Multi-stage taper optical fiber phase conjugation mirror and device and method for laser double-journey amplification thereof

Abstract

The invention discloses a multi-stage taper optical fiber phase conjugation mirror and a device and method for laser double-journey amplification of the multi-stage taper optical fiber phase conjugation mirror. The device for laser double-journey amplification comprises a laser, a first polarizing film, a lambada / 2 wave plate, a Faraday magnetic rotation device, a second polarizing film, a laser amplifier, a lambada / 4 wave plate, a first lens, a second lens and multi-stage taper optical fibers, wherein the laser, the first polarizing film, the lambada / 2 wave plate, the Faraday magnetic rotation device, the second polarizing film, the laser amplifier, the lambada / 4 wave plate, the first lens, the second lens and the multi-stage taper optical fibers are sequentially placed in the optical axis direction. The first lens is a convex lens, the second lens is a concave lens, a telescope system is formed by the first lens and the second lens, the focal length f1 of the first lens ranges from 100mm to 1000mm, and the focal length f2 of the second lens ranges from -20mm to -1000mm; the distance D1 between the first lens and the second lens satisfies the equation that D1=f1+f2, wherein the D1 ranges from 20mm to 1000mm. The multi-stage taper optical fiber phase conjugation mirror is high in damage threshold, low in stimulated brillouin scattering threshold, high in reflectivity and wide in dynamic working range, therefore, the conjugation mirror is applied to a high-power laser, and damage is avoided.

Description

technical field [0001] The invention relates to a multi-segment tapered optical fiber phase conjugate mirror and its laser double-pass amplification device and method. Background technique [0002] Stimulated Brillouin scattering (SBS) has been continuously used as a phase conjugate mirror to improve the quality of laser beams since it was proved that it can correct laser wavefront distortion. The dual-pass main oscillation-power amplification laser system (MOPA) with SBS phase conjugate mirror is an effective means to increase the laser output power without sacrificing the quality of the laser beam. [0003] At present, most of the existing high-repetition-frequency and high-energy MOPA systems based on SBS phase conjugate mirrors are based on liquid phase conjugate mirrors or gas phase conjugate mirrors. Although liquid and gas phase conjugate mirrors can have higher SBS reflectivity, and the development is relatively mature, there are various inconveniences in practical ...

AI Technical Summary

Problems solved by technology

Although there are also tapered fiber phase conjugate devices used in high repetition rate and high power laser systems, the dynamic range of this device is small, and it is difficult to be used in practical laser systems

The invention adopts a device and method of a multi-segment tapered fiber phase conjugate mirror, which overcomes the shortcomings of the common tapered fiber phase conjugate device, such as small dynamic range and easy damage to the end face, and has high laser reflectivity at the same time

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