| 摘要 |
An optical-fiber breakage detection system continuously monitors the integrity of a laser-guiding fiber, whether the laser itself is on or off. If an interruption is detected, the system may cut off, lock out, or reduce laser power, as appropriate. An optical element such as a beamsplitter is used to introduce an optical test signal into one end of the fiber so that the signal is carried by the fiber to the other end where the test signal is detected and employed to perform a desired function. In the preferred embodiment, the test signal is modulated and encoded to minimize false shut-downs. The source of the optical test signal is preferably disposed at the first location and carried by a second fiber to the remote location, enabling the test signal to be compared directly to the test signal as detected. The system is useful in a variety of applications, including systems of the type wherein the laser energy is used to induce a spectral emission from a sample disposed at the remote location, as in Raman or fluorescence detection. In such a configuration one or more additional fibers may be used to carry the spectral emission back to the first location, for example, for analysis purposes.
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