A Molecular Optical Channel Model Based on Phonon-Assisted Energy Transfer Phenomenon

Recent progress in the field of nanotechnology is enabling communication between nanodevices to be considered also for in-vivo applications. In particular, nanodevices enabling light-controlled process have started to attract a lot of interest in the research community, due to potential applications like healthcare wearable devices, intra-body applications, and optogenetics, whose main objective is to stimulate neurons by the means of the light signals. Leveraging on these premises, we consider upconversion phenomenon, namely the ability of specific nanoparticles to convert low energy radiations (e.g., near-infrared radiations) into higher energy radiation (e.g., visible light) via a non-linear process. Energy transfer as viable communication mean has been already considered based on the Förster-Resonance-Energy Transfer. In this paper, we focus on phonon-assisted energy transfer, and we analyze the requirements and conditions for generating optical signals from a genuine signal processing point of view. More specifically, based on information theory approach, we derive the conditions to minimize the error probability. We show that the dopant concentration, (i.e., the concentration of elements drugging a pure material in order to change its features) mostly influences the correct generation of the light signal. The performed analysis is based on experimental results.