| 摘要 |
PROBLEM TO BE SOLVED: To provide an analyzing device which can measure a polarization state of an optical fiber of a long distance. SOLUTION: As an optical pulse sent out from a pulse light source 2 is propagated through an optical fiber 1 to be measured, back scattered light is generated in the optical fiber 1. The back scattered light returns to the incidence end side of the optical fiber 1 to be measured whereon the optical pulse is made incident and led to an optical coupler 4 by an optical circulator 3. The optical coupler 4 divides the back scattered light of the optical fiber 1 sent out from the optical circulator 3 into signal light and monitoring light. An optical detector 5 detects the monitoring light and outputs a signal showing detection of the monitoring light to an optical amplifier 6. The optical amplifier 6 amplifies the signal light from the optical coupler 4 and sends out the signal light after amplification to a polarization analyzer 8. The optical amplifier 6 is so constituted that a gain may become variable and changes the gain in response to the signal from the optical detector 5. COPYRIGHT: (C)2011,JPO&INPIT |
