Ultrashort optical pulses with GHz repetition rate are required in a wide range of applications such as optical communication, bioimaging, and optical parametric oscillators. Specifically, an optical pulse train with low-timing jitter at high repetition rates is a fundamental requirement for several applications including photonic analog-digital converters, optical clock distribution, and low-noise microwave signal generation.

In this seminar, we will discuss the development of an optical clock source based on an active harmonic mode-locked fiber laser operating at 1560 nm wavelength and its performance in a sub-Nyquist photonic analog-to-digital converter operating at S (2-4 GHz), C (4-8 GHz) and X-band (8-12 GHz). We further discuss a novel control technique to stabilize the optical clock source from environmental disturbances such as temperature variation and vibration using a piezo-electric fiber stretcher.