1. Extended-range FMCW reflectometry using an optical loop with a frequency shifter
- Author
-
Koichi Iiyama, Ken-ichi Hayashi, and Xiao-qun Zhou
- Subjects
Optical path difference ,Refractive index ,Frequency modulated continuous wave reflectometry ,Spectrum analyzers ,Optical modulation amplitude ,Signal ,Waveguide (optics) ,Optics ,Bandwidth ,Interference (communication) ,Frequency domain analysis ,Frequency modulation ,Optical fibers ,Electrical and Electronic Engineering ,Reflectometry ,Optical fiber loop ,Physics ,Semiconductor lasers ,business.industry ,Distributed feedback lasers ,Frequency shifter ,Acoustooptical modulator ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Time-domain reflectometry ,Reference beam ,Signal interference ,Optical variables measurement ,business - Abstract
金沢大学工学部, We propose a novel method to extend the measurement range of FMCW reflectometry. In this method, an optical loop with a frequency shifter (working frequency fFS Hz) is incorporated in the reference arm of the reflectometry. As a result, the interference signal corresponding to the reference beam that circulates N rounds in the loop appears around (N × fFS) Hz, which means that the signals from different measurement ranges can be detected in different frequency domains. Therefore, it is possible to extend the measurement range. In the experiment, the measurement range is extended from 15 m to 48 m.
- Published
- 1996