Figure 4. Reflectance spectra of 1D-PC of BFO and (a) SrTiO3-substrate (b) DyScO3-substrate at various incident angles and their spectra are calculated by TMM

From

Tunable Photonic Band Gap in a One-Dimensional Lattice Substituted Multiferroic - Dielectric Photonic Crystals in Near Infrared Region

Sanjay Srivastava

Journal of Optoelectronics Engineering. 2014, 2(1), 7-20 doi:10.12691/joe-2-1-2