RT Journal Article T1 Bandpass filter implemented with blazed waveguide sidewall gratings in silicon-on-insulator A1 Villafranca Velasco, Aitor A1 Bock, Przemek J. A1 Cheben, Pavel A1 Calvo Padilla, María Luisa A1 Schmid, Jens H. A1 Lapointe, Jean A1 Xu, Dan-Xia A1 Janz, Siegfried A1 Delâge, André AB The fabrication and experimental characterisation of a two-stage bandpass filter based on curved waveguide sidewall gratings is reported for the silicon-on-insulator platform. At each cascaded filtering stage, the spectral components of the input signal are dispersed by the diffraction grating formed in the sidewall of a silicon strip waveguide. Different wavelengths are focused onto different positions along the Rowland circle and the filter central wavelength is selected by a specific receiver waveguide. By using two consecutive filtering stages, both the filter passband profile and the stopband rejection ratio are substantially increased. The grating is apodised and chirped to ensure a constant effective index along the grating length to minimise phase distortions. Blazed geometry is used to maximise the diffraction efficiency to the - 1st order. The device was fabricated with electron beam lithography and reactive ion etching using a single etch step. A bandwidth of 6.2 nm was measured near 1590 nm for the fabricated filter, with a roll-off of 4 dB/nm at the passband edge, and a stopband rejection of 40 dB. PB The Institution of Engineering and Technology (IET) SN 0013-5194 YR 2012 FD 2012-06-07 LK https://hdl.handle.net/20.500.14352/44170 UL https://hdl.handle.net/20.500.14352/44170 LA eng NO © The Institution of Engineering and Technology 2012.Financial support from the Spanish Ministry of Science and Innovation is acknowledged under grant TEC2008-04105. NO Ministerio de Ciencia e Innovación (MICINN), España DS Docta Complutense RD 9 abr 2025