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

Abstract

The invention relates to a preparation method of a multilayer dielectric film rectangular diffraction grating with a high damage threshold. The preparation method comprises the following steps: plating a multilayer dielectric film; etching on the Si wafer to prepare a rectangular Si grating mother set with a structure opposite to that of the target rectangular grating; transferring the pattern ofthe rectangular Si grating mother set by using a soft material template; forming a photoresist grating with a structure opposite to that of the target rectangular grating on the multilayer dielectricfilm through a soft material template by using an ultraviolet nano soft imprinting technology; depositing a film forming a grating on the photoresist grating by using an atomic layer deposition process; and removing the redundant thin film and the photoresist to form a required rectangular grating structure. Compared with the prior art, the method has the advantages that a trapezoidal grating structure caused by a traditional grating etching process is overcome, the problem that the electric field enhancement effect in the grating is intensified due to trapezoidal grating structure deviation is solved, the absorption defect caused by ion beam bombardment on the side wall of the dielectric grating in the etching process is avoided, and the laser damage threshold of the dielectric multilayerfilm diffraction grating is improved.

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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