Accuracy Improvement of a Miniature Laser Diode Interferometer by Compensating Nonlinear Errors and Active Stabilizing Laser Diode Wavelengths

Abstract

A miniature laser diode interferometer (MLDI), which can be embedded in precision machines or measurement equipment as an on-line measurement sensor, is designed. A compact laser diode (LD) is adopted as the laser source of the MLDI. The measurement accuracy of the MLDI is affected by the nonlinear errors induced by the installation errors and manufacturing errors of the optical elements and the stability and accuracy of the LD wavelength. An arithmetic is applied to eliminate the nonlinear errors, and an error sensitivity analysis is conducted to enhance the understanding of which error components are more important or influence the measurement accuracy of the MLDI. An active wavelength stabilizer based on a compact laser wavelength meter is proposed to improve the stability of the LD wavelength. A group of experiments are carried out to verify the effectiveness of the proposed methods and the capabilities of the MLDI.

Keywords

• laser interferometer
• laser diode
• nonlinear error
• wavelength stabilization