7 dB quadrature squeezing at 860 nm with periodically poled KTiOPO4

The authors observed -7.2 +/- 0.2 dB quadrature squeezing at 860 nm by using a subthreshold continuous-wave pumped optical parametric oscillator with a periodically poled KTiOPO4 crystal as a nonlinear optical medium. The squeezing level was measured with the phase of homodyne detection locked at the quadrature. The blue light induced infrared absorption was not observed in the experiment. (c) 2006 American Institute of Physics.