Abstract
Methods based on the Stark effect are reviewed for dither-free frequency stabilization of the opticallypumped submm laser. The CO2 pump laser was stabilized using either the linear absorption or the nonlinear Lamb dip of the submm lasant in an external Stark cell. Estimated frequency stability (Δf/f) of the order of 10-8-10-9, over a period of one hour, was obtained by these methods for several CO2laser lines. The frequencyof the submm laser was stabilized using the d.c. and a.c. Stark effects for a metal-dielectric rectangular waveguide laser. An estimated frequency stability of ±6×10-8 was obtained, for example, for 119, μmline of CH3OH laser for one hour recording.
