Adaptable Optical Microwaveguides From Mechanically Flexible Crystalline Materials. Issue 40 (31st May 2022)

• Record Type: Journal Article
• Authors: Chinnasamy, Ragaverthini; Ravi, Jada; Vinay Pradeep, Vuppu; Manoharan, Deepak; Emmerling, Franziska; Bhattacharya, Biswajit; Ghosh, Soumyajit; Chandrasekar, Rajadurai
• Is Part Of: Chemistry. Volume 28:Issue 40(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-31
• Subjects: crystal growth -- fluorescence -- mechanophotonics -- micromanipulation -- optical waveguides; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202200905
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Flexible organic crystals (elastic and plastic) are important materials for optical waveguides, tunable optoelectronic devices, and photonic integrated circuits. Here, we present highly elastic organic crystals of a Schiff base, 1‐((E)‐(2, 5‐dichlorophenylimino)methyl)naphthalen‐2‐ol (1 ), and an azine molecule, 2, 4‐dibromo‐6‐((E)‐((E)‐(2, 6‐dichlorobenzylidene)hydrazono)methyl)phenol (2 ). These microcrystals are highly flexible under external mechanical force, both in the macroscopic and the microscopic regimes. The mechanical flexibility of these crystals arises as a result of weak and dispersive C−H⋅⋅⋅Cl, Cl⋅⋅⋅Cl, Br⋅⋅⋅Br, and π⋅⋅⋅π stacking interactions. Singly and doubly‐bent geometries were achieved from their straight shape by a micromechanical approach using the AFM cantilever tip. Crystals of molecules 1 and 2 display a bright‐green and red fluorescence (FL), respectively, and selective reabsorption of a part of their FL band. Crystals 1 and 2 exhibit optical‐path‐dependent low loss emissions at the termini of crystal in their straight and even in extremely bent geometries. Interestingly, the excitation position‐dependent optical modes appear in both linear and bent waveguides of crystals 1 and 2, confirming their light‐trapping ability. Abstract : Bent waveguides, especially, singly and doubly bent waveguides are essential for the advancement of photonic technologies. Here, two chemically and optically different flexible organic crystals were fabricated into singly and doubly‐bent shapes from straight geometry using micromechanical manipulation technique to demonstrate optical waveguiding behavior which is required for photonic circuit applications. (Atomic force microscopy cantilever tip abbreviated as AFM cantilever)