Four-region grating for amplitude/phase dual modulation and manufacturing method of four-region grating

Abstract

The invention discloses a four-region grating for amplitude / phase dual modulation and a manufacturing method of the four-region grating. The four-region grating comprises a substrate which is divided into four regions according to one period in the horizontal direction, wherein four areas are respectively a high substrate layer, a high metal layer, a low substrate layer and a low metal layer in sequence from left to right; metal mask layers are arranged on the upper surfaces of the high metal layer and the low metal layer; heights of the low metal layer and the low substrate layer are different; and the total height of the high metal and the high substrate layer is the same. According to the four-region grating, a substrate is divided into four regions according to one period in the horizontal direction, transverse widths of the four regions are equal, heights of the four regions are different, and the four regions can improve accuracy of light intensity and phase dual control, so diffraction efficiency of 0-level light can be reduced, the energy is concentrated to + / -1 level, and the energy utilization rate is improved; and the signal contrast and the signal-to-noise ratio of systems such as a grating interferometer can be improved.

Description

technical field [0001] The invention belongs to the technical field of diffractive optical elements, and in particular relates to a four-area grating used for amplitude / phase dual modulation and a manufacturing method thereof. Background technique [0002] With the continuous development of high-precision technology, the demand for some unconventional grating devices is increasing. The existing phase modulation gratings mainly have two shortcomings: first, poor control accuracy and poor depth of phase modulation (the efficiency reduction for 0-order light is not enough, and the efficiency improvement for ±1 order is not enough); second, the structure is complex , The steepness of the side wall of the step cannot be accurately controlled, which is not conducive to process curing, so the phase of the grating cannot be accurately controlled. Although it is manufactured with high-precision equipment, the manufacturing process steps can be precisely controlled, but the processin...

AI Technical Summary

Problems solved by technology

The existing phase modulation gratings mainly have two disadvantages: first, poor control accuracy and poor depth of phase modulation (the efficiency reduction for 0-order light is not enough, and the efficiency improvement for ±1 order is not enough); second, the structure is complex , The steepness of the side wall of the step cannot be accurately controlled, which is not conducive to process curing, so the phase of the grating cannot be accurately controlled

Although it is manufactured with high-precision equipment, the manufacturing process steps can be precisely controlled, but the processing cost is very high, which is not conducive to mass production; and the phase modulation grating cannot meet the modulation of light intensity at the same time.

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