Appendix 2—figure 2. Three-dimensional finite-difference time-domain simulations of the electric field intensity distribution of the excitation spot in the presence of a freestanding zero-mode waveguide (ZMW) (compare Appendix 2—figure 1), at excitation wavelengths of 488 nm (A–D) and 640 nm (E–H).

Shown are the intensity distributions of the focused Gaussian beam in the absence (A, E) and presence (B–C, F–G) of the freestanding palladium ZMW. (D, H) The z-profiles of the intensity distribution along the center of the pore. The position of the palladium membrane is indicated as a gray shaded area.