Spectrum analysis technique is introduced to measure the time delay of the
silicon-on-insulator (SOI) micro-ring slow light device. The interference spectra of the TE and the
TM polarization are obtained based on dual-quadrature spectral interferometry technique. By
analyzing the observed spectral interference, the phase and time delay of the output optical pulse
of SOI micro-ring is estimated. This method has a very high accuracy of time measurement
because it avoids the impact of response speed of optoelectronic device, and moreover, it provides
a complete measurement of the complex electric field as a continuous function of frequency.