Abstract

Recently, waveguide evanescent field fluorescence (WEFF) microscopy was introduced and used to image and analyze cell–substrate contacts. Here, we establish a comprehensive electromagnetic theory in a seven-layer structure as a model for a typical waveguide–cell structure appropriate for WEFF microscopy and apply it to quantify cell–waveguide separation distances. First, electromagnetic fields at the various layers of a model waveguide–cell system are derived. Then, we obtain the dispersion relation or characteristic equation for TE modes with a stratified media as a cover. Waveguides supporting a defined number of modes are theoretically designed for conventional, reverse, and symmetric waveguide structures and then various waveguide parameters and the penetration depths of the evanescent fields are obtained. We show that the penetration depth of the evanescent field in a three-layer waveguide–cell structure is always lower than that of a seven-layer structure. Using the derived electromagnetic fields, the background and the excited fluorescence in the waveguide–cell gap, filled with water-soluble fluorophores, are analytically formulated. The effect of the waveguide structures on the fluorescence and the background are investigated for various modes. Numerical results are presented for the background and the stimulated fluorescence as functions of the water gap width for various waveguide structures, which can be used to find the water gap width. The results indicate that the background and excited fluorescence increase by increasing the penetration depth of the evanescent field. In addition, we show that for various guided modes of a conventional waveguide, the electric fields in the cell membrane and the cytoplasm are evanescent and they do not depend on the waveguide structure and the mode number. However, for the reverse symmetry and symmetric waveguide structures, the waves are sinusoidal in the cell membrane and the cytoplasm for the highest-order modes.

© 2018 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Highly confined surface imaging by solid immersion total internal reflection fluorescence microscopy

Lin Wang, Cvetelin Vasilev, Daniel P. Canniffe, Luke R. Wilson, C. Neil Hunter, and Ashley J. Cadby
Opt. Express 20(3) 3311-3324 (2012)

Surface plasmon-enhanced two-photon fluorescence microscopy for live cell membrane imaging

Ruei-Yu He, Yuan-Deng Su, Keng-Chi Cho, Chun-Yun Lin, Nan-Shan Chang, Chih-Han Chang, and Shean-Jen Chen
Opt. Express 17(8) 5987-5997 (2009)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (6)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (3)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (29)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription