| 摘要 |
PURPOSE:To provide a beam splitter which never deteriorates in the surface precision of a beam splitter substrate. CONSTITUTION:Three plane plates 23 are fitted onto the bottom surface 228 of the recessed place 22 of a 1st holder 21 with an epoxy adhesive 27. The unadhered surfaces of the respective plane plates are adjusted so that they are present on optically the same plane. The beam splitter 24, a spacer 25, and a compensating substrate 26 are inserted into and arranged in the recessed plate 22 in this order and the opening side is covered with a 2nd holder 28. Then a pressure member 29 is made to abut on the top surface of the compensating substrate 26 and energized toward the bottom surface side with the elastic force of a coil spring 31. Consequently, the respective members are sandwiched between the 1st and 2nd holders. Further, the plane plates, spacer, and pressure member are coaxially arranged. Consequently, the substrate is uniformly loaded and does not deform, so that the surface precision does not deteriorate. |
