finite-difference time-domain (fdtd) calculations  (ANSYS inc)

Journal: bioRxiv

Article Title: Intracellular photonic crystals in photosynthetic sea slugs form via a kidney-mediated biomineralisation pathway

doi: 10.64898/2026.05.07.723475

Figure Lengend Snippet: a) Bright-field upright optical microscope (Zeiss axioscope, 63X WI objective) of calcophores on the dorsal surface of E. viridis , showing both homogenous ‘glassy’ colour (right), and striped, opalescent ‘crystalline’ optical texture (left). Exposure time for ‘glassy’ images is 2.5X that of ‘crystalline’ ones. Scale bar, 20 µ m. b) Reciprocal space (K-space) images for calcophores showing both ‘glassy’ (bottom) and ‘crystalline’ (top) type optical appearance corresponding to real space images in a , glassy K-space images show homogenous colouring, with a very slight blue shift at high angles. Crystalline K-space images show a strong blue shift at higher scattering angles, and a highly textured, hexagonal colour distribution corresponding to the angular response of the photonic crystals. The edge of the circle in the K-space images corresponds to NA = 0.9 (scattering at 42 ° ). Images taken with Zeiss axioscope, 63X WI objective. c) Dark-field upright optical microscope images of a cluster of calcophores before and after 20 minutes exposure to air. Dark orange carotenoid volumes (top and bottom left) can be used as markers to correlate the calcophores in the two images. Of the 7 calcophores in the cluster 4 of them show a blue-shift. Scale bar, 50 µ m. FDTD simulations of 5 µ m diameter spherical photonic structures found in E. viridis . A gaussian beam of radius 1.25 µ m was used for all simulations. The particles have been simplified to perfect spheres. d) Simulated spectra for a correlated structure (photonic glass), with particle sizes varying from 140 - 200 nm. e) Simulated spectra for expanded FCC photonic crystal with particle-to-particle distances varying from 1 d to 2 d (where d is the diameter of one particle, in this case 160 ± 5 nm). The (111) plane is perpendicular to the detector for simulations. f) Simulated spectra for close packed spheres with polycrystallinity i.e. the simulated structure is composed of multiple crystallographic volumes for d = 140 - 200 nm. g) Experimental bright field spectra (Zeiss axioscope, 63X WI objective, 50 µ m fibre) spectra of E. viridis photonic calcophores, showing photonic glass-like response. Spectra are normalised to a silver mirror. h) Experimental bright field spectra (Zeiss axioscope, 63X WI objective, 50 µ m fibre) spectra of E. viridis photonic calcophores, showing photonic crystal-like response. Spectra are normalised to a silver mirror.

Article Snippet: To match the optical properties of the photonic structures described here to those observed by electron microscopy and to demonstrate an expanded-FCC lattice that captures the measured optical response, we used finite-difference time-domain (FDTD) calculations on structures generated by molecular dynamics ( ).

Techniques: Microscopy

Journal: iScience

Article Title: Tuning of Classical Electromagnetically Induced Reflectance in Babinet Chalcogenide Metamaterials

doi: 10.1016/j.isci.2020.101367

Figure Lengend Snippet: Configuration and Performance of the EIR Babinet Metamaterials (A) Schematic illustration of the Babinet metamaterials. The geometrical parameters are: T Au = 40 nm, T GST = 30 nm, d = 200 nm, l 1 = 250, l 2 = 350 nm, w = 50 nm, and P x = P y = 500 nm. (B) SEM image of the fabricated metamaterials. Inset: zoom-in image of the unit cell. (C) NIR complex refractive index of 30-nm-thick GST film for both as-deposited amorphous and thermal annealing crystalline phases, where the refractive index data were measured using ellipsometer over a spectral range of 1,000–2,200 nm. (D) The FTIR measured (top panel) and FDTD simulated (bottom panel) reflectance spectra of the Babinet metamaterials for both the amorphous (blue solid lines) and crystalline (red dashed lines) phases under p -polarized incident light.

Article Snippet: The finite-difference time-domain (FDTD) calculations performed with the commercial software package Lumerical Solutions software are presented on the bottom panel of D for comparison.

Techniques: Refractive Index

Journal: iScience

Article Title: Tuning of Classical Electromagnetically Induced Reflectance in Babinet Chalcogenide Metamaterials

doi: 10.1016/j.isci.2020.101367

Figure Lengend Snippet: Performance of the Babinet Metamaterials under s -polarized Incidence The (A) FTIR-measured and (B) FDTD-simulated reflectance spectra of the Babinet metamaterials for both the amorphous (blue solid lines) and crystalline (red dashed lines) phases under s -polarized incident light.

Article Snippet: The finite-difference time-domain (FDTD) calculations performed with the commercial software package Lumerical Solutions software are presented on the bottom panel of D for comparison.

Techniques:

Journal: iScience

Article Title: Tuning of Classical Electromagnetically Induced Reflectance in Babinet Chalcogenide Metamaterials

doi: 10.1016/j.isci.2020.101367

Figure Lengend Snippet: Electromagnetic Fields Distributions of the Babinet Phase Change Metamaterials under p -polarized Incidence 3D-FDTD simulation of total E -field intensity distributions for (A–C) amorphous metamaterials at the resonant wavelengths of (A) λ = 1,262 nm, (B) λ = 1,490 nm, (C) λ = 1,620 nm, and for (D–F) crystalline metamaterials at the resonant wavelengths of (D) λ = 1,480 nm, (E) λ = 1,662 nm, (F) λ = 1,790 nm.

Article Snippet: The finite-difference time-domain (FDTD) calculations performed with the commercial software package Lumerical Solutions software are presented on the bottom panel of D for comparison.

Techniques:

Journal: iScience

Article Title: Tuning of Classical Electromagnetically Induced Reflectance in Babinet Chalcogenide Metamaterials

doi: 10.1016/j.isci.2020.101367

Figure Lengend Snippet: Effect of the Various Metals on the Spectra The FDTD-simulated reflectance spectra of the Babinet metamaterials based on the various metal films of Au (black line), Ag (red line), Al (blue line), and Cu (green line) for both the (A) amorphous and (B) crystalline phases under p -polarized incident light.

Article Snippet: The finite-difference time-domain (FDTD) calculations performed with the commercial software package Lumerical Solutions software are presented on the bottom panel of D for comparison.

Techniques: