Manipulation of continuous variable orbital angular momentum squeezing and entanglement by pump shaping

Spatially structured quantum states, such as orbital angular momentum (OAM) squeezing and entanglement, is currently a popular topic in quantum optics. The method of generating and manipulating spatial quantum states on demand needs to be explored. In this paper, we generated OAM mode squeezed states of -5.4 dB for the LG+10 mode and -5.3 dB for the LG-1 0 mode directly by an optical parametric oscillator (OPO) for the first time. Additionally, we demonstrated that the OAM mode squeezed and entangled states were respectively generated by manipulating the nonlinear process of the OPO by controlling the relative phase of two beams of different modes, thus making two different spatial multimode pump beams. We characterized the Laguer re-Gaussian (LG) entangled states by indirectly measuring the squeezing for the HG10(45 degrees) mode and HG10(135 degrees) mode, and directly measuring the entanglement between the LG+1 0 and LG-1 0 modes. The effective manipulation of the OAM quantum state provides a novel insight into the continuous variable quantum state generation and construction on demand for high-dimensional quantum information and quantum metrology.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This paper presents the first direct generation of orbital angular momentum (OAM) mode squeezed states using an optical parametric oscillator (OPO). The squeezing rates for the LG+10 and LG-10 modes are -5.4 dB and -5.3 dB, respectively. Additionally, OAM mode squeezed and entangled states are generated by manipulating the nonlinear process of the OPO through controlling the relative phase of two different mode beams. The generated Laguer re-Gaussian (LG) entangled states are characterized by indirect measurement of squeezing and direct measurement of entanglement between different LG modes. The effective manipulation of OAM quantum states offers new insights into the generation and construction of high-dimensional quantum information and quantum metrology.