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Proceedings Paper

Improved velocity mismatch in traveling-wave coplanar waveguide photodetector with thick ground-metal-line
Author(s): Sang-Jun Yoon; Seong-Hae Ok; Young-Seol Yoon; Soon-Chel Kong; Young-Wan Choi
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Paper Abstract

Bandwidth of a traveling-wave photodetector (TWPD) is limited by the optical absorption coefficient, velocity and impedance mismatches, and the drift time of photo-generated carriers in the intrinsic region. In these parameters, velocity and impedance mismatches have much influence on the bandwidth of TWPD. In this paper, we focus on mismatches, and propose a novel design to enhance the bandwidth. In the new structure, the thickness of a ground electrode increases as much as the ridge thickness. It forces the structure to have characteristics similar to a coplanar waveguide. We simulate this structure by finite different time domain Method in three dimensions and look-over frequency dependent parameters by Fourier transform for the detailed analysis of microwave characteristics such as characteristic impedance, microwave effective index, and microwave attenuation of TWPD. As a result, we obtain 50 (Omega) impedance matching and 89.7 % velocity matching using our novel structure.

Paper Details

Date Published: 21 May 2002
PDF: 8 pages
Proc. SPIE 4650, Photodetector Materials and Devices VII, (21 May 2002); doi: 10.1117/12.467670
Show Author Affiliations
Sang-Jun Yoon, Chung-Ang Univ. (South Korea)
Seong-Hae Ok, Chung-Ang Univ. (South Korea)
Young-Seol Yoon, Chung-Ang Univ. (South Korea)
Soon-Chel Kong, Chung-Ang Univ. (South Korea)
Young-Wan Choi, Chung-Ang Univ. (South Korea)

Published in SPIE Proceedings Vol. 4650:
Photodetector Materials and Devices VII
Gail J. Brown; Manijeh Razeghi, Editor(s)

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