| 摘要 |
PURPOSE:To realize size reduction by propagation coherent light beams in two independent coils wound around the same drum and detecting rotating speeds, correcting the difference in optical propagation characteristics between the optical fibers, and adjusting the optical path difference between detection systems. CONSTITUTION:A beam emitted from, for example, a laser diode LD is split by a beam splitter BS and made incident to end parts 4 and 5 of the optical fibers through objective lenses LD. The incident beams turn around the same drum 3 with a radius (a) clockwise and counterclockwise by the same number of turns and emitted from end parts 4 and 5 of the optical fibers. The beams emitted from the output terminals 4 and 5 are collimated through lenses L and split and multiplexed by a beam splitter BS. Then, output beams are made incident to photodetectors D1 and D2, whose outputs are amplified differentially by an operational amplifier OP. |
