Vortex laser based on laser medium center zero gain structure

Abstract

A vortex laser based on a laser medium center zero gain structure is applied to optical tweezers, optical spanners and the field of optical communication. The vortex laser comprises a pumping source, an optical coupling system, an input mirror, a zero gain center laser medium, and an output mirror, all of which are arranged in sequence. The zero gain center laser medium is a piece of ceramic or crystal which is provided with a hole in the center and annularly doped with activated ions or doped with zero-activated ions in the center region. Fundamental transverse mode oscillation is inhibited by the zero gain center structure of the laser medium. Pure higher-order Laguerre-Gaussian (LG0, l(l>=1)) beam output is realized through mode matching. No other optical components are needed, and no pumping spot shaping is needed. The vortex laser has the advantages of high laser efficiency, wide scope of applications, simple operation, easy integration, and the like.

Description

technical field [0001] The invention relates to a vortex laser, especially a vortex laser based on a laser medium center zero-gain structure suitable for the field of laser technology Background technique [0002] Vortex light is a kind of beam with special properties such as helical phase wavefront, axial zero intensity distribution, and orbital angular momentum. In recent years, due to the special application of vortex beams in the trapping and trapping of tiny particles, conventional communication and quantum communication, the research on the generation and transmission characteristics of vortex beams has become more and more important. Since J.F. Ney discovered the optical vortex in 1974, researchers have conducted a lot of experimental research on how to generate the optical vortex. According to the difference in vortex laser generation technology, the current vortex lasers can be divided into two categories: the first category is based on the mode conversion of extra...

AI Technical Summary

Problems solved by technology

This type of laser is often limited by the material characteristics of the phase optical element itself, it is difficult to realize the integrated design with the laser resonator, the conversion efficiency is low, only a single wavelength can be converted, and the high-energy laser is easy to cause damage to the conversion element; One type is a vortex laser based on the direct oscillation of the laser transverse mode selection to generate vortex light

There are mainly three types: the first is to insert phase optical elements (phase grating, spatial light modulator, etc.) Limited to the material properties of the phase element, it is difficult to achieve high power and high efficiency operation

The second is to modulate the spot of the pump light into a ring, and realize the direct oscillation output of the vortex laser through the mode matching of the pump light and the oscillating laser. The modulation process of the pump light will inevitably lead to the complexity of the entire laser system.

The third type is relatively simple in structure, which is to use the point defect mirror as the input mirror or output mirror of the ordinary laser oscillator to force the vortex light to oscillate, but it is also accompanied by large intracavity loss, high laser threshold, and difficulty in high-power operation. and other shortcomings

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