Share Email Print

Journal of Nanophotonics

Waveguide evanescent field fluorescence microscopy: theoretical investigation of optical pressure on a cell
Author(s): Abdollah Hassanzadeh; Darya Azami
Format Member Price Non-Member Price
PDF $20.00 $25.00

Paper Abstract

The optical force of an evanescent field is useful for trapping individual proteins and molecules. We theoretically investigate the optical pressure exerted on an attached and well-spread cell on a waveguide in the vicinity of an evanescent field. To do this, the cell is modeled as a three-planar-layer (membrane-cytoplasm-membrane). These layers and a gap of water are used as a stratified cover medium for the waveguide. Then, the mode equation of a slab waveguide with a simple and semi-infinite cover medium is modified and solved graphically. The effects of the cell cytoplasm and membrane thicknesses and their refractive indices and the sample-waveguide separation distance on the optical pressure are numerically studied. The results show that the optical pressure increases when the cytoplasm thickness increases, but decreases when the cell membrane thickness is increased. Furthermore, the optical pressure does not significantly change when the sample film thickness increases to more than 0.2 of a wavelength. The optical pressure decreases when the waveguide-sample distance for a specific mode is increased, but can be attractive or repulsive depending on both the cytoplasm refractive index and the mode number.

Paper Details

Date Published: 15 August 2014
PDF: 12 pages
J. Nanophoton. 8(1) 083076 doi: 10.1117/1.JNP.8.083076
Published in: Journal of Nanophotonics Volume 8, Issue 1
Show Author Affiliations
Abdollah Hassanzadeh, Univ. of Kurdistan (Iran, Islamic Republic of)
Darya Azami, Univ. of Kurdistan (Iran, Islamic Republic of)

© SPIE. Terms of Use
Back to Top