Advanced inspection of nonplanar fiberoptic and photonic interfaces

Optical interconnect inspection has become increasingly challenging as connector and interface technologies evolve beyond simple, planar fiber terminations toward non-planar, multi-fiber, lensed, and chip-scale architectures. At the same time, inspection volumes have expanded dramatically, driven by data-center scaling, AI infrastructure, and high-density optical packaging, placing new demands on throughput, repeatability, and process control. Conventional inspection microscopes-largely optimized for bright-field imaging of flat connector end faces-struggle to maintain contrast and defect sensitivity across curved and structured interfaces, particularly at the periphery of the field of view. We present a multimodal optical inspection platform explicitly designed as an industrial process tool for modern optical interfaces. Rather than introducing new microscopy principles, the system integrates multiple, purpose-driven imaging modalities-including programmable modified Köhler illumination, oblique and pupil-engineered lighting, and dualmagnification workflows-within a single, repeatable microscope architecture. These modalities are engineered to preserve uniform irradiance over non-planar surfaces, enhance sensitivity to low-contrast and out-of-plane defects, and support robust inspection across a wide range of connector, lensed, and chip-scale interfaces. Representative results demonstrate applicability to single-fiber and array connectors, expanded-beam optics, VCSEL-based modules, and photonic chip interfaces, as well as indirect geometric inference of parameters such as radius of curvature and apex offset. The presented platform addresses the combined challenges of interface complexity and industrial-scale deployment, enabling reliable inspection at volumes approaching hundreds of millions of interfaces per year.