  We observed -7.2 dB quadrature squeezing at 860 nm by using a sub-threshold
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.
