| 摘要 |
PURPOSE:To obtain the constitution of a less-loss device by interposing an ultrasonic-wave polarizer between a laser light source and the input terminal of an optical fiber and by separating incident light and reflected light reflected in the fiber and emitted. CONSTITUTION:Pulses from a pulse generator 11 are supplied to a Q switch driver 23 through a delay circuit 22. This driver 23 drives a YAG laser 24, and between its output and an objective lens 14, a ultrasonic-wave polarizing element 27 is arranged. The polarizing element 27 is put in operation for an adequate time through a dedicated driver 28 controlled by a pulse control circuit 29 to separate and extract laser scattering light, arriving from an optical fiber 15, from an incident optical path, thereby sending it to a photodetector 16. Its output is passed through an amplifier 17, a box Kerr integrator 18, and a logarithmic amplifier 19 to obtain a drawing on an X-Y plotter 21. Thus, the loss accompanying the separation of the incident light and emitted light is reduced and the device has increased diagnostic distance. |
