Advances in the FDTD design and modeling of nano- and bio-photonics applications

In this paper we focus on the discussion of two recent unique applications of the finite-difference time-domain (FDTD) simulation method to the design and modeling of advanced nano- and bio-photonic problems. The approach that is adopted here focuses on the potential of the FDTD methodology to address newly emerging problems and not so much on its mathematical formulation. We will first discuss the application of a traditional formulation of the FDTD approach to the modeling of sub-wavelength photonics structures. Next, a modified total/scattered field FDTD approach will be applied to the modeling of biophotonics applications including optical phase contrast microscope (OPCM) imaging of cells containing gold nanoparticles (NPs) as well as its potential application as a modality for in vivo flow cytometry configurations. The conclusion provides a justification for the selection of the two specific examples and summarizes some of the insights that could open the opportunity for the application of the FDTD approach in new research areas.

► Review of two recent unique applications of the FDTD method. ► Refractive index engineering in sub-wavelength silicon waveguide crossings. ► Optical phase contrast imaging of gold nanoparticles in single bio cells. ► FDTD enables the optimization of the refractive-index contrast of the waveguide crossings. ► Optical clearing effect will enhance gold nanoparticle imaging contrast in bio cells. ► Summary of insights and potential challenges that could be helpful in applying the FDTD approach in new research areas.