| 摘要 |
PURPOSE:To decrease the fluctuation of interence fringes due to temperature change or vibration, in the interferometer including a reference light path and a sample light path, by constituting both light paths by solid mediums whose change in refractive index due to the temperature change is small. CONSTITUTION:The incident luminous flux of a Mach-Zehnder interferometer is divided into the reference light 2 and the sample light 3 by a semitransparent mirror 6-1. The reference light is inputted to a semi-transparent mirror 6-3 through a semi-transparent mirror 6-2 and a reflecting mirror 5 for changing the light path length. The sample light passes a sample 4 and reaches the semi- transparent mirror 6-3. Both light beams are synthesized and enter an interference fringe detector 7. In this way, since the solid mediums 8-1, 8-2, 8-3, and 8-4 whose change in the refractive index due to the temperature change is small are arranged in two light paths, the fluctuation in the interference frings due to the temperature change is decreased in comparison with the propagation in the air. The device also has high vibration resistance. A single mode optical fiber can be used as a solid medium. |
