Mid-infrared laser amplitude limiter based on backward stimulated Brillouin scattering of arsenic selenide optical fiber

Abstract

The invention provides a mid-infrared laser amplitude limiter based on backward stimulated Brillouin scattering of an arsenic selenide optical fiber. The amplitude limiter is formed by sequentially arranging an optical beam shrinking system, the arsenic selenide optical fiber and an optical beam expanding system, a light beam emitted by the optical beam shrinking system passes through the arsenic selenide optical fiber and then is emitted from the optical beam expanding system, the arsenic selenide optical fiber has higher weak light transmittance, weaker incident laser enters the arsenic selenide optical fiber through the light beam shrinking system, the optical power density of the light cannot reach the threshold value of backward stimulated Brillouin scattering generated by the optical fiber, so that the light can be normally transmitted forwards, and high-transmittance transmission of the weak light is achieved. Along with the increase of the power density of the incident light, the power density of the light reaches or exceeds the threshold value of backward stimulated Brillouin scattering of the optical fiber, and a great part of energy of the incident light is transferred to the backward Stokes light to be scattered back. According to the invention, the high transmission of weak light and high attenuation of strong light are realized for 3-5 [mu] m mid-infrared wide-spectrum laser, and a non-linear amplitude limiting effect of the mid-infrared laser is effectively achieved.

Description

technical field [0001] The invention relates to the fields of nonlinear fiber optics, guided wave optics, infrared optics, etc., and specifically relates to a mid-infrared laser limiter device based on arsenic selenide optical fiber backstimulated Brillouin scattering, which can be applied to require weak light and high transmission Non-linear laser limiting occasions with strong light and high attenuation rate. Background technique [0002] As an atmospheric communication window, the mid-infrared band has important application value and broad prospects in many fields such as industry, medical treatment, communication and military affairs. With the development of detection technology in the mid-infrared band, infrared imaging seekers and infrared imaging detectors play an important role in many applications due to their high sensitivity and long detection distance. Strong laser is an important means of interfering with infrared imaging detection. Through mid-infrared laser ...

AI Technical Summary

Problems solved by technology

Typical phase change materials such as VO 2 However, because the phase transition needs to absorb a certain amount of light energy to reach the temperature required for the phase transition, it often does not have a limiting effect on short pulse lasers with low repetition rates.

[0004] The existing infrared laser protective film design belongs to the category of linear laser limiting, and has a high transmittance in the mid-infrared 3~5μm band. This method cannot effectively prevent the interference and damage of 3~5μm strong laser

There are several phase transition based VO 2 Infrared laser protection, high phase transition temperature, long response time, low laser damage threshold, the photodetector may have been damaged before the phase transition

In addition, the existing protection methods are difficult to achieve high weak light transmittance in the 3~5μm mid-infrared wide spectrum, and at the same time have the ability to attenuate strong laser light

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