Device and method for generating hollow beam with adjustable polarization state

Abstract

A device and method for generating a hollow beam with an adjustable polarization state. The device includes a laser light source. Along the laser output direction of the laser source, a polarizer, a quarter-wave plate, a microscope objective lens, an optical fiber, and a collimator are sequentially arranged. lens and multidimensional adjustment mount, the microscopic objective lens is fixed on the fixture of the multidimensional adjustment mount, the input end of the optical fiber is fixed on the fiber support of the multidimensional adjustment mount, and the end face of the input end is located at the On the rear focal point of the above-mentioned microscopic objective lens, the end face of the output end of the optical fiber is located at the front focal point of the collimator lens, the optical fiber is a few-mode optical fiber, and the multi-dimensional adjustment frame also has a first knob, The second knob and the third knob respectively adjust the horizontal and pitch angles of the microscope objective lens through the fixture, so as to realize the off-axis incidence of the focused light beam on the optical fiber. The invention has the advantages of simple device structure and easy operation, and can realize high-quality hollow beam output with adjustable polarization state.

Description

technical field [0001] The invention relates to light beams, in particular to a device and method for generating hollow beams with adjustable polarization states. Background technique [0002] In recent years, with the development of optical trapping of microscopic particles and ultra-high resolution microscopy, hollow beams with spatially inhomogeneous polarization states have received more and more attention. The methods for obtaining spatially inhomogeneous hollow beams of polarization state are mainly divided into two types: active method and passive method. The more typical one is to use photonic crystal grating mirror as the laser output coupling mirror, and use rare earth ion doped fiber as the gain medium to obtain the active scheme of this beam. Through this active scheme, it is possible to obtain a high-power laser output of a spatially inhomogeneous hollow beam with a high polarization state, and the polarization purity of the beam is also high. However, the syst...

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Problems solved by technology

Through this active scheme, it is possible to obtain a higher power laser output of a spatially inhomogeneous hollow beam of polarization state, and the polarization purity of the beam is also high, but the design of the system is relatively complicated, and the pro...

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