MANUFACTURE OF DIFFRACTION GRATING

摘要

PURPOSE:To obtain a replica diffraction grating which has good surface accuracy and permits satisfactory baking by heating a matrix diffraction grating and a replica base plate which are brought into press contact with each other by a heat resistant adhesive agent layer up to the curing temp. of the adhesive agent layer at the heating rate at which the replica base plate is kept free from thermal strain. CONSTITUTION:An extremely thin oil film as a release agent and a thin Al film 3 forming a replica surface are vacuum-deposited on the surface of a matrix produced by depositing a thin Al film 2 by evaporation on a glass substrate 1 and forming many parallel grooves thereon and a glass substrate 5 is transferred via an uncured heat resistant adhesive agent layer 4 over the entire surface onto the film 3. The layer 4 is then heated to cure for one hour in a thermostatic chamber at the internal temp. thereof increased gradually up to 120 deg.C at 1 deg.C rate in about one minute so as to avoid generation of thermal strain in the substrates 1 and 5. When the substrate 5 is released from the matrix surface after the curing, the film 3 transfers onto the substrate 5 and a replica is manufactured. The resulted replica has the heat resistance up to about 200 deg.C while maintaining the flatness of the same high accuracy as that of the matrix.