Science Daily November 11, 2022
Integrated femtosecond pulse and frequency comb sources are critical components for a wide range of applications, including microwave photonics, communications, lidar, optical computing, and astronomy among other things. A team of researchers in the US (Harvard University, UCLA, Columbia University, industry) has demonstrated a chip-scale femtosecond pulse source implemented on an integrated lithium niobate photonic platform forming a time-lens system. The device was driven by a continuous-wave distributed feedback laser chip and controlled by a single continuous-wave microwave source without the need for any stabilization or locking. They measured femtosecond pulse trains with a 30-gigahertz repetition rate, flat-top optical spectra with a 10-decibel optical bandwidth of 12.6 nanometres, individual comb-line powers above 0.1 milliwatts, and pulse energies of 0.54 picojoules. The results represented a tunable, robust, and low-cost integrated pulsed light source with continuous-wave-to-pulse conversion efficiencies an order of magnitude higher than those achieved with previous integrated sources. The pulse generator may find applications in fields such as ultrafast optical measurement or networks of distributed quantum computers….read more. TECHNICAL ARTICLEÂ
Wavelength multiplexed, flat-top, high power electro-optic comb sources. Credit: Nature (2022)Â