Mikhail Maiorov - Academia.edu (original) (raw)

Papers by Mikhail Maiorov

Research paper thumbnail of Kinetic model of GaAs(100) growth from molecular beams

Technical Physics Letters, 1997

A kinetic model for the growth of GaAs(100) by molecular beam epitaxy is constructed. The element... more A kinetic model for the growth of GaAs(100) by molecular beam epitaxy is constructed. The elementary processes at the surface are analyzed, including chemisorption of atoms and molecules, incorporation of atoms into the crystal, decomposition of the crystal, and desorption of group-III atoms and group-V molecules in vacuum. The sticking coefficients and rate constants are obtained from a direct comparison with experimental data. The model can be used to determine the desorbed and reflected fluxes, the growth rate, and the coverage by groups III and V atoms as functions of the incident fluxes and temperature. The model can also be used to estimate the limits of validity of the thermodynamic approach and the minimum epitaxy temperature. The results of the calculations show good agreement with the experimental observations.

Research paper thumbnail of Model of the adsorption/desorption kinetics on a growing III–V compound surface

Surface Science, 1997

A kinetic approach for surface processes occurring on growing III-V compound (001)-oriented surfa... more A kinetic approach for surface processes occurring on growing III-V compound (001)-oriented surfaces is proposed. The model assumes the processes proceeding in a single adsorption layer. Four kinetic constants are introduced to describe species desorption, incorporation of atoms from adsorption layer to crystal and decomposition of the crystal. The approach allows one to determine growth rate of the crystal, conditions of extra phase appearance on the surface, minimum temperature of epitaxy and temperature of congruent evaporation, sticking coefficients of Group V species on the growing surface, etc. The proposed model is verified by comparing the theoretical predictions with available experimental data obtained for the GaAs(001) surface.

Research paper thumbnail of <title>High-brightness laser diode modules for Yb and Er fiber lasers</title>

Laser Source Technology for Defense and Security IV, 2008

ABSTRACT Recent progress in rare-earth doped fibers has allowed Yb-doped fiber lasers to be power... more ABSTRACT Recent progress in rare-earth doped fibers has allowed Yb-doped fiber lasers to be power-scaled to several kW&#39;s. Remarkably, the continued rise of the fiber laser output power into multi-kW range is being limited by the pump diodes rather than the fibers themselves. In this article we discuss our recent progress in the development of high-brightness fiber-coupled laser diode modules for pumping Yb and Er doped lasers. Pumps based on laser diode arrays as well as on multiple single emitter platforms will be described. The prospects of power scaling as well as expected limitations to different designs will be discussed. We demonstrate 976 nm pump module with 55W ex-fiber output power from 105 mum core diameter fiber. The coupling efficiency was 58%. Similar approach was used for realization of 1450 nm diodes and as a result over 15 W CW power was achieved from the fiber with the same aperture.

Research paper thumbnail of Design and characterization of 200-mW-class distributed feedback lasers at 1.55 μm

Conference Proceedings - International Conference on Indium Phosphide and Related Materials

High-power 1.55-μm distributed feedback lasers for radio-frequency applications have been designe... more High-power 1.55-μm distributed feedback lasers for radio-frequency applications have been designed, fabricated and characterized. By employing a broadened-waveguide design in a distributed feedback laser, continuous-wave single-mode performance up to 220 mW has been successfully demonstrated at a heat-sink temperature of -15°C. The average external differential quantum efficiency was 31% over the entire operating range. Single-mode power levels of 162 mW were observed at 15°C. Linewidths of 750 kHz and 1 MHz were measured at power levels of 73 mW and 114 mW, respectively. The relative intensity noise was measurement-limited at a value of -165 dB/Hz at 1 GHz for a power level of 114 mW

Research paper thumbnail of Effect of p-doping on the performance of high power 1.5-μm InGaAsP MQW lasers

Conference Proceedings. 2000 International Conference on Indium Phosphide and Related Materials (Cat. No.00CH37107), 2000

ABSTRACT High power 1.5-μm InGaAsP/InP lasers with two different p-cladding doping profiles were ... more ABSTRACT High power 1.5-μm InGaAsP/InP lasers with two different p-cladding doping profiles were fabricated and studied. Power saturation at high currents was observed. Experimental studies together with modeling results show that electron heterobarrier leakage limits the output power of 1.5-μm InGaAsP/InP lasers. A pulsed output power of 14 W was obtained from a 100 μm aperture laser with a doped p-cladding/SCH interface

Research paper thumbnail of High power InGaAsP/InP broad-waveguide single-mode ridge-waveguide lasers

OFC 2001. Optical Fiber Communication Conference and Exhibit. Technical Digest Postconference Edition (IEEE Cat. 01CH37171), 2001

ABSTRACT Single-mode broad-waveguide separate confinement ridge-waveguide InGaAsP/InP diode laser... more ABSTRACT Single-mode broad-waveguide separate confinement ridge-waveguide InGaAsP/InP diode lasers emitting in 1500 nm wavelength range have realized cw output power levels in excess of 400 mW. The high-power broad-waveguide structure design and ridge-waveguide fabrication technology along with device operational performance parameters will be discussed.

