Far-infrared distributed feedback gas laser

Theory and first operation of a distributed feedback gas laser is expanded. This goal has been achieved by an optically pumped 496μm CH
3
F laser equipped with a hollow metal waveguide with deep periodic corrugations. The period of corrugations is tuned by temperature variation. Single-mode operation is achieved. The working pressure of CH
3
F is up to 10 torr. Propagation of the laser beam is near the diffraction limit. The spectral linewidth of less than 22 MHz corresponds to the transform limit set by the 50 ns pulse duration. Temperature tuning curves of the laser output are in good agreement with theory.