An Unstable Cavity Laser

Abstract

The invention discloses an unstable cavity laser. The unstable cavity laser comprises a second reflector (5), and a first reflector (1), a gain medium (2), a curved surface polarization direction controller (3) and a polarizer (4) which are sequentially arranged along an optical axis, wherein the first reflector (1) and the second reflector (5) form an unstable cavity; the curved surface polarization direction controller (3) has a preset thickness, so that the polarization direction of a light beam penetrating through the curved polarization direction controller is rotated at different anglesalong with the increase of the radius of a light spot; the polarizer (4) is arranged according to a Brewster angle; the second reflector (5) is arranged on the optical axis of light reflected or transmitted by the polarizer (4); and the light correspondingly penetrating through the polarizer (4) or the light reflected by the polarizer (4) is output. The curved surface polarization direction controller and the polarizer are used cooperatively, so that the effects of similar Gaussian mirror and output mirror can be realized, and the polarized laser output with high light beam quality can be obtained while the thermal depolarization loss is reduced.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to an unstable cavity laser. Background technique [0002] Solid-state lasers with polarization, high power, and high beam quality have important applications in material processing and scientific research due to their large output energy, high peak power, compact device structure, and long service life. In order to obtain a polarized laser with high power and high beam quality, the prior art mainly adopts the following three methods, but these three methods themselves have the following disadvantages. [0003] 1) Stable resonator: If a stable resonator is used, high output power and high beam quality often cannot be satisfied at the same time, and the output beam is usually a Gaussian beam. Compared with an unstable resonator, the beam quality is usually poor. [0004] 2) The polarizer is directly inserted into the unstable resonant cavity: the appearance of the unstable resonant c...

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Problems solved by technology

However, if the method of directly inserting the polarizer into the unstable resonant cavity, due to the thermal effect of the gain medium, the degree of polarization of the polarized light oscillating in the resonant cavity will decrease, the loss will increase, and the output power will decrease; The thermal depolarization phenomenon makes the polarized light oscillating in the resonator lose a lot, resulting in a decrease in output power

[0005] 3) Insert a polarizer outside the unstable resonant cavity: Insert a polarizer outside the unstable resonant cavity, and after passing through the polarizer, polarize the natural light to obtain polarized light, but using this method loses at least half of the light intensity, and the loss is too large

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