Patent ID: 6587190
Filing Date: 2003-07-01
Classification: G01M

Abstract:
A system for measuring a chromatic dispersion in an optical fiber, comprising:a multimode Fabry-Perot laser diode adapted to generate optical pulses by gain switching; a highly dispersive optical fiber adapted to allow the optical pulses to pass therethrough and to separate respective optical pulses corresponding to each mode of the multimode laser diode to generate a time domain reference signal made up of a pulse train that includes a plurality of optical pulses separated by wavelength; a test optical fiber adapted to allow each of said optical pulses in said reference signal to pass therethrough and to vary a spacing of the optical pulses in the reference signal due to a chromatic dispersion characteristic of the test optical fiber; a high speed photodetector adapted to detect a variation in spacing of the optical pulses in said reference signal relative to the respective spacing of the optical pulses passing through said test optical fiber, and to generate electrical signals corresponding to said variation; and an RF spectrum analyzer adapted to measure frequencies of the electrical signals and thereby measure a chromatic dispersion characteristic of the test optical fiber, wherein an optical path of the reference signal is in line with and not separated from an optical path through the test optical fiber.