Compact Hz-level linewidth laser system

Increasing the compactness and robustness of laser stabilization systems is a critical need for the development of industrial applications of ultra-narrow linewidth lasers. In this aim, a compact optical setup based on the Pound-Drever-Hall scheme with a high finesse cavity was built with overall dimensions of L × W × H = 45 × 35 × 13 cm
³
. An external cavity diode laser (PLANEX
^™
, RIO Inc.) as well as a distributed-feedback fiber laser (Koheras Adjustik, NKT photonics) were stabilized using this system. The frequency stability was evaluated using a similar setup as reference. The combined relative stability of the systems reached 7·10
^-15
at 1s.