Ultra-Broadband Photonically Assisted Analog-to-Digital-Converters

<jats:title>Abstract</jats:title> <jats:p>We present recent progress made towards ultra-broadband photonically assisted analog-to-digital converters, that leverage both the low jitter of best-of-class mode-locked lasers as well as the capability of optics to break down broadband signals into multiple lower speed tributaries that can be better handled by electronics. We review in particular our work on both time- and frequency-domain approaches and give an outlook on how these architectures can be extended to include further signal processing tasks such as equalization. Optically triggered track-and-hold amplifiers are reported with an equivalent jitter below 80 fs rms in a signal frequency range from 20 GHz to 70 GHz. Frequency-domain architectures implementing optical arbitrary waveform measurement up to signal bandwidths of 610 GHz are also shown. Finally, an architecture allowing the deserialization and equalization of PAM4 signals is introduced and modeled for operation in 400 Gb/s links.</jats:p>