A spherical distributed Bragg reflector based on $a$-Si$_{1-x}$C$_{x}$ : H and $a$-SiO$_{2}$

A spherical distributed Bragg reflector (SDBR) for near-infrared applications is elaborated via plasma-enhanced chemical-vapor deposition. It consists of the alternating quarter-wave layers of amorphous hydrogenized silicon carbide ($a$-Si$_{1-x}$C$_{x}$ : H) and amorphous silicon oxide ($a$-SiO$_{2}$) deposited onto a glass microsphere. The reflection spectra of the SDBR are measured at different points of its surface. In all cases, the Bragg-reflection bands, as well as the wavelength range of their overlap, are detected, evidencing the presence of a complete photonic band gap in the SDBR obtained.