PREPARATION OF OPTICAL RESIN FILM

摘要

PURPOSE: To provide a preparing method of an optical resin film applicable for evening a substrate used for a waveguide type optical element, etc. CONSTITUTION: This preparing method includes a process to dispose a thermoplastic resin 64 which is not decomposed but has presents fluidity at temp. higher than heat distortion temp. on a flat part 62 and a recessed part of the substrate 61 having the recessed part which is nearly surrounded by this flat part 62, a process to dispose a flat plate 65 on the thermoplastic resin 64 so as to reach the flat part 62 of the substrate 61 to heat the resin 64 and the process to remove flat plate 65. A smoothness of the flat plate 65 is less than 1/10 of the wave length to be used.