High-reffectance-resolution optical reffectometry with synthesis of optical coherence function

A novel high-reflectance-resolution optical reflectometry technique with the synthesis of the optical coherence function for the diagnosis of fiber optic assembly modules is proposed. In this new scheme, the optical frequency of a light source is modulated doubly: one in a sinusoidal wave to synthesize the coherence function into a peak at an arbitrary position within the region under test for a distributed reflection/scattering measurement and the other in a linear sweep to perform the wavelength domain averaging optically for a high reflectance resolution. This approach is free from the numerical averaging required in conventional methods. A simulation shows that the reflectance resolution can be enhanced to the 0.1 dB level. An experimental demonstration is also presented.