Transcending shift-invariance in the paraxial regime via end-to-end inverse design of freeform nanophotonics

Abstract

Traditional optical elements and conventional metasurfaces obey shift-invariance in the paraxial regime. For imaging systems obeying paraxial shift-invariance, a small shift in input angle causes a corresponding shift in the sensor image. Shift-invariance has deep implications for the design and functionality of optical devices, such as the necessity of free space between components (as in compound objectives made of several curved surfaces). We present a method for nanophotonic inverse design of compact imaging systems whose resolution is not constrained by paraxial shift-invariance. Our method is end-to-end, in that it integrates density-based full-Maxwell topology optimization with a fully iterative elastic-net reconstruction algorithm. By the design of nanophotonic structures that scatter light in a non-shift-invariant manner, our optimized nanophotonic imaging system overcomes the limitations of paraxial shift-invariance, achieving accurate, noise-robust image reconstruction beyond shift-invariant resolution.

References in corpus (3)

• Why optics needs thickness
• Computational inverse design for ultra-compact single-piece metalenses free of chromatic and angular aberration
• Towards 3D-Printed Inverse-Designed Metaoptics

Cited by in corpus (5)

• End-to-End Optimization of Metasurfaces for Imaging with Compressed Sensing
• End-to-end design of multicolor scintillators for enhanced energy resolution in X-ray imaging
• Scalable freeform optimization of wide-aperture 3D metalenses by zoned discrete axisymmetry
• End-to-end metasurface design for temperature imaging via broadband Planck-radiation regression
• Inverse design for robust inference in integrated computational spectrometry