Low power autocorrelation technique based on the degree-of-polarization measurement

Based on the degree-of-polarization (DOP) measurement, an autocorrelation technique to measure the pulse width of chirp-free optical short pulse with a very low optical power (<−60 dBm) is demonstrated. The impacts of chirp and misalignment of the input light are also discussed in detail. The pulse width measurement results are consistent with the conventional second-harmonic generation (SHG) autocorrelation, while our autocorrelation technique does not require high input power or rigid optical alignment.