Mirror-integrated arrayed-waveguide grating on silicon-on-insulator

Abstract: In this paper we design and fabricate the first mirror-integrated silicon-on-insulator-based (SOI-based) arrayed-waveguide grating (AWG) with working functions. The fabricated AWG has a channel spacing of 1.6 nm centered at 1556 nm. We substitute the bent waveguides array in the traditional AWG configuration by adopting the structure of the mirror-integrated straight waveguides. Theoretical advantages of the new structure are demonstrated. Detailed description of the design procedure and the fabrication process is provided. Test results of both the traditional AWG and this design are delineated and analyzed, which shows that the total length of the waveguide array is reduced from 3.14 cm to 2.53 cm, and the holistic structure also becomes more compact. The crosstalk of the fabricated 1x8 AWG is better than –20 dB. The typical on-chip insertion loss is about 10 dB. Losses caused by the mirrors and the waveguides transmission are about 4.2 dB, both of which resulted from the imprecision in the fabrication process. Key words: integrated optics, optical demultiplexer, silicon-on-insulator, ridge waveguide, arrayed waveguide grating, mirror.