Author Affiliations
Abstract
Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, South China Normal University, Guangzhou 510006, China
We present an automatic repeat request (ARQ) free space optical (FSO) system, which consists of a pulse position modulation (PPM) hard decision and an ARQ. The new ARQ’s data error detection is based on a PPM hard decision’s results and can eliminate the traditional ARQ information redundancy. The results of the numerical simulation have a good agreement with theoretical analysis and show that the ARQ-FSO system can effectively improve the bit error rate (BER) performance of the direct hard decision PPM system. Additionally, the proposed system significantly improves the average throughput efficiency compared to traditional ARQ systems. These characteristics make the ARQ-FSO system suitable for application in low BER and complexity FSO scenarios.
010.1300 Atmospheric propagation 010.1330 Atmospheric turbulence 060.2605 Free-space optical communication Chinese Optics Letters
2017, 15(6): 060101
华南师范大学信息光电子科技学院,广东省微纳光子功能材料与器件重点实验室, 广东 广州 510006
设计了一种新型的基于金属表面等离子体激元(SPPs)的亚波长金属-绝缘体-金属(MIM)型类 电磁诱导透明(EIT)系统,该系统由一个直波导及其两边对称的齿形腔和纳米盘耦合而成。利用耦合模 式理论对结构进行分析,并通过时域有限差分方法(FDTD)进行数值模拟。当齿形腔和纳米盘的共振频率 相近,可以获得类EIT效应,改变齿形腔的长度和纳米盘的半径可以调节透明窗的位置。该装置可以用作高 性能的类EIT滤波器,透过率高达77.5%, 半高宽低至35.5 nm, 群指数高达65,为高度集成光网络提供了 一种新的方法,可应用于波长选择器、超快开关、光存储等设备。
纤维与波导光学 类EIT滤波器 时域有限差分方法 表面等离激元 慢光 fiber and waveguide optics electromagnetically induced transparency-like filt finite-difference time-domain surface plasmons slow light
Author Affiliations
Abstract
State Key Laboratory of Optoelectronic Materials and Technologies, