Towards a life-time-limited 8-octave-infrared photoconductive germanium detector

19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures

Pavlov, S.G.^1 ; Deßmann, N.^2 ; Pohl, A.^2 ; Abrosimov, N.V.^3 ; Mittendorff, M.^4,5 ; Winnerl, S.^4 ; Zhukavin, R Kh^6 ; Tsyplenkov, V.V.^6 ; Shengurov, D.V.^6 ; Shastin, V.N.^6,7 ; Hübers, H.-W.^1,8

Institute of Optical Sensor Systems, German Aerospace Center (DLR), Berlin

12489, Germany^1

Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin

10623, Germany^2

Leibniz-Institute for Crystal Growth, Berlin

12489, Germany^3

Helmholtz-Zentrum Dresden-Rossendorf, Dresden

01328, Germany^4

Technische Universität Dresden, Dresden

01069, Germany^5

Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhny Novgorod

603950, Russia^6

Nizhny Novgorod State University, Nizhny Novgorod

603950, Russia^7

Humboldt-Universität zu Berlin, Berlin

12489, Germany^8

关键词: Higher frequencies;    Liquid helium temperature;    Liquid nitrogen temperature;    Optical sensitivity;    Photoconductive detectors;    Pump-probe technique;    Reduced sensitivity;    Spectral sensitivity;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/647/1/012070/pdf
DOI  :  10.1088/1742-6596/647/1/012070

来源: IOP

【 摘 要 】

Ultrafast, ultra-broad-band photoconductive detector based on heavily doped and highly compensated germanium has been demonstrated. Such a material demonstrates optical sensitivity in the more than 8 octaves, in the infrared, from about 2 mm to about 8 μm. The spectral sensitivity peaks up between 2 THz and 2.5 THz and is slowly reduced towards lower and higher frequencies. The life times of free electrons/holes measured by a pump-probe technique approach a few tenths of picoseconds and remain almost independent on the optical input intensity and on the temperature of a detector in the operation range. During operation, a detector is cooled down to liquid helium temperature but has been approved to detect, with a reduced sensitivity, up to liquid nitrogen temperature. The response time is shorter than 200 ps that is significantly faster than previously reported times.