Frequency Stabilization of an External-Cavity Diode Laser against HI Molecule at 1.541 μm

Abstract

An External-Cavity Laser Diode was frequency locked on molecular absorption line R(3) of hydrogen iodide at 1.541 Am using the wavelength modulation technique. This molecular reference is very important in many fields like HD-WD W telecommunication system and interferometry. Preliminary measurements of the closed-loop error signal provided a relative frequency stability of9.5x10-'0 in a 160 Hz acquisition bandwidth.