneuve d' Ascq cedex (France); Chiappini, A; Chiasera, A; Ferrari, M [CNR-IFN, CSMFO Lab., Via alla Cascata 56/c, 38050 Povo-Trento (Italy); Righini, G C, E-mail: dnrsp@uohyd.ernet.i, E-mail: svrsp@uohyd.ernet.i, E-mail: krishna.vishunubhatla@polimi.i [CNR-IFAC, MDF Lab., Sesto Fiorentino (Firenze) (Italy)

    2009-10-21

    The femtosecond laser direct writing technique was employed to inscribe gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass. Using the butt coupling technique, a systematic study of waveguide loss with respect to input pulse energy and writing speed was performed to achieve the best waveguide with low propagation loss (PL). By pumping at 980 nm, we observed signal enhancement in these active waveguides in the telecom spectral region. The refractive index change was smooth and we estimated it to be {approx}10{sup -3}. The high quantum efficiency ({approx}80%) and a best PL of {approx}0.9 dB cm{sup -1} combined with signal enhancement makes Baccarat glass a potential candidate for application in photonics.

  9. High slope efficiency and high refractive index change in direct-written Yb-doped waveguide lasers with depressed claddings.

    Science.gov (United States)

    Palmer, Guido; Gross, Simon; Fuerbach, Alexander; Lancaster, David G; Withford, Michael J

    2013-07-15

    We report the first Yb:ZBLAN and Yb:IOG10 waveguide lasers fabricated by the fs-laser direct-writing technique. Pulses from a Titanium-Sapphire laser oscillator with 5.1 MHz repetition rate were utilized to generate negative refractive index modifications in both glasses. Multiple modifications were aligned in a depressed cladding geometry to create a waveguide. For Yb:ZBLAN we demonstrate high laser slope efficiency of 84% with a maximum output power of 170 mW. By using Yb:IOG10 a laser performance of 25% slope efficiency and 72 mW output power was achieved and we measured a remarkably high refractive index change exceeding Δn = 2.3 × 10(-2).

  10. Monolithic all-fiber repetition-rate tunable gain-switched single-frequency Yb-doped fiber laser.

    Science.gov (United States)

    Hou, Yubin; Zhang, Qian; Qi, Shuxian; Feng, Xian; Wang, Pu

    2016-12-12

    We report a monolithic gain-switched single-frequency Yb-doped fiber laser with widely tunable repetition rate. The single-frequency laser operation is realized by using an Yb-doped distributed Bragg reflection (DBR) fiber cavity, which is pumped by a commercial-available laser diode (LD) at 974 nm. The LD is electronically modulated by the driving current and the diode output contains both continuous wave (CW) and pulsed components. The CW component is set just below the threshold of the single-frequency fiber laser for reducing the requirement of the pump pulse energy. Above the threshold, the gain-switched oscillation is trigged by the pulsed component of the diode. Single-frequency pulsed laser output is achieved at 1.063 μm with a pulse duration of ~150 ns and a linewidth of 14 MHz. The repetition rate of the laser output can be tuned between 10 kHz and 400 kHz by tuning the electronic trigger signal. This kind of lasers shows potential for the applications in the area of coherent LIDAR etc.

  11. Nonreciprocal lasing and polarization selectivity in silicon ring Raman lasers based on micro- and nano-scale waveguides

    Science.gov (United States)

    Vermeulen, N.

    2012-06-01

    In this paper I present a generic model that describes the lasing characteristics of continuous-wave circular and racetrack-shaped ring Raman lasers based on micro- and nano-scale silicon waveguides, including their lasing directionality and polarization behavior. This model explicitly takes into account the effective Raman gain values for forward and backward lasing, the Raman amplification in the bus waveguide, and the spatial gain variations for different polarization states in the ring structure. I show numerically that ring lasers based on micro-scale waveguides generate unidirectional lasing in either the forward or backward direction because of an asymmetry in nonlinear losses at near-infrared telecommunication wavelengths, whereas those based on nanowires yield only backward lasing due to a non-reciprocity in effective gain. Furthermore, the model indicates that backward lasing can yield a significantly higher lasing output at the bus waveguide facets than lasing in the forward direction. Finally, considering a TE-polarized pump input for a (100) grown silicon ring Raman laser, I demonstrate numerically that the polarization state of the lasing radiation strongly depends on whether micro-scale or nano-scale waveguides are used.

  12. Study on relaxation oscillation of Er~(3+)/Yb~(3+) co-doped phosphate glass optical waveguide laser

    Institute of Scientific and Technical Information of China (English)

    LIU HuaDong; ZHANG XiaoXia; WU XianLi; ZHANG Qin; LIU YongZhi

    2009-01-01

    Based on the principle and fabrication of the optical waveguide laser, and through the configuration of the energy level of Er~(3+)/Yb~(3+) co-doped system, the time-dependent rate equations are formed and then solved by Runge-Kutta algorithm. The dynamic characteristic of the waveguide laser pumped unidirec-tionally by 980 nm LD is analyzed. The curves of the relaxation oscillation are drawn, showing that the photon number and inverted population vary alternately. The attenuation characteristic of the peak power is studied. It is gained that time constant changes with pump power, length of waveguide and the reflectivity of output mirror. Furthermore, the impact of the above three parameters on the frequency and end-time of relaxation oscillation is discussed. The frequency of relaxation oscillation is propor-tional to the pump power. Under high reflectivity conditions, the length of waveguide has a weak impact on the frequency. The end-time decreases as the three parameters increase. These features and results provide a theoretical basis for designing the Er~(3+)/Yb~(3+) co-doped phosphate optical waveguide laser.

  13. Power scaling from buried depressed-cladding waveguides realized in Nd:YVO4 by femtosecond-laser beam writing

    Science.gov (United States)

    Salamu, Gabriela; Pavel, Nicolaie

    2016-10-01

    We report on output power performances obtained by diode-laser pumping of buried cladding-waveguides that were inscribed with a femtosecond-laser beam writing technique in several Nd:YVO4 media. Continuous-wave output power of 3.4 W at 1.06 μm for an absorbed pump power at 808 nm of 10.3 W was obtained from a circular waveguide of 100-μm diameter that was realized in a 6.9-mm long, 0.5-at% Nd:YVO4 crystal; the slope efficiency with respect to the absorbed pump power was 0.36. The pump at 880 nm, directly into the 4F3/2 emitting level, was used to improve the waveguide output characteristics. With an absorbed pump power of 9.8 W at 880 nm, the same waveguide yielded 4.4 W at 1.06 μm, whereas for emission at 1.34 μm the output power reached 1.7 W; the slope efficiency improved to 0.47 for laser emission at 1.06 μm and reached 0.24 for operation at 1.34 μm. Results recorded from similar waveguides that were inscribed in 0.7-at% Nd:YVO4 and 1.0-at% Nd:YVO4 crystals are presented.

  14. Relativistic nonlinearity and wave-guide propagation of rippled laser beam in plasma

    Indian Academy of Sciences (India)

    R K Khanna; K Baheti

    2001-06-01

    In the present paper we have investigated the self-focusing behaviour of radially symmetrical rippled Gaussian laser beam propagating in a plasma. Considering the nonlinearity to arise from relativistic phenomena and following the approach of Akhmanov et al, which is based on the WKB and paraxial-ray approximation, the self-focusing behaviour has been investigated in some detail. The effect of the position and width of the ripple on the self-focusing of laser beam has been studied for arbitrary large magnitude of nonlinearity. Results indicate that the medium behaves as an oscillatory wave-guide. The self-focusing is found to depend on the position parameter of ripple as well as on the beam width. Values of critical power has been calculated for different values of the position parameter of ripple. Effects of axially and radially inhomogeneous plasma on self-focusing behaviour have been investigated and presented here.

  15. Femtosecond Carrier Dynamics and Modelocking in Monolithic CPM Lasers. [SB1

    DEFF Research Database (Denmark)

    Brorson, S.D.; Bischoff, Svend; MØrk, J.

    1996-01-01

    Femtosecond pump-probe measurements of the dynamics in both forward- and reverse-biased semiconductor optical waveguides arepresented. Slow (nanosecond) as well as ultrafast (femtosecond) dynamics are observed in both kinds of structures....

  16. Femtosecond Carrier Dynamics and Modelocking in Monolithic CPM Lasers. [SB1

    DEFF Research Database (Denmark)

    Brorson, S.D.; Bischoff, Svend; MØrk, J.;

    1996-01-01

    Femtosecond pump-probe measurements of the dynamics in both forward- and reverse-biased semiconductor optical waveguides arepresented. Slow (nanosecond) as well as ultrafast (femtosecond) dynamics are observed in both kinds of structures....

  17. Working characteristics of external distributed feedback polymer lasers with varying waveguiding structures

    Science.gov (United States)

    Huang, Wenbin; Shen, Su; Pu, Donglin; Wei, Guojun; Ye, Yan; Peng, Changsi; Chen, Linsen

    2015-12-01

    We report the fabrication and characterization of second-order external distributed feedback (DFB) lasers based on blue-emitting polymer poly (9, 9-dioctyl-fluorene) (PFO). The relief grating prepared in the photo-resist layer on top of the gain medium was directly employed as the resonator. The effect of various structural parameters including the thickness of the active film, the thickness of the residue layer, and the depth of the relief grating on performance of these polymer lasers was investigated. An analytical approach based on the slab waveguiding theory and the Bragg condition was developed to accurately determine the lasing wavelength. We found that laser threshold increases monotonously as the thickness of the residue layer increases. The presence of the residue layer between the relief grating and the organic semiconductor layer weakens the strength of light coupling between the two layers, leading to a decreased gain for the specific lasing mode. The lowest laser threshold level of 80 μJ cm-2 was obtained when the thickness of the gain medium was around 250 nm, indicating an optimum balance between light feedback provided by the grating and optical amplification in the organic semiconductor. Our results not only provide insights into working mechanisms of external DFB polymer lasers, but also design rules for fabricating them.

  18. Femtosecond laser writing of new type of waveguides in silver containing glasses (Conference Presentation)

    Science.gov (United States)

    Abou Khalil, Alain; Bérubé, Jean-Philippe; Danto, Sylvain; Desmoulin, Jean-Charles; Cardinal, Thierry; Petit, Yannick G.; Canioni, Lionel; Vallée, Réal

    2017-03-01

    Femtosecond laser writing in glasses is a growing field of research and development in photonics, since it provides a versatile, robust and efficient approach to directly address 3D material structuring. Laser-glass interaction process has been studied for many years, especially the local changes of the refractive index that have been classified by three distinct types (types I, II and III, respectively). These refractive index modifications are widely used for the creation of photonics devices such as waveguides [1], couplers, photonic crystals to fabricate integrated optical functions in glasses for photonic applications as optical circuits or integrated sensors. Femtosecond laser writing in a home-developed silver containing zinc phosphate glasses induces the creation of fluorescent silver clusters distributed around the laser-glass interaction voxel [2]. In this paper, we introduce a new type of refractive index modification in glasses. It is based on the creation of these photo-induced silver clusters allowing a local change in the refractive index Δn = 5×10-3, which is sufficient for the creation of waveguides and photonics devices. The wave guiding process in our glasses along these structures with original geometry is demonstrated for wavelengths from visible to NIR [3], giving a promising access to integrated optical circuits in these silver containing glasses. Moreover, the characterization of the waveguides is presented, including their original geometry, the refractive index change, the mode profile, the estimation of propagation losses and a comparison with simulation results. 1. K. M. Davis, K. Miura, N. Sugimoto, and K. Hirao, Opt. Lett. 21, 1729-1731 (1996). 2. M. Bellec, A. Royon, K. Bourhis, J. Choi, B. Bousquet, M. Treguer, T. Cardinal, J.-J. Videau, M. Richardson, and L. Canioni, The Journal of Physical Chemistry C 114, 15584-15588 (2010). 3. S. Danto, F. Désévédavy, Y. Petit, J.-C. Desmoulin, A. Abou Khalil, C. Strutynski, M. Dussauze, F

  19. Stable microwave generation in a dual-phase-shifted Al2O3:Yb3+ distributed-feedback waveguide laser

    NARCIS (Netherlands)

    Bernhardi, Edward; van Wolferen, Hendricus A.G.M.; Worhoff, Kerstin; de Ridder, R.M.; Pollnau, Markus

    A dual-wavelength distributed-feedback channel waveguide laser in ytterbium-doped aluminum oxide was used to create a microwave beat signal at ~15 GHz, with a frequency stability of ±2.5 MHz and a power stability of ±0.35 dB.

  20. Theoretical Studies of the Output Pulse with Variation of the Pumping Pulse for RF Excited CO2 Pulsed Waveguide Laser

    Institute of Scientific and Technical Information of China (English)

    A Rauf; ZHOU Wei; XIN Jian-guo

    2006-01-01

    The behavior of a RF-excited waveguide CO2 laser in the pulse regime is studied theoretically. The output pulse evolution is studied by applying three types of pulses namely the square, sine and the triangular ones as the excitation pulses. The frequency dependence behavior of the output pulse is also presented.

  1. Distributed feedback channel waveguide lasers in erbium- and ytterbium-doped Al2O3:Er3+ on silicon

    NARCIS (Netherlands)

    Bernhardi, Edward; van Wolferen, Hendricus A.G.M.; Worhoff, Kerstin; de Ridder, R.M.; Pollnau, Markus

    We present the fabrication and performance of distributed feedback channel waveguide lasers in erbium- and ytterbium-doped aluminium oxide. The low-threshold devices demonstrate slope efficiencies up to 67% and narrow linewidths as low as 1.7 kHz.

  2. Stable microwave generation in a dual-phase-shifted $Al_2O_3:Yb^{3+}$ distributed-feedback waveguide laser

    NARCIS (Netherlands)

    Bernhardi, E.H.; Wolferen, van H.A.G.M.; Wörhoff, K.; Ridder, de R.M.; Pollnau, M.

    2012-01-01

    A dual-wavelength distributed-feedback channel waveguide laser in ytterbium-doped aluminum oxide was used to create a microwave beat signal at ~15 GHz, with a frequency stability of ±2.5 MHz and a power stability of ±0.35 dB.

  3. Monolithic integration of an (Al)GaAs laser and an intracavity electroabsorption modulator using selective partial interdiffusion

    Science.gov (United States)

    O'Brien, S.; Shealy, J. R.; Wicks, G. W.

    1991-04-01

    The monolithic integration of an intracavity modulator with a multiple quantum well (Al)GaAs laser has been accomplished with the use of selective partial interdiffusion. Interdiffusion was used to create a blue-shifted and semitransparent modulator section in a ridge laser structure. In measuring the total optical output power from the devices, steady-state extinction ratios of 20 dB were measured at reverse biases of -4.6 and -3.6 V for modulator sections with lengths of 200 and 400 microns, respectively. Shifting of the lasing mode toward longer wavelengths was also observed making the structure useful as a tunable device and for frequency modulation applications.

  4. Ultrafast laser writing of optical waveguides in ceramic Yb:YAG: a study of thermal and non-thermal regimes

    Energy Technology Data Exchange (ETDEWEB)

    Benayas, A.; Jaque, D. [Universidad Autonoma de Madrid, Departamento de Fisica de Materiales, Madrid (Spain); Silva, W.F.; Jacinto, C. [Universidade Federal de Alagoas, Grupo de Fotonica e Fluidos Complexos, Instituto de Fisica, Maceio, Alagoas (Brazil); Rodenas, A.; Thomsom, R.R.; Psaila, N.D.; Reid, D.T.; Kar, A.K. [Heriot-Watt University, School of Engineering and Physical Sciences, Edinburgh (United Kingdom); Vazquez de Aldana, J. [Universidad de Salamanca, Grupo de Optica, Departamento de Fisica Aplicada, Facultad de Ciencias Fisicas, Salamanca (Spain); Chen, F.; Tan, Y. [Shandong University, School of Physics, Jinan (China); Torchia, G.A. [CONICET-CIC, Centro de Investigaciones Opticas, La Plata (Argentina)

    2011-07-15

    We report the improvement of ultrafast laser written optical waveguides in Yb:YAG ceramics by tailoring the presence of heat accumulation effects. From a combination of ytterbium micro-luminescence and micro-Raman structural analysis, maps of lattice defects and stress fields have been obtained. We show how laser annealing can strongly reduce the concentration of defects and also reduce compressive stress, leading to an effective 50% reduction in the propagation losses and to more extended and symmetric propagation modes. (orig.)

  5. Competition of Faraday rotation and birefringence in femtosecond laser direct written waveguides in magneto-optical glass.

    Science.gov (United States)

    Liu, Qiang; Gross, S; Dekker, P; Withford, M J; Steel, M J

    2014-11-17

    We consider the process of Faraday rotation in femtosecond laser direct-write waveguides. The birefringence commonly associated with such waveguides may be expected to impact the observable Faraday rotation. Here, we theoretically calculate and experimentally verify the competition between Faraday rotation and birefringence in two waveguides created by laser writing in a commercial magneto-optic glass. The magnetic field applied to induce Faraday rotation is nonuniform, and as a result, we find that the two effects can be clearly separated and used to accurately determine even weak birefringence. The birefringence in the waveguides was determined to be on the scale of Δn = 10(-6) to 10(-5). The reduction in Faraday rotation caused by birefringence of order Δn = 10(-6) was moderate and we obtained approximately 9° rotation in an 11 mm waveguide. In contrast, for birefringence of order 10(-5), a significant reduction in the polarization azimuth change was found and only 6° rotation was observed.

  6. Hybrid integration of III-V semiconductor lasers on silicon waveguides using optofluidic microbubble manipulation

    Science.gov (United States)

    Jung, Youngho; Shim, Jaeho; Kwon, Kyungmook; You, Jong-Bum; Choi, Kyunghan; Yu, Kyoungsik

    2016-07-01

    Optofluidic manipulation mechanisms have been successfully applied to micro/nano-scale assembly and handling applications in biophysics, electronics, and photonics. Here, we extend the laser-based optofluidic microbubble manipulation technique to achieve hybrid integration of compound semiconductor microdisk lasers on the silicon photonic circuit platform. The microscale compound semiconductor block trapped on the microbubble surface can be precisely assembled on a desired position using photothermocapillary convective flows induced by focused laser beam illumination. Strong light absorption within the micro-scale compound semiconductor object allows real-time and on-demand microbubble generation. After the assembly process, we verify that electromagnetic radiation from the optically-pumped InGaAsP microdisk laser can be efficiently coupled to the single-mode silicon waveguide through vertical evanescent coupling. Our simple and accurate microbubble-based manipulation technique may provide a new pathway for realizing high precision fluidic assembly schemes for heterogeneously integrated photonic/electronic platforms as well as microelectromechanical systems.

  7. Laser frequency stabilisation via quasi-monolithic, unequal arm-length Mach-Zehnder interferometer with balanced DC readout

    CERN Document Server

    Gerberding, Oliver; Mehmet, Moritz; Danzmann, Karsten; Heinzel, Gerhard

    2016-01-01

    Low frequency high precision laser interferometry is subject to excess laser frequency noise coupling via arm-length differences which is commonly mitigated by locking the frequency to a stable reference system. This is crucial to achieve picometer level sensitivities in the 0.1 mHz to 1 Hz regime, where laser frequency noise is usually high and couples into the measurement phase via arm-length mismatches in the interferometers. Here we describe the results achieved by frequency stabilising an external cavity diode laser to a quasi-monolithic unequal arm-length Mach-Zehnder interferometer read out at mid-fringe via balanced detection. This stabilisation scheme has been found to be an elegant solution combining a minimal number of optical components, no additional laser modulations and relatively low frequency noise levels. The Mach-Zehnder interferometer has been designed and constructed to minimise the influence of thermal couplings and to reduce undesired stray light using the optical simulation tool IfoCAD...

  8. 10 Gbps Colorless Optical Source in Wavelength-Division Multiplexed Passive Optical Networks for Monolithic Integration of Deep-Ridge Waveguide Electroabsorption Modulator with Planar Buried-Heterostructure Semiconductor Optical Amplifier

    Science.gov (United States)

    Kim, Dong Churl; Kim, Ki Soo; Kim, Hyun-Soo; Choi, Byung-Seok; Kwon, O.-Kyun

    2012-05-01

    For the 10 Gbps colorless optical source in wavelength-division multiplexed passive optical networks (WDM-PONs), we have fabricated a semiconductor optical amplifier-reflective electorabsorption modulator (SOA-REAM) by monolithic integration of deep-ridge waveguide REAM (DRW-REAM) with planar buried-heterostructure (PBH) SOA using a PNP-current blocking layer. The SOA-REAM has a spot-size convertor for easy fiber coupling. Using a butterfly module with an SMA connector, we have packaged the SOA-REAM. At a -10 dBm input power of 1550 nm, the saturation output power is about 6 dBm. At 10.7 Gbps, we can obtain clear eye diagrams, and the power penalty at 10-9 bit-error rate (BER) after 20 km transmission is less than 1 dB over 35 nm.

