| 摘要 |
PURPOSE:To stabilize the optical path of an optical beam by constructing an optical element which separates and reflects the injected optical beam and the supporting member thereof, rotating means whose thermal contact with the supporting member is large and which allows the supporting member to rotate at a predetermined angle as the temperature changes. CONSTITUTION:Optical elements 3, 4 are inserted into a supporting member 2, the thermal contact between the optical elements 3, 4 and the supporting member 2 being made large. An optical beam is injected onto such optical elements 3, 4, separated and reflected, only the optical beam of a specific wavelength is returned along the original optical path. When the temperatures of the optical elements 3, 4 increase by the injection of the optical beam, changes in the temperatures are transferred to a rotating means 27 so that the supporting member 2 may be rotated at a predetermined angle in a direction offsetting the change in the optical beam path, whereby any changes in the temperatures of the optical elements 3, 4 allow the optical path of the diffracted optical beam having the specific wavelength to be stable along the original path after a predetermined time. According to the constitution, the optical path of the optical beam can quickly be stabilized. |
