| 摘要 |
<p>A sensing element (150) is exposed into an environmental effect by modulating a light signal (128) and determining a path lenght as a function of the modulation signal. A detector (106, 108) detects light intensity. An electronics processor (126) receives the detector output and produces a modulation signal (128) for the light. The processor (126) further produces an output signal indicative of the environmental effect as a function of the modulating signal. The length of the optical path can be readily determined as a function of a 'proper' modulation frequency that produces a relatively constant output at the detector (108). Fiber optics and integrated optics are used. Used as LIDAR or for strain, temperature, chemical or as a fiber break detector.</p> |
