Abstract
We present generation of photon-subtracted squeezed state at 860nm, from continuous-wave squeezed vacua generated with a periodically-poled KTiOPO4 crystal as a nonlinear medium of a subthreshold optical parametric oscillator. We observe various kinds of photon-subtracted squeezed states, including “non-Gaussian” states similar to the single-photon state and superposition states of coherent states, simply by changing the pump power. Nonclassicality of the generated states clearly emerges as its negative region around the origin of the phase-space distributions, i. e., the Wigner functions. We obtain the value,-0.083 at the origin of the Wigner function, which is largest ever observed without any correction for experimental imperfections.
