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Arrays of InP-based avalanche photodiodes for photon counting

July 1, 2007
  |
Journal Article
Author:
Simon Verghese
…
Published in:
IEEE J. Sel. Top. Quantum Electron., Vol. 13, No. 4, July/August 2007, pp. 870-886.
Topic:
photonics
R&D area:
R&D group:

Summary

Arrays of InP-based avalanche photodiodes (APDs) with InGaAsP absorber regions have been fabricated and characterized in the Geiger mode for photon-counting applications. Measurements of APDs with InGaAsP absorbers optimized for 1.06 um wavelength show dark count rates (DCRs)
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Summary

Arrays of InP-based avalanche photodiodes (APDs) with InGaAsP absorber regions have been fabricated and characterized in the Geiger mode for photon-counting applications. Measurements of APDs with InGaAsP absorbers optimized for 1.06 um wavelength show dark count rates (DCRs)

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Arrays of InP-based avalanche photodiodes for photon counting

High-power, slab-coupled optical waveguide laser array packaging for beam combining

January 23, 2007
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Conference Paper
Author:
Leo J. Missaggia
…
Published in:
SPIE Vol. 6478, Photonics Packaging, Integration, and Interconnects VII, 23-25 January 2007, pp. 647806-1 - 647806-12.
Topic:
optics
R&D area:
R&D group:

Summary

Linear arrays of slab coupled optical waveguide lasers (SCOWL) are ideal sources for beam combining of array elements using techniques such as wavelength beam combining (WBC) and possibly coherent beam combining (CBC). SCOWL array elements have very high brightness, low divergence nearly diffraction limited output beams. Arrays of up to 1.2 cm in width containing as many as 240 elements have been demonstrated. In this presentation, the packaging techniques developed to ensure proper performance of SCOWL arrays will be described, with particular emphasis on the application to beam combining. A commercial high performance micro impingement cooler (MIC) was used to provide thermal management for these arrays. Based on performance data for this cooler, a numerical thermal model was constructed and used to investigate the thermal performance for several packaging schemes. In order to promote uniform optical performance of SCOWL array elements, assembly procedures, which included fluxless soldering using In and AuSn solder alloys, along with the use of thermal expansion matching materials were investigated. These techniques resulted in minimal contraction ([approx] 2 um) and smile ([approx]1 um) of the laser bar during the packaging procedure. Precise control of these parameters is required in order to minimize any detrimental impact on the resultant WBC beam quality. CBC of SCOWL arrays requires phase control of the array elements. Array packaging providing for individual electrical addressability of the array elements has been developed and demonstrated, allowing for phase control by current adjustment.
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Summary

Linear arrays of slab coupled optical waveguide lasers (SCOWL) are ideal sources for beam combining of array elements using techniques such as wavelength beam combining (WBC) and possibly coherent beam combining (CBC). SCOWL array elements have very high brightness, low divergence nearly diffraction limited output beams. Arrays of up to...

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High-power, slab-coupled optical waveguide laser array packaging for beam combining

Afterpulsing in Geiger-mode avalanche photodiodes for 1.06um wavelength

March 27, 2006
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Journal Article
Author:
Katharine E. Jensen
…
Published in:
Appl. Phys. Lett., Vol. 88, No. 13, 27 March 2006, pp. 133503-1 - 133503-3.
Topic:
photonics
R&D area:
R&D group:

Summary

We consider the phenomenon of afterpulsing in avalanche photodiodes (APDs) operating in gated and free-running Geiger mode. An operational model of afterpulsing and other noise characteristics of APDs predicts the noise behavior observed in the free-running mode. We also use gated-mode data to investigate possible sources of afterpulsing in these devices. For 30-um-diam, 1.06-um-wavelength InGaAsP/InP APDs operated at 290 K and 4 V overbias, we obtained a dominant trap lifetime of td=0.32 us, a trap energy of 0.11 eV, and a baseline dark count rate 245 kHz.
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Summary

We consider the phenomenon of afterpulsing in avalanche photodiodes (APDs) operating in gated and free-running Geiger mode. An operational model of afterpulsing and other noise characteristics of APDs predicts the noise behavior observed in the free-running mode. We also use gated-mode data to investigate possible sources of afterpulsing in these...

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Afterpulsing in Geiger-mode avalanche photodiodes for 1.06um wavelength

1.5-um Tapered-Gain-Region Lasers with High-CW Output Powers

October 1, 1998
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Journal Article
Author:
Joseph P. Donnelly
…
Published in:
IEEE Photonics Technol. Lett., Vol. 10, No. 10, October 1998, pp. 1377-1379.
Topic:
optics
R&D area:
R&D group:

Summary

High-power diode lasers consisting of a ridge-waveguide section coupled to a tapered region have been fabricated in 1.5um InGaAsP-InP multiple-quantum-well material. Self-focusing at high current densities and high-intensity input into the taper section has been identified as a fundamental problem in these devices that has to be dealt with. To date, continuous-wave output powers>1 W with=80% of the power in the near-diffraction-limited central lobe of the far field have been obtained through a judicious choice of device parameters.
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Summary

High-power diode lasers consisting of a ridge-waveguide section coupled to a tapered region have been fabricated in 1.5um InGaAsP-InP multiple-quantum-well material. Self-focusing at high current densities and high-intensity input into the taper section has been identified as a fundamental problem in these devices that has to be dealt with. To...

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1.5-um Tapered-Gain-Region Lasers with High-CW Output Powers

CW operation of monolithic arrays of surface-emitting AlGaAs diode lasers with dry-etched vertical facets and parabolic deflecting mirrors

October 1, 1993
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Journal Article
Author:
Joseph P. Donnelly
…
Published in:
IEEE Photonics Technol. Lett., Vol. 5, No. 10, October 1993, pp. 1146-1149.
Topic:
lasers
R&D area:
R&D group:

Summary

A monolithic two-dimensional array of surface-emitting AlGaAs diode lasers with dry-etched vertical facets and parabolic deflecting mirrors was mounted junction-side up on a W / Cu microchannel heatsink and evaluated under continuous-wave (CW) operating conditions. Both the facets and parabolic deflecting mirrors were etched using chlorine ion-beam-assistd etching. Threshold current densities of different sections of the array were consistently around 240 A/cm (to the second power), and measured CW differential quantum efficiencies were in the 46-48% range. CW power densities as high as 148 W/cm (to the second power) were achieved with an average temperature rise of less than 25 degrees C in this junction-side-up configuration.
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Summary

A monolithic two-dimensional array of surface-emitting AlGaAs diode lasers with dry-etched vertical facets and parabolic deflecting mirrors was mounted junction-side up on a W / Cu microchannel heatsink and evaluated under continuous-wave (CW) operating conditions. Both the facets and parabolic deflecting mirrors were etched using chlorine ion-beam-assistd etching. Threshold current...

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CW operation of monolithic arrays of surface-emitting AlGaAs diode lasers with dry-etched vertical facets and parabolic deflecting mirrors
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