Laser sources at 760 nm wavelength for metrology of length

Abstract

First set-up of the laser source based on the DFB (Distributed FeedBack) laser diode is presented. We used the DFB laser diode at 760 nm wavelength with mode-hop free tuning range above 1 nm and fiber output up to 10 mW. We present our first characteristics without external stabilization of the output wavelength. We compared our new DFB laser source with our previously developed laser source with VCSEL (Vertical Cavity Surface Emitting Laser) diode. Results are presented. Both laser sources were developed for laser interferometry, laser metrology of length. We present set-up of the laser interferometer proposed with respect to using of our laser sources. The design of optical set-up of the experimental interferometer is realized using fiber optics to reduce the influence of the index of refraction of air. The laser interferometer in the first set-up was used for absolute measurement of length. We used the method of the frequency stabilization on optical resonator to stabilize of frequency of laser diode and measurement of the tuneability of the wavelength.