Phys.org August 9, 2023
To replace bulk optics and fibres in high-precision and highly coherent applications, ultralow-noise laser sources integrated with other photonic components in a compact and robustly aligned on a single chip are preferred. However, there are two major issues preventing the realization of such photonic integrated circuits: the high phase noise of semiconductor lasers and the difficulty of integrating optical isolators directly on-chip. An international team of researchers (USA – UC Santa Barbara, Caltech, industry, Egypt) leveraged three-dimensional integration that resulted in ultralow-noise lasers with isolator-free operation for silicon photonics. Through multiple monolithic and heterogeneous processing sequences, direct on-chip integration of III–V gain medium, they demonstrated ultralow-loss silicon nitride waveguides with optical loss around 0.5 decibels per metre without the need for optical isolators. According to the researchers such photonic integrated circuits offer superior scalability for complex functionalities and volume production, as well as improved stability and reliability over time… read more. Open Access TECHNICAL ARTICLE
3D integrated Si PIC chip… Credit: Nature volume 620, pages78–85 (2023)Â