Broadband amplitude squeezing in a periodically poled KTiOPO_4 waveguide
  We generated -2.2 dB of broadband amplitude squeezing at 1064 nm in a periodically poled KTiOPO_4 (PPKTP) waveguide, by coupling of the fundamental and second harmonic continuous-wave fields. This is the largest amount of squeezing obtained to date in a KTP waveguide, limited by propagation losses. This result paves the way for further improvements by use of lower-loss buried ion-exchanged waveguides. 
Matthew Pysher, Russell Bloomer, Olivier Pfister, Christopher M.   Kaleva, Tony D. Roberts, and Philip Battle