An oam demultiplexing device and method based on coordinate transformation

Abstract

The present invention discloses an OAM demultiplexing device and method based on coordinate transformation. The device includes: a first phase mask, which is used to perform beam duplication on the input multiple information-carrying OAM beams and increase the phase of the OAM beams. After the gradient, the Cartesian-logarithmic polar transformation is completed, the concentric OAM beam with a spiral phase gradient is converted into a rectangular beam with a transverse phase gradient, and the rectangular beam is Fourier transformed and in the spectrum Surface imaging; the second phase mask is used to compensate the beam phase transformation caused by coordinate transformation, and at the same time focus the rectangular beams with different lateral phase gradients into narrow and long beams with different lateral positions; cylindrical lens is used for Squeeze a narrow beam into a Gaussian beam. The invention realizes the demultiplexing of multiple OAM light beams carrying information and realizes all-optical information processing, and the used devices are all passive devices, which can effectively reduce the power loss of the system.

Description

technical field [0001] The present invention relates to the technical fields of optics and optical communication, in particular to an OAM demultiplexing device and method based on coordinate transformation. Background technique [0002] Orbital Angular Momentum (OAM, Orbital Angular Momentum) is the basic physical quantity of classical mechanics and quantum mechanics. The OAM beam is a group of Orthogonal pattern set for , is the azimuth angle, is an integer representing the topological charge. The value of can theoretically reach infinity, which will provide optical communication with a degree of freedom with infinite capacity on the basis of traditional communication degrees of freedom such as amplitude, polarization, and frequency, and use them together as information modulation and The way of multiplexing will break through the limit of existing communication capacity, greatly improve the transmission rate of information, and have good communication confidentialit...

AI Technical Summary

Problems solved by technology

[0003] An important prerequisite for realizing OAM communication is to be able to detect multiple OAM states. However, in the existing OAM state multiplexing system, the The detection of the OAM state of the road requires An independent detection device, which greatly increases the cost of the system, and makes the system complicated, and the existing detection methods have not been widely used because of their complexity.

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