Parametric Amplification and Squeezing in Quasi-Phase-Matched Waveguides

Nonlinear optical waveguides hold promise as parametric amplifiers and as sources of quadrature-squeezed light. The confinement of the pump field drastically increases the efficiency of the nonlinear conversion. In addition, the control of the spatial mode profiles by the waveguide geometry should diminish the effect of gain-induced diffraction, which has been seen to limit the amount of attainable squeezing in bulk parametric crystals.1 Using subpicosecond laser pulses, we have observed parametric gain as well as quadrature squeezing in a quasi-phase matched KTP waveguide.