| 摘要 |
PURPOSE:To obtain a simple, small-sized gyroscope by using a semiconductor laser which has a diffraction grating formed on an active layer as a light source and composing a ring laser of a single-mode optical fiber without using an optical fiber coupler. CONSTITUTION:Light emitted by the active layer 13 is propagated clockwise and counterclockwise to an optical fiber loop 9 from its upper and lower ends and further travels in the loop plural times through the active layer 13. Simultaneously, part of the active layer propagated light is diffracted by the diffraction grating 14 and exits from the semiconductor laser 10 at right angles to the active layer 13 to the left as shown in a figure. Consequently, when the whole system rotates, the clockwise and counterclockwise propagated light beams in the ring lasers 9 and 10 differ in oscillation frequency by Sagnac effect. Consequently, those light beams interfere with each other and reach a photodetector 4 as a beat signal. The frequency of this beat signal is proportional to the rotary angular speed, so the rotary angular speed given to the system is known.
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