Publications

Refine Results

(Filters Applied) Clear All

Crosstalk characterization and mitigation in Geiger-mode avalanche photodiode arrays

Summary

Intra focal plane array (FPA) crosstalk is a primary development limiter of large, fine-pixel Geiger-mode avalanche photodiode (Gm-APD) arrays beyond 256×256 pixels. General analysis methods and results from MIT Lincoln Laboratory (MIT/LL) InP-based detector arrays will be presented.
READ LESS

Summary

Intra focal plane array (FPA) crosstalk is a primary development limiter of large, fine-pixel Geiger-mode avalanche photodiode (Gm-APD) arrays beyond 256×256 pixels. General analysis methods and results from MIT Lincoln Laboratory (MIT/LL) InP-based detector arrays will be presented.

READ MORE

Impact ionization in AlxGa1-xASySb1-y avalanche photodiodes

Summary

Avalanche photodiodes (APDs) have been fabricated in order to determine the impact ionization coefficients of electrons (alpha) and holes (beta) in AlxGa1-xAsySb1-y lattice matched to GaSb for three alloy compositions: (x=0.40, y=0.035), (x=0.55, y=0.045), and (x=0.65, y=0.054). The impact ionization coefficients were calculated from photomultiplication measurements made on specially designed APDs, which allowed for both pure electron and pure hole injection in the same device. Photo-multiplication measurements were made at temperatures ranging from 77K to 300K for all three alloys. A quasi-physical model with an explicit temperature dependence was used to express the impact ionization coefficients as a function of electric-field strength and temperature. For all three alloys, it was found that alpha < beta at any given temperature. In addition, the values of the impact ionization coefficients were found to decrease as the aluminum concentration of the AlGaAsSb alloy was increased. A value between 1.2 and 4.0 was found for beta/x, which is dependent on temperature, alloy composition, and electric-field strength.
READ LESS

Summary

Avalanche photodiodes (APDs) have been fabricated in order to determine the impact ionization coefficients of electrons (alpha) and holes (beta) in AlxGa1-xAsySb1-y lattice matched to GaSb for three alloy compositions: (x=0.40, y=0.035), (x=0.55, y=0.045), and (x=0.65, y=0.054). The impact ionization coefficients were calculated from photomultiplication measurements made on specially designed...

READ MORE

All-Active InGaAsP-InP Optical Tapered-Amplifier 1 X N Power Splitters

Published in:
IEEE Photonics Technol. Lett., Vol. 12, No. 8, August 2000, pp. 974-976.

Summary

All-active tapered-amplifier power splitters (TAPS) consisting of a single-mode input waveguide, which acts as a pre-amplifier, a two-dimensional (2-D) diffraction section, which amplifies the signal during the splitting process, and N single-mode output waveguides, which act as post-amplifiers, were fabricated in 1.3um InGaAsP quantum-well material. Gains in each output guide (power out of guide/input power) of greater than 10 dB with a uniformity of better than 0.5 dB from guide to guide were measured on a 1 x 8 TAPS device.
READ LESS

Summary

All-active tapered-amplifier power splitters (TAPS) consisting of a single-mode input waveguide, which acts as a pre-amplifier, a two-dimensional (2-D) diffraction section, which amplifies the signal during the splitting process, and N single-mode output waveguides, which act as post-amplifiers, were fabricated in 1.3um InGaAsP quantum-well material. Gains in each output guide...

READ MORE

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

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.
READ LESS

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...

READ MORE

Showing Results

1-4 of 4