Thermal cross-talk reduction in IR thermo-electric photodetectors by lock-in method: 4D numerical simulations and experimental verification

Werner Vandermeiren, Johan Stiens, Cathleen De Tandt, Gennady Shkerdin, Vladimir Kotov, Gustaaf Borghs, Peter Muys, Roger Vounckx

Onderzoeksoutput: Conference paper

1 Citaat (Scopus)

Samenvatting

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.
Originele taal-2English
TitelProceedings of the SPIE - Physics and Simulation of Optoelectronic Devices XVIII
RedacteurenBernd Witzigmann, Fritz Henneberger, Yasuhiko Arakawa, Marek Osinski
UitgeverijSPIE
Aantal pagina's9
Volume7597
ISBN van geprinte versie978-0-8194-7993-8
StatusPublished - 11 mrt 2010
EvenementUnknown - Stockholm, Sweden
Duur: 21 sep 200925 sep 2009

Publicatie series

NaamProceedings of the SPIE - Physics and Simulation of Optoelectronic Devices XVIII

Conference

ConferenceUnknown
LandSweden
StadStockholm
Periode21/09/0925/09/09

Bibliografische nota

Bernd Witzigmann; Fritz Henneberger; Yasuhiko Arakawa; Marek Osinski

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