Ultrasonic-Diffraction Shutters for Optical Maser Oscillators

The ultrasonic-diffraction effect was utilized as a shutter to gate and amplitude modulate the output of a ruby optical maser (laser) by regulating the optical feedback within the Fabry-Perot interferometer. In addition, an oscillation resembling limit cycle operation was induced in the ruby laser by an ultrasonic-progressive wave that periodically changed the optical path length between the interferometer reflectors by varying the refractive index.