5×5 Lattice Diffraction Grating Based on Two Single Ridge Gratings

Abstract

Disclosed is a 5x5 lattice diffraction grating based on two single ridge gratings. The 5x5 lattice diffraction grating consists of two one-dimensional single ridge gratings which are arranged in an up-to-down manner to be one body, and the grating periodic direction of the upper grating is perpendicular to the grating periodic direction of the lower grating. The grating periods are 1.309 micrometers. The duty ratio of the upper grating is 0.576 to 0.611, and the etching depth of the upper grating is 1.008 to 1.072 micrometers. The duty ratio of the lower grating is 0.5, and the etching depth of the lower grating is 0.873 to 0.897 micrometers. When TM polarized light is incident perpendicularly, a 5x5 lattice is generated with the total diffraction angle being 80 degree x 80 degree, the total diffraction efficiency greater than 93% and the uniformity better than 8%. The 5x5 lattice diffraction grating is processed by the combination of an electron beam direct writing device and a microelectronic deep etching process. The material taking is convenient, the cost is low, and the 5x5 lattice diffraction grating can be produced in batches and has important practical prospects.

Description

technical field [0001] The invention relates to a lattice diffraction element, especially a 5×5 lattice diffraction grating based on two single-ridge gratings for TM polarization at a wavelength of 633 nanometers. Background technique [0002] Diffraction gratings are the basic components of optical systems and have important applications in optical systems. They can be used as spectrometer beam splitters, beam splitters, wavelength selectors, etc., and have important applications in optical communication, optical information processing, optical computing, holography and other systems. irreplaceable role. The most commonly used diffraction grating as a lattice diffraction element is the Damman grating. The Damman grating is designed based on the scalar diffraction theory. Its diffraction angle is small, the remaining diffraction orders are many, and the total diffraction efficiency is not high. The Damman grating beam splitter can be used as a 1×3 beam splitter, and the hig...

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Problems solved by technology

The two-dimensional grating etched in the same dimension is difficult to manufacture and design, and the uniformity of beam splitting and diffraction efficiency cannot be guaranteed. Therefore, we propose a lattice diffraction grating based on two single-ridge gratings, which is easy to manufacture And the diffraction efficiency is high, and the beam splitting uniformity is good

As far as we know, so far, no one has given a high-density deep-etched 5×5 lattice diffraction grating design based on vector diffraction theory for a wavelength of 633 nanometers

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