| 摘要 |
PURPOSE:To easily and accurately measure the quantity of strain and a place where the strain is induced by making a monochromatic light pulse incident on the optical fiber to be measured from its one end and observing Brillouin scattered light which is scattered backward. CONSTITUTION:Pump light is made incident on the optical fiber 1 to be measured from its one end through a lens 11. This pump light is inputted to a modulator 81 through a laser diode 2 and an isolator 14 and modulated according to pulses from a pulse generator 82. The pump light propagated in this optical fiber 1 generates the Brillouin scattered light which travels in the opposite direction from the pump light. This Brillouin scattered light is extremely weak, so probe light is made incident on the optical fiber 1 from the other end. The probe light is made incident on the optical fiber 1 through a laser diode 3, an isolator 15, and a lens 12. Further, the output of a light receiver 7 is inputted to a box Kerr integrator 84 and integrated based upon the signal of the pulse generator 82 which is passed through a delay circuit 83 and the output is processed by a signal processing circuit 85. |
