A preparation method of multilayer dielectric film rectangular diffraction grating with high damage threshold

Abstract

The invention relates to a method for preparing a multilayer dielectric film rectangular diffraction grating with a high damage threshold, comprising the following steps: plating a multilayer dielectric film; etching on a Si sheet to prepare a rectangular Si grating master plate opposite to the target rectangular grating structure; Using a soft material template to transfer the pattern of a rectangular Si grating master; using ultraviolet nanosoft imprinting technology, a photoresist grating opposite to the target rectangular grating structure is formed on a multilayer dielectric film through a soft material template; A thin film constituting the grating is deposited on the photoresist grating; excess thin film and photoresist are removed to form a required rectangular grating structure. Compared with the prior art, the present invention overcomes the trapezoidal grating structure caused by the traditional grating etching process, solves the aggravation of the electric field enhancement effect in the grating caused by the deviation of the trapezoidal grating structure, and avoids the ion beam bombardment on the dielectric grating during the etching process. Absorption defects are generated on the sidewall, which increases the laser damage threshold of the dielectric multilayer diffraction grating.

Description

technical field [0001] The invention belongs to the field of manufacturing micro-nano optical devices, and relates to a method for preparing a grating, in particular to a method for preparing a multilayer dielectric film rectangular diffraction grating with a high damage threshold. Background technique [0002] The development of ultra-intense and ultra-short pulse lasers based on chirped pulse amplification technology provides a basis for the study of matter interaction under extreme physical conditions, which can promote the development and transformation of life sciences, nuclear physics, high-energy physics, and astrophysics. . Diffraction grating is the core component of chirped pulse amplification technology. At present, compared with traditional metal diffraction grating, dielectric multilayer film diffraction grating makes up for the disadvantages of metal materials in absorbing and resisting laser damage, and gradually occupies an important position in high-energy l...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a high damage threshold multi-layer dielectric film rectangular diffraction grating preparation method to overcome the difficulties and shortcomings of the traditional grating preparation method for the preparation of rectangular gratings with high damage thresholds, which can reduce the shape deviation caused by the rectangular structure of the grating. The electric field is enhanced, and the absorption defect caused by the bombardment of the ion beam on the side wall of the dielectric grating (where the electric field enhancement peak is located) in the traditional process is avoided, thereby improving the damage threshold of the multilayer dielectric film diffraction grating

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