  9. Mid-infrared laser light nulling experiment using single-mode conductive waveguides

    CERN Document Server

    Labadie, L; Maurand, R; Labeye, P; Kern, P; Arezki, B; Broquin, J -E

    2007-01-01

    Aims: In the context of space interferometry missions devoted to the search of exo-Earths, this paper investigates the capabilities of new single mode conductive waveguides at providing modal filtering in an infrared and monochromatic nulling experiment; Methods: A Michelson laser interferometer with a co-axial beam combination scheme at 10.6 microns is used. After introducing a Pi phase shift using a translating mirror, dynamic and static measurements of the nulling ratio are performed in the two cases where modal filtering is implemented and suppressed. No additional active control of the wavefront errors is involved. Results: We achieve on average a statistical nulling ratio of 2.5e-4 with a 1-sigma upper limit of 6e-4, while a best null of 5.6e-5 is obtained in static mode. At the moment, the impact of external vibrations limits our ability to maintain the null to 10 to 20 seconds.; Conclusions: A positive effect of SM conductive waveguide on modal filtering has been observed in this study. Further improv...

  10. Independent control of beam astigmatism and ellipticity using a SLM for fs-laser waveguide writing.

    Science.gov (United States)

    Ruiz de la Cruz, A; Ferrer, A; Gawelda, W; Puerto, D; Sosa, M Galván; Siegel, J; Solis, J

    2009-11-09

    We have used a low repetition rate (1 kHz), femtosecond laser amplifier in combination with a spatial light modulator (SLM) to write optical waveguides with controllable cross-section inside a phosphate glass sample. The SLM is used to induce a controllable amount of astigmatism in the beam wavefront while the beam ellipticity is controlled through the propagation distance from the SLM to the focusing optics of the writing set-up. The beam astigmatism leads to the formation of two separate disk-shaped foci lying in orthogonal planes. Additionally, the ellipticity has the effect of enabling control over the relative peak irradiances of the two foci, making it possible to bring the peak irradiance of one of them below the material transformation threshold. This allows producing a single waveguide with controllable cross-section. Numerical simulations of the irradiance distribution at the focal region under different beam shaping conditions are compared to in situ obtained experimental plasma emission images and structures produced inside the glass, leading to a very satisfactory agreement. Finally, guiding structures with controllable cross-section are successfully produced in the phosphate glass using this approach.

  11. Monolithic Ytterbium All-single-mode Fiber Laser with Direct Fiber-end Delivery of nJ-level Femtosecond Pulses

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry

    2008-01-01

    We demonstrate a monolithic, i.e. without any free-space coupling, all-single-mode passively modelocked Yb-fiber laser, with direct fiber-end delivery of 364−405 fs pulses of 4 nJ pulse energy using a low-loss hollow-core photonic crystal fiber compression....

  12. One-Watt level mid-IR output, singly resonant, continuous-wave optical parametric oscillator pumped by a monolithic diode laser

    NARCIS (Netherlands)

    Nieuwenhuis, Albert F.; Lee, Christopher James; Sumpf, Bernd; van der Slot, Petrus J.M.; Erbert, Götz; Boller, Klaus J.

    2010-01-01

    We report more than 1.1 Watt of idler power at 3373 nm in a singly resonant optical parametric oscillator (SRO), directly pumped by a single-frequency monolithic tapered diode laser. The SRO is based on a periodically poled MgO:LiNbO3 crystal in a four mirror cavity and is excited by 8.05 W of 1062

  13. A Sampled Grating DBR Laser Monolithically Integrated by Using SOAs with 22 mW Output Power and 51 ITU 100 GHz Channels over 43 nm

    Science.gov (United States)

    Liu, Yang; Ye, Nan; Zhou, Dai-Bing; Wang, Bao-Jun; Pan, Jiao-Qing; Zhao, Ling-Juan; Wang, Wei

    2011-02-01

    A sampled grating distributed Bragg reflector (SG-DBR) laser monolithically integrated with semiconductor optical amplifiers (SOAs), which has a tuning range over 43 nm from 1514.05 nm to 1557.4 nm covering 49 continuous and totally 51 ITU 100 GHz standard channels and an output power more than 22 mW for all output wavelengths, is successfully demonstrated.

  14. The Theory for the Dielectric Slab Waveguide with Complex Refractive Index Applied to GaAs Lasers

    DEFF Research Database (Denmark)

    Buus, Jens

    1977-01-01

    In this paper we investigate the homogeneous dielectric slab waveguide in the case of complex dielectric constants. A method for calculating the field distribution in a dielectric waveguide with an arbitrary symmetrical variation in the refractive index is developed, and some of the results...... are presented. The results are applied to the GaAs laser. It is fonud that the guiding mechanism is a combination of gain guiding and index antiguiding. Based on the calculations an explanation of the kinks on the light current characteristics is suggested....

  15. Broadband tunable external cavity laser using a bent-waveguide quantum-dot superluminescent diode as gain device

    Institute of Scientific and Technical Information of China (English)

    Wu Jian; Lü Xue-Qin; Jin Peng; Meng Xian-Quan; Wang Zhan-Guo

    2011-01-01

    A broadband tunable grating-coupled external cavity laser is realized by employing a self-assembled InAs/GaAs quantum-dot (QD) superluminescent diode (SLD) as the gain device. The SLD device is processed with a bent-waveguide structure and facet antireflection (AR) coating. Tuning bandwidths of 106 nm and 117 nm are achieved under 3-A and 3.5-A injection currents, respectively. The large tuning range originates essentially from the broad gain spectrum of self-assembled QDs. The bent waveguide structure combined with the facet AR coating plays a role in suppressing the inner-cavity lasing under a large injection current.

  16. Ultrafast laser inscribed integrated waveguide components for L-band interferometry

    Science.gov (United States)

    Arriola, A.; Mukherjee, S.; Choudhury, Debaditya; Labadie, L.; Thomson, R. R.

    2014-07-01

    In this paper we report the fabrication and mid-infrared characterization (λ = 3.39 μm) of evanescent field directional couplers. These devices were fabricated using the femtosecond laser direct-writing technique in commercially available Gallium Lanthanum Sulphide (GLS) glass substrates. We demonstrate that the power splitting ratios of the devices can be controlled by adjusting the length of the interaction section between the waveguides, and consequently we demonstrate power splitting ratios of between 8% and 99% for 3.39 μm light. We anticipate that mid-IR beam integrated-optic beam combination instruments based on this technology will be key for future mid-infrared astronomical interferometry, particularly for nulling interferometry and earth-like exoplanet imaging.

  17. Ultrafast Laser Inscription of a 121-Waveguide Fan-Out for Astrophotonics

    CERN Document Server

    Thomson, R R; Birks, T A; Brown, G; Allington-Smith, J; Bland-Hawthorn, J

    2012-01-01

    Using ultrafast laser inscription, we report the fabrication of a prototype three-dimensional 121-waveguide fan-out device capable of reformatting the output of a 120 core multicore fiber (MCF) into a one-dimensional linear array. When used in conjunction with an actual MCF, we demonstrate that the reformatting function using this prototype would result in an overall throughput loss of approximately 7.0 dB. However, if perfect coupling from the MCF into the fan-out could be achieved, the reformatting function would result in an overall loss of only approximately 1.7 dB. With adequate development, similar devices could efficiently reformat the output of so-called "photonic lanterns" fabricated using highly multicore fibers.

  18. Near-field microscopy of waveguide architectures of InGaN/GaN diode lasers

    Science.gov (United States)

    Friede, Sebastian; Tomm, Jens W.; Kühn, Sergei; Hoffmann, Veit; Wenzel, Hans; Weyers, Markus

    2016-11-01

    Waveguide (WG) architectures of 420 nm emitting InGaN/GaN diode lasers are analyzed by photoluminescence and photocurrent spectroscopy using a nearfield scanning optical microscope that scans along their front facets. The components of the ‘optical active cavity’, quantum wells, WGs, and cladding layers are individually inspected with a spatial resolution of ∼100 nm. Separate analysis of the p- and n-sections of the WG was achieved, and reveals defect levels in the p-part. Moreover, it is demonstrated that the homogeneity of the n-WG section directly affects the quantum wells that are grown on top of this layer. Substantially increased carrier capture efficiencies into InGaN/GaN-WGs compared to GaN-WGs are demonstrated.

  19. Hollow glass and plastic waveguides for the delivery of Er:YAG and CO2 laser radiation

    Science.gov (United States)

    Harrington, James A.; Rabii, Christopher D.; Dobin, Derek E.; Haan, David J.

    1998-01-01

    Hollow glass waveguides are an attractive fiber delivery system for both the 3 micrometers Er:YAG and 10.6 micrometers CO2 lasers. The losses for these waveguides are as low as 0.2 dB/m at CO2 laser wavelengths for guides with a 700 micrometers bore. At the shorter wavelengths of the Er:YAG laser the losses are higher than those predicted theoretically. This is shown to be a result of surface roughness of the inner coatings. These hollow guides are found to have losses which change little with time or cyclic flexure. A new version of these guides made from polycarbonate tubing is described and the losses for these guides are shown to compare favorably with those for the glass guides.

  20. Tuning of successively scanned two monolithic Vernier-tuned lasers and selective data sampling in optical comb swept source optical coherence tomography

    OpenAIRE

    Choi, Dong-hak; YOSHIMURA, Reiko; Ohbayashi, Kohji

    2013-01-01

    Monolithic Vernier tuned super-structure grating distributed Bragg reflector (SSG-DBR) lasers are expected to become one of the most promising sources for swept source optical coherence tomography (SS-OCT) with a long coherence length, reduced sensitivity roll-off, and potential capability for a very fast A-scan rate. However, previous implementations of the lasers suffer from four main problems: 1) frequencies deviate from the targeted values when scanned, 2) large amounts of noise appear as...

  1. Pulsed laser deposition of silicon dioxide thin films with silicone targets for fabricating waveguide devices

    Science.gov (United States)

    Okoshi, Masayuki; Kuramatsu, Masaaki; Inoue, Narumi

    2002-06-01

    Silicon dioxide (SiO2) thin films were deposited at room temperature by 193-nm ArF excimer laser ablation of silicone in oxygen atmosphere. Only the side chains of the target were photo-dissociated during ablation to deposit Si-O bonds on a substrate in high laser fluence at about 10 J/cm2. Oxygen gas worked to oxidize the Si-O bonds ejected from the target to from SiO2 thin films at the gas pressure of 4.4 X 10-2 Torr, in addition to reducing the isolated carbon mixed into the films. We also found that the deposited rate could control refractive index of the films. The refractive index of the film deposited at 0.05 nm/pulse is greater than that of the film at 0.1 nm/pulse. Thus, a 0.2-micrometers thick SiO2 cladding film deposited at 0.1 nm/pulse was firstly formed on the whole surface of a 100- micrometers -thick polyester film, and then a 0.6 micrometers -thick SiO2 core film at 0.05 nm/pulse was fabricated in a line on the sample. The sample functioned as a waveguide device for a 633-nm line of He-Ne laser.

  2. Room-temperature subnanosecond waveguide lasers in Nd:YVO4 Q-switched by phase-change VO2: A comparison with 2D materials

    Science.gov (United States)

    Nie, Weijie; Li, Rang; Cheng, Chen; Chen, Yanxue; Lu, Qingming; Romero, Carolina; Vázquez de Aldana, Javier R.; Hao, Xiaotao; Chen, Feng

    2017-01-01

    We report on room-temperature subnanosecond waveguide laser operation at 1064 nm in a Nd:YVO4 crystal waveguide through Q-switching of phase-change nanomaterial vanadium dioxide (VO2). The unique feature of VO2 nanomaterial from the insulating to metallic phases offers low-saturation-intensity nonlinear absorptions of light for subnanosecond pulse generation. The low-loss waveguide is fabricated by using the femtosecond laser writing with depressed cladding geometry. Under optical pump at 808 nm, efficient pulsed laser has been achieved in the Nd:YVO4 waveguide, reaching minimum pulse duration of 690 ps and maximum output average power of 66.7 mW. To compare the Q-switched laser performances by VO2 saturable absorber with those based on two-dimensional materials, the 1064-nm laser pulses have been realized in the same waveguide platform with either graphene or transition metal dichalcogenide (in this work, WS2) coated mirror. The results on 2D material Q-switched waveguide lasers have shown that the shortest pulses are with 22-ns duration, whilst the maximum output average powers reach ~161.9 mW. This work shows the obvious difference on the lasing properties based on phase-change material and 2D materials, and suggests potential applications of VO2 as low-cost saturable absorber for subnanosecond laser generation. PMID:28383017

  3. Room-temperature subnanosecond waveguide lasers in Nd:YVO4 Q-switched by phase-change VO2: A comparison with 2D materials

    Science.gov (United States)

    Nie, Weijie; Li, Rang; Cheng, Chen; Chen, Yanxue; Lu, Qingming; Romero, Carolina; Vázquez de Aldana, Javier R.; Hao, Xiaotao; Chen, Feng

    2017-04-01

    We report on room-temperature subnanosecond waveguide laser operation at 1064 nm in a Nd:YVO4 crystal waveguide through Q-switching of phase-change nanomaterial vanadium dioxide (VO2). The unique feature of VO2 nanomaterial from the insulating to metallic phases offers low-saturation-intensity nonlinear absorptions of light for subnanosecond pulse generation. The low-loss waveguide is fabricated by using the femtosecond laser writing with depressed cladding geometry. Under optical pump at 808 nm, efficient pulsed laser has been achieved in the Nd:YVO4 waveguide, reaching minimum pulse duration of 690 ps and maximum output average power of 66.7 mW. To compare the Q-switched laser performances by VO2 saturable absorber with those based on two-dimensional materials, the 1064-nm laser pulses have been realized in the same waveguide platform with either graphene or transition metal dichalcogenide (in this work, WS2) coated mirror. The results on 2D material Q-switched waveguide lasers have shown that the shortest pulses are with 22-ns duration, whilst the maximum output average powers reach ~161.9 mW. This work shows the obvious difference on the lasing properties based on phase-change material and 2D materials, and suggests potential applications of VO2 as low-cost saturable absorber for subnanosecond laser generation.

  4. Versatile large-mode-area femtosecond laser-written Tm:ZBLAN glass chip lasers.

    Science.gov (United States)

    Lancaster, D G; Gross, S; Fuerbach, A; Heidepriem, H Ebendorff; Monro, T M; Withford, M J

    2012-12-01

    We report performance characteristics of a thulium doped ZBLAN waveguide laser that supports the largest fundamental modes reported in a rare-earth doped planar waveguide laser (to the best of our knowledge). The high mode quality of waveguides up to 45 um diameter (~1075 μm(2) mode-field area) is validated by a measured beam quality of M(2)~1.1 ± 0.1. Benefits of these large mode-areas are demonstrated by achieving 1.9 kW peak-power output Q-switched pulses. The 1.89 μm free-running cw laser produces 205 mW and achieves a 67% internal slope efficiency corresponding to a quantum efficiency of 161%. The 9 mm long planar chip developed for concept demonstration is rapidly fabricated by single-step optical processing, contains 15 depressed-cladding waveguides, and can operate in semi-monolithic or external cavity laser configurations.

  5. The single-longitudinal-mode operation of a ridge waveguide laser based on two-dimensional photonic crystals

    Institute of Scientific and Technical Information of China (English)

    Wang Hua-Yong; Xu Xing-Sheng

    2013-01-01

    An electrically driven,single-longitudinal-mode GaAs based photonic crystal (PC) ridge waveguide (RWG) laser emitting at around 850 nm is demonstrated.The single-longitudinal-mode lasing characteristic is achieved by introducing the PC to the RWG laser.The triangle PC is etched on both sides of the ridge by photolithography and inductive coupled plasma (ICP) etching.The lasing spectra of the RWG lasers with and without the PC are studied,and the result shows that the PC purifies the longitudinal mode.The power per facet versus current and current-voltage characteristics have also been studied and compared.

  6. Femtosecond laser written optical waveguides in z-cut MgO:LiNbO3 crystal: Fabrication and optical damage investigation

    Science.gov (United States)

    Lv, Jinman; Cheng, Yazhou; Lu, Qingming; Vázquez de Aldana, Javier R.; Hao, Xiaotao; Chen, Feng

    2016-07-01

    We report on the fabrication of the dual-line waveguides and cladding waveguide in z-cut MgO:LiNbO3 crystal by femtosecond laser inscription. Due to the diverse modification of refractive index along TE/TM polarization induced by femtosecond laser pulses, the two geometries exhibit different guiding performances: the dual-line waveguides only support extraordinary index polarization, whilst the depressed cladding waveguide supports guidance along both extraordinary and ordinary index polarizations. The measured optical damage of these waveguides at the wavelength of 532 nm is higher than that of the previously reported ion-implanted waveguides in Zr-doped LiNbO3. The propagation loss of depressed cladding waveguide is measured as low as 0.94 dB/cm at 632.8 nm wavelength. It is found that the optical damage threshold (∼105 W/cm2) of the dual-line waveguide is one order of magnitude higher than that of the cladding waveguide (∼104 W/cm2).

  7. Eight-wavelength distributed-Bragg-reflector (DBR) laser array transmitter for WDM applications

    Science.gov (United States)

    Fallahi, Mahmoud; McGreer, K. A.; Delage, Andre; Neophytou, A.; Templeton, Ian M.; Champion, Garth; Chatenoud, F.; Barber, Richard A.; Wang, Weijian; He, Jian Jun; Koteles, Emil S.

    1995-03-01

    We report on the design, growth, fabrication and characterization of monolithic wavelength division multiplexed (WDM) laser array transmitter and receiver chips produced by the Canadian Solid State Optoelectronics Consortium. The transmitter chip includes multiple, discrete wavelength, distributed Bragg reflector (DBR) laser diodes monolithically integrated with waveguide combiners fabricated using an InGaAs/GaAs heterostructure. The corresponding wavelength demultiplexer unit is based on a Rowland circle grating spectrometer monolithically integrated with a metal-semiconductor-metal (MSM) detector array fabricated on an InGaAs/AlGaAs/GaAs heterostructure. The epitaxial layer wafers for both transmitter and receiver modules were grown in single molecular beam epitaxy (MBE) runs.

  8. 25 kHz narrow spectral bandwidth of a wavelength tunable diode laser with a short waveguide-based external cavity

    NARCIS (Netherlands)

    Oldenbeuving, R. M.; Klein, E. J.; Offerhaus, H. L.; Lee, C. J.; Song, H.; Boller, K. J.

    2013-01-01

    We report on the spectral properties of a diode laser with a tunable external cavity mirror, realized as an integrated optics waveguide circuit. Even though the external cavity is short compared to that of other narrow bandwidth external cavity lasers, the spectral bandwidth of this tunable laser is

  9. Efficient Second Harmonic Generation in 3D Nonlinear Optical-Lattice-Like Cladding Waveguide Splitters by Femtosecond Laser Inscription.

    Science.gov (United States)

    Nie, Weijie; Jia, Yuechen; Vázquez de Aldana, Javier R; Chen, Feng

    2016-02-29

    Integrated photonic devices with beam splitting function are intriguing for a broad range of photonic applications. Through optical-lattice-like cladding waveguide structures fabricated by direct femtosecond laser writing, the light propagation can be engineered via the track-confined refractive index profiles, achieving tailored output beam distributions. In this work, we report on the fabrication of 3D laser-written optical-lattice-like structures in a nonlinear KTP crystal to implement 1 × 4 beam splitting. Second harmonic generation (SHG) of green light through these nonlinear waveguide beam splitter structures provides the capability for the compact visible laser emitting devices. With Type II phase matching of the fundamental wavelength (@ 1064 nm) to second harmonic waves (@ 532 nm), the frequency doubling has been achieved through this three-dimensional beam splitter. Under 1064-nm continuous-wave fundamental-wavelength pump beam, guided-wave SHG at 532 nm are measured with the maximum power of 0.65 mW and 0.48 mW for waveguide splitters (0.67 mW and 0.51 mW for corresponding straight channel waveguides), corresponding to a SH conversion efficiency of approximately ~14.3%/W and 13.9%/W (11.2%/W, 11.3%/W for corresponding straight channel waveguides), respectively. This work paves a way to fabricate compact integrated nonlinear photonic devices in a single chip with beam dividing functions.

