Share Email Print

Proceedings Paper

Thermal crosstalk reduction in IR thermo-electric photodetectors by lock-in method: 4D numerical simulations and experimental verification
Author(s): W. Vandermeiren; J. Stiens; C. De Tandt; G. Shkerdin; V. Kotov; G. Borghs; P. Muys; R. Vounckx
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Laser induced temperature distributions inside doped semiconductor materials are used to derive laser beam profiles by means of the thermo-electric Seebeck effect. Thermal diffusion will lead to a discrepancy between the optical intensity profile of the laser beam and the measured temperature distribution inside the semiconductor. An advanced numerical 4D finite element model describing the laser induced spatial temperature distribution in function of time in a layered GaAs based structure was developed in Comsol Multiphysics. Non-linearities as the temperature dependence of the absorption coefficient, the thermal conductivity and the Seebeck coefficient were taken into account. This model was used to investigate the optical chopper frequency dependence on the spatial thermal cross-talk level and the responsivity near the illuminated surface of the detector structure. It was shown that the frequency dependent cross-talk level can be reduced significantly by applying short chopping periods due to the dependence of the thermal diffusion length on the frequency. The thermal cross-talk is reduced to -21 dB and -38.6 dB for the first and second neighboring pixel respectively for a lock-in frequency of 140 Hz. Experimental results of the spatial thermal cross-talk level and the responsivity were compared with simulations and satisfactory agreements between both were achieved. High power CO2 laser profile measurements obtained with our thermo-electric detector and a commercially available Primes detector were compared.

Paper Details

Date Published: 25 February 2010
PDF: 9 pages
Proc. SPIE 7597, Physics and Simulation of Optoelectronic Devices XVIII, 75970Y (25 February 2010); doi: 10.1117/12.841556
Show Author Affiliations
W. Vandermeiren, Vrije Univ. Brussel (Belgium)
J. Stiens, Vrije Univ. Brussel (Belgium)
C. De Tandt, Vrije Univ. Brussel (Belgium)
G. Shkerdin, Institute of Radio Engineering and Electronics (Russian Federation)
V. Kotov, Institute of Radio Engineering and Electronics (Russian Federation)
G. Borghs, IMEC (Belgium)
P. Muys, Lambda Research Optics Europe (Belgium)
R. Vounckx, Vrije Univ. Brussel (Belgium)

Published in SPIE Proceedings Vol. 7597:
Physics and Simulation of Optoelectronic Devices XVIII
Bernd Witzigmann; Fritz Henneberger; Yasuhiko Arakawa; Marek Osinski, Editor(s)

© SPIE. Terms of Use
Back to Top