Design of a Label-Free, Distributed Bragg Grating Resonator Based Dielectric Waveguide Biosensor

Photonics

Florian Kehl¹  David Bischof²  Markus Michler²  Mirjad Keka² 

[1] Laboratory of Biosensors and Bioelectronics (LBB), Swiss Federal Institute of Technology ETH, Gloriastrasse 35, Zürich CH-8092, Switzerland;University of Applied Sciences and Technology NTB, Werdenbergstrasse 4, Buchs CH-9470, Switzerland; E-Mails:

关键词: diffraction gratings;    waveguide grating couplers;    optical resonators;    fabry-pérot;    Bragg reflectors;    planar waveguides;    label-free biosensing;   

DOI  :  10.3390/photonics2010124

来源: mdpi

【 摘 要 】

In this work, we present a resonant, dielectric waveguide device based on distributed Bragg gratings for label-free biosensing applications. The refractive index sensitive optical transducer aims at improving the performance of planar waveguide grating sensor systems with limited Q-factor and dynamic range by combing the advantages of resonant cavities, such as a multitude of resonance peaks with high finesse, with the manageable complexity of waveguide grating couplers. The general sensor concept is introduced and supported by theoretical considerations as well as numerical simulations based on Coupled Mode Theory. In contrast to a single Bragg grating reflector, the presented Fabry-Pérot type distributed Bragg resonator exhibits an extended measurement range as well as relaxed fabrication tolerances. The resulting, relatively simple sensor structure can be fabricated with standard lithographic means and is independent of expensive light-sources and/or detectors, making an affordable but sensitive device, potentially suitable for point-of-care applications.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.