Taylor Amplitude Distribution for Low Sidelobe in Thin-Film Lithium Niobate Optical Phased Array

As a novel solid-state active steering beam chip, the integrated optical phased array (OPA) has been widely utilized in light detection and ranging (LiDAR), free-space optical communication, and biological imaging. In this study, we design and experimentally demonstrate a 16-channel OPA featuring a Taylor amplitude distribution to achieve an ultralow sidelobe level, implemented using a cascaded array of arbitrary ratio power splitters (ARPSs) on a silicon nitride (SiN) strip-loaded thin-film lithium niobate (TFLN) platform. The ARPSs are introduced to manipulate the amplitude distribution among the channel array, thereby suppressing sidelobe levels. The proposed TFLN-SiN OPA, utilizing a Taylor amplitude distribution, achieves a peak sidelobe level (PSLL) of 20.3 dB at 0°, an average sidelobe suppression ratio (SLSR) of 15.8 dB across the entire field of view (FOV), a two-dimensional beam steering capability with a FOV of 62° × 7.6°, and a beam divergence of 3.2° × 1.4°. This work highlights the significant advantages of the TFLN-SiN hybrid integrated OPA with a Taylor amplitude distribution, including low sidelobe levels, low power consumption, and high-speed beam steering.