| 摘要 |
PURPOSE:To prevent the influence of a dark current and a DC drift even if the rotation angular speed is constant, by using an optical switch to switch alternately directions of the incident light to an optical fiber ring and obtaining the quantity of phase shift on a basis of the difference of the intensity of detected light between respective cases. CONSTITUTION:The light from a light source 1 is divided into two by a translucent mirror 7, and one divided light is incident to a photodetector 6 as a reference light through a reflective mirror 8 and a translucent mirror 9, and the other is incident to an optical fiber ring 5 through an optical switch 10. This light becomes a counterclockwise light 4 when the optical switch is turned on as shown in figure by (a), and the light becomes a clockwise light 3 when the optical switch is turned off as shown in figure by (b), and thus, the light is transmitted through the ring 5 and is synthesized with the reference light by the photodetector. Though the quantity of phase shift between the reference light and the light transmitted through the ring includes rotation angular speed information, the optical switch is switched alternately to measure the difference of the intensity of detected light between respective cases of detect the quantity of phase shift in AC. |
