Physical Review A
Control of quantized photon states with cascade phase conjugators by modulation pumping
Tsuyoshi Fukuo, Tetsuo Ogawa
Abstract
Squeezing properties of a quantized photon field interacting with cascade four-wave-mixing materials (phase conjugators) are investigated theoretically by the transfer-matrix method. The controllability of the quantum fluctuation of the photon field is improved with the use of modulation pumping, in which phases of pumping beams of the phase conjugators are individually controlled even when their optical nonlinearity and/or the pumping power are fixed. By choosing appropriate numbers of phase conjugators and phase differences of the pump beams, incident coherent light is transformed to quadrature-phase-amplitude (QPA) squeezed states and photon-number-squeezed states. Optimal squeezing of both the QPA and photon number can be realized with this cascade system by modulation pumping. Partial (normal) reflection of light at surfaces of the phase conjugators is shown quantitatively to suppress the squeezing. Comparison with an ordinary method using a single-phase conjugator is also made.