Mechanophotonics—Mechanical Micromanipulation of Single‐Crystals toward Organic Photonic Integrated Circuits

Abstract

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.

Micromechanical Fabrication of Resonator Waveguides Integrated Four‐Port Photonic Circuit from Flexible Organic Single Crystals

“…[17][18][19][20][21] Atomic force microscopy (AFM) cantilever tip can be used to precisely micromanipulate flexible optical waveguiding crystals (mechanophotonics approach) using micromechanical operations such as lifting, cutting, bending, transferring (one substrate to another), and slicing. [18][19][20][21][26][27][28][29][30] Using some of the AFM-micromanipulation operations, we have fabricated a 2 × 2 directional coupler by integrating two flexible crystals. [19] For organic PICs (OPICs) fabrication, [29,30] resonators (ring resonator [RR] or cavities) and optical waveguides are essential components.…”

“…[18][19][20][21][26][27][28][29][30] Using some of the AFM-micromanipulation operations, we have fabricated a 2 × 2 directional coupler by integrating two flexible crystals. [19] For organic PICs (OPICs) fabrication, [29,30] resonators (ring resonator [RR] or cavities) and optical waveguides are essential components. When physically integrated with waveguides, a resonator could be used to control light propagation direction in the waveguides owing to its either clockwise or anti-clockwise light routing operation.…”

Exciton‐Polaritons and Their Bose–Einstein Condensates in Organic Semiconductor Microcavities

“…Recent years have witnessed rapid developments in fabrication of microscale flexible crystal-based organic photonic integrated circuits using mechanical micromanipulation. [109][110][111][112][113] The utilization of exciton-polariton effects in organic photonic elements can result in more complex functionalities and nanoscale polaritonic circuits with highly flexibility. However, there are still some problems to be solved, for example, although the formation of exciton-polaritons can be deduced from the sudden increasement of refractive index in the high-energy regime and exciton-polariton model fitting results of the energy-wavevector dispersion curves, it is difficult to obtain direct experimental evidence, which is usually the anticrossing feature of spectroscopically resolved polariton branches, by angle-resolved spectroscopy.…”

Exploring Axial Organic Multiblock Heterostructure Nanowires: Advances in Molecular Design, Synthesis, and Functional Applications

“…Organic low‐dimensional nanomaterials [ 1–7 ] have attracted much attention in recent years because of their promising applications in the field of optoelectronics including organic light‐emitting devices, [ 8,9 ] organic solid‐state lasers, [ 10–12 ] organic field‐effect transitions, [ 13 ] perovskite solar cells, [ 14 ] optical filters and circuits. [ 15–20 ] Furthermore, their outstanding compatibility and easy processability enable a fine topological control of both composition and geometry, thereby exhibiting excellent physicochemical features. [ 21–23 ] Among the organic low‐dimensional nanomaterials, organic 1D nanowires are considered promising candidates for optoelectronic applications, due to their distinctive size‐dependent confinement effect for photons or electrons, [ 24–26 ] which could provide good charge transport properties and photonic performances.…”