Author Affiliations
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, Chinashow less
Fig. 1. Schematic diagram of the SP-HBS and LP-HBS. The grating comprises simple dielectric bars with high refractive index, surrounded by a low-index medium, herein, InP and air. T, HCG period; , grating bar width; D, HCG duty cycle, ; , HCG thickness.
Fig. 2. Schematic diagrams of designing an SP-HBS: (a) a basic grating unit, A-B-A; (b) the periodical extending of basic grating units; (c) a formed SP-HBS.
Fig. 3. Designed grating bars of SP-HBS and LP-HBS distributed on the X axis and their geometric structural parameters: (a) and (b) periods; (c) and (d) duty cycles.
Fig. 4. Transmissivity distributions and phase distributions of the grating bars used in SP-HBS and LP-HBS: (a) and (b) transmissivity distributions; (c) and (d) phase distributions.
Fig. 5. Simulation results of SP-HBS and LP-HBS for the normal incidence of a 1.55 μm TM-polarization Gaussian plane wave: (a) and (b) the electric-field intensity distributions, (d) and (e) the results by measuring the cut lines at , 20 μm, and 40 μm in (a) and (b), with (a) and (d) for SP-HBS and (b) and (e) for the LP-HBS; the FWHM of incident light is 20 μm. (c) is the splitting effect of an SP-HBS with 9.9 μm width when the incident light () propagates from the near- to far-field, and (f) is the measurement results by cutting (c) at , 60 μm, and 90 μm.
Fig. 6. Simulation results of the SP-HBSs whose are (a) , (b) , (c) , (d) , (e) , and (f) . Insets are the normalized electric-field intensity of the cut line at .
Fig. 7. Simulation results of SP-HBS for the small-angle () oblique incidence of a 1.55 μm TM-polarization Gaussian (FWHM = 5 μm) plane wave. The deflection angles of beams A and B are 52.3° and 38.1°, respectively.