  10. Single-mode surface-emitting distributed feedback quantum-cascade lasers based on hybrid waveguide structure

    Institute of Scientific and Technical Information of China (English)

    Wanhong Guo; Junqi Liu; Jianyan Chen; Lu Li; Lijun Wang; Fengqi Liu; Zhanguo Wang

    2011-01-01

    Surface-emitting distributed feedback quantum-cascade lasers operating at λ≈7.8 μm are demonstrated.The metal-covered second-order grating is shallow-etched into the surface of a thin InGaAs contact and cladding layer. This forms a hybrid waveguide and used to achieve relatively low waveguide losses and high coupling strengths. The devices exhibit stable single-mode operation from 90 to 130 K with a side mode suppression ratio above 20 dB. A slope efficiency of 194 mW/A is obtained at 90 K, which is twice higher than that of the Fabry-Perot counterpart.%@@ Surface-emitting distributed feedback quantum-cascade lasers operating at λ≈7.8 μm are demonstrated.The metal-covered second-order grating is shallow-etched into the surface of a thin InGaAs contact and cladding layer.This forms a hybrid waveguide and used to achieve relatively low waveguide losses and high coupling strengths.The devices exhibit stable single-mode operation from 90 to 130 K with a side mode suppression ratio above 20 dB.A slope efficiency of 194 mW/A is obtained at 90 K, which is twice higher than that of the Fabry-Perot counterpart.

  11. Low-repetition rate femtosecond laser writing of optical waveguides in KTP crystals: analysis of anisotropic refractive index changes.

    Science.gov (United States)

    Butt, Muhammad Ali; Nguyen, Huu-Dat; Ródenas, Airán; Romero, Carolina; Moreno, Pablo; Vázquez de Aldana, Javier R; Aguiló, Magdalena; Solé, Rosa Maria; Pujol, Maria Cinta; Díaz, Francesc

    2015-06-15

    We report on the direct low-repetition rate femtosecond pulse laser microfabrication of optical waveguides in KTP crystals and the characterization of refractive index changes after the thermal annealing of the sample, with the focus on studying the potential for direct laser fabricating Mach-Zehnder optical modulators. We have fabricated square cladding waveguides by means of stacking damage tracks, and found that the refractive index decrease is large for vertically polarized light (c-axis; TM polarized) but rather weak for horizontally polarized light (a-axis; TE polarized), this leading to good near-infrared light confinement for TM modes but poor for TE modes. However, after performing a sample thermal annealing we have found that the thermal process enables a refractive index increment of around 1.5x10(-3) for TE polarized light, while maintaining the negative index change of around -1x10(-2) for TM polarized light. In order to evaluate the local refractive index changes we have followed a multistep procedure: We have first characterized the waveguide cross-sections by means of Raman micro-mapping to access the lattice micro-modifications and their spatial extent. Secondly we have modeled the waveguides following the modified region sizes obtained by micro-Raman with finite element method software to obtain a best match between the experimental propagation modes and the simulated ones. Furthermore we also report the fabrication of Mach-Zehnder structures and the evaluation of propagation losses.

  12. Theoretical study of annealed proton-exchanged Nd $LiNbO_{3}$ channel waveguide lasers with variational method

    CERN Document Server

    De Long Zhang; Yuan Guo Xie; Guilan, Ding; Yuming, Cui; Cai He Chen

    2001-01-01

    The controllable fabrication parameters, including anneal time, initial exchange time, channel width, dependences of TM/sub 00/ mode size, corresponding effective refractive index, effective pump area, and coupling efficiency between pump and laser modes in z-cut annealed proton-exchanged (APE) Nd:LiNbO/sub 3/ channel waveguide lasers were studied by using variational method. The effect of channel width on the surface index increment and the waveguide depth was taken into account. The features of mode size and effective refractive index were summarized, discussed, and compared with previously published experimental results. The effective pump area, which is directly proportional to threshold pump power, increases strongly, slightly, and very slightly with the increase of anneal time, channel width, and initial exchange time, respectively. However, the coupling efficiency, which is directly proportional to slope efficiency, remains constant (around 0.82) no matter what changes made to these parameters. The var...

  13. Hybrid III-V/SOI single-mode vertical-cavity laser with in-plane emission into a silicon waveguide

    DEFF Research Database (Denmark)

    Park, Gyeong Cheol; Xue, Weiqi; Semenova, Elizaveta;

    2015-01-01

    We report a III-V-on-SOI vertical-cavity laser emitting into an in-plane Si waveguide fabricated by using CMOS-compatible processes. The fabricated laser operates at 1.54 µm with a SMSR of 33 dB and a low threshold.......We report a III-V-on-SOI vertical-cavity laser emitting into an in-plane Si waveguide fabricated by using CMOS-compatible processes. The fabricated laser operates at 1.54 µm with a SMSR of 33 dB and a low threshold....

  14. Surface plasmon waveguides with gradually doped or NiAl intermetallic compound buried contact for terahertz quantum cascade lasers

    Science.gov (United States)

    Indjin, D.; Ikonić, Z.; Harrison, P.; Kelsall, R. W.

    2003-09-01

    Improved designs of surface plasmon waveguides for use in GaAs/AlGaAs terahertz quantum cascade lasers are presented. Modal losses and confinement factors are calculated for TM modes in metal-variably doped multilayer semiconductor and metal-intermetallic compound layer clad structures and compared with those obtained in recently realized metal-highly doped semiconductor clad layer structures. Considerable improvements of the mode confinement factors are predicted, and guidelines for choosing the confinement layer parameters are given.

  15. A medium-power small-scale slotted CO/sub 2/ waveguide laser with HF excitation

    Energy Technology Data Exchange (ETDEWEB)

    Vitruk, P.P.; Iatsenko, N.A.

    1989-03-01

    Experimental results are reported on the high-frequency capacitive discharge (HFCD) regime of a medium-power small-scale slotted waveguide CO2 laser. An output power of 100-200 W at an electrooptical efficiency of 5-6 percent was obtained using a CO2:N2:He = 1:1:3 mixture at a pressure of 8-12 torr at a low gas flowrate (0.2 liter/min). 8 refs.

  16. GHz modulation enabled using large extinction ratio waveguide-modulator integrated with 404 nm GaN laser diode

    KAUST Repository

    Shen, Chao

    2017-01-30

    A 404-nm emitting InGaN-based laser diode with integrated-waveguide-modulator showing a large extinction ratio of 11.3 dB was demonstrated on semipolar (2021) plane GaN substrate. The device shows a low modulation voltage of −2.5 V and ∼ GHz −3 dB bandwidth, enabling 1.7 Gbps data transmission.

  17. 50 mJ Monolithic 2 um Pulsed Fiber Laser Transmitter in 200 ns Regime with Transform-Limited Linewidth Based on Highly Tm-Doped Germanate Fibers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For NASA's various types of coherent LIDAR applications, NP Photonics propose to develop a 50 mJ monolithic 2 micron pulsed fiber laser transmitter in 200 ns regime...

  18. High packing density laser diode stack arrays using Al-free active region laser bars with a broad waveguide and discrete copper microchannel-cooled heatsinks

    Institute of Scientific and Technical Information of China (English)

    Zhigang Liu; Gaozhan Fang; Kecheng Feng

    2009-01-01

    A high packing density laser diode stack array is developed utilizing Al-free active region laser bars with a broad waveguide and discrete copper microchannel-cooled heatsinks. The microchannel cooling technology leads to a 10-bar laser diode stack array having the thermal resistance of 0.199 ℃/W, and enables the device to be operated under continuous-wave (CW) condition at an output power of 1200 W. The thickness of the discrete copper heatsink is only 1.5 mm, which results in a high packing density and a small bar pitch of 1.8 mm.

  19. Monolithic integration of MQW wavelength tunable DBR lasers with external cavity electroabsorption modulators by selective-area MOCVD

    Science.gov (United States)

    Lammert, Robert M.; Smith, Gary M.; Hughes, J. S.; Osowski, Mark L.; Jones, A. M.; Coleman, James J.

    1997-01-01

    The design and operation of multiple-quantum well (MQW) wavelength tunable distributed Bragg reflector (DBR) lasers with nonabsorbing gratings and monolithically integrated external cavity electroabsorption modulators fabricated by selective-area metal-organic chemical vapor deposition (MOCVD) are presented. Uncoated devices exhibit cw threshold currents as low as 10.5 mA with slope efficiencies of 0.21 W/A from the laser facet and 0.06 W/A from the modulator facet. After the application of facet coatings, slope efficiencies from the modulator facet increase to 0.14 W/A. Wavelength tuning of 7 nm is obtained by injection current heating of the DBR section. These devices exhibit extinction ratios of 18 dB from the modulator facet at a low modulator bias of 1 V, when measured with a broad-area detector. When coupled to a singlemode fiber, these devices exhibit high extinction ratios of 40 dB at a modulator bias of 1.25 V. Photo-generated current versus optical power plots indicate that the extinction ratios are not limited by carrier build- up in the modulator quantum wells.

  20. Planar-waveguide external cavity laser stabilization for an optical link with 10(-19) frequency stability.

    Science.gov (United States)

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

    2011-12-01

    We stabilized the frequency of a compact planar-waveguide external cavity laser (ECL) on a Fabry-Perot cavity (FPC) through a Pound-Drever-Hall scheme. The residual frequency stability of the ECL is 10(-14), comparable to the stability achievable with a fiber laser (FL) locked to an FPC through the same scheme. We set up an optical link of 100 km, based on fiber spools, that reaches 10(-19) relative stability, and we show that its performances using the ECL or FL are comparable. Thus ECLs could serve as an excellent replacement for FLs in optical links where cost-effectiveness and robustness are important considerations.

  1. Photonic integration using asymmetric twin-waveguides

    Science.gov (United States)

    Studenkov, Pavel V.

    A novel approach to fabrication of monolithic photonic integrated circuits based on the asymmetric twin- waveguide (ATG) structure is proposed and demonstrated. In contrast to the conventional integration methods relying on semiconductor regrowth, the ATG approach requires only one epitaxy step, while the integrated devices are defined by post-growth patterning. The ATG structure contains two evanescently coupled waveguide layers separated by a cladding layer. The upper layer provides optical gain for the active devices such as lasers and semiconductor optical amplifiers. The transparent lower layer is used to make waveguides and optical interconnects on the chip. Thus the ATG represents a versatile integration platform for cost- effective fabrication of photonic integrated circuits, similar in some respects to the electronic CMOS platform. Light propagation and coupling in the ATG structure are analyzed using the beam propagation method to optimize the layer design. It is shown that the asymmetric refractive index profile eliminates undesirable optical coupling between the waveguide layers. At the interfaces between the active and passive devices, lateral tapers are used to induce vertical coupling of light with a coupling loss of typically integrated devices can be separately optimized to achieve performance close to that of the conventional discrete components. The design of taper couplers is described in detail, and their performance is experimentally verified. Using the ATG approach, several integrated devices were fabricated in the InGaAsP/InP material system for λ = 1.55 μm wavelength operation. Lasers and semiconductor optical amplifiers with integrated waveguides were characterized to test the integration approach. Single-frequency, distributed Bragg reflector (DBR) lasers achieved output power of 11 mW with a 40 dB side-mode suppression ratio. A DBR laser with integrated electroabsorption modulator had a 24 dB extinction ratio between 0V and -2V bias

  2. A computer program for the design of optimum catalytic monoliths for CO2 lasers

    Science.gov (United States)

    Guinn, K.; Goldblum, S.; Noskowski, E.; Herz, R.

    1990-01-01

    Pulsed CO2 lasers have many applications in aeronautics, space research, weather monitoring and other areas. Full exploitation of the potential of these lasers is hampered by the dissociation of CO2 that occurs during laser operation. The development of closed-cycle CO2 lasers requires active CO-O2 recombination (CO oxidation) catalysts and design methods for implementation of catalysts inside lasers. The performance criteria and constraints involved in the design of catalyst configurations for use in a closed-cycle laser are discussed, and several design studies performed with a computerized design program that was written are presented. Trade-offs between catalyst activity and dimensions, flow channel dimensions, pressure drop, O2 conversion and other variables are discussed.

  3. Monolithic Integration of a DFB Superlattice Laser Using High Energy Ion Implantation

    Science.gov (United States)

    1991-02-13

    Considerations Relative to DFB/DBR Laser Fabrication .... 46 4.0 Materials Evaluation of Multi-Quantum Well/Superlattice Samples Fabricated by Molecular Beam...important to consider the disordering that can occur during annealing and its effects on device performance. 3.7 CONSIDERATIONS RELATIVE TO DFB/DBR LASER ... FABRICATION The structure examined in ts work is to be incorporated in a distributed feedback type laser. The resolution of the selective ion beam

  4. Time Domain Dynamic Analysis of 1550nm Monolithic Two Sections Mode Locked MQW Laser

    OpenAIRE

    DUMAN, Çağlar; ÇAKMAK, Bülent

    2015-01-01

    In this study, time domain dynamic model of a mode locked two sections DBR laser was obtained. Sort duration and high power optical pulse generation from a semiconductor laser was examined by using obtained model. For this aim, while one of the laser sections was thought as reverse biased and so acted as a saturable absorber, other section thought as forward biased with a DC current and so acted as a gain section. A semiconductor laser biased this way can produce mode locked pulses by suitabl...

  5. Advanced Waveguide Lasers Based on Optically Transparent Polycrystalline Materials for Power Scaling Studies

    Science.gov (United States)

    2015-02-20

    investigate cooling of the waveguides, and 2) control beam profile and improve oscillation efficiency. Optical qualities of ceramic composite samples were...of the waveguides, and 2) control beam profile and improve oscillation efficiency. Optical qualities of ceramic composite samples were inspected by...layer, YAG-Nd:YAG-YAG) and simple (mono-layer, Nd:YAG) ceramic waveguide structures to make large, high- quality samples for optimization and

  6. A Sampled Grating DBR Laser Monolithically Integrated by Using SOAs with 22mW Output Power and 51 ITU 100 GHz Channels over 43 nm

    Institute of Scientific and Technical Information of China (English)

    LIU Yang; YE Nan; ZHOU Dai-Bing; WANG Bao-Jun; PAN Jiao-Qing; ZHAO Ling-Juan; WANG Wei

    2011-01-01

    @@ A sampled grating distributed Bragg reflector (SG-DBR) laser monolithically integrated with semiconductor optical amplifiers (SOAs), which has a tuning range over 43nm from 1514.05 nm to 1557.4 nm covering 49 continuous and totally 51 ITU 100 GHz standard channels and an output power more than 22 mW for all output wavelengths, is successfully demonstrated.%A sampled grating distributed Bragg reflector (SG-DBR) laser monolithically integrated with semiconductor optical amplifiers (SOAs), which has a tuning range over 43nm from 1514.05nm to 1557.4 nm covering 49 continuous and totally 51 ITU 100 GHz standard channels and an output power more than 22 m W for all output wavelengths,is successfully demonstrated.

  7. Active mode locking at 50 GHz repetition frequency by half-frequency modulation of monolithic semiconductor lasers integrated with electroabsorption modulators

    Science.gov (United States)

    Sato, Kenji; Kotaka, Isamu; Kondo, Yasuhiro; Yamamoto, Mitsuo

    1996-10-01

    Active mode locking achieved at a 50 GHz repetition frequency by modulation at half (25 GHz) the cavity resonance frequency using a monolithic mode-locked InGaAsP laser integrated with an electroabsorption modulator is described. A pulse width of around 3 ps and a high suppression ratio of more than 33 dB of the intensity modulation at the driving frequency are obtained.

  8. High-modulation-efficiency, integrated waveguide modulator-laser diode at 448 nm

    KAUST Repository

    Shen, Chao

    2016-01-25

    To date, solid-state lighting (SSL), visible light communication (VLC) and optical clock generation functionalities in the blue-green color regime have been demonstrated based on discrete devices, including light-emitting diodes, laser diodes, and transverse-transmission modulators. This work presents the first integrated waveguide modulator-laser diode (IWM-LD) at 448 nm, offering the advantages of small-footprint, high-speed, and low power-consumption. A high modulation efficiency of 2.68 dB/V, deriving from a large extinction ratio of 9.4 dB and a low operating voltage range of 3.5 V, was measured. The electroabsorption characteristics revealed that the modulation effect, as observed from the red-shifting of the absorption edge, was resulted from the external-field-induced quantum-confined-Stark-effect (QCSE). A comparative analysis of the photocurrent versus wavelength spectra in semipolar- and polar-plane InGaN/GaN quantum wells (QWs) confirmed that the IWM-LD based on semipolar (20¯2 ¯1) QWs was able to operate in a manner similar to other III-V materials typically used in optical telecommunications, due to the reduced piezoelectric field. Utilizing the integrated modulator, a -3dB bandwidth of ~1 GHz was measured, and a data rate of 1 Gbit/s was demonstrated using on-off keying (OOK) modulation. Our experimental investigation highlighted the advantage of implementing the IWM-LD on the same semipolar QW epitaxy in enabling a high-efficiency platform for SSL-VLC dual-functionalities.

  9. Microfabrication with femtosecond laser processing : (A) laser ablation of ferrous alloys, (B) direct-write embedded optical waveguides and integrated optics in bulk glasses.

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Junpeng; McDaniel, Karen Lynn; Palmer, Jeremy Andrew; Yang, Pin; Griffith, Michelle Lynn; Vawter, Gregory Allen; Harris, Marc F.; Tallant, David Robert; Luk, Ting Shan; Burns, George Robert

    2004-11-01

    At Sandia National Laboratories, miniaturization dominates future hardware designs, and technologies that address the manufacture of micro-scale to nano-scale features are in demand. Currently, Sandia is developing technologies such as photolithography/etching (e.g. silicon MEMS), LIGA, micro-electro-discharge machining (micro-EDM), and focused ion beam (FIB) machining to fulfill some of the component design requirements. Some processes are more encompassing than others, but each process has its niche, where all performance characteristics cannot be met by one technology. For example, micro-EDM creates highly accurate micro-scale features but the choice of materials is limited to conductive materials. With silicon-based MEMS technology, highly accurate nano-scale integrated devices are fabricated but the mechanical performance may not meet the requirements. Femtosecond laser processing has the potential to fulfill a broad range of design demands, both in terms of feature resolution and material choices, thereby improving fabrication of micro-components. One of the unique features of femtosecond lasers is the ability to ablate nearly all materials with little heat transfer, and therefore melting or damage, to the surrounding material, resulting in highly accurate micro-scale features. Another unique aspect to femtosecond radiation is the ability to create localized structural changes thought nonlinear absorption processes. By scanning the focal point within transparent material, we can create three-dimensional waveguides for biological sensors and optical components. In this report, we utilized the special characteristics of femtosecond laser processing for microfabrication. Special emphasis was placed on the laser-material interactions to gain a science-based understanding of the process and to determine the process parameter space for laser processing of metals and glasses. Two areas were investigated, including laser ablation of ferrous alloys and direct

  10. Spectroscopy and ultra-narrow-linewidth lasers in rare-earth-doped amorphous $Al_2O_3$ waveguides on a silicon chip

    NARCIS (Netherlands)

    Bernhardi, E.H.; Agazzi, L.; Wörhoff, K.; Ridder, de R.M.; Pollnau, M.

