Spectral filters are experiencing an increasing demand in several applications of the silicon-
on-insulator (SOI) platform. Many works have demonstrated that arbitrary frequency
responses can be synthesized by apodizing the coupling coefficient profile of an integrated
Bragg grating. However, the high index contrast of the SOI platform hinders their
practical implementation, due to the difficulty of achieving the precise control required in
the Bragg strength. In this paper, we propose the implementation of spectral filters using
an architecture based on placing loading segments within the evanescent field region of a
photonic wire waveguide. The Bragg coupling coefficient can be accurately controlled by
simply moving the segments away from, or closer to, the waveguide core. The layerpeeling
algorithm, in conjunction with a Floquet-Bloch modal analysis, allows to determine
the spatial distribution of the segments that synthesizes the desired spectrum. The
proposed topology is verified by designing a filter with five arbitrary passbands.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
