ACTIVE OPTICAL FEEDBACK IN A DUAL-DIODE LASER CONFIGURATION APPLIED TO DISPLACEMENT MEASUREMENTS WITH A WIDE DYNAMIC-RANGE

The principles, experimental apparatus, and advantages of the use of an optical feedback technique for extended displacement measurements based on the use of a dual-diode laser configuration are described. This device is capable of creating a synthetic wavelength from the two lasers simultaneously through the frequency selectivity of the individual lasers, which respond only to their own wavelength. Theoretical analysis and experimental evidence are presented to show the feasibility of the measurement method and the simplicity of its operation.