Mechanical Processing of Naturally Bent Organic Crystalline Microoptical Waveguides and Junctions

Precise mechanical processing of optical microcrystals involves complex microscale operations viz. moving, bending, lifting, and cutting of crystals. Some of these mechanical operations can be implemented by applying mechanical force at specific points of the crystal to fabricate advanced crystalline optical junctions. Mechanically compliant flexible optical crystals are ideal candidates for the designing of such microoptical junctions. A vapor-phase growth of naturally bent optical waveguiding crystals of 1,4-bis(2-cyanophenylethynyl)benzene (1) on a surface forming different optical junctions is presented. In the solid-state, molecule 1 interacts with its neighbors via C-H...N hydrogen bonding and pi-pi stacking. The microcrystals deposited at a glass surface exhibit moderate flexibility due to substantial surface adherence energy. The obtained network crystals also display mechanical compliance when cut precisely with sharp atomic force microscope cantilever tip, making them ideal candidates for building innovative T- and Delta-shaped optical junctions with multiple outputs. The presented micromechanical processing technique can also be effectively used as a tool to fabricate single-crystal integrated photonic devices and circuits on suitable substrates.

Automated summary

This study presents a method for precise mechanical processing of optical microcrystals, allowing for the fabrication of advanced crystalline optical junctions by applying mechanical force at specific points of the crystal. The resulting network crystals can be used to construct innovative optical junctions with multiple outputs, showcasing mechanical compliance and flexibility.