Distributed Chromatic Dispersion Compensation Method Based on Mismatch Factor for High Resolution OFDR

Optical frequency domain reflectometry (OFDR) can provide a powerful tool for fiber components and devices diagnosis and characterization. However, apart from laser source phase noise, the impact of the chromatic dispersion effect on the system is severely increased with the measurement length and laser tunable range. We propose a distributed chromatic dispersion compensation method for the device under the test (DUT) with complex structures containing different dispersive media connections in OFDR. Based on the mismatch factor (which is related to the difference in dispersion coefficient between the reference fiber and DUT), chromatic dispersion errors in the signal from different dispersion mediums can be compensated segment by segment by constructing the dispersion phase error signal. The compensation method is evaluated by experiments on DUT with multiple material dispersion (including reduced-cladding single-mode fiber (RC SMF) and dispersion compensation fiber (DCF)) and various measurement distances. Finally, we experimentally analyzed the internal reflection of a multifunctional integrated optical chip (MFIOC). Sweeping the laser source by 160 nm, the input coupling, output coupling, beam splitting, and defect points are individually revealed with a high resolution better than 15 \mum. We believe that this approach enables high-precision quantitative measurements as well as accurate identification and localization of fault diagnosis for optical fibers and devices.