High-power narrow-band terahertz generation using large-aperture photoconductors

Author

Park, Sang-Gyu ; Weiner, A.M. ; Melloch, Michael R. ; Sider, C.W. ; Sider, J.L. ; Taylor, Antoinette J.

Author_Institution

Sch. of Electr. & Comput. Eng., Purdue Univ., West Lafayette, IN, USA

Volume

35

Issue

8

fYear

1999

fDate

8/1/1999 12:00:00 AM

Firstpage

1257

Lastpage

1268

Abstract

Large-aperture biased photoconductive emitters which can generate high-power narrow-band terahertz (THz) radiation are developed. These emitters avoid saturation at high fluence excitation and achieve enhanced peak power spectral density by employing a thick layer of short-lifetime low-temperature-grown GaAs (LT-GaAs) photoconductor and multiple-pulse excitation. THz waveforms are calculated from the saturation theory of large aperture photoconductors, and a comparison is made between theory and measurement. A direct comparison of the multiple-pulse saturation properties of THz emission from semi-insulating GaAs and LT GaAs emitters reveals a strong dependence on the carrier lifetime. In particular, the data demonstrate that saturation is avoided only when the interpulse spacing is longer than the carrier lifetime

Keywords

carrier lifetime; photoconducting devices; submillimetre wave antennas; submillimetre wave generation; GaAs; LT GaAs emitters; THz generation; THz waveforms; carrier lifetime; enhanced peak power spectral density; high fluence excitation; high-power narrow-band THz radiation generation; high-power narrow-band terahertz generation; interpulse spacing; large aperture photoconductor; large-aperture biased photoconductive emitters; large-aperture photoconductors; multiple-pulse excitation; multiple-pulse saturation properties; saturation theory; semi-insulating GaAs; short-lifetime low-temperature-grown GaAs photoconductor; strong dependence; thick layer; Charge carrier lifetime; Dipole antennas; Gallium arsenide; Laboratories; Narrowband; Optical pulses; Photoconductivity; Power generation; Pulse amplifiers; Ultrafast optics;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.777228

Filename

777228