Hermetically sealed diffraction optical element and production method thereof

摘要

The present invention provides a diffraction optical element comprising a first optical member having a first diffraction grating, a second optical member having a second diffraction grating, wherein the first and second optical members are stacked so that the first and second diffraction gratings face each other inside the stacked members and so that a space is formed between the diffraction gratings, and a sealing member for hermetically sealing the space between the diffraction gratings.