Photonic Integrated Circuit for Single Emitter Detection

Single emitters in wide-bandgap semiconductors are key elements of future optical quantum technologies, including sensors, circuits, and fiber communication. The standard approach to detecting and characterizing single emitters is optical fluorescence microscopy, which requires a laboratory infrastructure due to the use of free-space optics. However, in order to integrate single emitters into functional devices and operate them in demanding environments, the optics must be compact, robust, and low maintenance. PHOTONCHIP addresses this issue by replacing the free-space optics with a single photonic integrated circuit (PIC).In PHOTONCHIP, I will demonstrate a prototype PIC device that combines all optical functionality of single emitter detection – excitation and light collection at different wavelengths, lensed focusing, and fiber coupling – on a single chip. The PIC will shrink the size of the optics from meters to millimeters, reduce complexity and cost, and improve robustness with no need for optical re-alignment. Key technical innovations include broadband operation in the visible wavelength range, wavelength separation of excitation and fluorescent light, and integration of the microscope objective on chip.The prototype PIC will be developed on single nitrogen-vacancy (NV) center quantum emitters in diamond, providing the first commercial use case with existing applications in quantum sensors and communication networks. The PIC will simplify existing microscopy solutions, lead to lower system cost, extend use to cryogenic environments, and enable integration into portable sensors. More broadly, the chip will be developed as a generic platform for single emitter excitation, control and detection for optical and device metrology. Overall, the PIC has key potential for driving discovery and innovation in the critical EU technology areas of quantum and semiconductors.