RESUMO
A high performance optical phased array (OPA) combined with frequency-modulated continuous-wave (FMCW) technology is essential for coherent all-solid-state light detection and ranging (LiDAR). In this work, we propose and experimentally demonstrate a coaxial transceiver based on a single OPA for a LiDAR system, which releases the off-chip circulator and collimator. The proposed scheme is demonstrated on the commonly used silicon-on-insulator (SOI) platform. For realizing the long optical grating antenna with only one-step etching, the bound state in the continuum is harnessed to simplify the fabrication process and ease the fabrication precision. Experimental results indicate that the OPA is with 0.076° vertical beam divergence under a 1.5â mm-long grating antenna. The measured field of view (FOV) is 40° × 8° without grating lobes under a wavelength band of 60â nm. The coaxial transceiver of the single OPA is also demonstrated with the FMCW method for ranging measurement at different angles.
RESUMO
We propose and experimentally demonstrate a polarization multiplexed silicon optical phased array (OPA) with a wide scanning range. The two polarization states share the same power splitter tree and the phase shifter array. A polarization switch is introduced in front of the power splitter tree to manipulate the polarization state of the light in OPA. Through a polarization splitter-rotator (PSR), the light of two polarization states propagates into the superlattice grating antenna array. The wavelength tuning efficiency could be doubled by optimizing the parameters of the waveguide grating. We demonstrate the scheme on the commonly used 220â nm silicon-on-insulator (SOI) platform. Experimental results indicate that the 24.8° vertical scanning range could be realized with a high wavelength tuning efficiency of 0.31°/nm. The measured field of view (FOV) is 24.8 × 60°.