Expressive and Unclonable Photonic Circuits Based on Disordered Moiré Quasicrystals

Abstract: Structural symmetry in photonics has long been exploited to engineer devices with predictable, analytically describable behaviors. Yet this predictability often limits their expressivity, constraining complex interactions essential for advanced functionalities in computing, sensing, and security. Here we demonstrate how low symmetry integrated photonic circuits can unlock enhanced mode diversity and rich spectral complexity, enabling highly non-linear transformations of input signals into outputs. Our devices, physically unclonable moir\'e quasicrystal interferometers integrated on a silicon photonics platform, exhibit aperiodic and reconfigurable spectral responses and are characterized by analyticity breaking and erasable mutual information. Using dynamic thermo-optic control to drive their complex spectral dynamics, we demonstrate that these devices function as reconfigurable physical unclonable functions (rPUFs). We also highlight their ability to perform high-dimensional input--output transformations, emulating reservoir-inspired information processing in a compact photonic platform. This work bridges the gap between engineered and natural complexity in photonic systems, revealing new opportunities for scalable, energy-efficient, and information-dense opto-electronics with applications in secure communications, hardware security, advanced sensing, and optical information processing. Our results establish low-symmetry integrated photonics as a powerful resource for complex signal manipulation in photonic systems.