    2014-01-01

    Despite a strong fluorescence-quenching process that affects a significant fraction of erbium or ytterbium ions in amorphous Al2O3, channel waveguide lasers with 1.7 kHz linewidth at 1.5 µm or 55 mW output power at 1.0 µm, stable microwave beat-frequency generation, and intra-laser-cavity optical se

  11. Extremely wide lasing bandwidth from InAs/InP quantumdash ridge-waveguide laser near 1.6 μm

    KAUST Repository

    Khan, Mohammed Zahed Mustafa

    2013-01-01

    We demonstrate an ultra-broad lasing bandwidth (-3dB) of > 50 nm utilizing InAs/InGaAlAs/InP quantum-dash ridge-waveguide laser using chirped AlGaInAs barrier layer thickness. Our device exhibits a recorded bandwidth and significant improvement of laser characteristics

  12. Tunable Picosecond Laser Pulses via the Contrast of Two Reverse Saturable Absorption Phases in a Waveguide Platform

    Science.gov (United States)

    Tan, Yang; Chen, Lianwei; Wang, Dong; Chen, Yanxue; Akhmadaliev, Shavkat; Zhou, Shengqiang; Hong, Minghui; Chen, Feng

    2016-05-01

    How to enhance the optical nonlinearity of saturable absorption materials is an important question to improve the functionality of various applications ranging from the high power laser to photonic computational devices. We demonstrate the saturable absorption (SA) of VO2 film attributed to the large difference of optical nonlinearities between the two states of the phase-transition materials (VO2). Such VO2 film demonstrated significantly improved performance with saturation intensity higher than other existing ultrathin saturable absorbers by 3 orders due to its unique nonlinear optical mechanisms in the ultrafast phase change process. Owing to this feature, a Q-switched pulsed laser was fabricated in a waveguide platform, which is the first time to achieve picosecond pulse duration and maintain high peak power. Furthermore, the emission of this VO2 waveguide laser can be flexibly switched between the continuous-wave (CW) and pulsed operation regimes by tuning the temperature of the VO2 film, which enables VO2-based miniature laser devices with unique and versatile functions.

  13. Monolithic integration of widely tunable sampled grating DBR laser with tilted semiconductor optical amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yang; Ye Nan; Wang Baojun; Zhou Daibing; An Xin; Bian Jing; Pan Jiaoqing; Zhao Lingjuan; Wang Wei, E-mail: matsu@semi.ac.c [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2010-07-15

    High output powers and wide range tuning have been achieved in a sampled grating distributed Bragg reflector laser with an integrated semiconductor optical amplifier. Tilted amplifier and anti-reflection facet coating are used to suppress reflection. We have demonstrated sampled grating DBR laser with a tuning range over 38 nm, good wavelength coverage and peak output powers of more than 9 mW for all wavelengths.

  14. Design and evaluation of modelocked semiconductor lasers for low noise and high stability

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Christiansen, Lotte Jin;

    2005-01-01

    We present work on design of monolithic mode-locked semiconductor lasers with focus on the gain medium. The use of highly inverted quantum wells in a low-loss waveguide enables both low quantum noise, low-chirped pulses and a large stability region. Broadband noise measurements are performed...

  15. 2.1 μm waveguide laser fabricated by femtosecond laser direct-writing in Ho3+, Tm3+:ZBLAN glass.

    Science.gov (United States)

    Lancaster, D G; Gross, S; Ebendorff-Heidepriem, H; Fuerbach, A; Withford, M J; Monro, T M

    2012-03-15

    We report the first Ho3+ doped waveguide laser, which was realized by femtosecond direct-writing of a depressed cladding structure into ZBLAN glass. Tm3+ sensitizing allows the 9 mm long Ho3+ gain medium to be conveniently pumped at 790 nm, achieving an optical-to-optical slope efficiency of 20% and a threshold of 20 mW. The potentially widely tunable laser produces up to 76 mW at 2052 nm and also operates at shorter wavelengths near 1880 nm and 1978 nm for certain cavity configurations.

  16. Widely tunable narrow-linewidth 1.5 μm light source based on a monolithically integrated quantum dot laser array

    Science.gov (United States)

    Becker, A.; Sichkovskyi, V.; Bjelica, M.; Rippien, A.; Schnabel, F.; Kaiser, M.; Eyal, O.; Witzigmann, B.; Eisenstein, G.; Reithmaier, J. P.

    2017-05-01

    A monolithically integrated widely tunable narrow-linewidth light source was realized on an InP-based quantum dot (QD) gain material. The quasi zero-dimensional nature of QDs and the resulting low linewidth enhancement factor enabled standalone distributed feedback (DFB) lasers with intrinsic linewidths as low as 110 kHz. An integrated device comprising four DFB lasers with on-chip micro-heaters, a 3 dB-coupler network, and a semiconductor optical amplifier (SOA), which covers the entire C+ telecom band, exhibits a linewidth of below 200 kHz independent of the SOA operation current.

  17. Towards monolithic integration of mode-locked vertical cavity surface emitting laser

    Science.gov (United States)

    Aldaz, Rafael I.

    2007-12-01

    The speed and performance of today's high end computing and communications systems have placed difficult but still feasible demands on off-chip electrical interconnects. However, future interconnect systems may need aggregate bandwidths well into the terahertz range thereby making electrical bandwidth, density, and power targets impossible to meet. Optical interconnects, and specifically compact semiconductor mode-locked lasers, could alleviate this problem by providing short pulses in time at 10s of GHz repetition rates for Optical Time Division Multiplexing (OTDM) and clock distribution applications. Furthermore, the characteristic spectral comb of frequencies of these lasers could also serve as a multi-wavelength source for Wavelength Division Multiplexing (WDM) applications. A fully integrated mode-locked Vertical Cavity Surface Emitting Laser (VCSEL) is proposed as a low-cost high-speed source for these applications. The fundamental laser platform for such a device has been developed and a continuous-wave version of these lasers has been fabricated and demonstrated excellent results. Output powers close to 60mW have been obtained with very high beam quality factor of M2 unassisted ultrafast QD saturable absorbers, without the need to incorporate high concentrations of non radiative recombination centers by either ion-implantation or low temperature growth.

  18. Monolithic Hybrid and Passive Mode-Locked 40GHz Quantum Dot Laser Diodes

    DEFF Research Database (Denmark)

    Thompson, M. G.; Larsson, David; Rae, A. R.

    2006-01-01

    For the first time hybrid and passive mode-locking jitter performance is investigated in 40GHz quantum-dot mode-locked lasers. Record low passive mode-locking jitter of 219fs is presented, along with promising hybrid mode-locking results of 124fs.......For the first time hybrid and passive mode-locking jitter performance is investigated in 40GHz quantum-dot mode-locked lasers. Record low passive mode-locking jitter of 219fs is presented, along with promising hybrid mode-locking results of 124fs....

  19. Monolithic Hybrid and Passive Mode-Locked 40GHz Quantum Dot Laser Diodes

    DEFF Research Database (Denmark)

    Thompson, M. G.; Larsson, David; Rae, A. R.;

    2006-01-01

    For the first time hybrid and passive mode-locking jitter performance is investigated in 40GHz quantum-dot mode-locked lasers. Record low passive mode-locking jitter of 219fs is presented, along with promising hybrid mode-locking results of 124fs.......For the first time hybrid and passive mode-locking jitter performance is investigated in 40GHz quantum-dot mode-locked lasers. Record low passive mode-locking jitter of 219fs is presented, along with promising hybrid mode-locking results of 124fs....

  20. Millimeter-wave waveguiding using photonic band structures

    Science.gov (United States)

    Eliyahu, Danny; Sadovnik, Lev S.; Manasson, Vladimir A.

    2000-07-01

    Current trends in device miniaturization and integration, especially in the development of microwave monolithic integrated circuits, calls for flexible, arbitrarily shaped and curved interconnects. Standard dielectric waveguides and microstrip lines are subject to prohibitive losses and their functionality is limited because of their unflexible structures. The problem is addressed by confining the wave- guiding path in a substrate with a Photonic Band Gap structure in a manner that will result in the guided mode being localized within the band gap. Two devices implementing Photonic Band Structures for millimeter waves confinement are presented. The first waveguide is a linear defect in triangular lattice created in a silicon slab (TE mode). The structure consists of parallel air holes of circular cross sections. The silicon was laser drilled to create the 2D crystal. The second device consists of alumina rods arranged in a triangular lattice, surrounded by air and sandwiched between two parallel metal plates (TM mode). Electromagnetic wave (W-band) confinement was obtained in both devices for straight and bent waveguides. Three branch waveguides (intersecting line defects) was studied as well. Measurements confirmed the lowloss waveguide confinement property of the utilizing Photonic Band Gap structure. This structure can find applications in power combiner/splitter and other millimeter wave devices.

  1. Monolithic mode-locked lasers with deeply dry etched Bragg mirror

    DEFF Research Database (Denmark)

    Larsson, David; Yvind, Kresten; Hvam, Jørn Märcher

    Background: Semiconductor mode-locked lasers are attractive as components in futureultra high-speed telecommunication systems (160-640Gb/s); as picosecond pulse sources,clock-recovery devices and for demultiplexing in Optical Time Division Multiplexing(OTDM) systems. We have recently designed, fa...

  2. Monolithic integration of widely tunable sampled grating DBR laser with tilted semiconductor optical amplifier

    Science.gov (United States)

    Ye, Nan; Liu, Yang; Wang, BaoJun; Zhou, DaiBing; Pang, JiaoQing; Zhao, LingJuan; Wang, Wei

    2011-01-01

    More than 11mW output powers for all wavelengths from the fiber and over 49 nm range tuning in sampled grating distributed Bragg reflector laser with an integrated semiconductor optical amplifier which is enabling access to 110 ITU 50GHz channels is demonstrated. Tilted amplifier and anti-reflection facet coating are used to suppress reflection.

  3. Direct laser writing of a low-loss waveguide with independent control over the transverse dimension and the refractive index contrast between the core and the cladding.

    Science.gov (United States)

    Masselin, Pascal; Bychkov, Eugène; Coq, David Le

    2016-08-01

    In this Letter, we present the realization of a low-loss waveguide in a chalcogenide glass by direct laser writing technique in a particular configuration that allows the independent control over the diameter of the core and the magnitude of the refractive index contrast with the cladding. The waveguide is of multicore type and composed of 19 channels arranged on a hexagonal lattice. Each channel is obtained by stacking voxels of refractive index variation obtained by static exposure to femtosecond laser pulse burst. The distance between the channels can be used to vary the diameter of the waveguide, while the duration of laser burst controls the magnitude of the effective index and the propagation loss. We demonstrate that it can be reduced down to 0.11 dB/cm.

  4. In-volume waveguides by fs-laser direct writing in rare-earth-doped fluoride glass and phosphate glass

    Science.gov (United States)

    Esser, D.; Wortmann, D.; Gottmann, J.

    2009-02-01

    Refractive index modifications are fabricated in the volume of rare-earth-doped glass materials namely Er- and Pr-doped ZBLAN (a fluoride glass consisting of ZrF4, BaF2, LaF3, AlF3, NaF), an Er-doped nano-crystalline glass-ceramic and Yb- and Er-doped phosphate glass IOG. Femtosecond laser radiation (τ=500fs, λ=1045nm, f=0.1-5MHz) from an Ybfiber laser is focused with a microscope objective in the volume of the glass materials and scanned below the surface with different scan velocities and pulse energies. Non-linear absorption processes like multiphoton- and avalanche absorption lead to localized density changes and the formation of color centers. The refractive index change is localized to the focal volume of the laser radiation and therefore, a precise control of the modified volume is possible. The width of the written structures is analyzed by transmission light microscopy and additionally with the quantitative phase microscopy (QPm) software to determine the refractive index distribution perpendicular to a waveguide. Structures larger than 50μm in width are generated at high repetition rates due to heat accumulation effects. In addition, the fabricated waveguides are investigated by far-field measurements of the guided light to determine their numerical apertures. Using interference microscopy the refractive index distribution of waveguide cross-sections in phosphate glass IOG is determined. Several regions with an alternating refractive index change are observed whose size depend on the applied pulse energies and scan velocities.

  5. Bismuth telluride topological insulator nanosheet saturable absorbers for q-switched mode-locked Tm:ZBLAN waveguide lasers

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiantao; Gross, Simon; Withford, Michael J.; Fuerbach, Alexander [Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS) and MQ Photonics Research Centre, Dept. of Physics and Astronomy, Macquarie Univ., NSW (Australia); Zhang, Han; Guo, Zhinan [SZU-NUS Collaborative Innovation Centre for Optoelectronic Science and Technology, Key Lab. of Optoelectronic Devices and Systems of Ministry of Education, College of Optoelectronic Engineering, Shenzhen Univ. (China)

    2016-08-15

    Nanosheets of bismuth telluride (Bi{sub 2}Te{sub 3}), a topological insulator material that exhibits broadband saturable absorption due to its non-trivial Dirac-cone like energy structure, are utilized to generate short pulses from Tm:ZBLAN waveguide lasers. By depositing multiple layers of a carefully prepared Bi{sub 2}Te{sub 3} solution onto a glass substrate, the modulation depth and the saturation intensity of the fabricated devices can be controlled and optimized. This approach enables the realization of saturable absorbers that feature a modulation depth of 13% and a saturation intensity of 997 kW/cm{sup 2}. For the first time to our knowledge, Q-switched mode-locked operation of a linearly polarized mid-IR ZBLAN waveguide chip laser was realized in an extended cavity configuration using the topological insulator Bi{sub 2}Te{sub 3}. The maximum average output power of the laser is 16.3 mW and the Q-switched and mode-locked repetition rates are 44 kHz and 436 MHz, respectively. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Preparation of porous styrenics-based monolithic layers for thin layer chromatography coupled with matrix-assisted laser-desorption/ionization time-of-flight mass spectrometric detection.

    Science.gov (United States)

    Lv, Yongqin; Lin, Zhixing; Tan, Tianwei; Svec, Frantisek

    2013-11-01

    Monolithic 50 μm thin poly(4-methylstyrene-co-chloromethylstyrene-co-divinylbenzene) layers attached to 6.0 cm × 3.3 cm glass plates have been prepared, using a thermally initiated polymerization process. These layers had a well-defined porous structure with a globular morphology demonstrated with SEM images and exhibited superhydrophobic properties characterized with a water contact angle of 157°. They were then used for thin-layer chromatography of peptides and proteins fluorescently labeled with fluorescamine. The spots of individual separated compounds were visualized using UV light, and their identities were confirmed with a matrix-assisted laser desorption/ionization time of flight mass spectrometry. The presence of chloromethylstyrene units in the polymer enabled hypercrosslinking via a Friedel-Crafts alkylation reaction, and led to monoliths with much larger surface areas, which were suitable for separations of small dye molecules.

  7. Transient Thermal Analysis of Ridge Waveguide InAsP/InGaAsP MQW Lasers Operating in Pulse Driving Conditions

    Institute of Scientific and Technical Information of China (English)

    HE You-jun; ZHANG Yong-gang; LI Ai-zhen

    2003-01-01

    The transient thermal characteristics of the ridge waveguide InAsP/InGaAsP MQW lasers, especially in various pulse driving conditions,have been simulated by using FEM. The temperature at the active core of the laser versus the time has been calculated as well as pulse width dependence of the apparent thermal resistance.The results show that the thermal characteristics of the lasers are related to both the thermal conductivity and the specific heat of the materials.

  8. Hyperentangled photon sources in semiconductor waveguides

    DEFF Research Database (Denmark)

    Kang, Dongpeng; Helt, L. G.; Zhukovsky, Sergei

    2014-01-01

    We propose and analyze the performance of a technique to generate mode and polarization hyperentangled photons in monolithic semiconductor waveguides using two concurrent type-II spontaneous parametric down-conversion (SPDC) processes. These two SPDC processes are achieved by waveguide engineering...

  9. Nonlinear switching in multicore versus multimode waveguide junctions for mode-locked laser applications.

    Science.gov (United States)

    Nazemosadat, Elham; Mafi, Arash

    2013-12-16

    The main differences in nonlinear switching behavior between multicore versus multimode waveguide couplers are highlighted. By gradually decreasing the separation between the two cores of a dual-core waveguide and interpolating from a multicore to a multimode scenario, the role of the linear coupling, self-phase modulation, cross-phase modulation, and four-wave mixing terms are explored, and the key reasons are identified behind higher switching power requirements and lower switching quality in multimode nonlinear couplers.

  10. Continuous laser direct-writing of PbS nanoparticles inside transparent silica monoliths

    Science.gov (United States)

    Chahadih, Abdallah; El Hamzaoui, Hicham; Bernard, Rémy; Bois, Laurence; Beclin, Franc; Cristini, Odile; Capoen, Bruno; Bouazaoui, Mohamed

    2011-12-01

    Direct space-selective growth of PbS nanoparticles, embedded inside a transparent porous sol-gel derived silica matrix, has been achieved using continuous laser irradiation. Before the irradiation, the porous silica host has been soaked in a PbS precursor solution. The effect of the concentration of PbS precursors and of the incident laser power on the mean particle size was studied. Absorption spectroscopy, X-ray diffraction analysis, and TEM measurements were used to identify the PbS crystallites inside the xerogel and to estimate the average particle size. It has been shown that PbS crystallite sizes range between 3 and 13 nm depending on the PbS precursors concentration.

  11. Elimination of leakage of optical modes to GaN substrate in nitride laser diodes using a thick InGaN waveguide

    Science.gov (United States)

    Muziol, Grzegorz; Turski, Henryk; Siekacz, Marcin; Grzanka, Szymon; Perlin, Piotr; Skierbiszewski, Czesław

    2016-09-01

    A novel design consisting of a thick InGaN waveguide is proposed to fully eliminate leakage to the GaN substrate in nitride laser diodes. The design is based on the effective refractive index engineering and does not require the commonly used thick AlGaN claddings. The conditions required to fully eliminate the optical leakage are discussed. Experimental results from eight blue laser diodes with different indium contents and thicknesses of the InGaN waveguide grown by plasma-assisted molecular beam epitaxy are presented to validate the theoretical results.

  12. Picosecond pulses of coherent MM-wave radiation in a photoinjector-driven waveguide free-selected laser

    Energy Technology Data Exchange (ETDEWEB)

    Fochs, S.N.; Le Sage, G.P.; Feng, L. [Univ. of California, Davis, CA (United States)] [and others

    1995-12-31

    A 5 MeV, high repetition rate (2.142 GHz in burst mode), high brightness, tabletop photoinjector is currently under construction at the UC Davis Department of Applied Science, on the LLNL site. Ultrashort pulses of coherent synchrotron radiation can be generated by transversally accelerating the electron beam with a wiggler in either metallic or dielectric-loaded waveguide FEL structures. This interaction is investigated theoretically and experimentally. Subpicosecond photoelectron bunches will be produced in the photoinjector by irradiating a high quantum efficiency Cs{sub 2}Te (Cesium Telluride) photocathode with a train of 100 UV (210 nm), ultra-short (250 fs) laser pulses. These bunches will be accelerated in a 1-1/2 cell {pi}-mode X-band RF gun e energized by a 20 MW, 8,568 GHz SLAC klystron. The peak current is 0.25 kA (0.25 nC, 1 ps), with a normalized beam emittance {epsilon}{sub n}<2.5 {pi} mm-mrad. This prebunched electron beam is then transversally accelerated in a cylindrical waveguide by a 30-mm period, 10 period long helical wiggler. The peak wiggler field is adjusted to 8.5 kG, so that the group velocity of the radiated electromagnetic waves matches the axial velocity of the electron bunch (grazing condition, zero slippage). Chirped output pulses in excess of 2 MW power are predicted, with an instantaneous bandwidth extending from 125 GHz to 225 GHz and a pulse duration of 15 ps (HWHM). To produce even shorter pulses, a dielectric-loaded waveguide can be used. The dispersion relation of this waveguide structure has an inflection point (zero group velocity dispersion). If the grazing condition is satisfied at this point, the final output pulse duration is no longer determined by slippage, or by group velocity dispersion and bandwidth, but by higher-order dispersive effects yielding transform-limited pulses.

  13. On-chip generation and demultiplexing of quantum correlated photons using a silicon-silica monolithic photonic integration platform.

    Science.gov (United States)

    Matsuda, Nobuyuki; Karkus, Peter; Nishi, Hidetaka; Tsuchizawa, Tai; Munro, William J; Takesue, Hiroki; Yamada, Koji

    2014-09-22

    We demonstrate the generation and demultiplexing of quantum correlated photons on a monolithic photonic chip composed of silicon and silica-based waveguides. Photon pairs generated in a nonlinear silicon waveguide are successfully separated into two optical channels of an arrayed-waveguide grating fabricated on a silica-based waveguide platform.

  14. High-power monolithic single-mode diode lasers employing active photonic lattices

    Science.gov (United States)

    Botez, Dan

    2003-06-01

    Photonic-lattice structures with modulated gain, that is active photonic lattices (APLs), of large index steps and gain preferentially enhanced on the low-index lattice sites have been used, as early as 1988, for effective lateral-mode control range in large-aperture (100-200 microns) high-power coherent devices. Photonic-bandpass (PBP) structures relying on long-range resonant leaky-wave coupling, so called ROW arrays, have allowed stable, near-diffraction-limited beam operation to powers as high as 1.6W CW and 10W peak pulsed. Photonic-bandgap (PBG) structures with a built-in lattice defect, so called ARROW lasers, have provided up to 0.5W peak-pulsed stable, single-mode power and hold the potential for 1W CW reliable single-mode operation from apertures 8-10 microns wide. The solution for high-efficiency surface emission, from 2nd-order DFB/DBR lasers, in an orthonormal, single-lobe beam pattern was found in 2000. Recently, single-lobe and single-mode operation in a diffraction-limited beam orthonormal to the chip surface was demonstrated from 1.5mm-long DFB/DBR ridge-guide lasers. That opens the way for the realization of 2-D surface-emitting,2nd-order APLs for the stable generation of watts of CW single-lobe, single-mode power from large 2-D apertures, as well as scalability of such devices at the wafer level.

