Metaphotonic devices (VIS/IR)
My metaphotonics research on focuses on the design of devices that can perform differental optical functionalities (e.g., color separation, spectral analysis, ...) with ideal photon efficiencies in a (sub)wavelength footprint. The design of metaphotonic devices is based on highly efficient computational design and optimization methods derived from machine learning.
To illustrate my research in this area, I showed that metaphotonics can offer solutions to long standing problems in optics. For example, solid-state imaging relies on multiple optical functionalities, which are ideally photon efficient. Color is an important functionality in visible imaging. Achieving color functionality without loss of photons, however, represents a long standing challenge in integrated imaging systems. The standard approach uses absorbing color filters in a color filter array, which is very photon inefficient. In my work on metaphotonics, I recently introduced the concept of a metaphotonic color router that overcomes this long standing challenge.
A color router exploits the large number of degrees of freedom that are available when the optical stack region above the pixel photodetectors is nanopatterned with dielectric materials. It is a lossless device that routes all incident light based on color content directly, i.e., without any additional propagation outside of the device to separate colors, to the photodetectors. As a result, a color router can achieve color functionality without loss of photons, with a broadband, polarization-independent, and angularly robust response and within a subwavelength footprint.
This metaphotonic device example points to the possibility of light routing at the subwavelength scale with perfect photon efficiency for light properties in general. My approach thus forms a very general framework for detecting and analyzing properties of light at the subwavelength scale without photons being lost. This may open up opportunities in a variety of fields where nanophotonics plays a prominent role and where reliable measurement of light properties depends on collecting most, if not all, of the available photons.