| 摘要 |
PURPOSE:To quickly detect liquid with high reliability for a long distance by forming a clad enclosing a core of a plastic material and offcentering the core from the center of the clad so that the thinnest part is formed to <=10mum thickness. CONSTITUTION:This optical fiber for detecting liquid has basically the structure of a step index type waveguide consisting of the core 1 and the clad 2 enclosing the core; however, the core 1 and the clad 2 are not concentrical with each other and the core 1 is offcentered from the clad 2 so that the thinnest part 3 of the clad 2 is formed to <=10mum. An increase in loss arises when the liquid contacts such optical fiber for detecting liquid and the penetrating liquid arrives at the boundary face with the core. The liquid is, therefore, detected extremely quickly with the high reliability for a long distance if light pulses are entered to the fiber and the backward scattered light is detected. The detection of the position where the fiber is immersed in the liquid is detectable as well. |