Research paper thumbnail of Influence of multilevel crystallization on the intensity oscillations of diffracted highenergy electrons during growth of aluminum arsenide by molecular beam epitaxy

Technical Physics Letters, 1997

Research paper thumbnail of Diode laser pumping sources for cryogenically cooled solid-state lasers

Laser Source Technology for Defense and Security IV, 2008

ABSTRACT One of the recent advances in solid-state laser (SSL) defense technology is the 100W lev... more ABSTRACT One of the recent advances in solid-state laser (SSL) defense technology is the 100W level Er-doped &quot;eye-safe&quot; laser with low quantum defect pumping at 1.53mum. Major technical challenges in achieving high-wattage devices include increasing the system power conversion efficiency and arranging the removal of heat from both the crystal and the pumps. It is known that performance of the crystal can be improved dramatically by cryogenic cooling. Hence, it is desirable to have cryo-cooled pumps to realize ergonomic and efficient diode-pumped SSL with unified cryogenic cooling. In this paper we report on the development of LN2-cooled InP-based lambda~1.5-1.6 mum diode pumps. The broad area lasers demonstrated 11W in continuous-wave (CW) regime at an operating current of 20A. Despite the highest CW power measured to date from an InP-based emitter, we did not observe catastrophic optical mirror damage. The spectral width of the radiation from a cooled device decreased 1.5-2 from its room-temperature value, which will significantly improve pumping efficiency. We show that laser diode design has to be optimized for performance at cryogenic temperatures. Reviewing the data on LN2 cooled lasers emitting in the wavelength range of 1.13 - 1.8 mum, we discuss the route to increase the power conversion of the LN2 cooled InP-based pumps to greater than 60% and further narrow and stabilize the laser emission spectrum.

Research paper thumbnail of Reliability assessment of GaAs- and InP-based diode lasers for high-energy single-pulse operation

SPIE Proceedings, 2009

ABSTRACT With the maturing of high-power diode laser technology, studies of laser-assisted igniti... more ABSTRACT With the maturing of high-power diode laser technology, studies of laser-assisted ignition of a variety of substances are becoming an increasingly popular research topic. Its range of applications is wide - from fusing in the defense, construction and exploration industries to ignition in future combustion engines. Recent advances in InP-based technology have expanded the wavelength range that can be covered by multi-watt GaAs- and InP-based diode lasers to about 0.8 to 2 mum. With such a wide range, the wattage is no longer the sole defining factor for efficient ignition. Ignition-related studies should include the interaction of radiation of various wavelengths with matter and the reliability of devices based on different material systems. In this paper, we focus on the reliability of pulsed laser diodes for use in ignition applications. We discuss the existing data on the catastrophic optical damage (COD) of the mirrors of the GaAsbased laser diodes and come up with a non-destructive test method to predict the COD level of a particular device. This allows pre-characterization of the devices intended for fusing to eliminate failures during single-pulse operation in the field. We also tested InP-based devices and demonstrated that the maximum power is not limited by COD. Currently, devices with &gt;10W output power are available from both GaAs- and InP-based devices, which dramatically expands the potential use of laser diodes in ignition systems.

Research paper thumbnail of Processes limiting the performance of InAs/GaSb superlattice mid-infrared PIN mesa photodiodes

Semiconductor Photodetectors III, 2006

In this study, we examine processes limiting the performance of 4 micron superlattice pin photodi... more In this study, we examine processes limiting the performance of 4 micron superlattice pin photodiodes for different temperature and mesa size regimes. We show that the performance of large mesa photodiodes at low temperature is most severely limited by a trap-assisted tunneling leakage current (x300), while small mesa sizes are additionally limited by perimeter leakage (x20). At room temperature, large mesa photodiodes are limited by the diffusion current, and small mesa photodiodes are further limited by the perimeter leakage (x100). To reduce or eliminate the impact of perimeter leakage, we have tried passivating the mesa sidewalls with SiN, an approach that was only minimally successful. We have also laid the groundwork for another approach to elimination of perimeter leakage currents, namely, elimination of the sidewalls altogether through planar processing techniques. Planar processing schemes require the deposition of a thick, wide bandgap semiconductor or "window layer" on top of the homojunction. We compare the performance of two otherwise identical InAs/GaSb superlattice homojunction detectors, except one with a GaSb window layer, and one without. We show that inclusion of the thick GaSb window layer does not degrade detector performance.

