Confocal reflectance microscopy for determination of microbubble resonator thickness

Optical Micro Bubble Resonators (OMBR) are emerging as new type of sensors characterized by high Q-factor and embedded micro-fluidic. Sensitivity is related to cavity field penetration and, therefore, to the resonator thickness. At the state of the art, methods for OMBR's wall thickness evaluation rely only on a theoretical approach. The purpose of this study is to create a non-destructive method for measuring the shell thickness of a microbubble using reflectance confocal microscopy. The method was validated through measurements on etched capillaries with different thickness and finally it was applied on microbubble resonators. (C) 2015 Optical Society of America