Large-scale nanophotonic phased array
Large-scale nanophotonic phased array
复制标题
DOI：
10.1038/nature11727
复制
发表时间：
2013-01-10
期刊：
影响因子：
64.8
通讯作者：
Watts, Michael R.
中科院分区：
文献类型：
--
作者：
Sun, Jie;Timurdogan, Erman;Watts, Michael R.
无线电频率的电磁相控阵是众所周知的，使从通信到雷达、广播和天文学的各种应用成为可能。利用大规模相控阵产生任意辐射方向图的能力一直是人们追求的目标。虽然部署大规模射频相控阵极其昂贵和繁琐(2)，但光学相控阵有一个独特的优势，即更短的光学波长为大规模集成提供了希望(3)。然而，短的光学波长也对制作提出了严格的要求。因此，尽管已经用各种平台(4-8)和最近的芯片尺度纳米光子学(9-12)研究了光学相控阵，但到目前为止所有的演示都局限于一维或小规模的二维阵列。本文报道了一种大规模的二维纳米光子相控阵的演示。在该相控阵中，和(4,096)个光学纳米天线密集地集成在一个硅芯片上，面积为576微米×576微米，所有的纳米天线在功率上精确平衡，并在远场中进行相位对准，以产生设计好的、复杂的远场辐射方向图。我们还通过8×8阵列的动态波束控制和整形演示了所提出的NPA可以实现有源相位可调。这项工作表明，坚固的设计加上最先进的互补金属氧化物半导体技术，可以在紧凑而廉价的纳米光子芯片上实现大规模的NPA。反过来，这使得能够使用NPA产生任意辐射图案，从而将相控阵的功能扩展到传统的光束聚焦和转向之外，为在通信、激光探测和测距、三维全息术和生物医学科学等应用中的大规模部署打开了可能性。
Electromagnetic phased arrays at radio frequencies are well known and have enabled applications ranging from communications to radar, broadcasting and astronomy(1). The ability to generate arbitrary radiation patterns with large-scale phased arrays has long been pursued. Although it is extremely expensive and cumbersome to deploy large-scale radiofrequency phased arrays(2), optical phased arrays have a unique advantage in that the much shorter optical wavelength holds promise for large-scale integration(3). However, the short optical wavelength also imposes stringent requirements on fabrication. As a consequence, although optical phased arrays have been studied with various platforms(4-8) and recently with chip-scale nanophotonics(9-12), all of the demonstrations so far are restricted to one-dimensional or small-scale two-dimensional arrays. Here we report the demonstration of a large-scale two-dimensional nanophotonic phased array (NPA), in which 64 x 64 (4,096) optical nanoantennas are densely integrated on a silicon chip within a footprint of 576 mu m x 576 mu m with all of the nanoantennas precisely balanced in power and aligned in phase to generate a designed, sophisticated radiation pattern in the far field. We also show that active phase tunability can be realized in the proposed NPA by demonstrating dynamic beam steering and shaping with an 8 x 8 array. This work demonstrates that a robust design, together with state-of-the-art complementary metal-oxide-semiconductor technology, allows large-scale NPAs to be implemented on compact and inexpensive nanophotonic chips. In turn, this enables arbitrary radiation pattern generation using NPAs and therefore extends the functionalities of phased arrays beyond conventional beam focusing and steering, opening up possibilities for large-scale deployment in applications such as communication, laser detection and ranging, three-dimensional holography and biomedical sciences, to name just a few.