A grating-based narrowband wavelength selective reflector on silicon on insulator waveguide is proposed here. The 500 nm thick silicon waveguide is used in the reflector design. The design consists of dual-etch layers for different grating sets separated by the center cavity. The dutycycle, grating-period, and side etching depth are optimized for achieving high reflection and narrow bandwidth. The proposed reflector shows a reflection of 96 % with a full-width halfmaximum bandwidth of 1.5 nm at 1550 nm wavelengths.