Waveguide Encoded Lattices (WELs): Slim Polymer Films with Panoramic Fields of View (FOV) and Multiple Imaging Functionality

Abstract

When encoded with a 3D network of interconnected and pentadirectional waveguides, an otherwise passive polymer film transforms into an intelligent optical element-a waveguide encoded lattice (WEL)-that combines a panoramic field of view, infinite depth of field and powerful capacity to perform multiple imaging operations such as divergence-free transmission, focusing, and inversion. The lattices are moreover operable with coherent and incoherent light at all visible wavelengths, both individually (e.g., narrow band sources such as lasers, light-emitting diodes) and collectively (e.g., incandescent sources). This combination of properties is unprecedented in singlecomponent films and the WEL structures represent a new class of flexible, slim films that could confer advanced optical functionalities when integrated with light-based technologies (e.g., solar panels, smart phone cameras, and smart screens) and are amenable to the design and fabrication of new miniaturized optical and optoelectronic devices.

A Slim Polymer Film with a Seamless Panoramic Field of View: The Radially Distributed Waveguide Encoded Lattice (RDWEL)

“…Inspired by the collective behavior of ommatidia, we are developing new classes of multifunctional polymer films, which are inscribed with dense arrays or lattices of cylindrical waveguides . In striking contrast to the predominantly hemispherical architectures of natural and artificial compound eyes, these waveguide encoded lattices (WELs) are flexible, slim (≤3 mm), and optically flat, which provides ease of integration into existing light‐based technologies such as solar cells, cameras, and smart screens.…”

“…Significantly, there was no overlap between these five ranges and the consequent discontinuities—or gaps—in the FOV prevented cross‐talk between nonparallel waveguides. This, in turn, enabled sophisticated imaging functions such as panoramic imaging, inversion, and focusing that would normally require bulky optics …”

“…To the best of our knowledge, this represents the greatest panoramic FOV of any known planar system . We inscribe such radially distributed WELs (RDWELs) with a large, converging population of self‐trapped filaments in a thermomechanically robust epoxide medium . We show that the resulting single‐component microstructure retains the advantages of a planar configuration and also offers excellent imaging functionality in terms of the density, angular span, and wavelength sensitivity of its constituent waveguides.…”

“…Moreover, the ≈40 µm diameter of each waveguide imparts a high degree of spatial imaging resolution. Importantly, the RDWEL is versatile with respect to its operating wavelengths; because its waveguides are polychromatic and multimoded, the RDWEL operates both with the broad spectral range emitted by incandescent sources (such as ambient sunlight) and the discrete wavelength ranges emitted by lasers and light‐emitting diodes (LEDs) . We detail below the design rationale, fabrication, and microstructural characterization of the RDWEL and then elucidate its optical properties.…”

“…Figure is a scheme of the RDWEL, which is a periodic stack of xz planes, each containing up to 200 cylindrical waveguides that are monotonically oriented over an arc spanning ±33.0°. Each waveguide is 40 µm in diameter with a refractive index contrast, Δ n ≥ 0.001 relative to its surroundings where n = 1.510 . From previous studies, we know that these parameters enable waveguides to confine multimoded, polychromatic light including incandescent white light with an angular acceptance range of 5.6° .…”