OPTICAL ELEMENT HAVING MULTIPLE OPTICAL FUNCTIONAL SURFACES, SPECTRAL DEVICE, AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To solve the problem that effect such as peeling and a crack of an optical functional surface occurs due to thermal expansion coefficient difference of material constituting an optical element if temperature difference under use environment of the optical element constituted of a plurality of materials or temperature difference between manufacturing environment and the use environment is large.SOLUTION: An optical element comprises an intermediate layer between a base material and a reflective layer, where the intermediate layer has heat expansion coefficient of the middle of the base material and the reflective layer.SELECTED DRAWING: Figure 1