Blind signal reconstruction for continuous-time photonic time-stretch analog-to-digital converters.

Here, we propose a blind signal reconstruction scheme for continuous-time photonic time stretch (CT-PTS) analog-to-digital converters (ADCs). The dynamic envelope extraction is realized online through low-pass filtering avoiding the effect of system parameter fluctuation. Channel mismatch is blindly corrected by processing the overlapping segments between adjacent channels using the least mean squares algorithm. The proposed scheme is experimentally validated on a four-channel CT-PTS ADC. The spurious free dynamic range of the CT-PTS ADC has a more than 10.9 dB improvement after mismatch correction. Frequency measurement with an error of less than ±7 MHz is achieved in the frequency range of 1 GHz to 26.25 GHz. A 10 MHz frequency resolution is also validated through a dual-tone test at 10 GHz.