Pixelated Balanced Homodyne Detection via Time-Multiplexed Spatial-Structured Local Oscillator

Pixelated quantum-limited balanced homodyne detection represents a groundbreaking advancement in quantum optics, enabling unprecedented sensitivity in image processing and sensing by operating at the fundamental quantum noise limit. This technique allows for the direct imaging of displaced-squeezed-vacuum fields, significantly enhancing low-light imaging capabilities in applications such as biomedical sensing and astronomical observations. Its advantage lies in surpassing classical limits for noise reduction and phase-sensitive detection, facilitating quantum-enhanced super-resolution imaging using squeezed light and enabling precise quantum sensing in environments with minimal photon flux, opening new frontiers in fields ranging from quantum metrology to secure communication. Attempts at its realization, most often by parallel arraying, have faced major technical challenges in achieving appreciable resolutions. We propose a method of structuring the local oscillator into an orthonormal basis of spatial modes via spatial light modulator, time-multiplexing shots to decompose signals into their superposing coefficients. When combined with interspersed phase reference pulses to account for laser phase drift, these coefficients can accurately reconstruct the signal spatial structure.