Optical beam frequency modulation by using surface‐acoustic‐wave delay line oscillator

摘要

A frequency‐modulation technique for an optical beam is described, which uses a surface‐acoustic‐wave delay line oscillator. The surface wave propagating on a piezoelectric substrate is mode converted to a longitudinal wave at one end of the substrate plate immersed in water. The sound wave operates as a grating for an optical beam. The use of this type of grating for the frequency modulation is demonstrated for a combination of a He–Ne 0.6328‐μm laser and a 2.8‐MHz surface‐wave device.