Optical phased arrays (OPAs), the optical counterpart of phased arrays at radio frequencies, can electronically steer an optical beam without any moving parts. To achieve a 180° field of view (FOV), the array emitters should be spaced a half-wavelength apart or less. However, a conventional OPA based on a waveguide grating array suffers from strong cross talk between adjacent waveguides when the pitch is a half-wavelength or less. Here, we theoretically describe and experimentally demonstrate a two-dimensional aliasing-free beam steering regime for an integrated OPA with the entire 180° FOV. We achieve this by using a half-wavelength-pitch waveguide array combined with a trapezoidal slab grating as a single emitter. Our OPA also features a low sidelobe level of <−19dB${\lt}{-}19\;{\rm dB}$ while the beam is steered from −40∘${-}{40}^\circ$ to +40∘${+}{40}^\circ$, breaking the trade-off between FOV and beam quality. The chip-based OPA with a large beam steering range and high beam quality provides a promising route for a compact, solid-state, cost-effective, and high-performance light detection and ranging system, enabling a wide range of classical and quantum applications.

中文翻译：

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具有 180 度视场的硅光学相控阵，用于 2D 光束转向

光学相控阵 (OPA) 是相控阵在射频上的光学对应物，可以在没有任何移动部件的情况下以电子方式控制光束。为了实现 180° 视场 (FOV)，阵列发射器的间距应为半波长或更小。然而，当间距为半波长或更小时，基于波导光栅阵列的传统 OPA 会遭受相邻波导之间的强串扰。在这里，我们从理论上描述并通过实验证明了用于具有整个 180° FOV 的集成 OPA 的二维无混叠光束转向机制。我们通过使用半波长间距波导阵列与梯形平板光栅作为单个发射器来实现这一点。我们的 OPA 还具有< − 19的低旁瓣电平d B${\lt}{-}19\;{\rm dB}$当光束从− 40 ∘${-}{40}^\circ$转向+ 40 ∘${+}{40}^\circ$时，打破了 FOV 和光束质量之间的权衡。具有大光束转向范围和高光束质量的基于芯片的 OPA 为紧凑、固态、具有成本效益和高性能的光检测和测距系统提供了一条有前途的途径，可实现广泛的经典和量子应用.