Squeezed Sight from a singly resonant frequency doubler

R. Paschotta, K. Fiedler, P. K�rz +1 more

Hidemi Tsuchida

Amplitude-squeezed light at 431 nm has been generated from a singly resonant frequency doubler with a KNbO3 crystal. The frequency doubler is designed to resonate only the fundamental mode and is pumped by a frequency-stabilized Ti:sapphire laser. Noise reduction of 2.4 dB at 7.5 MHz is observed in the second-harmonic mode with a coherent excitation of 65 mW. With the detection efficiency taken into account, the actual noise reduction is estimated to be 5.2 dB.

David Gevaux

V. V. Dodonov, D. V. Zhivotchenko, Vladimir I. Man’ko

Sujing Zhang, Yongmin Li, Jianli Liu +1 more

Both fundamental and second harmonic amplitude squeezed lights were generated from an external cavity-enhanced singly resonant PPKTP frequency doubler. The effect of input coupling and fundamental power on the squeezing was experimentally investigated. It was shown that the optimal conditions (input coupling and fundamental power) are different for the squeezing of the fundamental and second harmonic lights. An agreement between experiment and theoretical prediction was found.

R. Paschotta, Matthew J. Collett, Peter Kürz +3 more

We present a new technique for the efficient and simple production of amplitude-squeezed light with high coherent excitation, using a frequency doubler, in which only the fundamental wave is resonantly enhanced. Our theory predicts up to nearly 90% squeezing in the second-harmonic wave under ideal conditions. In our first experiment we measured up to 30% squeezing [having taken into account the limited quantum efficiency (63%) of our detection system] in a stable 50 mW beam. Compared to doubly resonant frequency doubling our new approach has considerable technical advantages.