Method for flexibly regulating and controlling self-focusing focal length of self-focusing light beam

Abstract

The invention discloses a method for flexibly regulating and controlling the self-focusing focal length of a self-focusing light beam. According to the method, a phase hologram that has a secondary phase factor and is generated by using a computer holographic technology is loaded to a spatial light modulator; the self-focusing focal length of a round Airy beam is regulated and controlled by changing the coefficient of the secondary phase factor and the round Airy beam with the required self-focusing focal length is generated, so that the halo distribution is clear and the focusing effect is good. The cubic phase hologram is generated by utilizing a computer holographic technology, so that the cost is hardly required; focusing effects of lenses with different focal lengths on the round Airybeam can be reflected; and compared with the mode of generating the round Airy beam by using Fourier space, the disclosed method does not need a Fourier transform lens. Moreover, the regulation and control mode is convenient to operate; the self-focusing focal length can be regulated and controlled more flexibly; and a specific research task can be completed.

Description

technical field [0001] The invention relates to a method for regulating the self-focusing focal length of a self-focusing light beam, and specifically discloses a method for regulating the focal length by applying a secondary phase factor to the phase of the self-focusing light field. Background technique [0002] In 2010, Efrimidis extended the self-accelerating Airy beam in the Cartesian coordinate system to the cylindrical coordinate system, and proposed a self-focusing circular Airy beam [Optics Letters, 2010, 35(23): 4045-4047]. [0003] In 2011, Greenfield proposed a simple method to generate different concave accelerated transmission beams, that is, by designing the phase distribution of the spatial light modulator, one-dimensional accelerated beams with different preset trajectories can be obtained. In 2015, Zhang theoretically studied 1D and 2D circular Airy beams with different initial velocities [Romanian Reports in Physics, 2015,67(3):1099-1107]. [0004] Changi...

AI Technical Summary

Problems solved by technology

[0004] Changing the incident angle of the beam and calculating the phase hologram of the circular Airy light field corresponding to different focal lengths can both control the self-focusing focal length of the circular Airy beam. Although the two are easy to implement, it is necessary to add mechanical control and recalculate the phase distribution of the light field. The operation is more complicated, and the self-focusing focal length of the circular Airy beam cannot be flexibly adjusted

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