Biosensing with optically coupled 4D microresonators

Abstract

Multiplexed structures out of dual optically coupled 4D microtoroids fabricated with two-photon polymerization and their biosensing-relevant application are discussed. We analyze the sensing performance for detection of small pH value alteration around the neutral solution for independent and optically coupled resonators that are characterized by appearance of the additional signal for back-radiated mode. We demonstrate detectability of pH value changes at the level of 0.01 by using the signal back-radiated mode in the coupled regime together with the material-enhanced spectral shift.