| 摘要 |
PURPOSE:To enable the use even at a place of a plenty of electric noise and a high temperature and radiation atmosphere by detecting reflected lights on a medium whose refractive index varies due to temperature after light enters an optical fiber. CONSTITUTION:A light source 11 modulated by a pulse from a pulse generator 12 and emits an optical pulse. The optical pulse enters one end of an optical fiber 14 through a directivity coupler 13 and propagates to the side of a thermosensitive medium 15. The core of the fiber 14 is different in the refractive index from the medium 15, the pulse is reflected on the contact surface with the medium 15 and propagates to the side of the light source 11 through the fiber 14. The reflected lights are separated from the incident light with the coupler 13 and reaches the detector section 16, where the incident optical pulse is converted into an electrical signal with a photo detector such as abalanche photo diode and displayed with an oscilloscope or the like. A pulse for synchronization is applied to the detector section 16 from the generator 12. |
