High power ring laser with diffraction grating coupling and axial mode selection

The performance of a high power, diffraction grating coupled ring resonator laser is described. A cw output power of four kilowatts at 10.6 microns in a near diffraction limited beam was obtained. The active medium was generated by a gas dynamic laser. Axial mode selection in resonator was used in conjunction with the Doppler shifted gain of the flowing medium to control the direction of oscillation. It is deduced from the directional behavior of the laser and the mode selective properties of the resonator that single frequency operation was obtained.