Quantum Applications Based on Optical Meta-devices

Abstract

Optical meta-devices, with their exceptional ability to manipulate light at the subwavelength scale, offer a promising pathway towards the miniaturization and integration of quantum information technologies. Nevertheless, conventional quantum optical systems often encounter challenges such as structural complexity, limited efficiency, and functional constraints in applications like random number generation, precision metrology, and display.
To address these limitations, this thesis systematically explores the design and application of meta-devices for quantum applications. By deeply integrating the light-manipulating capabilities of nanostructures with quantum optical properties, we develop three high-performance functional systems: a metalens-array-based quantum random number generator, a geometric-phase metasurface displacement sensor, and a quantum-correlated holographic display platform.
In the domain of quantum random number generation, we design a high-numerical-aperture gallium nitride metalens array. Utilizing high-dimensional entangled photon pairs generated via spontaneous parametric down-conversion, true random sequences are extracted through single photon detection and coincidence counting. This approach significantly increases random bit density per unit area, passes the NIST statistical test suite, and maintains robustness against generative adversarial network-based attacks.
For displacement measurement, we propose a metasurface-based sensor leveraging geometric phase modulation. Through optimized structural design, nanoscale displacements are transduced into phase shifts of quantum states. Combined with NOON state generation, the system achieves measurement precision beyond the classical limit while maintaining a linear response across a broad dynamic range.
In quantum holography, we develop a dielectric metasurface enabling polarization-multiplexed dual-channel holography display. Using quantum correlation imaging techniques, high-fidelity holographic reconstruction is demonstrated even at the single-photon level, exhibiting strong resilience against environmental noise. This platform opens up new possibilities for future quantum-encrypted displays and augmented reality interfaces.
In general, this thesis confirms the unique value of meta-devices in enhancing the performance of quantum systems and expanding their application scope. By enabling multidimensional control over quantum optical states, our work provides feasible technical pathways and device foundations for the development of integrated quantum information processing, high-security communication, and ultra-sensitive detection systems.

Date of Award	10 Jul 2026
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Din-ping TSAI (Supervisor)