Multimode quantum properties of a self-imaging optical parametric oscillator: Squeezed vacuum and Einstein-Podolsky-Rosen-beams generation

Abstract

We investigate the spatial quantum properties of the light emitted by a perfectly spatially degenerate optical parametric oscillator ͑self-imaging optical parametric oscillator͒. We show that this device produces local squeezing for areas bigger than a coherence area that depends on the crystal length and pump width. Furthermore, it generates local EPR beams in the far field. We show, calculating the eigenmodes of the system, that it is highly multimode for realistic experimental parameters.

Tomography of mode-tunable coherent single-photon subtractor

“…As our single-photon subtractor is designed for parametric multimode sources [3,42], we now characterize it with a mode basis approximating the eigenmodes of this process: HG modes {HG 0 , HG 1 , . .…”

“…preparation of hybrid multimode entangled states [10,20,21], distillation of multipartite entanglement [23,27], measurement-based quantum computing [13,44], etc. In addition, our tomography method is not limited to characterize time-frequency modes, but can be generally applied to other types of light modes such as spatial [42], polarization [45], spatiotemporal [46] modes, and it can be extended to characterize a general multimode quantum process [33]. In particular, it will be useful for identifying couplings among many connected modes (e.g.…”

“…We have implemented various single-photon subtractions such as a subtraction for one HG mode and a coherent subtraction for several HG modes. The subtraction matrices obtained in the wavelength-band modes reveal the modes of the single-photon subtractions in the wavelength domain, and the subtraction matrices in the HG modes directly show the coherence between different HG modes, which is required for parametric multimode sources [3,42]. A high mode selectivity (typically larger than 0.9) and low imperfections (dark count contribution around 1% and optical loss around 2 %) of the single-photon subtractor show its direct applicability to generate multimode non-Gaussian states.…”

Spatial fluctuations in an optical parametric oscillator below threshold with an intracavity photonic crystal

“…It is known that OPOs are useful devices giving spatially entangled states generation below threshold [42,53,54]. Let us analyze in this regime how the modulation introduced by the PC modifies quantum correlated states at opposite points in the far field.…”

Why a hole is like a beam splitter: A general diffraction theory for multimode quantum states of light

“…The quantum properties of diffracted Gaussian beams, or other paraxial beams, have received less attention, although some of previous works are found in Refs. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Though many previous analyses do take multiple Gaussian modes under consideration, a clear and systematic description of the interaction amongst Gaussian modes is lacking.…”