We study 200 nm thick hydrogenated amorphous silicon (a-Si:H) optical strip waveguides fabricated by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique over PECVD silicon oxide on top of standard silicon wafer. The layer of a-Si:H is etched by Reactive Ion Etching (RIE). The ability to deposit a-Si:H at low temperatures (~250°C) by PECVD renders it a promising material for integration of optical waveguides with microelectronics. Waveguides with width varying from 2 μm to 10 μm exhibit low loss. Material refractive index data of a-Si:H is measured by reflectometry and is used in simulations. A high refractive index contrast between a-Si:H and air allows tight optical confinement of modes. We demonstrate Bragg gratings fabricated by e-beam writing technology on top of the waveguides. The period of the grating is approximately 300 nm and the depth of the grooves is about 30 nm. The grating on top of the waveguide act as mirror.