Development of a sinusoidal phase-shifting self-mixing interferometer for real-time displacement measurement with nanometer accuracy

Abstract

By combining the principles of sinusoidal phase-shifting technique and self-mixing interferometry, a novel instrument has been developed for real-time displacement measurement with nanometer accuracy. The sinusoidal phase shifting is introduced by an electro-optic modulator and the displacement of the object is measured by analyzing the harmonic components in the interference signal during each phase-shifting period. Theoretical analysis and simulation results are presented and some error sources are discussed in detail. The displacement measurement experiments by using a high precision nano-positioning stage and a long-range linear stage are performed to verify the performance of the interferometer. The measurement results of the interferometer are in good agreement with the data from a commercial dual-frequency interferometer, showing that the development of the interferometer is feasible for implementation in a real-time displacement sensor with high accuracy.

Recent developments in fiber-based optical frequency comb and its applications

“…Length is a basic physical quantity and its precision measurement is of great significance in both the frontier of fundamental science and advanced technology, such as the test for the Einstein's general theory of relativity [136], direct imaging of a black hole [137], satellite attitude control and the largescale manufacturing. Traditional techniques for precision distance measurement are usually based on the laser interferometry [138] and time-of-flight methods [139]. Although subwavelength-resolution can be attained, the interferometric techniques rely on incremental measurement of phase accumulation so the measurement process should not be interrupted and the measurement range is limited within several tens of meters.…”

A phase modulation method of sine signal for dual-active-valve piezoelectric pump

“…The sine signal phase modulation method and circuit proposed can be directly applied to a variety of measurement systems, even as the constituent part of measurement systems, especially in precision measurements and optical measurements [21][22][23][24][25]. Moreover, a combination of miniature precision actuator and measuring equipment is expected to achieve dynamic measurement and tracking measurement, and it is also expected to realize unmanned measurement in the pipelines, in the cavity of complex structures, and even in the radiation and toxic environments [26][27][28][29][30]. The method proposed is well suitable for the drive and control of many kinds of miniature precise linear actuators, rotary actuators and multidegree-of-freedom actuators.…”

A novel algorithm for laser self-mixing sensors used with the Kalman filter to measure displacement

“…The reflected or scattered light is injected back into the laser cavity, superimposed on the existing laser cavity field, and interferes with the existing field. The research on optical feedback during recent decades has led to an interesting field for a new practical application, laser self-mixing interferometry (SMI) [1][2][3][4][5][6]. It was first proposed in 1968 for use as a Doppler velocimeter with a gas laser [7].…”