Planar Reconfigurable Optics For Imaging Technologies – PROFIT

Background – In the current era of images, integrated reconfigurable optical elements are essential building blocks to improve the performance of new photonic devices, all the way from the consumer market, with displays and cameras, to the research and clinic environments with advanced microscopy. To respond to new demands, several technological solutions have been proposed, including tuneable lenses, spatial light modulators and reconfigurable metasurfaces, involving a variety of actuation mechanisms. However, to date, wavefront shaping technologies do not meet the needs of many emerging photonics applications, including displays and advanced imaging, which require a combination of compacity, cost-efficiency, operation in transmission mode, and reconfigurability beyond simple refocusing.

Rationale – The PROFIT project leverages on a concept recently introduced by the proposers, in which the phase of the transmitted light is shaped by using the thermo-optical effect, i.e. the temperature dependence of the refractive index of most dielectric materials (physical effect involved in mirages). By engineering the tempera-ture landscape in a thermo-optical material, one forms a distribution of refractive index associated to a desired optical element (coined as Smartlens). In a recent collaboration (Berto et al, Nature Photonics, 2019), the proposers have demonstrated the feasibility of the Smartlens approach and started exploring its potential in the context of free-form planar optics. Despite its great promises, the Smartlens concept is still in its infancy, with several limitations that currently prevent its application to advanced imaging.

Overall objectives & specific aims – The PROFIT project aims at addressing these scientific and technological challenges and applying the developed technology in the contexts of endoscopy and microscopy. The first aim of the project is to enhance the performance of an individual Smartlens by increasing its transmittivity, its dynamic range and, beyond tunability, to demonstrate reconfigurability, i.e. the possibility to change optical function. The second aim is to extend operation to an ensemble of Smartlenses by combining thermal management and new optical architectures. Finally, our third aim is to demonstrate that, among its various potential applications, the developed technique can provide powerful, yet simple, solutions to the problems of in-depth and high-speed imaging, which are crucial to the progress of the currently thriving field of neurophotonics.

Expected results – By combining their complementary expertises, the proposers bring together all the knowhow and skills, from photonic engineering, heat management to advanced imaging and neurophotonics, necessary to design, implement and apply the creative solutions proposed in PROFIT. Beyond advanced endoscopy and microscopy which we address here, the outcomes of the project are foreseen to impact all fields of photonics, and benefit a broad range of applications, either for scientific (e.g. adaptive optics) or consumer (e.g. cell-phone imaging, displays) systems.