Device for detecting topological charge of optical vortex beam based on radial grating spoke number

Abstract

The invention provides a device for detecting the topological charge of an optical vortex beam based on a radial grating spoke number. A core element of the device is a radial grating lifting apparatus with a spoke number ranging from 2 to 20, the radial gratings with different spoke numbers can fall onto a light path platform in sequence, and a to-be-detected optical vortex beam can just pass through. A to-be-detected optical vortex beam enters the radial grating lifting apparatus and passes through the falling radial grating, and a charge-coupled device therebehind receives a diffraction pattern and displays the diffraction pattern in a computer. The topological charge of the optical vortex beam is detected by observing whether a bright spot exists in an optical axis part of the diffraction pattern or not. Different from a traditional topological charge detection device, the device does not need to introduce an additional reference light beam, the diffraction pattern can be observedvery visually, and the judgment of the topological charge number is faster and more accurate. The device provided by the invention simple and easy to operate.

Description

technical field [0001] The invention belongs to the field of optical measurement, and relates to a device for detecting the topological charge of a vortex beam based on radial grating spokes. Background technique [0002] Optical Vortices have phase term (where is the tangential angle, l is the topological charge, which can take any integer), and its phase is unevenly distributed in the cross-section of the beam. Research shows that the angular momentum properties of vortex beams are related to the vortex phase term, where the topological charge l can take any integer. Thus, the angular momentum beams carrying different topological charges constitute an infinitely large orthogonal orbital angular momentum state space, which makes it have the communication potential of a large-capacity channel. Due to their unique angular momentum properties, vortex beams have been successfully applied in various fields such as quantum information, plasmons, and information storage. Now...

AI Technical Summary

Problems solved by technology

Interferometry requires an ideal reference beam, the optical path is complicated, and it is easily disturbed by the environment, while the diffraction method requires special diffraction elements

The existing vortex beam detection method has complicated detection devices, complex diffraction intensity patterns, and difficult analysis of detection results

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