Continuous variable entanglement of phase locked light beams

Abstract

We explore in detail the possibility of intracavity generation of continuous-variable (CV) entangled states of light beams under mode phase-locked conditions. We show that such quantum states can be generated in self-phase locked nondegenerate optical parametric oscillator (NOPO) based on a type-II phase-matched down-conversion combined with linear mixer of two orthogonally polarized modes of the subharmonics in a cavity. A quantum theory of this device, recently realized in the experiment, is developed for both sub-threshold and above-threshold operational regimes. We show that the system providing high level phase coherence between two generated modes, unlike to the ordinary NOPO, also exhibits different types of quantum correlations between photon numbers and phases of these modes. We quantify the CV entanglement as two-mode squeezing and show that the maximal degree of the integral two-mode squeezing(that is 50% relative to the level of vacuum fluctuations) is achieved at the pump field intensity close to the generation threshold of self-phase locked NOPO, provided that the constant of linear coupling between the two polarizations is much less than the mode detunings. The peculiarities of CV entanglement for the case of unitary, non-dissipative dynamics of the system under consideration is also cleared up.

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Cited by in corpus (10)

• Experimental continuous-variable entanglement from a phase-difference-locked optical parametric oscillator
• Multiphoton blockades in pulsed regimes beyond the stationary limits
• Flexible generation of correlated photon pairs in different frequency ranges
• Quadrature entanglement and photon-number correlations accompanied by phase-locking
• Phase-locking at low-level of quanta
• Enhanced phase estimation with coherently boosted two-mode squeezed beams and its application to optical gyroscopes
• Universal behavior of the geometric entanglement measure of many-qubit W states
• Generation of two-color polarization-entangled optical beams with a self-phase-locked two-crystal Optical Parametric Oscillator
• Multiple resonant manipulation of qubits by train of pulses
• Chaotic spin-spin entanglement on a recursive lattice