Open AccessAnalysis of AM-to-PM conversion in MUTC photodiodes based on an equivalent circuit model
Author(s) -
Zhenjie Song,
Zhiqi Zhou,
Jian Huang,
Xinbo Zou,
Chun Yang,
Baile Chen
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.441677
Subject(s) - photodiode , photocurrent , energy conversion efficiency , materials science , optics , electrical impedance , equivalent circuit , optoelectronics , microwave , physics , voltage , quantum mechanics
High-speed, high power-handling photodiodes with sufficiently low amplitude-to-phase (AM-to-PM) conversion coefficients are critical components in the systems that generate ultra-stable microwave signals. This paper reports the AM-to-PM conversion in modified uni-traveling carrier photodiodes (MUTC-PDs) with 20 µm and 40 µm diameters. The contributions of AM-to-PM conversions from the carrier transit-time and impedance were quantified systematically based on a photocurrent-dependent nonlinear equivalent circuit model. It is found that the AM-to-PM conversion in 40 µm PD is dominated by the nonlinear impedance, while for 20 µm PD, the transit-time impacts the AM-to-PM conversion more significantly. These results imply that, for large PDs, the nonlinearity of the PDs' photocurrent-dependent impedance is the critical reason causing AM-to-PM conversion.