Mechanophotonics - a guide to integrating microcrystals toward monolithic and hybrid all-organic photonic circuits.

Molecular crystals are emerging as a non-silicon alternative for the construction of all-organic photonic integrated circuits (OPICs). The advent of flexible molecular crystals and the development of atomic force microscopy tip-based mechanical micromanipulation (mechanophotonics) techniques facilitate the construction of many proof-of-principle OPICs. This article validates the reason for using organic crystals as alternate non-silicon materials for OPIC fabrication. It also guides the readers by introducing several crystal-based photonic modules and OPIC prototypes, their passive and active light transduction potentials, and the possibility of implementing well-known photo-physical concepts viz. optical energy transfer and reabsorbance mechanisms. There is also an urgent need to develop a suitable technique for creating geometrically and dimensionally well-defined organic crystals displaying photonic attributes. Finally, the goal should be to build a library of selected optical crystals to facilitate the construction of OPICs with a pick-and-place approach.