Polarization-insensitive space folding laser resonator

Abstract

The invention discloses a polarization-insensitive space folding laser resonator which comprises a total-reflection mirror, 4*N turning mirrors, an output mirror and a laser working medium, wherein the total-reflection mirror and the output mirror are perpendicular to an optical axis, and the centers of the total-reflection mirror and the output mirror are located on the optical axis; and the 4*N turning mirrors are highly reflecting plane mirrors, and the centers of the 4*N turning mirrors are located on the optical axis, wherein the normal lines of 2*N turning mirrors are parallel to the meridian plane, and an included angle between the normal lines of two adjacent turning mirrors is 90 DEG; the normal lines of the rest 2*N turning mirrors are parallel to the sagittal plane, an included angle between the normal lines of the rest two adjacent turning mirrors is also 90 DEG, and the included angles between the normal lines of the 4*N turning mirrors and the optical axis are 45 DEG; and the laser working medium is located on all folding arms perpendicular to the total-reflection mirror. The laser resonator eliminates the polarization selection phenomenon of the turning mirrors in the same plane. The polarization property of output laser is decided by the polarization selection characteristic of the total-reflection mirror. The higher the output power is, the better the beam quality is. The laser resonator can be applied to medium-power and high-power gas or solid laser devices.

Description

technical field [0001] The invention belongs to the field of laser devices, and relates to a laser resonant cavity, in particular to a polarization-insensitive spatially folded laser resonant cavity. Background technique [0002] In laser industrial applications, such as laser welding, laser cutting and other fields. The polarization characteristics of laser light have a great influence on these applications. For example, in laser cutting, the cutting quality obtained by using linearly polarized light as the cutting beam is not high, and the uniformity is very poor. However, the cutting quality obtained by using circularly polarized light and random polarized light is better than that obtained by linearly polarized light. [0003] General industrial high-power lasers use folded cavities in the same plane, and the output is linearly polarized light. Before application, it is generally necessary to use a phase retardation mirror with a quarter-wavelength phase retardation t...

AI Technical Summary

Problems solved by technology

However, the cavity length of this type of laser is limited, so the output power of the laser is also limited.

Therefore, although this type of straight cavity laser is non-selective to polarization, it cannot output high-power laser and is difficult to use in industrial processing.

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