A Broadband High Reflection High Threshold Low Dispersion Mirror and Its Design Method

Abstract

The present invention proposes a broadband high-reflection high-threshold low-dispersion mirror and its design method. The structure of the broadband high-reflection high-threshold low-dispersion mirror is G / M / C / A, wherein G represents the base layer, M represents the metal film layer, and C Represents a dielectric film layer, A represents an air layer, and the dielectric film layer is composed of a single layer of dielectric film material or alternately stacked with a low refractive index dielectric film material and a high refractive index dielectric film material. The invention utilizes the wide reflection bandwidth and excellent dispersion characteristics of the metal, and combines the characteristics of high reflectivity and strong laser damage resistance of the dielectric film. By adjusting the number and thickness of the dielectric film, the dispersion and reflectance within different bandwidths can be regulated, thereby A broadband high-reflection high-threshold low-dispersion mirror for pulse transmission in ultrafast laser systems is designed.

Description

A broadband, high-reflection, high-threshold, low-dispersion mirror and its design method technical field The invention belongs to the ultrafast laser thin film field, especially relate to the broadband low dispersion in the femtosecond pulse laser system Mirror is a kind of mirror used for optical path transmission of femtosecond laser system. Background technique Ultra-intense ultra-short laser is the highest known light intensity (W / cm 2 ) light source that can create unprecedented Ultra-strong electromagnetic fields, ultra-high energy densities, and ultra-fast time scales combine extreme physical conditions, in attosecond science, ultra-fast chemistry, Materials science, nuclear physics and nuclear medicine, high energy physics and other fields have significant application value, in scientific research, national defense and civil use, etc. More and more show its unique charm. In recent years, femtoseconds (ie fs, 10 ‑15 s) terawatts (i.e. TW, 10 12 W...

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Problems solved by technology

At present, the international literature reports on these three kinds of low dispersion mirrors generally focus on the damage threshold test of low dispersion mirrors, and do not give a systematic low dispersion mirror design method, and the wavelength band is relatively single

[0005] Traditional metal mirrors have a wide reflection bandwidth, but their reflectivity is not high, and their damage threshold is low due to the strong absorption properties of metals

Although the all-dielectric film mirror has high reflectivity and high resistance to laser damage, its reflection bandwidth is relatively narrow, which is far from meeting the requirements of broadband high reflection transmission in femtosecond laser systems

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