Phase mask plate of integer-order vortex beam with fractional-order vortex profile and optical path system

Abstract

The invention provides a phase mask plate of an integer-order vortex beam with a fractional-order vortex profile. A generated novel vortex beam simultaneously has the topological charge of the integer-order vortex and the light intensity profile of the fractional-order vortex. The phase mask plate generates a vortex beam by inputting the phase mask plate into a reflection type spatial light modulator, wherein the transmission rate function expression of the phase mask plate is a formula which is as shown in the specification, wherein A (x, y) is an amplitude modulation function and is used forchanging the profile of the incident coherent light field so as to improve the quality of the vortex beam and avoid the interference of a phase modulation signal and an amplitude modulation signal; ang (.) is an angle-solving function of an imaginary number; rem (.) is a complementary function; m is the topological charge value of the beam, and n is a phase step factor, wherein n is greater thanm; the phase step can be compressed by changing the value of n, so that the required phase step size is generated; theta is the polar angle of a polar coordinate system; and 2 <pi>x/d is a blazed grating item, and is used for generating a blazed grating with a period of d, so that the energy is concentrated in +1 stage diffraction.

Description

technical field [0001] The invention relates to the field of particle manipulation, in particular to a phase mask of a vortex beam and a corresponding optical path system. Background technique [0002] A large number of studies on the orbital angular momentum in the light field mainly focus on vortex beams, which have been applied in many fields, such as light manipulation of particles, optical imaging, optical communication, optical remote sensing and so on. Because of its wide application value, it has become a major research hotspot in the field of structured light field in recent years. [0003] There have been a lot of research results on integer-order vortex beams. As early as 1996, Simpson, N.B. et al. proposed that optical vortex can be used as an "optical wrench" in the field of micro-manipulation [J.Mod.Opt.1996, 2485-2491]. In recent years, the research on the manipulation of particles by vortex light fields with special structures is also in the ascendant [Optic...

AI Technical Summary

Problems solved by technology

However, the orbital angular momentum of each photon in two adjacent half-integer vortex beams differs by a reduced Planck constant Difficult to achieve continuous change

[0004] To sum up, there is still a lack of a new type of vortex beam, which has both the topological charge of the integer order vortex and the light intensity profile of the fractional vortex, to deal with the topological charge of the notched vortex beam in the field of micromanipulation. Continuous regulation of

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