Terahertz-frequency photoconductive detectors fabricated from metal-organic chemical vapor deposition-grown Fe-doped InGaAs
2011; American Institute of Physics; Volume: 98; Issue: 12 Linguagem: Inglês
10.1063/1.3571289
ISSN1520-8842
AutoresOsama Hatem, J. E. Cunningham, E. H. Linfield, C. Wood, A. G. Davies, Paul J. Cannard, M.J. Robertson, D.G. Moodie,
Tópico(s)Photonic and Optical Devices
ResumoWe report the detection of terahertz frequency radiation using photoconductive antennas fabricated from Fe-doped InGaAs, grown by metal-organic chemical vapor deposition. Coherent photoconductive detection is demonstrated using femtosecond laser pulses centered at either an 800 or a 1550 nm wavelength. The InGaAs resistivity and the sensitivity of photoconductive detection are both found to depend on the Fe-doping level. We investigate a wide range of probe laser powers, finding a peak in detected signal for ∼5 mW probe power, followed by a reduction at larger powers, attributed to screening of the detected THz field by photo-generated carriers in the material. The measured signal from Fe:InGaAs photoconductive detectors excited at 800 nm is four times greater than that from a low-temperature-grown GaAs photodetector with identical antenna design, despite the use of a ten times smaller probe power.
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