Semiconductor quantum dot in an optical cavity has been the workhorse of quantum photonics, enabling many exciting demonstrations such as photon blockade, and some of the best quantum light sources and spin-photon interfaces - crucial for implementation of quantum networks. An alternative platform for such networks has recently emerged, based on color centers embedded in wide bandgap materials, such as silicon vacancy (SiV) in diamond, with small quantum emitter in homogeneous broadening being one of its most attractive features.
However, in addition to high quality quantum devices, successful implementation of such quantum hardware requires classical photonic circuits that are scalable, robust to errors, and exhibit minimal losses. In particular, losses in in/out coupling to chips and increased circuit complexities resulting from post-fabrication tuners are particularly detrimental to quantum circuits. Inverse design in photonics (which combines methods of optimization / artificial intelligence with
photonics) offers a powerful tool to design and implement photonic circuits with superior properties, including robustness to errors in fabrication and temperature, compact footprints, novel functionalities, and greater than 97% coupling efficiencies for very simple designs.