Photochemically Switchable Interconnected Microcavities for All‐Organic Optical Logic Gate

Abstract

Optical microcavities confine molecular luminescence and transfer it to a far longer distance than the conventional Förster resonant energy transfer process. Such cavity‐mediated energy transfer is advantageous for use in optical circuitry. However, to realize all‐organic optical circuits, optical gate operation with organic materials is indispensable. Here, all‐organic optical gates consisting of polymer whispering gallery mode (WGM) resonators that work as the optical source, drain, and gate, which are interconnected with polymer microfiber, are demonstrated. Photoirradiation of the source sphere, as an optical input, triggers the blue fluorescence that transmits to the gate sphere through the fiber. The fiber interconnection enhances both the light confinement efficiency in the individual spheres and the light transmission efficiency between distant spheres. The gate sphere contains photoisomerizable fluorescent dye that converts, in its closed state, the blue emission into green light, which is again transmitted to the drain sphere through the fiber and lets the sphere emit red light as an output. This optical cascade is switched on and off upon photoisomerization of the dye in the gate sphere. Furthermore, an energy cascade equipped with two gate spheres works as an OR‐type logic gate, demonstrating potential utility for the future all‐organic and all‐optical integrated devices.

Micrometer‐Scale Optical Web Made of Spider Dragline Fibers with Optical Gate Operations

“…Also note that light scattering by the first excitation of MS‐ 1 hardly causes the direct excitation of the green‐fluorescent microspheres, as shown in our previous study using blue‐ and green‐fluorescent microspheres separately located on a substrate. [ 23 ]…”

Molecular and Supramolecular Designs of Organic/Polymeric Micro-photoemitters for Advanced Optical and Laser Applications

“…Here, optical gate operation is achieved by making the central microsphere of a triple sphere chain photoswitchable (see Figure ). When the sphere on the left side is photoexcited, blue emission is generated and transferred to the central DAE-doped microsphere, and in the case where the DAE is in the closed form, further energy transfer cascade occurs to the microsphere on the right side as red WGM PL (output ON). Upon irradiation of the central sphere with visible light, the closed-form DAE is photoisomerized to the open form, resulting in the inhibition of the energy transfer cascade from left to right (output OFF).…”

Motor-like microlasers functioning in biological fluids

“…This can be explained through cavity-mediated radiative energy transfer. 18,36,37 Owing to the close proximity and efficient energy transfer, the lasing intensity of the micromotor significantly decreased while the emission intensity of the red droplet increased simultaneously. On this basis, stimulated emission from red droplets could also be turned off by propelling away from the lasing micromotor.…”