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, […]