  15. Miniaturized dielectric waveguide filters

    Science.gov (United States)

    Sandhu, Muhammad Y.; Hunter, Ian C.

    2016-10-01

    Design techniques for a new class of integrated monolithic high-permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled transverse electromagnetic filters with the same unloaded Q-factor. Designs for Chebyshev and asymmetric generalised Chebyshev filter and a diplexer are presented with experimental results for an 1800 MHz Chebyshev filter and a 1700 MHz generalised Chebyshev filter showing excellent agreement with theory.

  16. Monolithic spectrometer

    Science.gov (United States)

    Rajic, Slobodan; Egert, Charles M.; Kahl, William K.; Snyder, Jr., William B.; Evans, III, Boyd M.; Marlar, Troy A.; Cunningham, Joseph P.

    1998-01-01

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

  17. Monolithic mode-locked lasers with deeply dry etched Bragg mirror

    DEFF Research Database (Denmark)

    Larsson, David; Yvind, Kresten; Hvam, Jørn Märcher

    gasmixture, gas flow, chamber pressure and the power supplied to the plasma2.Figure 1: SEM micrograph of a deeply etched 2nd order grating and waveguidein InP. 1K. yvind et al, Phot. Technology Letters 16, 975-977 (2004)2Y. Feurprier et al., J. Vac. Sci. A 16(3), 1552-1559 (1998)...... section, such as self-phase modulation. The solution to this problem is to integratethe laser with a wavelength selective Bragg grating. Another advantage of the gratingshould be lower noise. Deep Reactive Ion Etching (RIE) of the grating is a key for lowcostmass production of these lasers, making...... and high index regions (etched andunetched), is 240 nm for a 1st order grating and 480 nm for the 2nd order.Fabrication: The mask for the grating is formed by a combination of E-beam writing andUV-lithography. The resist pattern is transferred to a 100 nm SiO2-film, with a CHF3(Freon) based dry etch...

  18. Densification behavior, doping profile and planar waveguide laser performance of the tape casting YAG/Nd:YAG/YAG ceramics

    Science.gov (United States)

    Ge, Lin; Li, Jiang; Qu, Haiyun; Wang, Juntao; Liu, Jiao; Dai, Jiawei; Zhou, Zhiwei; Liu, Binglong; Kou, Huamin; Shi, Yun; Wang, Zheng; Pan, Yubai; Gao, Qingsong; Guo, Jingkun

    2016-10-01

    The sintering behavior and doping concentration profile of the planar waveguide YAG/Nd:YAG/YAG ceramics by the tape casting and solid-state reaction method were investigated on the basis of densification trajectory, microstructure evolution, and Nd3+ ions diffusion. The porosity of the green body by tape casting and cold isostatic pressing is about 38.6%. And the green bodies were consolidated from 1100 °C to 1800 °C for 0.5-20 h to study the densification and the doping diffusion behaviors. At the temperature higher than 1500 °C, pure YAG phase is formed, followed by the densification and grain growth process. With the increase of temperature, two sintering stages occur, corresponding to remarkable densification and significant grain growth, respectively. The mechanism controlling densification at 1550 °C is grain boundary diffusion. The diffusion of Nd3+ ions is more sensitive to temperature than the sintering time, and the minimum temperature required for the obvious diffusion of Nd3+ ions is higher than 1700 °C. Finally, planar waveguide YAG/1.5 at.%Nd:YAG/YAG transparent ceramics with in-line transmittance of 84.8% at 1064 nm were obtained by vacuum-sintering at 1780 °C for 30 h. The fluorescence lifetime of 4F3/2 state of Nd3+ in the specimen is about 259 μs. The prepared ceramic waveguide was tested in a laser amplifier and the laser pulse was amplificated from 87 mJ to 238 mJ, with the pump energy of 680 mJ.

  19. Low-loss 3D-laser-written mid-infrared LiNbO3 depressed-index cladding waveguides for both TE and TM polarizations.

    Science.gov (United States)

    Nguyen, Huu-Dat; Ródenas, Airán; Vázquez de Aldana, Javier R; Martín, Guillermo; Martínez, Javier; Aguiló, Magdalena; Pujol, Maria Cinta; Díaz, Francesc

    2017-02-20

    We report mid-infrared LiNbO3 depressed-index microstructured cladding waveguides fabricated by three-dimensional laser writing showing low propagation losses (~1.5 dB/cm) at 3.68 µm wavelength for both the transverse electric and magnetic polarized modes, a feature previously unachieved due to the strong anisotropic properties of this type of laser microstructured waveguides and which is of fundamental importance for many photonic applications. Using a heuristic modeling-testing iteration design approach which takes into account cladding induced stress-optic index changes, the fabricated cladding microstructure provides low-loss single mode operation for the mid-IR for both orthogonal polarizations. The dependence of the localized refractive index changes within the cladding microstructure with post-fabrication thermal annealing processes was also investigated, revealing its complex dependence of the laser induced refractive index changes on laser fabrication conditions and thermal post-processing steps. The waveguide modes properties and their dependence on thermal post-processing were numerically modeled and fitted to the experimental values by systematically varying three fundamental parameters of this type of waveguides: depressed refractive index values at sub-micron laser-written tracks, track size changes, and piezo-optic induced refractive index changes.

  20. Ion-exchanged Er3+/Yb3+ co-doped waveguide amplifiers longitudinally pumped by broad area lasers.

    Science.gov (United States)

    Donzella, V; Toccafondo, V; Faralli, S; Di Pasquale, F; Cassagnettes, C; Barbier, D; Figueroa, H Hernandez

    2010-06-07

    A multimode pumping scheme for Er(3+)/Yb(3+) co-doped waveguide amplifiers based on broad area lasers at around 980 nm is presented. The proposed amplifier is fabricated by ion-exchange (IE) technique on silicate and phosphate glasses. The highly efficient energy transfer from Yb(3+) to Er(3+) ions, combined with the use of low cost and high power broad area laser, allows the realization of high performance and cost-effective integrated amplifiers. The structure has been designed and numerically studied using a 3D finite element modelling tool, and over 3 dB/cm small signal gain has been predicted for an optimized amplifier. Preliminary characterization of an amplifier structure provides a first experimental evidence of the novel multimode longitudinal pumping.

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

    CERN Document Server

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

    2011-01-01

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

  2. Polarization bistability in strained ridge-waveguide InGaAsP/InP lasers: Experiment and theory

    Science.gov (United States)

    Berger, G.; Müller, R.; Klehr, A.; Voss, M.

    1995-06-01

    New experimental and theoretical results on TE/TM bistability in 1.3 μm ridge-waveguide InGaAsP/InP bulk lasers at room temperature are presented. Measured polarization resolved light power-current (P-I) characteristics as well as lateral near- and far-field patterns are compared with results from a theoretical model based on the paraxial wave equations for TE- and TM-polarized modes and the diffusion equation for the carrier distribution. The model was numerically evaluated by use of the beam propagation method. The observed TE/TM bistability is explained by the interplay of three different effects: (i) Tensile stress of about 109 dyn/cm2 promotes the TM gain strongly enough to compete with the TE mode. (ii) Improved TM waveguiding due to an enhancement of the effective refractive index near the beam axis caused by carrier depletion with increasing current leads to the onset of TM lasing and TE/TM switching. (iii) The TE/TM transition is accompanied by an abrupt increase of spatial hole burning in the lateral carrier distribution. Because of this nonlinear effect, a lower current is needed to switch the laser back to TE, giving rise to a hysteresis loop in the P-I characteristics and to TE/TM polarization bistability.

  3. Ultra-broad range organic solid-state laser from a dye-doped holographic grating quasi-waveguide configuration

    Science.gov (United States)

    Liu, Minghuan; Liu, Yonggang; Peng, Zenghui; Mu, Quanquan; Cao, Zhaoliang; Lu, Xinghai; Ma, Ji; Xuan, Li

    2017-08-01

    This paper reports the ultra-broad 149.1 nm lasing emission from 573.2 to 722.3 nm using a simple [4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran] (DCM)-doped holographic polymer-dispersed liquid crystal (HPDLC) grating quasi-waveguide configuration by varying the grating period. The lasing emission beams show s-polarization property. The quasi-waveguide structure, which contained the cover glass, the DCM-doped HPDLC grating, the semiconducting polymer film poly[-methoxy-5-(2‧-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV), and the substrate were confirmed to decrease lasing threshold and broaden lasing wavelength. The operational lifetime of the device is 240 000 pulses, which corresponds to an overall laser duration of more than 6 h at a repetition rate of 10 Hz. In addition, the dual-wavelength lasing range from the 8th and 9th order is over 40 nm. The electrical tunability of the dual-wavelength lasing emission is over 1 nm. The experimental results facilitated the decreased lasing threshold and broadened lasing wavelength range of organic solid-state lasers.

  4. Widely tunable monolithic dual-mode laser for W-band photonic millimeter-wave generation and all-optical clock recovery.

    Science.gov (United States)

    Pan, Biwei; Guo, Lu; Zhang, Limeng; Lu, Dna; Huo, Li; Lou, Caiyun; Zhao, Lingjuan

    2016-04-10

    We demonstrate a monolithic dual-mode amplified feedback laser for photonic millimeter-wave generation and all-optical clock recovery. Dual-mode lasing with beating frequency around 100 GHz was realized by using a single-mode distributed feedback (DFB) laser with a short feedback cavity that was integrated by simple quantum-well intermixing technology. By tuning the bias currents of the laser sections, the beating-frequency can be continuously tuned from 75 to 109 GHz, almost covering the entire W-band (75-110 GHz). Furthermore, by using this device, an all-optical clock recovery for 100 Gbit/s return-to-zero on-off-keying signal was achieved with a timing jitter of 301 fs.

  5. Crystal Growth and Characterization of Epitaxial Layers of Laser and Nonlinear Optical Materials for Thin-Disk and Waveguide laser applications

    Energy Technology Data Exchange (ETDEWEB)

    W Bolanos; M Segura; J Cugat; J Carvajal; X Mateos; M Pujol; R Solé; F Díaz; M Aguiló; et. al.

    2011-12-31

    This paper summarizes the main results we obtained in our laboratories in relation with crystalline layers obtained by liquid phase epitaxial growth of lanthanide doped KLu(WO{sub 4}){sub 2} and Nb:RbTiOPO{sub 4} grown on KLu(WO{sub 4}){sub 2} and RbTiOPO{sub 4} substrates, respectively. Macroscopic defect free epitaxial layers were grown and characterized in terms of their compositional homogeneity, structural stress in the layer/substrate interface and laser and waveguiding performances.

  6. Enantioseparation of N-derivatized amino acids by micro-liquid chromatography/laser induced fluorescence detection using quinidine-based monolithic columns.

    Science.gov (United States)

    Wu, Huihui; Wang, Qiqin; Ruan, Meng; Peng, Kun; Zhu, Peijie; Crommen, Jacques; Han, Hai; Jiang, Zhengjin

    2016-03-20

    A novel carbamoylated quinidine based monolith, namely poly(O-9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-co-ethylene dimethacrylate (poly(MQD-co-EDMA)), was prepared for the micro-LC enantioseparation of N-derivatized amino acids. The influence of the mobile phase composition, including the organic modifier proportion, the apparent pH and the buffer concentration, on the enantioresolution of N-derivatized amino acids was systematically investigated. Satisfactory column performance in terms of permeability, efficiency and reproducibility was obtained in most cases. The majority of the enantiomers of the tested N-protected amino acids, including 3,5-DNB, 3,5-DClB, FMOC, 3,5-DMB, p-NB, m-ClB, p-ClB and B derivatives, could be baseline separated on the poly(MQD-co-EDMA) monolithic column within 25min. A self-assembled laser induced fluorescence (LIF) detector was employed to improve sensitivity when analyzing 7-nitro-2,1,3-benzoxadiazole (NBD) derivatives of amino acids. Ten NBD-derivatized amino acids, including arginine and histidine whose enantioseparation on quinidine carbamate based CSPs has not been reported so far, were enantioresolved on the poly(MQD-co-EDMA) monolith column. It is worth noting that the d-enantiomers of NBD-derivatized amino acids eluted first, except in the case of glutamic acid. The LOD values obtained with the LIF detector were comparable to those reported using conventional LC-FL methods. The prepared poly(MQD-co-EDMA) monolithic column coupled with the LIF detector opens up interesting perspectives to the determination of trace D-amino acids in biological samples.

  7. Femtosecond laser microfabrication of optical waveguides in commercial microfluidic lab-on-a-chip

    NARCIS (Netherlands)

    Osellame, R.; Martinez-Vazquez, R.; Ramponi, R.; Cerullo, G.; Dongre, C.; Dekker, R.; Hoekstra, Hugo; Pollnau, Markus

    One of the main challenges of lab-on-a-chip technology is the on-chip integration of photonic functionalities by manufacturing optical waveguides for sensing biomolecules flowing in the microchannels. Such integrated approach has many advantages over traditional free-space optical sensing, such as

  8. Optical sensing in microchip capillary electrophoresis by femtosecond laser written waveguides

    NARCIS (Netherlands)

    Martinez-Vázquez, R.; Osellame, R.; Cretich, M.; Dongre, C.; Hoekstra, H.J.W.M.; Vlekkert, van den H.; Ramponi, R.; Pollnau, M.; Chiari, M.; Cerullo, G.

    2009-01-01

    Capillary electrophoresis separation in an on-chip integrated microfluidic channel is typically monitored with bulky, bench-top optical excitation/detection instrumentation. Optical waveguides allow confinement and transport of light in the chip directing it to a small volume of the microfluidic cha

  9. Femtosecond laser microfabrication of optical waveguides in commercial microfluidic lab-on-a-chip

    NARCIS (Netherlands)

    Osellame, R.; Martinez-Vazquez, R.; Ramponi, R.; Cerullo, G.; Dongre, C.; Dekker, R.; Hoekstra, H.J.W.M.; Pollnau, M.

    2008-01-01

    One of the main challenges of lab-on-a-chip technology is the on-chip integration of photonic functionalities by manufacturing optical waveguides for sensing biomolecules flowing in the microchannels. Such integrated approach has many advantages over traditional free-space optical sensing, such as c

  10. Monolithic microchannel heatsink

    Science.gov (United States)

    Benett, William J.; Beach, Raymond J.; Ciarlo, Dino R.

    1996-01-01

    A silicon wafer has slots sawn in it that allow diode laser bars to be mounted in contact with the silicon. Microchannels are etched into the back of the wafer to provide cooling of the diode bars. To facilitate getting the channels close to the diode bars, the channels are rotated from an angle perpendicular to the diode bars which allows increased penetration between the mounted diode bars. This invention enables the fabrication of monolithic silicon microchannel heatsinks for laser diodes. The heatsinks have low thermal resistance because of the close proximity of the microchannels to the laser diode being cooled. This allows high average power operation of two-dimensional laser diode arrays that have a high density of laser diode bars and therefore high optical power density.

  11. High-repetition-rate quasi-CW side-pumped mJ eye-safe laser with a monolithic KTP crystal for intracavity optical parametric oscillator.

    Science.gov (United States)

    Cho, C Y; Chen, Y C; Huang, Y P; Huang, Y J; Su, K W; Chen, Y F

    2014-04-01

    We demonstrate a high-repetition-rate millijoule passively Q-switched eye-safe Nd:YVO(4) laser pumped by a quasi-CW diode stack. A theoretical analysis has been explored for the design criteria of generating TEM(n,0) mode in the diode-stack directly side-pumping configuration. We successfully generate TEM(n,0) modes at 1064 nm by adjusting the gain medium with respected to the laser axis. We further observe the spatial cleaning ability for generating an nearly TEM(0,0) mode output at 1573 nm with a monolithic OPO cavity. At the repetition rate up to 200 Hz, the output pulse energy reaches 1.21 mJ with the threshold pump energy of 17.9 mJ.

  12. Comparison of the noise performance of 10 GHz repetition rate quantum-dot and quantum well monolithic mode-locked semiconductor lasers

    DEFF Research Database (Denmark)

    Carpintero, G.; Thompson, M. G.; Yvind, Kresten

    2011-01-01

    Mode-locked lasers are commonly used in carrier-wave signal generation systems because of their excellent phase noise performance. Owing to the importance of this key parameter, this study presents a like-for-like comparison of the noise performance of the passive mode-locked regime of two devices...... and the shape of the noise pedestals, both depending on the passive mode-locked bias conditions. Nevertheless, the dominant contribution of the RF linewidth to the phase noise, which is significantly narrower for the QD laser, makes this material more suitable for optical generation of low-noise millimetre...... fabricated with different material gain systems, one quantum well and the other quantum dot (QD), both with a monolithic all-active two-section mode-locked structure. Two important factors are identified as having a significant effect on the noise performance, the RF linewidth of the first harmonic...

  13. Optical displacement measurement using a monolithic Michelson interferometer

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1997-04-01

    Contactless optical displacement measurement has the potential for a variety of industrial and scientific applications. For highly accurate displacement measurements at distances below 1 m, interferometric methods are preferred over most other methods. This is mainly because of the good resolution and the possibility of doing the measurements in real-time. Furthermore, the use of direct bandgap semiconductor materials also enables the fabrication of a compact interferometer-based device which unites all necessary components, including the light emitter, on a single chip. In this paper, a monolithically integrated optical displacement sensor fabricated in the GaAs/AlGaAs material system is reported. This single chip microsystem is configured as a double Michelson interferometer and comprises a distributed Bragg reflector laser, photodetectors, phase shifters and waveguide couplers. In the course of this paper, we will also briefly discuss possible scientific and industrial applications of such devices.

  14. The role of the gas/plasma plume and self-focusing in a gas-filled capillary discharge waveguide for high-power laser-plasma applications

    CERN Document Server

    Ciocarlan, C.; Islam, M. R.; Ersfeld, B.; Abuazoum, S.; Wilson, R.; Aniculaesei, C.; Welsh, G. H.; Vieux, G.; Jaroszynski, D. A.; 10.1063/1.4822333

    2013-01-01

    The role of the gas/plasma plume at the entrance of a gas-filled capillary discharge plasma waveguide in increasing the laser intensity has been investigated. Distinction is made between neutral gas and hot plasma plumes that, respectively, develop before and after discharge breakdown. Time-averaged measurements show that the on-axis plasma density of a fully expanded plasma plume over this region is similar to that inside the waveguide. Above the critical power, relativistic and ponderomotive selffocusing lead to an increase in the intensity, which can be nearly a factor of 2 compared with the case without a plume. When used as a laser plasma wakefield accelerator, the enhancement of intensity can lead to prompt electron injection very close to the entrance of the waveguide. Self-focusing occurs within two Rayleigh lengths of the waveguide entrance plane in the region, where the laser beam is converging. Analytical theory and numerical simulations show that, for a density of 3.01018 cm3, the peak normalized...

  15. Air plasma waveguide using pico-sec and nano-sec laser pulses

    Science.gov (United States)

    Pandey, Pramod K.; Gupta, Shyam L.; Narayanan, V.; Thareja, Raj K.

    2012-02-01

    We report a shock driven plasma in air breakdown using pump-probe to elucidate the hydrodynamic evolution of air plasma waveguide. Imaging of the evolution of air plasma plume is used to investigate the pump pulse effect on the plume dynamic. Imaging of the channeled pulse through evolved waveguide shows five time enhancement in Rayleigh length at 7 ns delay of probe pulse with respect to pump pulse. The evolved channel radius rch≈37μm has been shown to couple the maximum energy of the probe pulse yielding the electron density difference Δne~1018cm-3 between axis and periphery of the channel. The air plasma wave guide is shown to support the fundamental mode at optimum delay.

