Spatial resolution of omni-resonant imaging

TL;DR

This paper investigates how the spectral linewidth of a planar cavity influences the spatial resolution in omni-resonant imaging, revealing that resolution improves at longer wavelengths due to negative angular dispersion.

Contribution

It demonstrates that the spectral linewidth of the cavity resonance determines spatial resolution and uncovers the counterintuitive wavelength dependence caused by intrinsic angular dispersion.

Findings

Spatial resolution is dictated by the cavity's spectral linewidth.

Resolution improves at longer wavelengths due to negative angular dispersion.

Results have implications for solar windows and nonlinear image processing.

Abstract

Omni-resonance refers to the broadening of the spectral transmission through a planar cavity, not by changing the cavity structure, but by judiciously preconditioning the incident optical field. As such, broadband imaging can be performed through such a cavity with all the wavelengths simultaneously resonating. We examine here the spatial resolution of omni-resonant imaging and find that the spectral linewidth of the cavity resonance determines the spatial resolution. Surprisingly, the spatial resolution improves at longer wavelengths because of the negative angular dispersion intrinsic to Fabry-Perot resonances, in contrast to conventional diffraction-limited optical imaging systems where the spatial resolution improves at shorter wavelengths. These results are important for applications ranging from transparent solar windows to nonlinear resonant image processing.