Quantum optics has emerged as a key technology to sense and characterize quantum states, generate quantum random numbers, distribute continuous-variable quantum keys, teleport entangled photon qubits, and secure long-distance communication. Developing high-precision quantum optical instruments enables sub-shot noise sensing and has the potential to revolutionize high energy physics research and experiments in dark matter search, characterization of atomic force, detection of gravitational waves, and high-performance computation. Optical balanced homodyne detectors are essential building blocks in both quantum and classical high-sensitivity phase measurements, but major performance limitations of the homodyne detector are observed on efficiency, speed, and imbalance. We will address the problem by developing an innovative ultra-low-noise integrated photonicelectronic detector for high-efficiency photodetectors in an advanced monolithic high-speed silicon photonics process. A single-chip solution will greatly lower the noise contributions caused by interconnects and large parasitic capacitance, and improve the operation speed. High-speed ultra-low-noise readout electronics will be implemented in a novel architecture including a differential current-mode amplifier, a shaper, and a level-crossing discriminator. The commonmode rejection ratio will be substantially improved through a novel real-time photonic-electronic calibration technique. During Phase I, we will develop an ultra-low-noise microelectronic readout chain with integrated optical components for a monolithic balanced homodyne detector. High-efficiency photodetection will be demonstrated by low noise equivalent power and high clearance above the noise floor at low optical powers with wide noise sidebands. Additionally, we will develop a photonic-electronic real-time calibration technique to substantially improve the common-mode rejection ratio in the high-frequency range. Lastly, we will demonstrate the feasibility of cryogenic operation of the monolithic balanced homodyne detector through simulations based on modified models upon previous cryogenic design experience and available experimental data of the process in a cryogenic environment. This high-efficiency ultra-low-noise homodyne detector will enable a range of next-generation high-precision instruments for quantum science research and development in academia and the high-tech industry, also facilitating high-energy physics research experiments for scientific discoveries. The detector prototype will be commercialized through customer engagement in Phase II, customized for early adopters, and later expanded to a wider range of the optical detector market including quantum computing, long-distance secure communications, and automobile.