  16. Semipolar III–nitride quantum well waveguide photodetector integrated with laser diode for on-chip photonic system

    Science.gov (United States)

    Shen, Chao; Lee, Changmin; Stegenburgs, Edgars; Holguin Lerma, Jorge; Khee Ng, Tien; Nakamura, Shuji; DenBaars, Steven P.; Alyamani, Ahmed Y.; El-Desouki, Munir M.; Ooi, Boon S.

    2017-04-01

    A high-performance waveguide photodetector (WPD) integrated with a laser diode (LD) sharing the single InGaN/GaN quantum well active region is demonstrated on a semipolar GaN substrate. The photocurrent of the integrated WPD is effectively tuned by the emitted optical power from the LD. The responsivity ranges from 0.018 to 0.051 A/W with increasing reverse bias from 0 to 10 V. The WPD shows a large 3 dB modulation bandwidth of 230 MHz. The integrated device, being used for power monitoring and on-chip communication, paves the way towards the eventual realization of a III–nitride on-chip photonic system.

  17. Direct laser writing of near-IR step-index buried channel waveguides in rare earth doped YAG.

    Science.gov (United States)

    Rodenas, A; Benayas, A; Macdonald, J R; Zhang, J; Tang, D Y; Jaque, D; Kar, A K

    2011-09-01

    A new (to our knowledge) ultrashort laser pulse irradiation regime that allows us to directly modify and increase the refractive index of rare earth doped YAG polycrystalline ceramics has been identified. Single-mode buried channel waveguides in both Ho:YAG and Er:YAG ceramics at the near-IR wavelengths of 1.55 μm and 1.95 μm are demonstrated by fabricating positive square step-index cores. Minimum propagation losses of 1.5 dB cm(-1) at a 1.51 μm wavelength have been preliminarily obtained. Confocal microluminescence mapping reveals that the increased refractive index regions retain the near-IR spectral properties of Er3+ ions in the YAG crystalline matrix.

  18. Semipolar III–nitride quantum well waveguide photodetector integrated with laser diode for on-chip photonic system

    KAUST Repository

    Shen, Chao

    2017-02-28

    A high-performance waveguide photodetector (WPD) integrated with a laser diode (LD) sharing the single InGaN/GaN quantum well active region is demonstrated on a semipolar GaN substrate. The photocurrent of the integrated WPD is effectively tuned by the emitted optical power from the LD. The responsivity ranges from 0.018 to 0.051 A/W with increasing reverse bias from 0 to 10 V. The WPD shows a large 3 dB modulation bandwidth of 230 MHz. The integrated device, being used for power monitoring and on-chip communication, paves the way towards the eventual realization of a III–nitride on-chip photonic system.

  19. Versatile fs laser-written glass chip lasers

    Science.gov (United States)

    Lancaster, D. G.; Gross, S.; Fuerbach, A.; Ebendorff Heidepriem, H.; Monro, T. M.; Withford, M. J.

    2013-03-01

    We report laser-written chip lasers with potential to be a platform planar technology versatile enough to cover the visible through to the mid-infrared spectral region. By femtosecond laser direct-writing a thulium doped fluoride based glass host (ZBLAN), we have demonstrated a 151% quantum efficiency λ=1.9 μm laser with a close to diffraction limited beam quality (M2~ 1.12 +/- 0.08) with 225 nm of continuous tunability in a device that can be rapidly fabricated by singlestep optical processing. The 9 mm long planar chip developed for concept demonstration contains fifteen large modearea waveguides that can operate in semi-monolithic or external cavity laser configurations. This chip laser has achieved the highest quantum efficiency from a planar glass waveguide laser. The depressed cladding geometry supports the largest fundamental modes reported for a rare-earth doped waveguide laser thereby favouring high peak-power operation which is demonstrated by achieving 1.9 kW peak-power pulses when Q-switched.

  20. Tuning of successively scanned two monolithic Vernier-tuned lasers and selective data sampling in optical comb swept source optical coherence tomography.

    Science.gov (United States)

    Choi, Dong-Hak; Yoshimura, Reiko; Ohbayashi, Kohji

    2013-01-01

    Monolithic Vernier tuned super-structure grating distributed Bragg reflector (SSG-DBR) lasers are expected to become one of the most promising sources for swept source optical coherence tomography (SS-OCT) with a long coherence length, reduced sensitivity roll-off, and potential capability for a very fast A-scan rate. However, previous implementations of the lasers suffer from four main problems: 1) frequencies deviate from the targeted values when scanned, 2) large amounts of noise appear associated with abrupt changes in injection currents, 3) optically aliased noise appears due to a long coherence length, and 4) the narrow wavelength coverage of a single chip limits resolution. We have developed a method of dynamical frequency tuning, a method of selective data sampling to eliminate current switching noise, an interferometer to reduce aliased noise, and an excess-noise-free connection of two serially scanned lasers to enhance resolution to solve these problems. An optical frequency comb SS-OCT system was achieved with a sensitivity of 124 dB and a dynamic range of 55-72 dB that depended on the depth at an A-scan rate of 3.1 kHz with a resolution of 15 μm by discretely scanning two SSG-DBR lasers, i.e., L-band (1.560-1.599 μm) and UL-band (1.598-1.640 μm). A few OCT images with excellent image penetration depth were obtained.

  1. Design of integrated scanning laser Doppler velocitmeter using arrayed waveguide gratings

    Science.gov (United States)

    Maru, Koichi; Fujii, Yusaku; Obokata, Tomio; Ishima, Tsuneaki; Yupapin, Preecha; Pornsuwancharoen, Nithitroth; Juthanggoon, Thanaprasert

    2009-07-01

    An integrated scanned differential LDV has been proposed using planar lightwave circuit (PLC) technology. By using the proposed LDV, the measurement position can be scanned in depth direction without any mechanical movement. The PLC technology is utilized in the proposed design for achieving a compact optical circuit. The characteristics of the proposed LDV are simulated with a design model based on grating equations for AWGs. The simulation result reveals that the measurement position can be changed over the range of 46 mm in the depth direction without mechanical movement when the displacement between output sides of two waveguide arrays is 30 mm.

  2. Turnable Semiconductor Laser Spectroscopy in Hollow Optical Waveguides, Phase II SBIR

    Energy Technology Data Exchange (ETDEWEB)

    Gregory J. Fetzer, Ph.D.

    2001-12-24

    In this study a novel optical trace gas sensor based on a perforated hollow waveguide (PHW) was proposed. The sensor has been given the acronym ESHOW for Environmental Sensor using Hollow Optical Waveguides. Realizations of the sensor have demonstrated rapid response time (<2s), low minimum detection limits (typically around 3 x 10-5 absorbance). Operation of the PHW technology has been demonstrated in the near-infrared (NIR) and mid0infrared (MIR) regions of the spectrum. Simulation of sensor performance provided in depth understanding of the signals and signal processing required to provide high sensitivity yet retain rapid response to gas changes. A dedicated sensor electronics and software foundation were developed during the course of the Phase II effort. Commercial applications of the sensor are ambient air and continuous emissions monitoring, industrial process control and hazardous waste site monitoring. There are numerous other applications for such a sensor including medical diagnosis and treatment, breath analysis for legal purposes, water quality assessment, combustion diagnostics, and chemical process control. The successful completion of Phase II resulted in additional funding of instrument development by the Nations Institute of Heath through a Phase I SBIR grant and a strategic teaming relationship with a commercial manufacture of medical instrumentation. The purpose of the NIH grant and teaming relationship is to further develop the sensor to monitor NO in exhaled breath for the purposes of asthma diagnosis.

  3. Low-loss polarization-maintaining fusion splicing of single-mode fibers and hollow-core photonic crystal fibers, relevant for monolithic fiber laser pulse compression

    DEFF Research Database (Denmark)

    Kristensen, Jesper Toft; Houmann, Andreas; Liu, Xiaomin;

    2008-01-01

    B. The reciprocal HC-PCF-to-PM-SMF splice loss is found to be 2.19 ± 0.33 dB, which is caused by the mode evolution in HC-PCF. The return loss in both cases was measured to be −14 dB. We show that a splice defect is caused by the HC-PCF cleave defect, and the lossy splice can be predicted at an early stage...... of the splicing process. We also demonstrate that the higher splice loss compromises the PM properties of the splice. Our splicing technique was successfully applied to the realization of a low-loss, environmentally stable monolithic PM fiber laser pulse compressor, enabling direct end-of-the-fiber femtosecond...

  4. Preparation of a Waveguide Array in Flame Hydrolysis Deposited GeO2-SiO2 Glasses by Excimer Laser Irradiation

    Institute of Scientific and Technical Information of China (English)

    吴远大; 邢华; 张乐天; 李爱武; 于永森; 张玉书

    2002-01-01

    SiO2 glass films doped with GeO2 were prepared by the flame hydrolysis deposition method, then annealed at 1200. C. After exposure to high pressure hydrogen, the as-deposited films were irradiated with excimer laser pulses operated at 248nm. The induced refractive index change (the growth of index change was 0.33%) was measured by a spectroscopic ellipsometer. A waveguide array has been written in the film by irradiation through a phase mask.

  5. Mathematical modeling of output power in RF-excited CO2 waveguide lasers

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Theoretical analysis model has been established for CO2 laser to describe the process of dynamic emission in the electrooptically Q-switched laser .The electron excitation and the energy-transfer of vibration level and the rotational relaxation of rotational levels are described. The comparison between this model and a set of coupled rat equations model are discussed.

  6. High-repetition-rate XeCl waveguide laser without gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, C.P.; Gordon C. III; Moutoulas, C.; Feldman, B.J.

    1987-03-01

    Operation of a microwave discharge XeCl laser at pulse-repetition rates extending to 8 kHz without flow of the laser gas is reported. Present limits on pulse-repetition rate appear to be imposed by thermally induced refractive-index gradients.

  7. Thermal Characterization of 1.3μm InAsP/InGaAsP Ridge Waveguide MQW Lasers Based on Spectroscopy Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experimental way to analyze the thermal characterization of semiconductor lasers based on spectroscopy method under pulse driving conditions has been developed. By using this way the thermal characteristics of strain compensated 1.3μm InAsP/InGaAsP ridge waveguide MQW laser diodes have been investigated. Results show that by measuring and analyzing the lasing spectra under appropriate driving parameters and temperature ranges, the thermal resistance of the laser diodes could be deduced easily. A higher thermal resistance of 640K/W has been measured on a narrow ridge laser chip without soldering. Other thermal and spectral properties of the lasers have also been measured and discussed.

  8. Monolithically Integrated Ge-on-Si Active Photonics

    Directory of Open Access Journals (Sweden)

    Jifeng Liu

    2014-07-01

    Full Text Available Monolithically integrated, active photonic devices on Si are key components in Si-based large-scale electronic-photonic integration for future generations of high-performance, low-power computation and communication systems. Ge has become an interesting candidate for active photonic devices in Si photonics due to its pseudo-direct gap behavior and compatibility with Si complementary metal oxide semiconductor (CMOS processing. In this paper, we present a review of the recent progress in Ge-on-Si active photonics materials and devices for photon detection, modulation, and generation. We first discuss the band engineering of Ge using tensile strain, n-type doping, Sn alloying, and separate confinement of Γ vs. L electrons in quantum well (QW structures to transform the material towards a direct band gap semiconductor for enhancing optoelectronic properties. We then give a brief overview of epitaxial Ge-on-Si materials growth, followed by a summary of recent investigations towards low-temperature, direct growth of high crystallinity Ge and GeSn alloys on dielectric layers for 3D photonic integration. Finally, we review the most recent studies on waveguide-integrated Ge-on-Si photodetectors (PDs, electroabsorption modulators (EAMs, and laser diodes (LDs, and suggest possible future research directions for large-scale monolithic electronic-photonic integrated circuits on a Si platform.

  9. Edge Couplers with relaxed Alignment Tolerance for Pick-and-Place Hybrid Integration of III-V Lasers with SOI Waveguides

    CERN Document Server

    Romero-García, Sebastian; Merget, Florian; Shen, Bin; Witzens, Jeremy

    2013-01-01

    We report on two edge-coupling and power splitting devices for hybrid integration of III-V lasers with sub-micrometric silicon-on-insulator (SOI) waveguides. The proposed devices relax the horizontal alignment tolerances required to achieve high coupling efficiencies and are suitable for passively aligned assembly with pick-and-place tools. Light is coupled to two on-chip single mode SOI waveguides with almost identical power coupling efficiency, but with a varying relative phase accommodating the lateral misalignment between the laser diode and the coupling devices, and is suitable for the implementation of parallel optics transmitters. Experimental characterization with both a lensed fiber and a Fabry-P\\'erot semiconductor laser diode has been performed. Excess insertion losses (in addition to the 3 dB splitting) taken as the worst case over both waveguides of respectively 2 dB and 3.1 dB, as well as excellent 1 dB horizontal loss misalignment ranges of respectively 2.8 um and 3.8 um (worst case over both i...

  10. Highly efficient optical filter based on vertically coupled photonic crystal cavity and bus waveguide

    Science.gov (United States)

    Debnath, Kapil; Welna, Karl; Ferrera, Marcello; Deasy, Kieran; Lidzey, David G.; O'Faolain, Liam

    2013-01-01

    We experimentally demonstrate a new optical filter design based on a vertically coupled photonic crystal cavity and a bus waveguide monolithically integrated on the silicon on insulator platform. The use of a vertically coupled waveguide gives flexibility in the choice of the waveguide material and dimensions, dramatically lowering the insertion loss while achieving very high coupling efficiencies to wavelength scale resonators

  11. Highly efficient optical filter based on vertically coupled Photonic crystal cavity and bus waveguide

    CERN Document Server

    Debnath, Kapil; Ferrera, Marcello; Deasy, Kieran; Lidzey, David G; O'Faolain, Liam

    2012-01-01

    We experimentally demonstrate a new optical filter design based on a vertically coupled photonic crystal cavity and a bus waveguide monolithically integrated on the silicon on insulator platform. The use of a vertically coupled waveguide gives flexibility in the choice of the waveguide material and dimensions, dramatically lowering the insertion loss while achieving very high coupling efficiencies to wavelength scale resonators

  12. Power characteristics of planar index-antiguided waveguide lasers with transverse mode competition

    Directory of Open Access Journals (Sweden)

    Chaofan Wang

    2016-12-01

    Full Text Available We report comprehensive analysis of output characteristics of homogeneously broadened index-antiguided slab lasers with transverse mode competition. Robust single fundamental mode operation is achieved when the distributive modal loss due to index antiguiding dominates the output coupling loss. Maximal laser efficiency under single fundamental mode operation is investigated numerically for various combinations of single-pass gains and losses. We show analytically that an asymptotic limit of such efficiency exists that is solely determined by the loss ratio between the fundamental and 1st higher-order modes, which equals 66.7% for planar index antiguided lasers.

  13. Hollow waveguide cavity ringdown spectroscopy

    Science.gov (United States)

    Dreyer, Chris (Inventor); Mungas, Greg S. (Inventor)

    2012-01-01

    Laser light is confined in a hollow waveguide between two highly reflective mirrors. This waveguide cavity is used to conduct Cavity Ringdown Absorption Spectroscopy of loss mechanisms in the cavity including absorption or scattering by gases, liquid, solids, and/or optical elements.

  14. Improved characteristics of ultraviolet AlGaN multiple-quantum-well laser diodes with step-graded quantum barriers close to waveguide layers

    Science.gov (United States)

    Cai, Xuefen; Li, Shuping; Kang, Junyong

    2016-09-01

    Ultraviolet AlGaN multiple-quantum-well laser diodes (LDs) with step-graded quantum barriers (QBs) instead of conventional first and last QBs close to waveguide layers are proposed. The characteristics of this type of laser diodes are numerically investigated by using the software PICS3D and it is found that the performances of these LDs are greatly improved. The results indicates that the structure with step-graded QBs exhibits higher output light power, slope efficiency and emission intensity, as well as lower series resistance and threshold current density under the identical condition, compared with conventional LD structure.

  15. Pulse laser head with monolithic thermally bonded microchip operating at 1.5 μm wavelength

    Science.gov (United States)

    Młyńczak, Jarosław; Kopczyński, Krzysztof; Belghachem, Nabil; Kisielewski, Jarosław; Stepień, Ryszard; Wychowaniec, Marek; Galas, Jacek; Litwin, Dariusz; CzyŻewski, Adam

    2016-12-01

    On the basis of thermally bonded Er,Yb:glass/Co:MALO microchip a laser head pumped by fiber coupled laser diode was designed. The performance of the laser head were investigated and the main output parameters were determined. The energy over 40 μJ in 3.8 ns pulse with repetition rate of 0.735 kHz was achieved. The laser head characterized by such parameters can successfully be used in tele-detection applications.

  16. Monolithically integrated optoelectronic down-converter (MIOD)

    Science.gov (United States)

    Portnoi, Efrim L.; Venus, G. B.; Khazan, A. A.; Gorfinkel, Vera B.; Kompa, Guenter; Avrutin, Evgenii A.; Thayne, Iain G.; Barrow, David A.; Marsh, John H.

    1995-06-01

    Optoelectronic down-conversion of very high-frequency amplitude-modulated signals using a semiconductor laser simultaneously as a local oscillator and a mixer is proposed. Three possible constructions of a monolithically integrated down-converter are considered theoretically: a four-terminal semiconductor laser with dual pumping current/modal gain control, and both a passively mode-locked and a passively Q-switched semiconductor laser monolithically integrated with an electroabsorption or pumping current modulator. Experimental verification of the feasibility of the concept of down conversion in a laser diode is presented.

  17. 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

    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....... 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...

  18. Helium and hydrogen plasma waveguides for high-intensity laser channeling

    Science.gov (United States)

    Zgadzaj, Rafal Bogumil

    The results of cross polarized pump-probe experiments in preformed He plasma waveguides are reported. Pump and probe have same wavelength and duration of 800nm and 80fs respectively. Peak pump intensity is Iguided = 0.2x1018 W/cm2 ˜1000 Iprobe. Single shot probe spectra and mode profiles at the channel exit are discriminated from the pump with a polarization analyzer and captured at various relative time delays Deltat. Frequency-domain interference (FDI) between the probe and a weak depolarized component of the pump is observed for |Deltat| ≳ 100fs. Although the depolarized component is nearly undetectable through measurement of pump leakage alone, FDI sensitively reveals its substantially non-Gaussian structure. The possible depolarization mechanisms are analyzed. When probe is positioned at the leading edge of the pump, Deltat ≲ 0, its spectrum suffers a blue shift not measurable in the transmitted pump itself. The evidence suggests the channel interior is fully ionized and the partially formed channel ends are the origin of both depolarization and blue shift. A robust, pulsed, differentially-pumped plasma channel generation cell for high intensity guiding experiments has been developed. The design includes an axicon lens, windows for transverse interferometry, and permits injection of one or two different gases (main gas plus high Z seed gas) with several millisecond injection times and simultaneous 0.1ms pressure sensing resolution. Very well formed plasma waveguides have been formed in helium as well as hydrogen, at repeatable and well controlled pressures up to 1000Torr, with very uniform interior density, rapid density drop at boundaries, and very low exterior density. The possible danger associated with the use of large amounts of hydrogen was considered and a complex safety system was designed, constructed and used. Extensive analysis of channel profile reconstruction through transverse interferometry was performed. This includes an intuitive

  19. Effect of optical waveguiding mechanism on the lasing action of chirped InAs/AlGaInAs/InP quantum dash lasers

    KAUST Repository

    Khan, Mohammed Zahed Mustafa

    2013-03-04

    We report on the atypical emission dynamics of InAs/AlGaInAs/InP quantum dash (Qdash) lasers employing varying AlGaInAs barrier thickness (multilayer-chirped structure). The analysis is carried out via fabry-perot (FP) ridge (RW) and stripe waveguide (SW) laser characterization corresponding to the index and gain guided waveguiding mechanisms, respectively, and at different current pulse width operations. The laser emissions are found to emerge from the size dispersion of the Qdash ensembles across the four Qdash-barrier stacks, and governed by their overlapping quasi-zero dimensional density of states (DOS). The spectral characteristics demonstrated prominent dependence on the waveguiding mechanism at quasi-continuous wave (QCW) operation (long pulse width). The RW geometry showed unusual spectral split in the emission spectra on increasing current injection while the SW geometry showed typical broadening of lasing spectra. These effects were attributed to the highly inhomogeneous active region, the nonequilibrium carrier distribution and the energy exchange between Qdash groups across the Qdash-barrier stacks. Furthermore, QCW operation showed a progressive red shift of emission spectra with injection current, resulted from active region heating and carrier depopulation, which was observed to be minimal in the short pulse width (SPW) operation. Our investigation sheds light on the device physics of chirped Qdash laser structure and provides guidelines for further optimization in obtaining broad-gain laser diodes. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  20. Growth of AlGaN stripes with semipolar side facets as waveguide claddings for semipolar laser structures

    Energy Technology Data Exchange (ETDEWEB)

    Leute, Robert Anton Richard; Forghani, Kamran; Lipski, Frank; Scholz, Ferdinand [Institut fuer Optoelektronik, Universitaet Ulm (Germany); Tischer, Ingo; Neuschl, Benjamin; Thonke, Klaus [Institut fuer Quantenmaterie, Gruppe Halbleiterphysik, Universitaet Ulm (Germany)

    2011-07-01

    Selective area growth of group III nitrides allows the epitaxy of semipolar facets with reduced piezoelectric field on 2-inch sapphire substrates. Additionally, the 3D growth of stripes, pyramids or the like enables us to manipulate the extraction and propagation of light by changing the surface topology. LEDs grown on GaN stripes with {l_brace}11 anti 22{r_brace} facets and GaN stripes with {l_brace}10 anti 11{r_brace} facets have been published. The fabrication of laser structures with resonators along the stripes depends critically on the controlled growth of a waveguide cladding for optical confinement, typically realized by AlGaN layers. However, the growth parameters of AlGaN are challenging for selective epitaxy. The high growth temperature promotes lateral growth, leading to the emergence of an undesirable c-plane facet, whereas the reduced selectivity of the mask material for Al atoms leads to polycrystalline growth on masked areas. We investigate the selective growth of AlGaN with Al contents up to 10% with structured SiO{sub 2} and SiN{sub x} masks. The influence of mask geometries (stripes parallel m and perpendicular to m, variable opening sizes and periods) on topology, material quality and Al incorporation is examined. Therefore, we present SEM investigations, spatially resolved cathodoluminescence as well as low temperature photoluminescence.

