PDMM: A Physical Dual-Modality Mapping Architecture for Robust Volumetric Photonic Computing via Orthogonal Noise Suppression

Orthogonal Noise Suppression: A Fundamental Physical Mechanism for Robust Photonic Computing A critical and industry-relevant physical mechanism embedded in the PDMM architecture is orthogonal noise suppression, derived from the inherent spatio-temporal scale separation between distinct physical origins of fluctuations. Thermal vibrations, atomic-level energy-level fluctuations, and local lattice perturbations within thulium-doped media occur at characteristic angstrom-scale spatial displacements and microsecond-to-millisecond temporal scales. In contrast, unwanted optical-electronic noise—including propagation scattering, detector readout noise, and mode jitter—exhibits nanometer-to-micrometer spatial scales and picosecond-scale temporal dynamics. These two classes of disturbance occupy physically orthogonal domains, enabling natural, passive separation of computational signals from noise without complex active stabilization, active feedback, or precision temperature control. This mechanism is not a minor engineering tweak, but a foundational physical property that resolves a long-standing bottleneck in practical photonic computing: environmental sensitivity and scalability barriers. By exploiting orthogonal noise characteristics, PDMM achieves robust, repeatable computation in ambient conditions, eliminating the need for ultra-stable laboratories, complex isolation systems, and cryogenic cooling that have constrained conventional coherent photonic architectures to laboratory settings. The orthogonal suppression principle thus enables reliable deployment of volumetric photonic hardware in real-world environments, drastically lowering manufacturing and operational costs while strengthening stability. In this framework, noise is no longer an error source to be eliminated, but a physically bounded, scale-separable component that supports stochastic computing and natural annealing, further reinforcing the architectural robustness and industrial viability of PDMM.