TITLE:
An Optical Path Length Modulator for Laser Diode Self-Mixing Interference
AUTHORS:
Xianfeng Hu
KEYWORDS:
Self-Mixing Interference, Optical Path Length, Phase Modulator, Vibration
JOURNAL NAME:
Optics and Photonics Journal,
Vol.7 No.1,
January
22,
2017
ABSTRACT: Transparent liquid flattening or stretching realizes optical path length modulation. A flat thin seal transparent cavity, one flank is an electromagnetic driving membrane and is filled over with transparent liquid. Vibration of the membrane makes the liquid compressing or stretching, changes the liquid layer thickness, i.e. the optical path length of light through the liquid layer. The liquid layer compressed is equivalent to increase membrane tension. The membrane has higher resonant frequency. The cavity diameter 10 mm modulation frequency is about 18 kHz.