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

    Science.gov (United States)

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

    2012-06-18

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

  2. Operation of an InAs quantum-dot embedded GaAs photonic crystal slab waveguide laser by using two-photon pumping for photonics integrated circuits

    Directory of Open Access Journals (Sweden)

    H. Oda

    2016-06-01

    Full Text Available The development of small sized laser operating above room temperature is important in the realization of optical integrated circuits. Recently, micro-lasers consisting of photonic crystals (PhCs and whispering gallery mode cavities have been demonstrated. Optically pumped laser devices could be easily designed using photonic crystal-slab waveguides (PhC-WGs with an air-bridge type structure. In this study, we observe lasing at 1.3μm from two-photon pumped InAs-quantum-dots embedded GaAs PhC-WGs above room temperature. This type of compact laser shows promise as a new light source in ultra-compact photonics integrated circuits.

  3. Study on improvement of the laser uniformity transformation of overlapping-image waveguide cavity

    Institute of Scientific and Technical Information of China (English)

    Zebin Fan; Junchang Li; Chongguang Li; Kun Ma

    2005-01-01

    @@ After propagating through the overlapping-image integral mirror, the interference fringe is a major factor that affects the uniformity of the image plane. In this paper, a He-Ne laser is used as light source, and the complex amplitude of the incident laser beam is modulated by an alternating electric field controlled vibrating mirror that is placed before the optical system. The experimental results show that after propagating through the overlapping-image integral mirror, not only the contrast of the interference fringes on the image plane is depressed, but also the uniformity of the intensity distribution of the transformed light beam is improved. Finally, based on the experimental results, two optical systems that can be applied to high power laser uniformity transformation are presented.

  4. Tuning of successively scanned two monolithic Vernier-tuned lasers and selective data sampling in optical comb swept source optical coherence tomography

    Science.gov (United States)

    Choi, Dong-hak; Yoshimura, Reiko; Ohbayashi, Kohji

    2013-01-01

    Monolithic Vernier tuned super-structure grating distributed Bragg reflector (SSG-DBR) lasers are expected to become one of the most promising sources for swept source optical coherence tomography (SS-OCT) with a long coherence length, reduced sensitivity roll-off, and potential capability for a very fast A-scan rate. However, previous implementations of the lasers suffer from four main problems: 1) frequencies deviate from the targeted values when scanned, 2) large amounts of noise appear associated with abrupt changes in injection currents, 3) optically aliased noise appears due to a long coherence length, and 4) the narrow wavelength coverage of a single chip limits resolution. We have developed a method of dynamical frequency tuning, a method of selective data sampling to eliminate current switching noise, an interferometer to reduce aliased noise, and an excess-noise-free connection of two serially scanned lasers to enhance resolution to solve these problems. An optical frequency comb SS-OCT system was achieved with a sensitivity of 124 dB and a dynamic range of 55-72 dB that depended on the depth at an A-scan rate of 3.1 kHz with a resolution of 15 μm by discretely scanning two SSG-DBR lasers, i.e., L-band (1.560-1.599 μm) and UL-band (1.598-1.640 μm). A few OCT images with excellent image penetration depth were obtained. PMID:24409394

  5. Fabrication and characteristics of GaAs-AlGaAs tunable laser diodes with DBR and phase-control sections integrated by compositional disordering of a quantum well

    Science.gov (United States)

    Hirata, Takaaki; Maeda, Minoru; Suehiro, Masayuki; Hosomatsu, Haruo

    1991-06-01

    GaAs-AlGaAs rib-waveguide graded-index separate-confinement heterostructure (GRINSCH) single-quantum-well (SQW) tunable distributed Bragg reflector (DBR) laser diodes were fabricated by (EB) lithography, ion implantation, and two-step metalorganic vapor phase epitaxy (MOVPE) growth. Active and passive waveguides were monolithically integrated by the compositional disordering of quantum-well heterostructures using silicon ion implantation. First-order gratings and rib waveguides were adopted with EB lithography to improve lasing characteristics, and they have wide application to photonic integrated circuits (PICs). Waveguide losses of partially disordered GRINSCH-SQW passive waveguides were as low as 4.4/cm at the lasing wavelength. A narrow linewidth as low as 560 kHz and a frequency tuning of more than 2.9 THz were obtained. The results show that this fabrication process is useful for PICs.

  6. Packaged, High-Power, Narrow-Linewidth Slab-Coupled Optical Waveguide External Cavity Laser (SCOWECL)

    Science.gov (United States)

    2010-12-01

    efficiency. With the 20% reflecli vity FBG, the laser ex hibi ts a threshold of 0.9 A and reaches a CW peak power of 0.37 W aI 4 A. The peak effic ...twice the photon energy . The SCOWECL is expected to find applications in free space coherent optical communications and in microwave photollic...Dai , " High effic ient and narrow linewidlh fiber laser based on fiber grat ing Fabry- Perot cavity," Frolltiers of Oploeieclrollics il/ Chinll, vol

  7. Monolithic integration of hybrid III-V/Si lasers and Si-based modulators for data transmission up to 25Gbps

    Science.gov (United States)

    Ferrotti, Thomas; Blampey, Benjamin; Jany, Christophe; Duprez, Hélène; Chantre, Alain; Boeuf, Frédéric; Seassal, Christian; Ben Bakir, Badhise

    2017-02-01

    In this paper, the 200mm silicon-on-insulator (SOI) platform is used to demonstrate the monolithic co-integration of hybrid III-V/silicon Distributed Bragg Reflector (DBR) tunable lasers and silicon Mach-Zehnder modulator (MZMs), to achieve fully integrated hybrid transmitters for silicon photonics. The design of each active component, as well as the fabrication process steps of the whole architecture are described in details. Data transmission rate up to 25Gb/s has been reached for transmitters using MZMs with active lengths of 2mm and 4mm. Extinction ratios of respectively 2.9dB and 4.7dB are obtained by applying drive voltages of 2.5V peak-to-peak on the MZMs. 25Gb/s data transmission is demonstrated at 1303.5nm and 1315.8nm, with the possibility to tune the operating wavelength by up to 8.5nm in each case, by using metallic heaters above the lasers Bragg reflectors.

  8. Waveguide device and method for making same

    Science.gov (United States)

    Forman, Michael A.

    2007-08-14

    A monolithic micromachined waveguide device or devices with low-loss, high-power handling, and near-optical frequency ranges is set forth. The waveguide and integrated devices are capable of transmitting near-optical frequencies due to optical-quality sidewall roughness. The device or devices are fabricated in parallel, may be mass produced using a LIGA manufacturing process, and may include a passive component such as a diplexer and/or an active capping layer capable of particularized signal processing of the waveforms propagated by the waveguide.

  9. Switchable random laser from dye-doped polymer dispersed liquid crystal waveguides

    NARCIS (Netherlands)

    Xiao, Shumin; Song, Qinghai; Wang, Feng; Liu, Liying; Liu, Jianhua; Xu, Lei

    2007-01-01

    A dye-doped polymer-dispersed liquid crystal (PDLC) film has been fabricated for random lasing action. In this PDLC film, the sizes of most liquid crystal (LC) droplets ranged from 200 to 500 nm. When the sample is optically pumped, ultrahigh Q (>10 000) lasing modes and a collimated laser beam can

  10. Mode-locked InAs/InP quantum-dash-based DBR laser with monolithically integrated SOA

    Science.gov (United States)

    Joshi, Siddharth; Chimot, Nicolas; Barbet, Sophie; Accard, Alain; Lelarge, François

    2014-02-01

    We present the first demonstration of InAs/InP Quantum Dash based single-section frequency comb generator designed for use in photonic integrated circuits. The laser cavity is closed using a specific Bragg reflector without compromising the mode-locking performance of the laser. This enables the integration of single-section mode- locked laser on photonic integrated circuits as on-chip frequency comb source. As a demonstration, we integrate the Fabry Perot laser with a semiconductor optical amplifier. Such a device could be used for amplification or modulation of the frequency generated comb. We thus investigate the device operation to obtain a NRZ modulated comb.

  11. Quantum dot lasers and integrated guided wave devices on Si

    Science.gov (United States)

    Yang, Jun; Mi, Zetian; Bhattacharya, Pallab

    2007-02-01

    We have studied the growth and characteristics of self-organized InGaAs/GaAs quantum dot lasers and their monolithic integration with waveguides and quantum well electroabsorption modulators on Si. Utilizing multiple layers of InAs quantum dots as effective dislocation filters near the GaAs-Si interface, we have demonstrated high performance quantum dot lasers grown directly on Si that exhibit, for the first time, relatively low threshold current (J th = 900 A/cm2), large characteristic temperature (T 0 = 278 K), and output slope efficiency ( >=0.3 W/A). Focused-ion-beam milling has been used to form high-quality facets for the cavity mirror and coupling groove of an integrated laser/waveguide system on Si. We have also achieved a groove-coupled laser/modulator system on Si that exhibits a coupling coefficient greater than 20% and a modulation depth of ~ 100% at 5 V reverse bias.

  12. Photonic waveguide engineering using pulsed lasers – A novel approach for non-clean room fabrication!

    OpenAIRE

    Jha, A.; Murray, M; Irranejad, M.; Zhao, Z.; Fernandez, TT; Hogg, RA; Zhang, ZY; Bamiedakis, N; Plenty, RV; White, IH

    2015-01-01

    This is the accepted manuscript. The final version is available from IEEE at http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6876466. Over the last 25 years has seen an unprecedented increase in the growth of phonic components based on semiconductor and solid-state lasers, glass and polymer based optical fibres, and organic LEDs. Emerging technology for component engineering must embed dissimilar materials based devices into an integrated form which is more efficient. In this...

  13. The effect of asymmetric barrier layers in the waveguide region on power characteristics of QW lasers

    DEFF Research Database (Denmark)

    Zubov, F. I.; Zhukov, A. E.; Shernyakov, Yu M.

    2015-01-01

    Current-voltage and light-current characteristics of quantum-well lasers have been studied at high drive currents. The introduction of asymmetric barrier layers adjacent to the active region caused a significant suppression of the nonlinearity in the light-current characteristic and an increase...... in the external differential efficiency. As a result, the maximum wallplug efficiency increased by 9%, while the output optical power increased by 29%....

  14. High-power Yb- and Tm-doped double tungstate channel waveguide lasers

    NARCIS (Netherlands)

    Dalfsen, van K.; Geskus, D.; Ay, F.; Wörhoff, K.; Aravazhi, S.; Pollnau, M.

    2011-01-01

    The potassium double tungstates KGd(WO4)2, KY(WO4)2, and KLu(WO4)2 are excellent candidates for solid-state lasers because of their high refractive index of ~2.0-2.1, the large transition cross-sections of rare-earth (RE3+) ions doped into these hosts, and a reasonably large thermal conductivity of

  15. Ultrafast direct laser writing of cladding waveguides in the 0.8CaSiO{sub 3}-0.2Ca{sub 3}(PO{sub 4}){sub 2} eutectic glass doped with Nd{sup 3+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Martínez de Mendívil, J., E-mail: jon.martinez@uam.es; Lifante, G. [Departamento de Física de Materiales, C-04, Facultad de Ciencias, Universidad Autónoma de Madrid, 28.049 Madrid (Spain); Sola, D.; Peña, J. I. [Departamento de Ciencia y Tecnología de Materiales y Fluidos, Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, 50.018 Zaragoza (Spain); Vázquez de Aldana, J. R. [Grupo de Investigación en Microprocesado de Materiales con Láser, Departamento de Física Aplicada, Universidad de Salamanca, 37.008 Salamanca (Spain); Aza, A. H. de; Pena, P. [Instituto de Cerámica y Vidrio-CSIC, 28.049 Madrid (Spain)

    2015-01-28

    We report on tubular cladding optical waveguides fabricated in Neodymium doped Wollastonite-Tricalcium Phosphate glass in the eutectic composition. The glass samples were prepared by melting the eutectic powder mixture in a Pt-Rh crucible at 1600 °C and pouring it in a preheated brass mould. Afterwards, the glass was annealed to relieve the inner stresses. Cladding waveguides were fabricated by focusing beneath the sample surface using a pulsed Ti:sapphire laser with a pulsewidth of 120 fs working at 1 kHz. The optical properties of these waveguides have been assessed in terms of near-field intensity distribution and transmitted power, and these results have been compared to previously reported waveguides with double-line configuration. Optical properties have also been studied as function of the temperature. Heat treatments up to 700 °C were carried out to diminish colour centre losses where waveguide's modes and transmitted power were compared in order to establish the annealing temperature at which the optimal optical properties were reached. Laser experiments are in progress to evaluate the ability of the waveguides for 1064 nm laser light generation under 800 nm optical pumping.

  16. InP-based monolithically integrated 1310/1550nm diplexer/triplexer

    Science.gov (United States)

    Silfvenius, C.; Swillo, M.; Claesson, J.; Forsberg, E.; Akram, N.; Chacinski, M.; Thylén, L.

    2008-11-01

    Multiple streams of high definition television (HDTV) and improved home-working infrastructure are currently driving forces for potential fiber to the home (FTTH) customers [1]. There is an interest to reduce the cost and physical size of the FTTH equipment. The current fabrication methods have reached a cost minimum. We have addressed the costchallenge by developing 1310/(1490)/1550nm bidirectional diplexers, by monolithic seamless integration of lasers, photodiodes and wavelength division multiplexing (WDM) couplers into one single InP-based device. A 250nm wide optical gain profile covers the spectrum from 1310 to 1550nm and is the principal building block. The device fabrication is basically based on the established configuration of using split-contacts on continuos waveguides. Optical and electrical cross-talks are further addressed by using a Y-configuration to physically separate the components from each other and avoid inline configurations such as when the incoming signal travels through the laser component or vice versa. By the eliminated butt-joint interfaces which can reflect light between components or be a current leakage path and by leaving optically absorbing (unpumped active) material to surround the components to absorb spontaneous emission and nonintentional reflections the devices are optically and electrically isolated from each other. Ridge waveguides (RWG) form the waveguides and which also maintain the absorbing material between them. The WDM functionality is designed for a large optical bandwidth complying with the wide spectral range in FTTH applications and also reducing the polarization dependence of the WDM-coupler. Lasing is achieved by forming facet-free, λ/4-shifted, DFB (distributed feedback laser) lasers emitting directly into the waveguide. The photodiodes are waveguide photo-diodes (WGPD). Our seamless technology is also able to array the single channel diplexers to 4 to 12 channel diplexer arrays with 250μm fiber port

  17. Low-Loss 256-Channel AWG Module with Monolithically Integrated Spot-Size Converters

    Institute of Scientific and Technical Information of China (English)

    M. Itoh; S. Kamei; M. Ishii; Y. Hida; T. Shibata; Y. Hibino

    2003-01-01

    We developed a compact fiber-pigtailed 256-channel AWG module with 1.5% △ waveguides.By monolithically integrating spot-size converters with input/output waveguides, we achieved a lowinsertion loss of 2.6-4.1 dB with a low background crosstalk of -40 dB.

  18. Low-Loss 256-Channel AWG Module with Monolithically Integrated Spot-Size Converters

    Institute of Scientific and Technical Information of China (English)

    M.; Itoh; S.; Kamei; M.; Ishii; Y.; Hida; T.; Shibata; Y.; Hibino

    2003-01-01

    We developed a compact fiber-pigtailed 256-channel AWG module with 1.5% A waveguides. By monolithically integrating spot-size converters with input/output waveguides, we achieved a low insertion loss of 2.6-4.1 dB with a low background crosstalk of-40 dB.

  19. Eigenpolarization theory of monolithic nonplanar ring oscillators

    Science.gov (United States)

    Nilsson, Alan C.; Gustafson, Eric K.; Byer, Robert L.

    1989-01-01

    Diode-laser-pumped monolithic nonplanar ring oscillators (NPROs) in an applied magnetic field can operate as unidirectional traveling-wave lasers. The diode laser pumping, monolithic construction, and unidirectional oscillation lead to narrow linewidth radiation. Here, a comprehensive theory of the eigenpolarizations of a monolithic NPRO is presented. It is shown how the properties of the integral optical diode that forces unidirectional operation depend on the choice of the gain medium, the applied magnetic field, the output coupler, and the geometry of the nonplanar ring light path. Using optical equivalence theorems to gain insight into the polarization characteristics of the NPRO, a strategy for designing NPROs with low thresholds and large loss nonreciprocities is given. An analysis of the eigenpolarizations for one such NPRO is presented, alternative optimization approaches are considered, and the prospects for further reducing the linewidths of these lasers are briefly discussed.

  20. Coupling of metal-organic frameworks-containing monolithic capillary-based selective enrichment with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry for efficient analysis of protein phosphorylation.

    Science.gov (United States)

    Li, Daojin; Yin, Danyang; Chen, Yang; Liu, Zhen

    2017-05-19

    Protein phosphorylation is a major post-translational modification, which plays a vital role in cellular signaling of numerous biological processes. Mass spectrometry (MS) has been an essential tool for the analysis of protein phosphorylation, for which it is a key step to selectively enrich phosphopeptides from complex biological samples. In this study, metal-organic frameworks (MOFs)-based monolithic capillary has been successfully prepared as an effective sorbent for the selective enrichment of phosphopeptides and has been off-line coupled with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for efficient analysis of phosphopeptides. Using š-casein as a representative phosphoprotein, efficient phosphorylation analysis by this off-line platform was verified. Phosphorylation analysis of a nonfat milk sample was also demonstrated. Through introducing large surface areas and highly ordered pores of MOFs into monolithic column, the MOFs-based monolithic capillary exhibited several significant advantages, such as excellent selectivity toward phosphopeptides, superb tolerance to interference and simple operation procedure. Because of these highly desirable properties, the MOFs-based monolithic capillary could be a useful tool for protein phosphorylation analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Resolution limits of laser spectroscopic absorption measurements with hollow glass waveguides.

    Science.gov (United States)

    Chen, Jia; Hangauer, Andreas; Strzoda, Rainer; Amann, Markus Christian

    2010-10-01

    In this paper, resolution limits of laser spectroscopy absorption measurements with hollow capillary fibers are investigated. Furthermore, a concept of sensitive near-infrared sensing utilizing hollow fiber directly coupled with vertical-cavity surface-emitting lasers is developed. By performing wavelength modulation spectroscopy, the smallest absorbance that can be detected by the fiber sensor was determined to be 10(-4), limited by a random modulation of the fiber transmission function (modal noise). By mechanically vibrating the fiber, a sensor resolution of 10(-5) in absorbance is achieved. Because the random modulation on the fiber transmission function limits the detection sensitivity, its physical reasons are analyzed. One contribution is found to be the partial integration of the far field, and the amplitude of the spectral features is inversely proportional to the square root of the integrated speckle points number. Therefore, careful design of the fiber-detector outcoupling is necessary. It turned out that incoupling alignment is not of much influence with respect to the spectral background. The residual spectral background is caused by mode-dependent effects and can be lowered by vibrating the fiber mechanically.