Research paper thumbnail of Practical Framework for Intellectual Property Valuation

Intellectual Property in Academia, 2011

... Mathematically, the time T* can be written in terms ofp and q as Tqp* ln=()(3.4) pq+Jiang, Ba... more ... Mathematically, the time T* can be written in terms ofp and q as Tqp* ln=()(3.4) pq+Jiang, Bass, and Bass (2006) proved another very important prop-erty ofthe sales rate curve (Equation 3.3): if (p< q), which is almost Page 86. ...

Research paper thumbnail of Waveguide collapse In InGaAsP ridge-waveguide lasers with weak lateral optical confinement

Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Technical Digest (IEEE Cat. No.01CH37170), 2001

ABSTRACT The maximum CW powers for single-mode diode lasers are limited by tolerable current and ... more ABSTRACT The maximum CW powers for single-mode diode lasers are limited by tolerable current and photon densities in their active regions. The maximum width of a single-mode laser active region is inversely proportional to √ΔnB, where ΔnB is the built-in refractive index step at the active region boundary. In this paper, λ=1.5 μm InGaAsP/InP SCH 3QW broad-waveguide (600 nm) ridge waveguide lasers with low values of ΔnB (5 - 7×10-3) have been investigated

Research paper thumbnail of 14xx nm DFB InGaAsP/InP pump lasers with 500 mW CW output power for WDM combining

Optical Fiber Communication Conference and Exhibit

In conclusion, we have demonstrated 14xx nm DFB pump InGaAsP/InP ridge waveguide lasers with a re... more In conclusion, we have demonstrated 14xx nm DFB pump InGaAsP/InP ridge waveguide lasers with a record CW chip power level of 500 mW and ex-fiber or module power of 300 mW. Narrow emission line with very weak current/temperature peak position dependence allows us to use conventional wavelength multiplexing techniques to combine output of DFB pumps with different wavelengths into one

Research paper thumbnail of 2.3- to 2.7-μm room-temperature cw operation of InGaAsSb/AlGaAsSb broad-contact and single-mode ridge-waveguide SCH-QW diode lasers

SPIE Proceedings, 1999

In the work we continue our studies of broadened waveguide separate confinement InGaAsSb/AlGaAsSb... more In the work we continue our studies of broadened waveguide separate confinement InGaAsSb/AlGaAsSb quantum well diode lasers grown by MBE on n-GaSb substrates. To avoid the structure degradation associated with the miscibility gap in the 2.3 - 2.7 micrometer ...

Research paper thumbnail of 100 mW external cavity laser with a 1405-1575 nm tuning range

Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges

ABSTRACT InGaAsP-InP strained multiquantum well structures similar to those described ins were us... more ABSTRACT InGaAsP-InP strained multiquantum well structures similar to those described ins were used for tilted ridge waveguide (TRWG) gain chip fabrication. Lateral mode confinement is provided by a dual-channel ridge waveguide structure prepared by conventional photolithography in conjunction with chemical etching.

Research paper thumbnail of 2.2-2.5 /spl mu/m InGaAsSb/AlGaAsSb QW diode laser with extraordinarily wide (/spl Delta//spl lambda/ = 300 nm) optical gain spectrum

Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Technical Digest (IEEE Cat. No.01CH37170), 2001

ABSTRACT form only given. Spectroscopy and environmental monitoring are among the prospective app... more ABSTRACT form only given. Spectroscopy and environmental monitoring are among the prospective applications of mid-infrared diode lasers. Achievement of the widest tuning range for these lasers is highly desirable. The typical tuning range of commercially available external cavity tunable lasers is below 100 nm in the 2-/spl mu/m range. To expand this range it is necessary to employ a gain media with a wider optical gain spectrum. The switching of the laser emission wavelength between the ground n = 1 and the first excited n = 2 states in a quantum well has previously been reported in for GaAs/AlGaAs QW lasers. We suggest involving the first excited states into the light amplification in order to expand the gain spectrum bandwidth. In this work we determined the structural design and experimental conditions for GaSb-based lasers in order to attain the widest gain spectrum (the full-width at half-maximum was /spl Delta//spl lambda/ = 300 nm) at reasonable gain flatness: for the structure with quantum well width of 200 A at near-room temperature the depth of the valley between gain peaks did not exceed 10 cm/sup -1/.

