| 摘要 |
PURPOSE:For considerably reducing lock-in range in width, to insert a pin hole for limiting the diameter of laser beam in the light path in a ring oscillator. CONSTITUTION:A ring laser is made of reflections 1 - 3 and a laser tube 4 to generate laser beams 5 and 6. A pin hole plate 12 is inserted on the side where the laser beam 13 of said laser pipe 4 has a larger diameter so that the diameter of said laser beam 13 is not limited by the thin pipe end 10 of said laser pipe 4 but limited by said pin hole plate 12. The both sides of said pin hole plate 12 is coated with the black paint having a superior beam absorption factor or treated to blacken so that no beam is diffused backward from the vicinity of hole. Thereby, the diameter of the said layer beam 13 at the thin pipe end 10 of said laser pipe 4 is made much smaller than the inner diameter of said thin pipe 4. Therefore, the backward diffusion of beam from the thin pipe end 10 of said laser pipe 4 can be decreased, lock-in range can be considerably decreased in width, and a laser gyroscope can be improved in measurement accuracy. |
