| 摘要 |
Above a Peltier element disposed on a bottom of a case, bases that are platy members of two or more layers and have different expansion coefficients from each other are stacked. At least on a partial region of the base serving as an uppermost layer, a suppression member having an expansion coefficient different from that of the base serving as the uppermost layer is further provided. An optical element is disposed on the base and/or the suppression member. Even when a warp is likely to occur in the Peltier element, a stacked-plate structure of the base, the base, and the suppression member suppresses an occurrence of such a warp, whereby warps hardly occur in the base and the suppression member, and a shift hardly occurs in an optical axis between a beam splitter and an etalon. |