Research paper thumbnail of High-power 1300-nm Fabry-Perot and DFB ridge-waveguide lasers

Novel In-Plane Semiconductor Lasers, 2002

In this paper we summarize the results [1] on the development of high power 1300 nm ridge wavegui... more In this paper we summarize the results [1] on the development of high power 1300 nm ridge waveguide Fabry-Perot and distributed-feedback (DFB) lasers. Improved performance of MOCVD grown InGaAsP/InP laser structures and optimization of the ridge waveguide design allowed us to achieve more than 800 mW output power from 1300 nm single mode Fabry-Perot lasers. Despite the fact that the beam aspect ratio for ridge lasers (30 o × 12 o) is higher than that for buried devices, our modeling and experiments demonstrated that the fiber coupling efficiency of about 75-80% could be routinely achieved using a lensed fiber or a simple lens pair. Fiber power of higher than 600 mW was displayed. Utilizing similar epitaxial structures and device geometry, the 1300 nm DFB lasers with output power of 500 mW have been fabricated. Analysis of the laser spectral characteristics shows that the high power DFB lasers can be separated into several groups. The single frequency spectral behavior was exhibited by about 20 % of all studied DFB lasers. For these lasers, side-mode suppression increases from 45 dB at low current up to 60 dB at maximum current. About 30 % of DFB lasers, at all driving currents, demonstrate multi-frequency spectra consisting of 4-8 longitudinal modes with mode spacing larger than that for Fabry-Perot lasers of the same cavity length. Both single frequency and multi frequency DFB lasers exhibit weak wavelength-temperature dependence and very low relative intensity noise (RIN) values. Fabry-Perot and both types of DFB lasers can be used as pump sources for Raman amplifiers operating in the 1300 nm wavelength range where the use of EDFA is not feasible. In addition, the single-mode 1300 nm DFB lasers operating in the 500 mW power range are very attractive for new generation of the cable television transmission and local communication systems.

Research paper thumbnail of Spectral and noise characteristics of Fabry-perot and DFB 14xx nm InGaAs/InP pump lasers for Raman and Er-doped fiber amplifiers

Journal of Lightwave Technology, 2003

ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performan... more ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performance were fabricated. Spectral and noise characteristics of these devices are compared and contrasted. Single frequency and multi-frequency DFB devices display low RIN values of –165 dB/Hz.

Research paper thumbnail of Spectral and noise characteristics of Fabry-perot and DFB 14xx nm InGaAs/InP pump lasers for Raman and Er-doped fiber amplifiers

Journal of Lightwave Technology, 2003

ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performan... more ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performance were fabricated. Spectral and noise characteristics of these devices are compared and contrasted. Single frequency and multi-frequency DFB devices display low RIN values of –165 dB/Hz.

Research paper thumbnail of <title>New room temperature CW InGaAsSb/AlGaAsSb QW ridge diode lasers and their application to CO measurements near 2.3 μm</title>

Air Monitoring and Detection of Chemical and Biological Agents II, 1999

ABSTRACT In this work the spectral characteristics of a new type of mid-infrared diode laser are ... more ABSTRACT In this work the spectral characteristics of a new type of mid-infrared diode laser are discussed and an application for CO trace gas detection is demonstrated. The InGaAsSb/AlGaAsSb QW diode lasers operating in the spectral range of 2.0 - 2.7 micrometer in continuous wave (CW) regime at room temperature (RT) were developed last year. Earlier, the spectral range of RT CW operation for diode lasers was limited by 2.0 - 2.1 micrometer. The extension of wavelength to 2.7 micrometer was achieved for InGaAsSb/AlGaAsSb quantum well (QW) lasers by employing for QWs new quasi-ternary InGaSb(As) compositions that are out of the miscibility gap for InGaAsSb materials. Single spatial mode ridge lasers emitting at 2.2 - 2.7 micrometer have parameters similar to those of the infrared lasers with (lambda) less than 2 micrometer widely used for spectroscopic application. At operating currents about 80 - 200 mA and temperatures up to +50 degrees Celsius, these lasers emit CW output power of several milliwatts. Investigation of the laser spectra has revealed the current and temperature ranges where a single longitudinal mode dominates with side mode suppression of 22 - 25 dB. The dominant mode can be tuned in wavelength by varying current or temperature. The lasers were used to record high-resolution CO absorption lineshapes (2v band near 2.3 micrometer) in a static cell (14.9-cm path). Probed CO transitions were selected for applications to in situ measurements in high- temperature combustion flows. In general, the measured CO absorption lineshapes agreed with theoretical Voigt profiles calculated using the HITRAN database to within 2%. For a minimum detectable absorbance of 0.01% and a 1-meter long path, the CO measurement sensitivity for the probed R30 transition near 2.302 micrometer was 5 - 10 ppm at 1000 K. This value is about two orders of magnitude better than the sensitivity reported for CO detection with conventional diode lasers that probe transitions in the 3v band near 1.56 micrometer. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints

