| Proj No. | A2085-251 |
| Title | Compact sinusoidal silicon waveguide array for chip-scale optical phased arrays |
| Summary | Due to the rapid development of photonic integrated circuits (PICs), chip-scale optical phased arrays (OPAs) hold the promise of ultra-fast inertia-free beam steering, flexibility in arbitrary beam shaping, and large-scale CMOS-compatible fabrication. These advantages make this solution ideal for applications such as light detection and ranging (LIDAR), holographic displays, and free-space optical communications. The waveguide emitters of current silicon OPAs are typically a few microns apart, which is effective in reducing crosstalk but at the expense of steering range. Therefore, an important research direction for existing OPAs is to reduce the emitter spacing as much as possible without increasing the crosstalk between neighbouring waveguides, so as to obtain a large steering range. Many schemes have been proposed to achieve this goal. For example, researchers have implemented low crosstalk half-wavelength spaced waveguide arrays by minimising the propagation length. In this scheme, the half-wavelength spacing has a crosstalk of -11 dB. It should be noted that this approach may not be conducive to commercial packaging due to the short waveguide length. However, the minimum gap between the strip and the waveguide is 27.5 nm, which is challenging to fabricate. In this project, we will investigate a sinusoidal silicon waveguide array. Coupling between waveguides is reduced by introducing an artificial periodic potential during waveguide propagation. We will experimentally demonstrate a simple but very effective method of constructing OPA emitters based on arrays of sinusoidal silicon waveguides. The small pitch emitters that will be designed in this programme will allow for a 180° beam steering range and an effective reduction in power consumption. The project will cover waveguide optics, semiconductor device physics and advanced numerical simulation tools. The learning curve should be to (1) understand the theory of higher-order mode coupling in guided-wave optics, (2) simulate basic waveguide structures and obtain their optimal coupling parameters, (3) optimise the performance of the structures in conjunction with algorithms such as inverse design or deep learning, and (4) as an exemplar, if the simulations turn out to be sufficiently interesting, we will attempt to fabricate devices. Through these studies, students will gain basic knowledge in optical communication and complete training in optical device design and preparation, which will help them understand the field of optical communication and prepare them to master this emerging on-chip communication and transmission technology. |
| Supervisor | Ast/P Guangwei Hu (Loc:S1 > S1 B1B > S1 B1B 39, Ext: +65 67904337) |
| Co-Supervisor | - |
| RI Co-Supervisor | - |
| Lab | Photonics I (Loc: S1-B3a-08) |
| Single/Group: | Single |
| Area: | Microelectronics and Biomedical Electronics |
| ISP/RI/SMP/SCP?: |