Abstract

The coherency, which is linked to the spectral linewidth, is an important property of a laser, as it strongly influences the system performances in various domains of application [1]. Several methods have been proposed to measure the laser linewidth, among which the Delayed Self-Heterodyne Technique (DSHT) [2]. In this paper, we propose a novel and simple method to measure the laser linewidth based on Rayleigh Backscattering (RB) effect. Our technique requires relative intensity noise (RIN) measurement. Contrary to DSHT, it avoids the use of an acousto-optic frequency-shifter, which infers the bandwidth detection and of a Mach-Zehnder interferometer.

© 2009 IEEE