Opt Lett. 2020 Apr 1;45(7):1934-1937. doi: 10.1364/OL.385201.
Compact beam steering in the visible spectral range is required for a wide range of emerging applications, such as augmented and virtual reality displays, optical traps for quantum information processing, biological sensing, and stimulation. Optical phased arrays (OPAs) can shape and steer light to enable these applications with no moving parts on a compact chip. However, OPA demonstrations have been mainly limited to the near-infrared spectral range due to the fabrication and material challenges imposed by the shorter wavelengths. Here, we demonstrate the first chip-scale phased array operating at blue wavelengths (488 nm) using a high-confinement silicon nitride platform. We use a sparse aperiodic emitter layout to mitigate fabrication constraints at this short wavelength and achieve wide-angle beam steering over a 50° field of view with a full width at half-maximum beam size of 0.17°. Large-scale integration of this platform paves the way for fully reconfigurable chip-scale three-dimensional volumetric light projection across the entire visible range.
在许多新兴应用中，如增强现实和虚拟现实显示器、用于量子信息处理的光学陷阱、生物传感和刺激等，都需要在可见光光谱范围内实现紧凑的光束转向。光学相控阵 (OPA) 可以通过无移动部件的紧凑芯片来塑造和引导光线，从而实现这些应用。然而，由于较短波长带来的制造和材料挑战，OPA 的演示主要限于近红外光谱范围。在这里，我们使用高约束氮化硅平台展示了第一个在蓝色波长（488nm）下工作的芯片级相控阵。我们使用稀疏的非周期性发射器布局来减轻这个短波长的制造限制，并在 50°视场范围内实现广角光束转向，半最大值光束尺寸为 0.17°。该平台的大规模集成为整个可见光范围内完全可重构的芯片级三维体积光投影铺平了道路。
