Measurement of Amplitude and Phase of Optical Pulse Using a Silicon Photonics Optical Correlator

We demonstrate the measurement of amplitude and phase of optical pulses using an optical correlator chip fabricated by silicon photonics. The amplitude and phase of the pulses are retrieved from a spectrogram obtained using the optical correlator and a tunable filter; the former comprising of an array of 32 two-photon absorption photodiodes embedded on a silicon waveguide of length 1.36 mm. The spectrum of the pulse under test is resolved by a tunable filter that scans the filtering wavelength in 0.117-nm steps, and the correlation waveform at each resolved wavelength is measured by the optical correlator, resulting in the acquisition of the spectrogram. The amplitude and phase of a-few-ps-wide pulses without chirp and with the chirps of 1.8 and -1.5 ps/nm were successfully measured.