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.
A 1×8 multimode interference coupler with a strong confinement structure in the multimode region was proposed and fabricated on silicon-on-insulator material. In the multimode region, the waveguide was etched to the buried silica layer so as to realize the strong confinement and obtain better resolution of the self-imaging effect, while in the input/output ports, the rib waveguides with the large cross-section rib structure were designed to satisfy the single-mode condition, with which the device could be efficiently coupled with single-mode fibers or other waveguide devices. The fabrication process was also specially designed to eliminate the photolithography alignment error.
Planar lightwave circuits based on silicon are playing important roles in integrated optical systems. The integrated waveguide turning mirror (IWTM) is essential component for the compactness of optical devices. We designed and fabricated an integrated waveguide turning mirror with a 90° directional change in SOI. The mirror was etched by induct-coupled-plasma etching (ICP) first. Then the surface was enhanced by wet anisotropic etching. This two-step process introduced a compact IWTM with smooth and vertical surface. Compared with the mirror fabricated by wet anisotropic etching only, the mirror fabricate by the two-step process is better to meet the requirement of compact design.
A novel optical waveguide rectangular ring resonator is designed and fabricated in silicon-on-insulator (SOl). The resonator is composed of four straight waveguides connected by four 90° directional change-turning mirrors. This merged structure allows compact size and low loss. The input and output waveguides to couple energy into and out from the resonator are also designed and optimized in this work.
Planar lightwave circuits based on silicon are playing important roles in integrated optical systems. Integrated waveguide turning mirror (IWTM) is essential component for the compactness of optical devices. We design an integrated waveguide turning mirror with a 90 degree(s) directional change in SOI, which diminishes the primary loss from the displacement of waveguide and mirror and has very low mirror surface roughness. In this paper, the theory, design and fabrication of this IWTM are introduced. A beam splitter using the structure is fabricated to test the performances, and expected results are obtained.