Frequency stabilization at the sub-kilohertz level of an external cavity diode laser

A simple external cavity diode laser (ECDL) in a Littrow configuration was established and actively frequency-stabilized by using a side-of-fringe stabilization technique. A wavelength tuning range of 60 nm for the spectral range between 1000 and 1060 nm was demonstrated by rotating the diffraction grating. A sub-kilohertz frequency stabilization of the ECDL was achieved. The linewidth of the laser was narrowed from 160 kHz to 400 Hz by laser frequency locking to a flank of a Fabry-Perot interferometer peak.