Research paper thumbnail of Kinetic model of GaAs(100) growth from molecular beams

Technical Physics Letters, 1997

A kinetic model for the growth of GaAs(100) by molecular beam epitaxy is constructed. The element... more A kinetic model for the growth of GaAs(100) by molecular beam epitaxy is constructed. The elementary processes at the surface are analyzed, including chemisorption of atoms and molecules, incorporation of atoms into the crystal, decomposition of the crystal, and desorption of group-III atoms and group-V molecules in vacuum. The sticking coefficients and rate constants are obtained from a direct comparison with experimental data. The model can be used to determine the desorbed and reflected fluxes, the growth rate, and the coverage by groups III and V atoms as functions of the incident fluxes and temperature. The model can also be used to estimate the limits of validity of the thermodynamic approach and the minimum epitaxy temperature. The results of the calculations show good agreement with the experimental observations.

Research paper thumbnail of Model of the adsorption/desorption kinetics on a growing III–V compound surface

Surface Science, 1997

A kinetic approach for surface processes occurring on growing III-V compound (001)-oriented surfa... more A kinetic approach for surface processes occurring on growing III-V compound (001)-oriented surfaces is proposed. The model assumes the processes proceeding in a single adsorption layer. Four kinetic constants are introduced to describe species desorption, incorporation of atoms from adsorption layer to crystal and decomposition of the crystal. The approach allows one to determine growth rate of the crystal, conditions of extra phase appearance on the surface, minimum temperature of epitaxy and temperature of congruent evaporation, sticking coefficients of Group V species on the growing surface, etc. The proposed model is verified by comparing the theoretical predictions with available experimental data obtained for the GaAs(001) surface.

Research paper thumbnail of <title>High-brightness laser diode modules for Yb and Er fiber lasers</title>

Laser Source Technology for Defense and Security IV, 2008

ABSTRACT Recent progress in rare-earth doped fibers has allowed Yb-doped fiber lasers to be power... more ABSTRACT Recent progress in rare-earth doped fibers has allowed Yb-doped fiber lasers to be power-scaled to several kW&#39;s. Remarkably, the continued rise of the fiber laser output power into multi-kW range is being limited by the pump diodes rather than the fibers themselves. In this article we discuss our recent progress in the development of high-brightness fiber-coupled laser diode modules for pumping Yb and Er doped lasers. Pumps based on laser diode arrays as well as on multiple single emitter platforms will be described. The prospects of power scaling as well as expected limitations to different designs will be discussed. We demonstrate 976 nm pump module with 55W ex-fiber output power from 105 mum core diameter fiber. The coupling efficiency was 58%. Similar approach was used for realization of 1450 nm diodes and as a result over 15 W CW power was achieved from the fiber with the same aperture.

Research paper thumbnail of Design and characterization of 200-mW-class distributed feedback lasers at 1.55 μm

Conference Proceedings - International Conference on Indium Phosphide and Related Materials

High-power 1.55-μm distributed feedback lasers for radio-frequency applications have been designe... more High-power 1.55-μm distributed feedback lasers for radio-frequency applications have been designed, fabricated and characterized. By employing a broadened-waveguide design in a distributed feedback laser, continuous-wave single-mode performance up to 220 mW has been successfully demonstrated at a heat-sink temperature of -15°C. The average external differential quantum efficiency was 31% over the entire operating range. Single-mode power levels of 162 mW were observed at 15°C. Linewidths of 750 kHz and 1 MHz were measured at power levels of 73 mW and 114 mW, respectively. The relative intensity noise was measurement-limited at a value of -165 dB/Hz at 1 GHz for a power level of 114 mW

Research paper thumbnail of Effect of p-doping on the performance of high power 1.5-μm InGaAsP MQW lasers

Conference Proceedings. 2000 International Conference on Indium Phosphide and Related Materials (Cat. No.00CH37107), 2000

ABSTRACT High power 1.5-μm InGaAsP/InP lasers with two different p-cladding doping profiles were ... more ABSTRACT High power 1.5-μm InGaAsP/InP lasers with two different p-cladding doping profiles were fabricated and studied. Power saturation at high currents was observed. Experimental studies together with modeling results show that electron heterobarrier leakage limits the output power of 1.5-μm InGaAsP/InP lasers. A pulsed output power of 14 W was obtained from a 100 μm aperture laser with a doped p-cladding/SCH interface

Research paper thumbnail of High power InGaAsP/InP broad-waveguide single-mode ridge-waveguide lasers

OFC 2001. Optical Fiber Communication Conference and Exhibit. Technical Digest Postconference Edition (IEEE Cat. 01CH37171), 2001

ABSTRACT Single-mode broad-waveguide separate confinement ridge-waveguide InGaAsP/InP diode laser... more ABSTRACT Single-mode broad-waveguide separate confinement ridge-waveguide InGaAsP/InP diode lasers emitting in 1500 nm wavelength range have realized cw output power levels in excess of 400 mW. The high-power broad-waveguide structure design and ridge-waveguide fabrication technology along with device operational performance parameters will be discussed.

