MANUFACTURE OF HOLOGRAM DIFFRACTION GRATING

PURPOSE:To manufacture stably a diffraction grating by hologram recording with photoresists by coating a substrate with a photoresist, curing the photoresist to form an underlayer, coating the underlayer with a photoresist, and recording hologram. CONSTITUTION:A substrate 23 is coated with a photoresist, this photoresist is cured to such a degree that stripping is practically prevented, and the resulting underlayer is coated with a photoresist to form a recording layer 22. Laser light from a laser light source 11 is split with a beam splitter 13, converged with objective lenses 17, 17' through mirrors 15, 15', converted into a pencil of parallel rays with a collimating lens, and irradiated on the recording layer 22 in a superimposed state. Interference fringes of the pencil of parallel rays are recorded on the layer 22, and the layer 22 is developed to form a diffraction grating.