Extended distance range optical low-coherence reflectometer

摘要

An improved optical low-coherence reflectometer is disclosed for use in measuring the strength and location of optical reflections. The invention utilizes a reference signal comprising multiple copies of a light signal to increase the range of distance measurements over which the reflectometer operates. Each copy of the light signal is delayed by a different amount. Embodiments in which the copies are generated with a ring resonator, a Fabry-Perot cavity, and multiple fiber delay lines are described.