Patent attributes
An optical device according to an aspect of the invention includes: a plurality of optical elements; a base which supports the plurality of optical elements; and a plurality of element holders which holds the plurality of optical elements and each includes a holder side flow passage for cooling liquid to flow therein, the plurality of element holders holding the plurality of optical elements to connect the plurality of optical elements and the cooling liquid flowing in the holder side flow passage in a heat transferable manner. The base includes a plurality of plate members which are layered on each other to form at least one base side flow passage for the cooling liquid to flow therein. The plurality of element holders and the base can be connected to each other, so that the holder side flow passage and the at least one base side flow passage communicate with each other.
