Method for generating orbital angular momentum states of multiple coaxial orbits at one time

Abstract

The invention discloses a method for generating angular momentum states of multiple coaxial orbits at one time, which comprises the following steps that 1, after being collimated by a collimator, Gaussian light is fed from a laser into a light beam deflection device; 2, the Gaussian beam deflects at different angles under the control of a controller of the light beam deflection device, and the emitted Gaussian beam irradiates different positions of the circular array vortex Dammann grating after passing through a collimation system composed of a plurality of lenses, so as to form a circular array vortex Dammann grating; the light beam transmitted by the circular array vortex Dammann grating is converted into a plurality of coaxial orbital angular momentum light beams with different topological charge values, and a plurality of concentric circle patterns are displayed on a focal plane. According to the invention, the light beam deflection device and the improved circular array vortex Dammann grating are applied to the field of generation of orbital angular momentum light beams, and a novel rapid generation method for a plurality of coaxial orbital angular momentum states is realized.

Description

technical field [0001] The invention relates to the field of orbital angular momentum, in particular to a method for generating multiple coaxial orbital angular momentum states at one time. Background technique [0002] Orbital Angular Momentum (OAM) is one of the frontiers and hotspots in the field of quantum optics in recent years. In classical electromagnetic field theory, the angular momentum of the electromagnetic field is divided into spin angular momentum related to circular polarization and orbital angular momentum related to the space helical phase structure. During free-space transport, the spin angular momentum (SAM) and orbital angular momentum (OAM) remain unchanged. In 1992, Allen et al pointed out that for a beam with a helical phase factor exp(ilθ), each photon has The orbital angular momentum of , where l is the azimuth index of the beam, also known as the topological charge, the value can range from negative infinity to positive infinity, and its size de...

AI Technical Summary

Problems solved by technology

The traditional Damman grating produces a square diffraction field distribution, which is limited in some special occasions

[0007] In the prior art, the application publication number is CN101726868A, which discloses a method and device for realizing beam orbital angular momentum state multiplexing encoding, specifically disclosing lasers, polarizers, beam expanders, spatial light modulators, wave plates, Fourier Transform transmission, on the rear focal plane of the Fourier transform lens, form multiple beams in different orbital angular momentum states that are evenly distributed on

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