Hidemi TSUCHIDA

Electrotechnical Laboratory, 1-1-4, Umezono, Tsukuba, Ibaraki, 305 Japan

(Received May 31, 1996; Accepted July 3, 1996)

Frequency doubling of a Ti:sapphire laser with a KNbO₃ crystal has been used to generate wavelength tunable amplitude-squeezed lights in the second harmonic mode. The crystal is placed in an enhancement cavity designed to resonate only the fundamental mode, and the phase matching condition is achieved by changing the crystal temperature. Noise reduction of 1.8-2.0 dB below the shot noise level is observed between 427.28 and 433.76 nm.

Key words : squeezed states, quantum noise, frequency doubling, wavelength tunability, Ti:sapphire laser, KNbO₃