Interferometric transmission probing with coded mutual intensity

Abstract

We introduce a new interferometric imaging methodology that we term interferometry with coded mutual intensity, which allows selectively imaging photon paths based on attributes such as their length and endpoints. At the core of our methodology is a new technical result that shows that manipulating the spatial coherence properties of the light source used in an interferometric system is equivalent, through a Fourier transform, to implementing light path probing patterns. These patterns can be applied to either the coherent transmission matrix, or the incoherent light transport matrix describing the propagation of light in a scene. We test our theory by building a prototype inspired by the Michelson interferometer, extended to allow for programmable phase and amplitude modulation of the illumination injected in the interferometer. We use our prototype to perform experiments such as visualizing complex fields, capturing direct and global transport components, acquiring light transport matrices, and performing anisotropic descattering, both in steady-state imaging and, by combining our technique with optical coherence tomography, in transient imaging. CCS Concepts: • Computing methodologies → Computational photography.

Swept-Angle Synthetic Wavelength Interferometry

“…Lastly, optical coherence tomography (OCT) [Gkioulekas et al 2015;Huang et al 1991;Kotwal et al 2020] is another interferometric technique that uses broadband illumination for micron-scale depth sensing. OCT decouples range and resolution, allowing unambiguously imaging arbitrary depth ranges at micrometer resolution, albeit at a steep increase in acquisition time-from a few seconds for PSI and heterodyne interferometry, to hours for OCT.…”

“…Proposed spatial illumination and acquisition modulation schemes include epipolar imaging [O'Toole et al 2015[O'Toole et al , 2016, high-spatial-frequency illumination [Nayar et al 2006;Reddy et al 2012] and spatio-temporal code illumination [Achar et al 2017;Gupta et al 2015;O'Toole et al 2014a]. Lastly, prior work has shown how to implement similar probing capabilities in interferometric systems, by exploiting the spatio-temporal coherence properties of the illumination injected into the scanned scene [Gkioulekas et al 2015;Kotwal et al 2020].…”

End-to-end complex lens design with differentiate ray tracing

“…End-to-end Optics Design. Co-designing of optics and post-processing has demonstrated superior performance over traditional heuristic approaches in single-lens color imaging [Chakrabarti 2016;Peng et al 2019], HDR imaging [Metzler et al 2020Sun et al 2020a], single image depth estimation [Boominathan et al 2020;Chang and Wetzstein 2019a;Haim et al 2018;Kotwal et al 2020;Wu et al 2019a,b;Wu et al 2020;Zhang et al 2018], microscopy imaging [Horstmeyer et al 2017;Kellman et al 2019;Nehme et al 2019;Shechtman et al 2016].…”

Polarimetric Spatio-Temporal Light Transport Probing

“…Combining these two threads of spatial and temporal dimensions makes it possible to reason over rich decompositions that encode how light travels at a given time and position. Such joint spatio-temporal analysis has been implemented using frequency-aware probing methods with a correlation sensor-illumination pair [O'Toole et al 2014a] or, recently, using an interferometric setup with programmable amplitude and phase modulators [Kotwal et al 2020]. The spatio-temporal transport structure enables direct-indirect separation for multipath interference removal [Agresti and Zanuttigh 2018;Naik et al 2015;Whyte et al 2015].…”

“…Joint spatio-temporal decomposition has also been explored recently [Kotwal et al 2020;O'Toole et al 2014a]. While these existing light-transport decomposition methods have been successful for geometric understanding of scenes, the simultaneous analysis of scene materials poses an open challenge.…”