Research paper thumbnail of Influence of multilevel crystallization on the intensity oscillations of diffracted highenergy electrons during growth of aluminum arsenide by molecular beam epitaxy

Technical Physics Letters, 1997

Research paper thumbnail of Diode laser pumping sources for cryogenically cooled solid-state lasers

Laser Source Technology for Defense and Security IV, 2008

ABSTRACT One of the recent advances in solid-state laser (SSL) defense technology is the 100W lev... more ABSTRACT One of the recent advances in solid-state laser (SSL) defense technology is the 100W level Er-doped &quot;eye-safe&quot; laser with low quantum defect pumping at 1.53mum. Major technical challenges in achieving high-wattage devices include increasing the system power conversion efficiency and arranging the removal of heat from both the crystal and the pumps. It is known that performance of the crystal can be improved dramatically by cryogenic cooling. Hence, it is desirable to have cryo-cooled pumps to realize ergonomic and efficient diode-pumped SSL with unified cryogenic cooling. In this paper we report on the development of LN2-cooled InP-based lambda~1.5-1.6 mum diode pumps. The broad area lasers demonstrated 11W in continuous-wave (CW) regime at an operating current of 20A. Despite the highest CW power measured to date from an InP-based emitter, we did not observe catastrophic optical mirror damage. The spectral width of the radiation from a cooled device decreased 1.5-2 from its room-temperature value, which will significantly improve pumping efficiency. We show that laser diode design has to be optimized for performance at cryogenic temperatures. Reviewing the data on LN2 cooled lasers emitting in the wavelength range of 1.13 - 1.8 mum, we discuss the route to increase the power conversion of the LN2 cooled InP-based pumps to greater than 60% and further narrow and stabilize the laser emission spectrum.

Research paper thumbnail of Reliability assessment of GaAs- and InP-based diode lasers for high-energy single-pulse operation

SPIE Proceedings, 2009

ABSTRACT With the maturing of high-power diode laser technology, studies of laser-assisted igniti... more ABSTRACT With the maturing of high-power diode laser technology, studies of laser-assisted ignition of a variety of substances are becoming an increasingly popular research topic. Its range of applications is wide - from fusing in the defense, construction and exploration industries to ignition in future combustion engines. Recent advances in InP-based technology have expanded the wavelength range that can be covered by multi-watt GaAs- and InP-based diode lasers to about 0.8 to 2 mum. With such a wide range, the wattage is no longer the sole defining factor for efficient ignition. Ignition-related studies should include the interaction of radiation of various wavelengths with matter and the reliability of devices based on different material systems. In this paper, we focus on the reliability of pulsed laser diodes for use in ignition applications. We discuss the existing data on the catastrophic optical damage (COD) of the mirrors of the GaAsbased laser diodes and come up with a non-destructive test method to predict the COD level of a particular device. This allows pre-characterization of the devices intended for fusing to eliminate failures during single-pulse operation in the field. We also tested InP-based devices and demonstrated that the maximum power is not limited by COD. Currently, devices with &gt;10W output power are available from both GaAs- and InP-based devices, which dramatically expands the potential use of laser diodes in ignition systems.

Research paper thumbnail of Processes limiting the performance of InAs/GaSb superlattice mid-infrared PIN mesa photodiodes

Semiconductor Photodetectors III, 2006

In this study, we examine processes limiting the performance of 4 micron superlattice pin photodi... more In this study, we examine processes limiting the performance of 4 micron superlattice pin photodiodes for different temperature and mesa size regimes. We show that the performance of large mesa photodiodes at low temperature is most severely limited by a trap-assisted tunneling leakage current (x300), while small mesa sizes are additionally limited by perimeter leakage (x20). At room temperature, large mesa photodiodes are limited by the diffusion current, and small mesa photodiodes are further limited by the perimeter leakage (x100). To reduce or eliminate the impact of perimeter leakage, we have tried passivating the mesa sidewalls with SiN, an approach that was only minimally successful. We have also laid the groundwork for another approach to elimination of perimeter leakage currents, namely, elimination of the sidewalls altogether through planar processing techniques. Planar processing schemes require the deposition of a thick, wide bandgap semiconductor or "window layer" on top of the homojunction. We compare the performance of two otherwise identical InAs/GaSb superlattice homojunction detectors, except one with a GaSb window layer, and one without. We show that inclusion of the thick GaSb window layer does not degrade detector performance.