  2. Fabrication and optical testing of hybrid SiO2: azo-polymer based planar waveguides for NLO/SHG laser emission

    Science.gov (United States)

    Torres-Zúñiga, V.; Morales-Saavedra, O. G.; Pérez-Martínez, A. L.

    2015-01-01

    Predesigned push-pull azo-dye polymers were homogeneously dispersed within a SiO2 sol-gel matrix synthesized via the sonogel (SG) route. High-quality spin-coated films were obtained with these hybrid structures in the liquid sol-phase. The spectroscopic UV- Vis analyses reveal the appropriate insertion of these organic compounds within the highly pure SG-environment whereas the thermal (DSC) analysis and photoacoustic measurements evidence the thermomechanical stability of the amorphous hybrid layers. As the optical attenuation, refractive index and film thickness values of the obtained films are adequate for opto-electronic applications; these hybrid films were implemented to fabricate optical waveguiding prototypes. In this sense, functional planar waveguides were fabricated for nonlinear optical (NLO) applications after performing a molecular ordering via a corona DC-poling procedure in order to achieve a macroscopic polar order (ferroelectric and noncentrosymmetric arrangement of the organic chromophores). The poled films were then able to exhibit stable NLO-waveguiding effects as excited with a Nd:YAG laser system in order to generate second harmonic waves travelling within the planar layer.

  3. Monoliths in Bioprocess Technology

    Directory of Open Access Journals (Sweden)

    Vignesh Rajamanickam

    2015-04-01

    Full Text Available Monolithic columns are a special type of chromatography column, which can be used for the purification of different biomolecules. They have become popular due to their high mass transfer properties and short purification times. Several articles have already discussed monolith manufacturing, as well as monolith characteristics. In contrast, this review focuses on the applied aspect of monoliths and discusses the most relevant biomolecules that can be successfully purified by them. We describe success stories for viruses, nucleic acids and proteins and compare them to conventional purification methods. Furthermore, the advantages of monolithic columns over particle-based resins, as well as the limitations of monoliths are discussed. With a compilation of commercially available monolithic columns, this review aims at serving as a ‘yellow pages’ for bioprocess engineers who face the challenge of purifying a certain biomolecule using monoliths.

  4. Direct-writing of PbS nanoparticles inside transparent porous silica monoliths using pulsed femtosecond laser irradiation

    Science.gov (United States)

    Chahadih, Abdallah; El Hamzaoui, Hicham; Bernard, Rémy; Boussekey, Luc; Bois, Laurence; Cristini, Odile; Le Parquier, Marc; Capoen, Bruno; Bouazaoui, Mohamed

    2011-10-01

    Pulsed femtosecond laser irradiation at low repetition rate, without any annealing, has been used to localize the growth of PbS nanoparticles, for the first time, inside a transparent porous silica matrix prepared by a sol-gel route. Before the irradiation, the porous silica host has been soaked within a solution containing PbS precursors. The effect of the incident laser power on the particle size was studied. X-ray diffraction was used to identify the PbS crystallites inside the irradiated areas and to estimate the average particle size. The localized laser irradiation led to PbS crystallite size ranging between 4 and 8 nm, depending on the incident femtosecond laser power. The optical properties of the obtained PbS-silica nanocomposites have been investigated using absorption and photoluminescence spectroscopies. Finally, the stability of PbS nanoparticles embedded inside the host matrices has been followed as a function of time, and it has been shown that this stability depends on the nanoparticle mean size.

  5. Narrow linewidth single-mode semiconductor laser development for coherent detection lidar

    Science.gov (United States)

    Mansour, Kamjou; Ksendzov, Alexander; Menzies, Robert T.; Maker, Paul D.; Muller, Richard E.; Manfra, M. J.; Turner, George W.

    2003-01-01

    High power, tunable, single mode, narrow linewidth semiconductor lasers in the 2.05-(micro)m wavelength region are needed to develop semiconductor laser reference oscillators for optical remote sensing from Earth orbit. 2.05-I1/4m narrow linewidth monolithic distributed feedback (DFB) and distributed Bragg reflector (DBR) with the external grating ridge waveguide lasers fabricated from epitaxially grown InGaAs/InGaAsP/InP and in InGaAsSb/AlGaAsSb/GaSb heterostructures are reported.

  6. Narrow linewidth single-mode semiconductor laser development for coherent detection lidar

    Science.gov (United States)

    Mansour, Kamjou; Ksendzov, Alexander; Menzies, Robert T.; Maker, Paul D.; Muller, Richard E.; Manfra, M. J.; Turner, George W.

    2003-01-01

    High power, tunable, single mode, narrow linewidth semiconductor lasers in the 2.05-(micro)m wavelength region are needed to develop semiconductor laser reference oscillators for optical remote sensing from Earth orbit. 2.05-I1/4m narrow linewidth monolithic distributed feedback (DFB) and distributed Bragg reflector (DBR) with the external grating ridge waveguide lasers fabricated from epitaxially grown InGaAs/InGaAsP/InP and in InGaAsSb/AlGaAsSb/GaSb heterostructures are reported.

  7. BeZnCdSe quantum-well ridge-waveguide laser diodes under low threshold room-temperature continuous-wave operation

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jijun [Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093 (China); Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Akimoto, Ryoichi, E-mail: r-akimoto@aist.go.jp [Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan)

    2015-10-19

    Low threshold current ridge-waveguide BeZnCdSe quantum-well laser diodes (LDs) have been developed by completely etching away the top p-type BeMgZnSe/ZnSe:N short-period superlattice cladding layer, which can suppress the leakage current that flows laterally outside of the electrode. The waveguide LDs are covered with a thick SiO{sub 2} layer and planarized with chemical-mechanical polishing and a reactive ion etching process. Room-temperature lasing under continuous-wave condition is achieved with the laser cavity formed by the cleaved waveguide facets coated with high-reflectivity dielectric films. For a 4 μm-wide green LD lasing around a wavelength of 535 nm, threshold current and voltage of 7.07 mA and 7.89 V are achieved for a cavity length of 300 μm, and the internal differential quantum efficiency, internal absorption loss, gain constant, and nominal transparency current density are estimated to be 27%, 4.09 cm{sup −1}, 29.92 (cm × μm)/kA and 6.35 kA/(cm{sup 2 }× μm), respectively. This compact device can realize a significantly improved performance with much lower threshold power consumption, which would benefit the potential application for ZnSe-based green LDs as light sources in full-color display and projector devices installed in consumer products such as pocket projectors.

  8. A Monolithic Micro-Tensile Tester for Investigating Silicon Dioxide Polymorph Micromechanics, Fabricated and Operated Using a Femtosecond Laser

    Directory of Open Access Journals (Sweden)

    Christos-Edward Athanasiou

    2015-09-01

    Full Text Available Mechanical testing of materials at the microscales is challenging. It requires delicate procedures not only for producing and handling the specimen to be tested, but also for applying an accurate and controlled force. This endeavor is even more challenging when it comes to investigating the behavior of brittle materials such as glass. Here, we present a microtensile tester for investigating silica glass polymorphs. The instrument is entirely made of silica and for which the same femtosecond laser is not only used for fabricating the device, but also for operating it (loading the specimen as well as for performing in situ measurements. As a proof-of-concept, we present a stress-strain curve of fused silica for unprecedented high tensile stress of 2.4 GPa, as well as preliminary results of the elastic modulus of femtosecond laser-affected zones of fused silica, providing new insights on their microstructures and mechanical behavior.

  9. Compact 4-channel AWGs for CWDM and LAN WDM in data center monolithic applications

    Science.gov (United States)

    Pan, Pan; An, Junming; Wang, Yue; Zhang, Jiashun; Wang, Liangliang; Qi, Ying; Han, Qin; Hu, Xiongwei

    2015-12-01

    InP-based 4-channel AWGs for Coarse Wavelength Division Multiplexing (CWDM) with channel spacing of 20 nm and Local Area Network (LAN) WDM with channel spacing of 800 GHz are designed and fabricated. The deep-ridge waveguide is used to make the chip compact, chip size of AWG for CWDM is 0.55×3.9 mm2 and for LAN WDM is 1.6×3 mm2. The measured results indicate that, the insertion losses are -5 dB and -7 dB, crosstalk levels are below -25 dB and -24 dB for AWG with 20 nm channel spacing and 800 GHz channel spacing, respectively. These AWGs can be integrated with lasers and detectors array monolithically for data center applications.

  10. 3D laser-written silica glass step-index high-contrast waveguides for the 3.5 μm mid-infrared range.

    Science.gov (United States)

    Martínez, Javier; Ródenas, Airán; Fernandez, Toney; Vázquez de Aldana, Javier R; Thomson, Robert R; Aguiló, Magdalena; Kar, Ajoy K; Solis, Javier; Díaz, Francesc

    2015-12-15

    We report on the direct laser fabrication of step-index waveguides in fused silica substrates for operation in the 3.5 μm mid-infrared wavelength range. We demonstrate core-cladding index contrasts of 0.7% at 3.39 μm and propagation losses of 1.3 (6.5) dB/cm at 3.39 (3.68) μm, close to the intrinsic losses of the glass. We also report on the existence of three different laser modified SiO₂ glass volumes, their different micro-Raman spectra, and their different temperature-dependent populations of color centers, tentatively clarifying the SiO₂ lattice changes that are related to the large index changes.

  11. Experimental Study of RF-excited Diffusion Cooled Off-axis Unstable Resonator with High Frequency Modulation in a Waveguide CO2 Laser

    Institute of Scientific and Technical Information of China (English)

    Abdul Rauf; ZHOU Xiao-guang; ZHANG Heng-li; XIN Jian-guo

    2007-01-01

    The experimental study of the laser beam parameters of the pulse repetitive RF-excited diffusion cooled waveguide CO2 laser are presented. The measurements are carried out for the pumping pulse duration of 100 μs and pulse repetitive rates 5 - 14 kHz. The average power density delivered to the active medium is 76 W/cm3. Three types of the pulses,namely the square, the sine and the triangular ones have been applied at the input as pumping pulses and their effects on the output power and the delay time have been studied. The output power of the radiation versus input power, pressure of the laser gas mixture and modulation frequency has been investigated. The results indicate that the output peak power for the three types of pulses increases with increase of the pressure of the laser gas mixture and with the input power where as it decreases with the repetition frequency. The delay time of the output pulse decreases with the increase of the repetition frequency and input power, where as it increases with the increase of the pressure of the laser gas mixture. The behavior of the output power and the delay time with duty cycle for square pulse has also been investigated.

  12. Narrow ridge waveguide high power single mode 1.3-μm InAs/InGaAs ten-layer quantum dot lasers

    Directory of Open Access Journals (Sweden)

    Cao Q

    2007-01-01

    Full Text Available AbstractTen-layer InAs/In0.15Ga0.85As quantum dot (QD laser structures have been grown using molecular beam epitaxy (MBE on GaAs (001 substrate. Using the pulsed anodic oxidation technique, narrow (2 μm ridge waveguide (RWG InAs QD lasers have been fabricated. Under continuous wave operation, the InAs QD laser (2 × 2,000 μm2 delivered total output power of up to 272.6 mW at 10 °C at 1.3 μm. Under pulsed operation, where the device heating is greatly minimized, the InAs QD laser (2 × 2,000 μm2 delivered extremely high output power (both facets of up to 1.22 W at 20 °C, at high external differential quantum efficiency of 96%. Far field pattern measurement of the 2-μm RWG InAs QD lasers showed single lateral mode operation.

  13. Hollow waveguide for urology treatment

    Science.gov (United States)

    Jelínková, H.; Němec, M.; Koranda, P.; Pokorný, J.; Kőhler, O.; Drlík, P.; Miyagi, M.; Iwai, K.; Matsuura, Y.

    2010-02-01

    The aim of our work was the application of the special sealed hollow waveguide system for the urology treatment - In our experimental study we have compared the effects of Ho:YAG (wavelength 2100 nm) and Er:YAG (wavelength 2940 nm) laser radiation both on human urinary stones (or compressed plaster samples which serve as a model) fragmentation and soft ureter tissue incision in vitro. Cyclic Olefin Polymer - coated silver (COP/Ag) hollow glass waveguides with inner and outer diameters 700 and 850 μm, respectively, were used for the experiment. To prevent any liquid to diminish and stop the transmission, the waveguide termination was utilized.

  14. Gratings in polymeric waveguides

    Science.gov (United States)

    Mishakov, G.; Sokolov, V.; Kocabas, A.; Aydinli, A.

    2007-04-01

    Laser-induced formation of polymer Bragg grating filters for Dense Wavelength Division Multiplexing (DWDM) applications is discussed. Acrylate monomers halogenated with both fluorine and chlorine, which possess absorption losses less than 0.25 dB/cm and wide choice of refractive indices (from 1.3 to 1.5) in the 1.5 μm telecom wavelength region were used. The monomers are highly intermixable thus permitting to adjust the refractive index of the composition within +/-0.0001. Moreover they are photocurable under UV exposure and exhibit high contrast in polymerization. These properties make halogenated acrylates very promising for fabricating polymeric waveguides and photonic circuits. Single-mode polymer waveguides were fabricated on silicon wafers using resistless contact lithography. Submicron index gratings have been written in polymer waveguides using holographic exposure with He-Cd laser beam (325 nm) through a phase mask. Both uniform and apodized gratings have been fabricated. The gratings are stable and are not erased by uniform UV exposure. The waveguide gratings possess narrowband reflection spectra in the 1.5 μm wavelength region of 0.4 nm width, nearly rectangular shape of the stopband and reflectivity R > 99%. The fabricated Bragg grating filters can be used for multiplexing/demultiplexing optical signals in high-speed DWDM optical fiber networks.

  15. Record bandwidth and sub-picosecond pulses from a monolithically integrated mode-locked quantum well ring laser.

    Science.gov (United States)

    Moskalenko, Valentina; Latkowski, Sylwester; Tahvili, Saeed; de Vries, Tjibbe; Smit, Meint; Bente, Erwin

    2014-11-17

    In this paper, we present the detailed characterization of a semiconductor ring passively mode-locked laser with a 20 GHz repetition rate that was realized as an indium phosphide based photonic integrated circuit (PIC). Various dynamical regimes as a function of operating conditions were explored in the spectral and time domain. A record bandwidth of the optical coherent comb from a quantum well based device of 11.5 nm at 3 dB and sub-picosecond pulse generation is demonstrated.

  16. Microwave properties of monolithic Y-Ba-Cu-O transmission line devices fabricated by the laser-writing patterning technique

    Energy Technology Data Exchange (ETDEWEB)

    Maung, W.N.; Butler, D.P. [Southern Methodist Univ., Dallas, TX (United States). Electrical Engineering Dept.; Xiong, W. [Univ. of Rochester, NY (United States). Dept. of Electrical Engineering; Kula, W.; Sobolewski, R. [Univ. of Rochester, NY (United States). Dept. of Electrical Engineering]|[Polish Academy of Sciences, Warszawa (Poland). Inst. of Physics

    1994-12-31

    The authors report on the microwave characteristics of coplanar strip transmission line devices fabricated in epitaxial YBaCuO thin films deposited on LaAlO{sub 3} substrates using the novel laser-writing patterning technique. This technique uses laser heating to selectively anneal regions of an oxygen depleted YBaCuO thin film to form local superconducting phases. In this manner, superconductive coplanar strip transmission line structures surrounded by the semiconducting YBaCuO phase were patterned with no photomasks, surface contamination or edge degradation. The propagation characteristics of transmission line devices were measured with a HP8510 network analyzer from 1 to 20 GHz. At 300 K, the transmission line circuits displayed poor transmission characteristics due to the high conductivity of the semiconducting phase and small conductivity enhancement of the oxygenated regions. As the circuits were cooled below 89 K, the {Tc} of the superconducting phase, the measured S{sub 21} was near 0 dB indicating little attenuation along the high quality transmission lines. Q-factors as high as 5,000 were measured from coplanar strip transmission line resonator circuits at 6 GHz and 24 K.

  17. Monolithically integrated mid-infrared sensor using narrow mode operation and temperature feedback

    Science.gov (United States)

    Ristanic, Daniela; Schwarz, Benedikt; Reininger, Peter; Detz, Hermann; Zederbauer, Tobias; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried

    2015-01-01

    A method to improve the sensitivity and selectivity of a monolithically integrated mid-infrared sensor using a distributed feedback laser (DFB) is presented in this paper. The sensor is based on a quantum cascade laser/detector system built from the same epitaxial structure and with the same fabrication approach. The devices are connected via a dielectric-loaded surface plasmon polariton waveguide with a twofold function: it provides high light coupling efficiency and a strong interaction of the light with the environment (e.g., a surrounding fluid). The weakly coupled DFB quantum cascade laser emits narrow mode light with a FWHM of 2 cm-1 at 1586 cm-1. The room temperature laser threshold current density is 3 kA/cm2 and a pulsed output power of around 200 mW was measured. With the superior laser noise performance, due to narrow mode emission and the compensation of thermal fluctuations, the lower limit of detection was expanded by one order of magnitude to the 10 ppm range.

  18. Monolithically integrated mid-infrared sensor using narrow mode operation and temperature feedback

    Energy Technology Data Exchange (ETDEWEB)

    Ristanic, Daniela; Schwarz, Benedikt, E-mail: benedikt.schwarz@tuwien.ac.at; Reininger, Peter; Detz, Hermann; Zederbauer, Tobias; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics and Center for Micro- and Nanostructures, Vienna University of Technology, Floragasse 7, Vienna 1040 (Austria)

    2015-01-26

    A method to improve the sensitivity and selectivity of a monolithically integrated mid-infrared sensor using a distributed feedback laser (DFB) is presented in this paper. The sensor is based on a quantum cascade laser/detector system built from the same epitaxial structure and with the same fabrication approach. The devices are connected via a dielectric-loaded surface plasmon polariton waveguide with a twofold function: it provides high light coupling efficiency and a strong interaction of the light with the environment (e.g., a surrounding fluid). The weakly coupled DFB quantum cascade laser emits narrow mode light with a FWHM of 2 cm{sup −1} at 1586 cm{sup −1}. The room temperature laser threshold current density is 3 kA∕cm{sup 2} and a pulsed output power of around 200 mW was measured. With the superior laser noise performance, due to narrow mode emission and the compensation of thermal fluctuations, the lower limit of detection was expanded by one order of magnitude to the 10 ppm range.

  19. Fast Tuneable InGaAsP DBR Laser Using Quantum-Confined Stark-Effect-Induced Refractive Index Change

    OpenAIRE

    Pantouvaki, M.; Renaud, C. C.; Cannard, P; Robertson, M. J.; Gwilliam, R; Seeds, A. J.

    2007-01-01

    We report a monolithically integrated InGaAsP DBR ridge waveguide laser that uses the quantum-confined Stark effect (QCSE) to achieve fast tuning response. The laser incorporates three sections: a forward-biased gain section, a reverse-biased phase section, and a reverse-biased DBR tuning section. The laser behavior is modeled using transmission matrix equations and tuning over similar to 8 nm is predicted. Devices were fabricated using post-growth shallow ion implantation to reduce the loss ...

  20. Monolithic integration of an InGaAsP InP strained DFB laser and an electroabsorption modulator by ultra-low-pressure selective-area-growth MOCVD

    Science.gov (United States)

    Zhao, Q.; Pan, J. Q.; Zhou, F.; Wang, B. J.; Wang, L. F.; Wang, W.

    2005-06-01

    The design and basic characteristics of a strained InGaAsP-InP multiple-quantum-well (MQW) DFB laser monolithically integrated with an electroabsorption modulator (EAM) by ultra-low-pressure (22 mbar) selective-area-growth (SAG) MOCVD are presented. A fundamental study of the controllability and the applicability of band-gap energy by using the SAG method is performed. A large band-gap photoluminescence wavelength shift of 88 nm was obtained with a small mask width variation (0-30 µm). The technique is then applied to fabricate a high performance strained MQW EAM integrated with a DFB laser. The threshold current of 26 mA at CW operation of the device with DFB laser length of 300 µm and EAM length of 150 µm has been realized at a modulator bias of 0 V. The devices also exhibit 15 dB on/off ratio at an applied bias voltage of 5 V.