Double-layer offset grating for 1×2 beam splitting of normal-incidence quartz with tm polarization

Abstract

The invention relates to a TM (Transverse Magnetic)-polarized vertical-incidence quartz 1*2 beam-splitting dual-layer staggered optical grating, which is formed by an upper optical grating and a lower optical grating which are same in structural parameters and are relatively staggered. The upper optical grating and the lower optical grating are tightly coupled without forming a gap. The period of the upper optical grating and the lower optical grating is 1326-1323 nanometers, the ridge width is 609-612 nanometers, the offset is 177-179 nanometers and the total optical grating depth is 2016-2018 nanometers. When TM-polarized light is vertically incident, the total diffraction efficiency of transmitted light can be higher than 96 percent and the uniformity of a beam splitter is better than 3.10 percent. The TM-polarized vertical-incidence quartz 1*2 beam-splitting dual-layer staggered optical grating provided by the invention is manufactured by using an electron beam direct-writing device in combination with a microelectronic deep etching process, and has the advantages that the materials are convenient to obtain, the manufacturing cost is low, the mass production can be realized and the practical prospect is important.

Description

technical field [0001] The invention relates to a transmission quartz grating, in particular to a double-layer staggered grating for 1064 nanometer wavelength TM polarization and vertical incident quartz 1×2 beam splitting. Background technique [0002] Beam splitters are the basic components in optical systems and have important applications in optical systems. It plays an irreplaceable role in optical communication, optical information processing, optical computing, holography and other systems. The traditional beam splitter is expensive due to the complicated process, and the laser damage threshold is not high. Fused silica is an ideal grating material, which has high optical quality: stable performance, high damage threshold, and high-efficiency beam-splitting grating designed and manufactured from fused silica, with simple structure and simple process flow. Therefore, etching high-density deep-etched fused silica gratings has broad application prospects as a new type ...

AI Technical Summary

Problems solved by technology

But as far as we know, so far, no one has given the design of a quartz 1×2 beam-splitting double-layer offset grating on a fused silica substrate for the commonly used wavelength of 1064 nanometers.

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