Open AccessDynamic range beyond 100 dB for polarization mode coupling measurement based on white light interferometer
Author(s) -
Chuang Li,
Jun Yang,
Zhangjun Yu,
Yonggui Yuan,
Bing Wu,
Feng Peng,
Jianzhong Zhang,
Ai Zhou,
Yu Zhang,
Zhihai Liu
Publication year - 2016
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.24.016247
Subject(s) - optics , interferometry , dynamic range , polarization (electrochemistry) , extinction ratio , polarization mode dispersion , beat (acoustics) , white light interferometry , interference (communication) , physics , materials science , optical fiber , telecommunications , computer science , wavelength , chemistry , channel (broadcasting)
This paper presents a method to improve the dynamic range of white light interferometer (WLI) based polarization mode coupling (PMC) measurement system beyond 100 dB. The limitation of interference beat noise is overcame by analyzing in detail the inherent noises that have impacts on the detection sensitivity. An improved PMC measurement system and method are proposed for testing ultra-high polarization extinction ratio (PER) of polarization-related devices. The method can improve dynamic range dramatically through eliminating interference beat noise and enhancing the tested interference intensity simultaneously, which are verified theoretically and experimentally. In addition, a Y-junction with ~80 dB PER of LiNbO 3 chip corresponding to a weak signal is tested as an application example. The results demonstrate that the high PER interferogram can be identified clearly and steadily with standard deviation 0.9 dB (3σ) @ ~80 dB. This proposed method is highly beneficial in fabrication and evaluation for polarization devices with ultra-high PER.