Polarization-independent high-efficiency two-dimensional reflecting Dammann grating for wave band with central wavelength of 1064 nanometers

Abstract

A polarization-independent high-efficiency two-dimensional reflecting Dammann grating for wave band with central wavelength of 1064 nanometers is structurally characterized in that a fused quartz substrate is sequentially coated with an aluminum oxide film, a gold film, an aluminum oxide film and a fused quartz film, the aluminum oxide film between the gold film and the fused quartz film is a connection layer, and a rectangular-groove grating is etched on the fused quartz film layer. The grating cycle is 1,917-1,027 nanometers, the coordinate of a normalized phase mutation point is 0.265-0.275, the grating depth is 730-740 nanometers, and the connection layer is 92-102 nanometers thick. When TE (transverse electric) or TM (transverse magnetic) polarization light of the Dammann grating performs perpendicular incidence, 2*2 beam splitting of the wave band with the central wavelength of 1064 nanometers can be realized, the total diffraction efficiency is larger than 85% basically. The Dammann grating is machined with an optical hologram recording technique or by a laser direct writing device in combination with a microelectronic deep etching process and a film coating technique, materials are convenient to obtain, the manufacturing cost is low, large batch production can be realized, and the Dammann grating has important practical prospect.

Description

technical field [0001] The invention relates to a reflective grating, in particular to a polarization-independent high-efficiency two-dimensional reflective Damman grating in the 1064 nanometer band. Background technique [0002] Grating is the basic element in the optical system, has become a very important optical element in modern optical technology, and plays an important role in scientific research and national economy. The Damman grating is a binary phase grating that can efficiently generate a uniform light intensity lattice at the far field of the Fourier transform of incident monochromatic light. Orthogonal binary phase grating is widely used because of its simple design, mature manufacturing process, and no need for precise registration. Two-dimensional gratings play a very important role in three-dimensional displacement measurement systems and three-dimensional scanning imaging systems. Due to the shortcomings of traditional reflective gratings such as low diff...

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Problems solved by technology

As far as we know, so far, no one has given a two-dimensional polarization-independent high-efficiency reflective Damman grating for the commonly used 1064 nanometer band.

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