Symmetric chromatic separated gratings

Abstract

The present invention relates to a kind of symmetric type color separating grating. Each cycle of the grating includes three steps of phase, which is characterized in that it has a center symmetric configuration with the lowest notch in each cycle at the center of the cycle. The depth of these three steps of phase is h1=h2=lambda / n-1, the sums of the width of each step of phase are equal: wl1+wl2=w21+w22=w3, and all parts of each step are equal: wl1+wl2=w21=w22=d / 6, wherein * is wavelength of incident base frequency, d is cycle of the grating, n is refractive index of the material of the substrate. The color separating grating of the invention can solve effectively the remaining problems of the light with the base frequency and double frequency resulting from the error of alignment of the module plate.

Description

technical field

[0001] The invention relates to a color separation grating for separating triple frequency light from fundamental frequency light and double frequency light, especially a symmetrical color separation grating manufactured by binary optical technology, which can eliminate overlay templates Inter-alignment error, improve yield, reduce cost, and facilitate manufacturing. Background technique

[0002] In many applications such as laser processing, cutting, cleaning, and laser material modification, we often need tripled light for optical experiments, because shorter wavelength lasers interact better with matter. In fact, due to reasons such as laser triple frequency conversion efficiency, the fundamental frequency (ω) light, double frequency (2ω) light, and triple frequency (3ω) light are all mixed in the optical path. We hope that the required frequency (3ω) The light can be kept running in the optical path, and other unwanted frequency light can be filtered out...

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