Title :
Ultra-broadband coherent terahertz spectroscopy using asymmetric excitation of photoconductive structures
Author :
Upadhya, P.C. ; Fan, W.H. ; Burnett, A. ; Shen, Y.C. ; Beere, H.E. ; Davies, A.G. ; Linfield, E.H.
Author_Institution :
Sch. of Electron. & Electr. Eng., Leeds Univ., UK
Abstract :
We report recent progress in the generation of ultra-broadband (>14.0 THz) coherent terahertz (THz) radiation, with high dynamic signal-to-noise ratio (>1000), using asymmetric excitation of carriers in biased low-temperature-grown GaAs (LT-GaAs) photoconductive structures. The generated ultrashort THz temporal wave form is characterized by both free space electro-optic sampling (using 20-μm-thick ZnTe and 150-μm-thick GaP crystals) and a LT-GaAs photoconductive receiver. Spectral features originating from optical phonon resonances in the emitter and detector materials are observed in this frequency range. The use of this system to probe dielectric properties of materials is also discussed.
Keywords :
cryogenic electronics; electro-optical devices; gallium arsenide; gallium compounds; photoconducting devices; submillimetre wave generation; submillimetre wave spectroscopy; zinc compounds; 150 micron; 20 micron; GaAs; GaP; ZnTe; asymmetric excitation; detector materials; dielectric properties; electro-optic sampling; emitter materials; optical phonon resonances; photoconductive receiver; photoconductive structures; signal-to-noise ratio; terahertz radiation; terahertz spectroscopy; ultra-broadband spectroscopy; ultrashort terahertz waveform; Crystalline materials; Dielectric materials; Gallium arsenide; Optical materials; Optical receivers; Photoconducting materials; Photoconductivity; Signal generators; Signal to noise ratio; Spectroscopy;
Conference_Titel :
Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics, 2005. IRMMW-THz 2005. The Joint 30th International Conference on
Print_ISBN :
0-7803-9348-1
DOI :
10.1109/ICIMW.2005.1572607
