PURPOSE: To manufacture a diffraction grating easily and inexpensively by etching a silicon single crystal plate to form a diffraction grating pattern and obtaining a metal mold having a reversed pattern by an electroforming method using the grating pattern.
CONSTITUTION: A plurality of linear masks 13 for etching are arranged on smooth surface 11 of silicon single crystal substrate 12, and substrate 12 is etched to form diffraction grating pattern 15 having grooves 14 with a saw-toothed section. Electrically conductive support 16 is attached to substrate 12, and surface 11 is coated with electrically conductive layer 20 by vapor deposition. Substrate 12 is then dipped in vessel 22 filled with electrolytic soln. 21 to form metal layer 25 by electroforming, and layer 25 is peeled from surface 11 of substrate 12 and worked at the periphery to obtain metal mold M with reversed pattern 27 formed. Mold M is combined with other metal mold (not shown) to manufacture a diffraction grating.
KUROKAWA TAKASHI
KATAYAMA YUUZOU
FUJII YOUJI
