Dielectric-coating structure reflecting mirror used for chirp pulse amplification optical spectrum shaping

Abstract

The present invention relates to a chirp pulse amplifying spectrum shaping dielectric film structure reflector, which comprises a transparent substrate, a high reflectance film system, an anaglyph structure and an external protective layer. Wherein, the high reflectance film system is composed of a plurality of staggered dielectric films. A high reflectance film layer and a lower reflectance film layer of the high reflectance film closely contact the anaglyph structure. The anaglyph structure can take a plurality of shapes, such as a micro-lens high transparency film system structure, an air dielectric structure, a glass anaglyph structure or other transparent dielectric structures, including semiconductor structures. As a high-power laser chirp pulse with a plane wave structure vertically casts onto the reflector, the laser passes through the high reflectance film system and the anaglyph structure and all residual lasers are reflected to back of the reflector through the transparent substrate. Reflex intensity distribution is modulated to a needed spectrum distribution structure. The reflector of the present invention can be inserted into any place of an amplifier link and improve capacity to distinguish shaping spectrum chromatic dispersion to a certain level. Scope modulation exceeds 60% without changing phase position, thus adapting to PW devices.

Description

technical field [0001] The invention relates to a dielectric film reflector, in particular to a novel reflector with a multi-layer dielectric film structure used for high-power laser chirped pulse amplification for modulating spectrum shaping. Background technique [0002] In the research of ICF inertial confinement nuclear fusion, the physical experiment has very strict requirements on the pulse parameters of the high-power laser output, and in the design of the Shenguang II kilojoule petawatt high-power amplification system, the problem that people care about is to modulate the corresponding pulse Spatio-temporal characteristics and spectral characteristics, in which the modulated spectral shaping of the chirped pulse is mainly to eliminate the influence of the gain narrowing effect and the gain saturation effect in the chirped pulse amplification as much as possible. Such as literature: [0003] Zhang Bin, Lu Baida, "The Inverse Problem of Multistage and Multipass Pulse ...

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Problems solved by technology

[0004] It can also be seen from the above documents that the international general method mainly has the following shortcomings: 1. Adding a tunable air-gap etalon to the regenerative amplifier to adjust the spectrum, but this adjustment is more complicated, and in the Shenguang II kilojoule petawatt high-power amplification system In the optical parametric chirped pulse amplification technique (OPCPA) is used to replace the regenerative amplifier, so it is not applicable

But this approach is not practical for systems beyond the terawatt level

3. The long-wavelength injection method makes the gain narrowing benefit to compensate for the saturation effect, but this method also affects the stability of the system

However, the color resolution of AOPDF can only be used for broadband chirped pulse systems such as titanium sapphire, and is not suitable for neodymium glass systems.

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