Mode locking of argon ion laser by use of cylindrical ultrasonic waves

The phenomenon of light diffraction by a cylindrical ultrasonic wave has been investigated. The diffraction was applied in a new type of acousto–optic modulator used for laser mode locking. The paper describes the modulator and presents results on mode locking of argon ion laser. The mode locking was obtained by means of a cylindrical acoustic wave launched in water at the frequencies of ultrasound 33–34 MHz. A standing wave regime of operation of the modulator resulted in a reliable generation of laser pulses with the duration 720 ps.