Share Email Print

Proceedings Paper

Finite-difference time-domain modeling and experimental characterization of planar waveguide fluorescence sensors
Author(s): Jyrki S. Kimmel; Douglas A. Christensen
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

The finite-difference time-domain method (FDTD) is a powerful numerical technique for solving Maxwell's equations in a discretized space and time grid. Its applications have up to now been in the analysis of electrically large structures in the microwave domain, and the scope of investigations has been extended only recently to the optical region. Because of computer memory limitations, the method is generally restricted to configurations which extend to the order of tens of wavelengths in three dimensions, or hundreds of wavelengths in two dimensions. Optical sensor structures are therefore of suitable size to be modeled with FDTD, and e.g., fluorescence sensor design can benefit from the use of FDTD in optimization of the waveguide structures. In general, the integration of chemical and optical design is difficult, but FDTD can bring the two design approaches closer together. One of the main advantages of FDTD is its ability to include near-field effects, such as distribution of protein molecules on the active surface of optical sensors in the model, which has been shown to be important is estimating the fluorescent excitation and collection efficiencies of molecules on surfaces. In addition, for planar structures, two-dimensional models are adequate for studying many aspects of sensor design. We applied FDTD to design planar fluorescence sensors. Excitation and emission models were analyzed for planar waveguide structures with side collection of emitted light in mind. Planar waveguides were fabricated on fused silica substrates and the characteristics of the waveguides were compared to the model. Good agreement was found with the FDTD modeling to the physical model, and based on this knowledge, an FDTD sensor model was prepared predicting good fluorescence excitation and emission side collection efficiencies.

Paper Details

Date Published: 1 March 1992
PDF: 11 pages
Proc. SPIE 1587, Chemical, Biochemical, and Environmental Fiber Sensors III, (1 March 1992); doi: 10.1117/12.56541
Show Author Affiliations
Jyrki S. Kimmel, Univ. of Utah (United States)
Douglas A. Christensen, Univ. of Utah (United States)

Published in SPIE Proceedings Vol. 1587:
Chemical, Biochemical, and Environmental Fiber Sensors III
Robert A. Lieberman, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?