Phys.org July 27, 2023
The formation of a broadband optical frequency comb relies on careful engineering of the group velocity dispersion (GVD) of the waveguide, which is challenging for platforms where the GVD is mainly determined by the material.
An international team of researchers (USA – UC Santa Barbara, Egypt) has generated a 60 GHz quantum-dot (QD) mode-locked laser in which both the amplitude-modulated (AM) and the frequency-modulated (FM) comb could be generated independently. The high four-wave-modulated (FWM) efficiency of –5 dB allowed the QD laser to generate FM comb efficiently. They demonstrated that the Kerr nonlinearity could be practically engineered to improve the FM comb bandwidth without the need for GVD engineering. The maximum 3-dB bandwidth that their QD platform could deliver was as large as 2.2 THz. According to the researchers their study gives novel insights into the improvement of FM combs and paves the way for small-footprint, electrically pumped, and energy-efficient frequency combs for silicon photonic integrated circuits (PICs) … read more. Open Access TECHNICAL ARTICLEÂ
Design of the 60 GHz QD mode-locked laser. Credit: Light: Science & Applications volume 12, Article number: 182 (2023).