Generation of strongly squeezed continuous-wave light at 1064 nm

A compact and effcient source of amplitude-squeezed light is described. It employs a semi-monolithic degenerate MgO:LiNbO(3) optical parametric amplifier pumped by a frequency-doubled Nd:YAG laser at 532 nm. Injection-seeding of the amplifier by a 1064 nm wave permits active stabilization of the cavity length and stable operation. At a pump power of 380 mW, a maximum noise reduction of 6.5 dB in the amplitude fluctuations of the 0.2 mW 1064 nm wave was detected. The average detected noise reduction in continuous operation over 14 minutes was 6.2 dB. Taking the detection effciency into account, this corresponds to a squeezing of 7.2 dB in the emitted wave.