Mechanophotonics-Mechanical Micromanipulation of Single-Crystals toward Organic Photonic Integrated Circuits.

The advent of molecular crystals as "smart" nanophotonic components namely, organic waveguides, resonators, lasers, and modulators are drawing wider attention of solid-state materials scientists and microspectroscopists. Crystals are usually rigid, and undeniably developing next-level crystalline organic photonic circuits of complex geometries demands using mechanically flexible crystals. The mechanical shaping of flexible crystals necessitates applying challenging micromanipulation methods. The rise of atomic force microscopy as a mechanical micromanipulation tool has increased the scope of mechanophotonics and subsequently, crystal-based microscale organic photonic integrated circuits (OPICs). The unusual higher adhesive energy of the flexible crystals to the surface than that of crystal shape regaining energy enables carving intricate crystal geometries using micromanipulation. This perspective reviews the progress made in a key research area developed by my research group, namely mechanophotonics-a discipline that uses mechanical micromanipulation of single-crystal optical components, to advance nanophotonics. The precise fabrication of photonic components and OPICs from both rigid and flexible microcrystal via AFM mechanical operations namely, moving, lifting, cutting, slicing, bending, and transferring of crystals are presented. The ability of OPICs to guide, split, couple, and modulate visible electromagnetic radiation using passive, active, and energy transfer mechanism are discussed as well with recent literature examples.