Journal: Interface Focus

Article Title: Reflections on iridescent neck and breast feathers of the peacock, Pavo cristatus

doi: 10.1098/rsfs.2018.0043

Figure Lengend Snippet: Modelling the reflectance spectra of the blue barbules for normally incident light. (a) Real and imaginary effective refractive index profiles (at 500 nm) of the model barbule (inset). (b) Reflectance spectra for TE-polarized light calculated for half the model barbule using the EMM and FDTD methods. (c) Reflectance spectra for TM-polarized light calculated for the same model barbule. Inset: TE-light is polarized parallel and TM-light perpendicular to the melanosome longitudinal axis.

Article Snippet: The barbules appeared to be about specular-reflecting, and because the reference was a diffuse white reflectance tile (Avantes WS-2), the MSP reflectance signals were scaled to the modelled peak intensity.

Techniques: Refractive Index

Journal: Interface Focus

Article Title: Reflections on iridescent neck and breast feathers of the peacock, Pavo cristatus

doi: 10.1098/rsfs.2018.0043

Figure Lengend Snippet: Imaging scatterometry and angle-resolved reflectance spectra of a distal part of a peacock neck feather. (a) Scatterogram of a single barbule cell illuminated by a narrow-aperture, unpolarized light beam (indicated by the white dot). (b) Scatterogram of a few barbule cells illuminated with a hemispherical, wide-aperture beam. The beam was vertically polarized (indicated by the up–down arrow), parallel to the barbule; the black bar at 9 o'clock is due to the shadow of the glass micropipette holding the barb. (c) Reflectance spectra for TE-polarized light as a function of the angle of light incidence (varying from 0° to 70°). (d) Reflectance spectra for TM-polarized light as a function of the angle of light incidence. The plane of incidence was parallel to the feather's rachis.

Article Snippet: The barbules appeared to be about specular-reflecting, and because the reference was a diffuse white reflectance tile (Avantes WS-2), the MSP reflectance signals were scaled to the modelled peak intensity.

Techniques: Imaging

Journal: Interface Focus

Article Title: Reflections on iridescent neck and breast feathers of the peacock, Pavo cristatus

doi: 10.1098/rsfs.2018.0043

Figure Lengend Snippet: Reflectance and absorbance spectra of peacock neck feather barbules measured with a microspectrophotometer and calculated by EMM modelling. (a) Reflectance spectra measured at the distal (blue and green) regions, scaled by set-up-specific factor and modelled spectra. (b) Absorbance spectra measured at the distal region in air and immersed in water, and modelled spectra for a barbule in air and water, where (1) the water was assumed to be only present outside the barbule, and (2) the air channels were also assumed to be filled with water. (c) Reflectance spectra of the three model cases of (b).

Article Snippet: The barbules appeared to be about specular-reflecting, and because the reference was a diffuse white reflectance tile (Avantes WS-2), the MSP reflectance signals were scaled to the modelled peak intensity.

Techniques:

Journal: Interface Focus

Article Title: Reflections on iridescent neck and breast feathers of the peacock, Pavo cristatus

doi: 10.1098/rsfs.2018.0043

Figure Lengend Snippet: Modelled angle-dependent reflection characteristics of a melanosome–air channel stack. (a) Reflectance spectra of the photonic structure of figure 4 for TE-polarized light calculated with the EMM method. (b) The same as in (a), but for TM-polarized light. (c) Peak wavelength of the reflectance spectra for TE- and TM-polarized light as a function of the angle of light incidence calculated with the EMM as well as the FDTD method. (d) Peak reflectance of the calculated spectra.

Article Snippet: The barbules appeared to be about specular-reflecting, and because the reference was a diffuse white reflectance tile (Avantes WS-2), the MSP reflectance signals were scaled to the modelled peak intensity.

Techniques:

Journal: Interface Focus

Article Title: Reflections on iridescent neck and breast feathers of the peacock, Pavo cristatus

doi: 10.1098/rsfs.2018.0043

Figure Lengend Snippet: Reflectance spectra of the two-dimensional photonic structures of peacock barbules dependent on size disorder calculated with the FDTD method. (a) The size of the melanosomes was varied randomly with a different amount of maximal change (σm), keeping the air channel size constant. (b) The size of the air channels was varied randomly with a different amount of maximal change (σa), keeping the melanosome size constant. (c) The effect of disorder when varying both diameters randomly up to a maximum variation of 30%.

Article Snippet: The barbules appeared to be about specular-reflecting, and because the reference was a diffuse white reflectance tile (Avantes WS-2), the MSP reflectance signals were scaled to the modelled peak intensity.

Techniques: