摘要 |
A method of fabricating a diffraction grating by utilizing a single substrate comprises the steps of forming a photosensitive material layer and a light transmission reducing film having a predetermined pattern integrally with each other on the substrate, exposing the photosensitive material layer by exposure irradiation light via the light transmission reducing film, and developing the photosensitive material layer after exposure. It is composed so that the direction of exposure and the direction of development are opposite to each other. It is possible to fabricate a diffraction grating in which each grating is formed on a predetermined substrate at a predetermined pitch and a root portion in a cross-section of each diffraction grating is constricted. In this way, it is possible to reduce or eliminate interfaces, so that the generation of noise light can be effectively suppressed and a diffraction grating having a high diffraction efficiency can be made.
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