Sharma Ankita, Straguzzi John N, Xue Tianyuan, Govdeli Alperen, Chen Fu Der, Stalmashonak Andrei, Sacher Wesley D, Poon Joyce K S
Max Planck Institute of Microstructure Physics, Halle (Saale), Germany.
Department of Electrical and Computer Engineering, University of Toronto, Toronto, Canada.
Nanophotonics. 2024 Mar 8;13(12):2241-2249. doi: 10.1515/nanoph-2023-0819. eCollection 2024 May.
A challenge in optical phased arrays (OPAs) is to achieve single-lobe emission using densely spaced emitters without incurring inter-waveguide optical crosstalk. Here, we propose to heuristically optimize the amplitude and phase of each grating antenna in an OPA to correct for optical non-idealities, including fabrication variations and inter-waveguide crosstalk. This method was applied to a silicon photonic integrated circuit with 1 mm-long gratings at 775 nm spacing for operation in a wavelength range of 1450-1650 nm. We achieved a wide two-dimensional beam-steering range of 110° × 28°, evaluated over a 127° × 47° field-of-view (FOV). Within this FOV, we measured an average sidelobe suppression of 8.2 dB and focused on average, 34.5 % of the emitted power into the main lobe. We achieved a peak sidelobe suppression of 14.5 dB and 50 % of the power concentrated in the main lobe. The approach is suitable for applications that require alias-free out-of-plane emission.
光学相控阵（OPA）面临的一个挑战是，在使用密集排列的发射器实现单瓣发射的同时，避免波导间的光学串扰。在此，我们建议通过启发式方法优化OPA中每个光栅天线的幅度和相位，以校正光学非理想因素，包括制造差异和波导间串扰。该方法应用于一个硅光子集成电路，其光栅长度为1毫米，间距为775纳米，工作波长范围为1450 - 1650纳米。我们在127°×47°的视场（FOV）内评估，实现了110°×28°的宽二维光束转向范围。在该视场内，我们测得平均旁瓣抑制为8.2分贝，平均有34.5%的发射功率聚焦到主瓣中。我们实现了14.5分贝的峰值旁瓣抑制，且50%的功率集中在主瓣中。该方法适用于需要无杂散面外发射的应用。
