A method and device for testing the nonlinear effect i*l value of an optical element

Abstract

The invention discloses a method and device for testing the nonlinear effect I*L value of an optical element. The method focuses a laser beam in the body of the optical element by using a lens with a focal length smaller than the thickness of the optical element and adjusting the position of the optical element. At the same time, the laser energy density of the laser irradiated on the incident surface of the optical element to be tested is adjusted to be less than the laser damage threshold of the incident surface of the optical element to be tested, and the disturbance-induced small-scale self-focusing effect under non-focusing conditions is simulated, which solves the traditional In the test method, since the damage of the incident surface of the optical element occurs before the self-focusing filament damage in the body, the problems of laser loss such as scattering and defect absorption caused by the damage of the incident surface of the optical element not only improve the test accuracy, but also provide for the optical element in the test method. Safe use in high-power laser installations and improving the resistance of materials to laser damage provide additional assistance.

Description

technical field [0001] The invention relates to the technical field of optical detection, in particular to a method and device for testing the nonlinear effect I*L value of an optical element. Background technique [0002] In laser inertial confinement fusion, the filamentary damage of optical elements caused by the nonlinear small-scale self-focusing effect has become a bottleneck problem that limits the laser output power and increases the risk and cost of device operation. The small-scale self-focusing effect is due to the local instability of the beam caused by the phase and amplitude modulation of the laser during transmission in the nonlinear medium, which splits the beam into high-intensity filaments to induce material damage. The I*L value of a nonlinear medium is one of the important bases for evaluating its small-scale self-focusing effect. I is the peak power density of the incident laser, and L is the distance from the initiation point of filamentation damage to ...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the present invention provides a method and device for testing the nonlinear effect I*L value of an optical element. By adopting the method of focusing the laser beam in the optical element body, the disturbance-induced small-scale self-improvement under non-focusing conditions is simulated. The focus effect solves the problem of laser loss such as scattering and defect absorption caused by the damage of the incident surface of the optical element in the traditional test method because the damage of the incident surface of the optical element occurs before the self-focusing filament damage in the body, which not only improves the test accuracy , and also provide more help for the safe use of optical components in high-power laser devices and to improve the ability of materials to resist laser damage

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