Photonic Analog-to-Digital Conversion with Femtosecond Lasers

Progress in developing high speedAnalog-to-Digital Converters (ADCs) occurs rather slowly due to the inherent jitter in electronic sampling and the difficulty in integrating low noise microwave sources. Currently, this electronic jitter is on the order of 100 femtoseconds in the most advanced CMOS circuitry. Advances in femtosecond lasers and laser stabilization have led to the development of sources of ultrafast optical pulse trains that show timing jitter on the level of a few femtoseconds over the time spans of typical sampling windows and can be made even smaller in the future. This paper reviews the progress made towards low noise femtosecond lasers, its jitter characterization, and its application in high-speed, high-resolution analog-to-digital conversion. Index Terms – Ultrafast optics, timing jitter in mode-locked lasers, photonic analog-to-digital conversion, femtosecond lasers