Pulse generation with an acousto‐optic frequency shifter in a passive cavity

A train of pulses is generated by coupling the cw output of a single frequency He‐Ne laser into a passive ring ‘‘cavity’’ which contains an acousto‐optic frequency shifter. Each cavity pass shifts the frequency of the wave by 80 MHz. This results in an intensity pattern which is an Airy function in time. For a single frequency input, the output pulse width is 2 ns with a repetition rate of 80 MHz. Data are also presented on the output of this device for multimode cw input.