Open AccessFundamental limit of detection of photonic biosensors with coherent phase read-out
Author(s) -
Í. Molina-Fernández,
Jonas Leuermann,
Alejandro OrtegaMoñux,
J. Gonzalo WangüemertPérez,
Robert Halir
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.012616
Subject(s) - interferometry , photonics , astronomical interferometer , resonator , optics , limit (mathematics) , biosensor , mach–zehnder interferometer , detection limit , physics , computer science , materials science , nanotechnology , mathematical analysis , statistics , mathematics
Photonic biosensors offer label-free detection of biomolecules for applications ranging from clinical diagnosis to food quality monitoring. Both sensors based on Mach-Zehnder interferometers and ring resonators are widely used, but are usually read-out using different schemes, making a direct comparison of their fundamental limit of detection challenging. A coherent detection scheme, adapted from optical communication systems, has been recently shown to achieve excellent detection limits, using a simple fixed-wavelength source. Here we present, for the first time, a theoretical model to determine the fundamental limit of detection of such a coherent read-out system, for both interferometric and resonant sensors. Based on this analysis, we provide guidelines for sensor optimization in the presence of optical losses and show that interferometric sensors are preferable over resonant structures when the sensor size is not limited by the available sample volume.