Optical step frequency reflectometer

The carrier generated by a solid-state laser can be frequency shifted by a significant amount. This fact was exploited to implement a high-resolution optical-fiber fault locator. A resolution of 4 mm was achieved. Compared to the resolution of a frequency-domain reflectometer that shifts the frequency of the AM modulation of the light, the proposed fault locator has a resolution about 1000 times better. The potential of developing the proposed reflectometer into an ultrahigh-resolution integrated optics fault locator is also discussed. UFaipxr