Research paper thumbnail of Practical Framework for Intellectual Property Valuation

Intellectual Property in Academia, 2011

... Mathematically, the time T* can be written in terms ofp and q as Tqp* ln=()(3.4) pq+Jiang, Ba... more ... Mathematically, the time T* can be written in terms ofp and q as Tqp* ln=()(3.4) pq+Jiang, Bass, and Bass (2006) proved another very important prop-erty ofthe sales rate curve (Equation 3.3): if (p< q), which is almost Page 86. ...

Research paper thumbnail of Waveguide collapse In InGaAsP ridge-waveguide lasers with weak lateral optical confinement

Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Technical Digest (IEEE Cat. No.01CH37170), 2001

ABSTRACT The maximum CW powers for single-mode diode lasers are limited by tolerable current and ... more ABSTRACT The maximum CW powers for single-mode diode lasers are limited by tolerable current and photon densities in their active regions. The maximum width of a single-mode laser active region is inversely proportional to √ΔnB, where ΔnB is the built-in refractive index step at the active region boundary. In this paper, λ=1.5 μm InGaAsP/InP SCH 3QW broad-waveguide (600 nm) ridge waveguide lasers with low values of ΔnB (5 - 7×10-3) have been investigated

Research paper thumbnail of 14xx nm DFB InGaAsP/InP pump lasers with 500 mW CW output power for WDM combining

Optical Fiber Communication Conference and Exhibit

In conclusion, we have demonstrated 14xx nm DFB pump InGaAsP/InP ridge waveguide lasers with a re... more In conclusion, we have demonstrated 14xx nm DFB pump InGaAsP/InP ridge waveguide lasers with a record CW chip power level of 500 mW and ex-fiber or module power of 300 mW. Narrow emission line with very weak current/temperature peak position dependence allows us to use conventional wavelength multiplexing techniques to combine output of DFB pumps with different wavelengths into one

Research paper thumbnail of 2.3- to 2.7-μm room-temperature cw operation of InGaAsSb/AlGaAsSb broad-contact and single-mode ridge-waveguide SCH-QW diode lasers

SPIE Proceedings, 1999

In the work we continue our studies of broadened waveguide separate confinement InGaAsSb/AlGaAsSb... more In the work we continue our studies of broadened waveguide separate confinement InGaAsSb/AlGaAsSb quantum well diode lasers grown by MBE on n-GaSb substrates. To avoid the structure degradation associated with the miscibility gap in the 2.3 - 2.7 micrometer ...

Research paper thumbnail of 100 mW external cavity laser with a 1405-1575 nm tuning range

Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges

ABSTRACT InGaAsP-InP strained multiquantum well structures similar to those described ins were us... more ABSTRACT InGaAsP-InP strained multiquantum well structures similar to those described ins were used for tilted ridge waveguide (TRWG) gain chip fabrication. Lateral mode confinement is provided by a dual-channel ridge waveguide structure prepared by conventional photolithography in conjunction with chemical etching.

Research paper thumbnail of 2.2-2.5 /spl mu/m InGaAsSb/AlGaAsSb QW diode laser with extraordinarily wide (/spl Delta//spl lambda/ = 300 nm) optical gain spectrum

Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Technical Digest (IEEE Cat. No.01CH37170), 2001

ABSTRACT form only given. Spectroscopy and environmental monitoring are among the prospective app... more ABSTRACT form only given. Spectroscopy and environmental monitoring are among the prospective applications of mid-infrared diode lasers. Achievement of the widest tuning range for these lasers is highly desirable. The typical tuning range of commercially available external cavity tunable lasers is below 100 nm in the 2-/spl mu/m range. To expand this range it is necessary to employ a gain media with a wider optical gain spectrum. The switching of the laser emission wavelength between the ground n = 1 and the first excited n = 2 states in a quantum well has previously been reported in for GaAs/AlGaAs QW lasers. We suggest involving the first excited states into the light amplification in order to expand the gain spectrum bandwidth. In this work we determined the structural design and experimental conditions for GaSb-based lasers in order to attain the widest gain spectrum (the full-width at half-maximum was /spl Delta//spl lambda/ = 300 nm) at reasonable gain flatness: for the structure with quantum well width of 200 A at near-room temperature the depth of the valley between gain peaks did not exceed 10 cm/sup -1/.

