Kharratian Soheila, Urey Hakan, Onbaşlı Mehmet C
Department of Materials Science and Engineering, Koç University, Sarıyer, Istanbul, 34450, Turkey.
Department of Electrical and Electronics Engineering, Koç University, Sarıyer, Istanbul, 34450, Turkey.
Sci Rep. 2019 Jan 24;9(1):644. doi: 10.1038/s41598-018-37317-9.
Magnetooptical spatial light modulators (MOSLMs) are photonic devices that encode information in photonic waveforms by changing their amplitude and phase using magnetooptical Faraday or Kerr rotation. Despite the progress on both MO materials and switching methods, significant improvements on materials engineering and SLM design are needed for demonstrating low-power, multicolor, analog and high-contrast MOSLM devices. In this study, we present design rules and example designs for a high-contrast and large figure-of-merit MOSLM using three-color magnetophotonic crystals (MPC). We demonstrate for the first time, a three-defect MPC capable of simultaneously enhancing Faraday rotation, and high-contrast modulation at three fundamental wavelengths of red, green and blue (RGB) within the same pixel. We show using 2D finite-difference time-domain simulations that bismuth-substituted yttrium iron garnet films are promising for low-loss and high Faraday rotation MOSLM device in the visible band. Faraday rotation and loss spectra as well as figure-of-merit values are calculated for different magnetophotonic crystals of the form (H/L)/(D/L)/(H/L). After an optimization of layer thicknesses and MPC configuration, Faraday rotation values were found to be between 20-55° for losses below 20 dB in an overall thickness less than 1.5 µm including three submicron garnet defect layers. The experimental demonstration of our proposed 3-color MOSLM devices can enable bistable photonic projectors, holographic displays, indoor visible light communication devices, photonic beamforming for 5 G telecommunications and beyond.
磁光空间光调制器（MOSLMs）是一种光子器件，它通过磁光法拉第或克尔旋转来改变光子波形的幅度和相位，从而在光子波形中编码信息。尽管在磁光材料和开关方法方面都取得了进展，但要展示低功耗、多色、模拟和高对比度的MOSLM器件，仍需要在材料工程和SLM设计方面有显著改进。在本研究中，我们提出了使用三色磁光子晶体（MPC）的高对比度和大品质因数MOSLM的设计规则和示例设计。我们首次展示了一种三缺陷MPC，它能够在同一像素内同时增强法拉第旋转，并在红、绿、蓝（RGB）三个基本波长处实现高对比度调制。我们使用二维时域有限差分模拟表明，铋取代的钇铁石榴石薄膜有望用于可见光波段低损耗和高法拉第旋转的MOSLM器件。针对不同形式（H/L）/（D/L）/（H/L）的磁光子晶体，计算了法拉第旋转和损耗光谱以及品质因数。在优化层厚度和MPC配置后，发现在包括三个亚微米石榴石缺陷层的总厚度小于1.5 µm且损耗低于20 dB的情况下，法拉第旋转值在20 - 55°之间。我们所提出的三色MOSLM器件的实验演示能够实现双稳态光子投影仪、全息显示器、室内可见光通信设备、用于5G及以后的光子波束形成。
