Ito Hiroyuki, Tatebe Tomoki, Abe Hiroshi, Baba Toshihiko
Opt Express. 2018 Oct 1;26(20):26145-26155. doi: 10.1364/OE.26.026145.
We proposed and demonstrated a wavelength-division multiplexing (WDM) optical beam-steering device consisting of a thermally controlled doubly periodic Si two-dimensional bulk photonic crystal waveguide and coupled microring multiplexers. Beam forming and steering while maintaining a sharp profile is much easier in this device than with optical phased arrays which need the fine phase control. By dividing the range of beam-steering angles into different wavelength channels, it is possible to cover a wide range of angles, even when each angle is small. In this study, we fabricated a device with four wavelength channels, each of which showed beam steering of 4°-5° as a result of heating, resulting in a total of 16°. Two-dimensional steering is also achieved by loading a collimator lens and selecting one waveguide from those arrayed. We evaluated 112 resolution points with four wavelengths and 448 points in total by switching four waveguides. If this WDM concept is introduced into light detection and ranging and the number of wavelengths is increased, it will be possible to increase the sensing throughput, which is usually constrained by the round-trip time of light, by simultaneous parallel operation.
我们提出并展示了一种波分复用（WDM）光束转向装置，它由一个热控双周期硅二维体光子晶体波导和耦合微环复用器组成。与需要精细相位控制的光学相控阵相比，该装置在保持尖锐轮廓的同时进行光束形成和转向要容易得多。通过将光束转向角范围划分到不同的波长通道，即使每个角度较小，也能够覆盖很宽的角度范围。在本研究中，我们制作了一个具有四个波长通道的装置，每个通道在加热时都表现出4° - 5°的光束转向，总共可达16°。通过加载准直透镜并从排列的波导中选择一个，还可实现二维转向。我们通过切换四个波导评估了四个波长下的112个分辨率点，总共448个点。如果将这种WDM概念引入光探测与测距领域并增加波长数量，那么通过同时并行操作，就有可能提高通常受光往返时间限制的传感通量。