Research paper thumbnail of High-power 1300-nm Fabry-Perot and DFB ridge-waveguide lasers

Novel In-Plane Semiconductor Lasers, 2002

In this paper we summarize the results [1] on the development of high power 1300 nm ridge wavegui... more In this paper we summarize the results [1] on the development of high power 1300 nm ridge waveguide Fabry-Perot and distributed-feedback (DFB) lasers. Improved performance of MOCVD grown InGaAsP/InP laser structures and optimization of the ridge waveguide design allowed us to achieve more than 800 mW output power from 1300 nm single mode Fabry-Perot lasers. Despite the fact that the beam aspect ratio for ridge lasers (30 o × 12 o) is higher than that for buried devices, our modeling and experiments demonstrated that the fiber coupling efficiency of about 75-80% could be routinely achieved using a lensed fiber or a simple lens pair. Fiber power of higher than 600 mW was displayed. Utilizing similar epitaxial structures and device geometry, the 1300 nm DFB lasers with output power of 500 mW have been fabricated. Analysis of the laser spectral characteristics shows that the high power DFB lasers can be separated into several groups. The single frequency spectral behavior was exhibited by about 20 % of all studied DFB lasers. For these lasers, side-mode suppression increases from 45 dB at low current up to 60 dB at maximum current. About 30 % of DFB lasers, at all driving currents, demonstrate multi-frequency spectra consisting of 4-8 longitudinal modes with mode spacing larger than that for Fabry-Perot lasers of the same cavity length. Both single frequency and multi frequency DFB lasers exhibit weak wavelength-temperature dependence and very low relative intensity noise (RIN) values. Fabry-Perot and both types of DFB lasers can be used as pump sources for Raman amplifiers operating in the 1300 nm wavelength range where the use of EDFA is not feasible. In addition, the single-mode 1300 nm DFB lasers operating in the 500 mW power range are very attractive for new generation of the cable television transmission and local communication systems.

Research paper thumbnail of Spectral and noise characteristics of Fabry-perot and DFB 14xx nm InGaAs/InP pump lasers for Raman and Er-doped fiber amplifiers

Journal of Lightwave Technology, 2003

ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performan... more ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performance were fabricated. Spectral and noise characteristics of these devices are compared and contrasted. Single frequency and multi-frequency DFB devices display low RIN values of –165 dB/Hz.

Research paper thumbnail of Spectral and noise characteristics of Fabry-perot and DFB 14xx nm InGaAs/InP pump lasers for Raman and Er-doped fiber amplifiers

Journal of Lightwave Technology, 2003

ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performan... more ABSTRACT 14xx nm InGaAsP/InP DFB and Fabry-Perot ridge waveguide lasers with comparable performance were fabricated. Spectral and noise characteristics of these devices are compared and contrasted. Single frequency and multi-frequency DFB devices display low RIN values of –165 dB/Hz.

Research paper thumbnail of <title>New room temperature CW InGaAsSb/AlGaAsSb QW ridge diode lasers and their application to CO measurements near 2.3 μm</title>

Air Monitoring and Detection of Chemical and Biological Agents II, 1999

ABSTRACT In this work the spectral characteristics of a new type of mid-infrared diode laser are ... more ABSTRACT In this work the spectral characteristics of a new type of mid-infrared diode laser are discussed and an application for CO trace gas detection is demonstrated. The InGaAsSb/AlGaAsSb QW diode lasers operating in the spectral range of 2.0 - 2.7 micrometer in continuous wave (CW) regime at room temperature (RT) were developed last year. Earlier, the spectral range of RT CW operation for diode lasers was limited by 2.0 - 2.1 micrometer. The extension of wavelength to 2.7 micrometer was achieved for InGaAsSb/AlGaAsSb quantum well (QW) lasers by employing for QWs new quasi-ternary InGaSb(As) compositions that are out of the miscibility gap for InGaAsSb materials. Single spatial mode ridge lasers emitting at 2.2 - 2.7 micrometer have parameters similar to those of the infrared lasers with (lambda) less than 2 micrometer widely used for spectroscopic application. At operating currents about 80 - 200 mA and temperatures up to +50 degrees Celsius, these lasers emit CW output power of several milliwatts. Investigation of the laser spectra has revealed the current and temperature ranges where a single longitudinal mode dominates with side mode suppression of 22 - 25 dB. The dominant mode can be tuned in wavelength by varying current or temperature. The lasers were used to record high-resolution CO absorption lineshapes (2v band near 2.3 micrometer) in a static cell (14.9-cm path). Probed CO transitions were selected for applications to in situ measurements in high- temperature combustion flows. In general, the measured CO absorption lineshapes agreed with theoretical Voigt profiles calculated using the HITRAN database to within 2%. For a minimum detectable absorbance of 0.01% and a 1-meter long path, the CO measurement sensitivity for the probed R30 transition near 2.302 micrometer was 5 - 10 ppm at 1000 K. This value is about two orders of magnitude better than the sensitivity reported for CO detection with conventional diode lasers that probe transitions in the 3v band near 1.56 micrometer. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints