Wavelength Modulating Self-Mixing Interferometer
- Resource Type
- Article
- Authors
- Guo, Dong Mei; Jiang, Hai Qing
- Source
- Applied Mechanics and Materials; September 2017, Vol. 870 Issue: 1 p15-20, 6p
- Subject
- Language
- ISSN
- 16609336; 16627482
Self-mixing interference (SMI) was used to measure the displacement with a resolution of λ/2 by counting the interference signal peaks. In order to increase the measurement accuracy beyond λ/2, sinusoidal wavelength modulation (SWM) technique is introduced in SMI in this paper. Wavelength modulation of the laser beam is obtained by sinusoidal modulating the injection current of the laser diode. Fourier analysis method is proposed to demodulate the phase. Experimentally, the micro-movements of a high precision commercial PZT have been reconstructed, which can obtain a displacement measurement resolution of a few nanometers. It provides a potential displacement sensor with high accuracy and quite compact configuration.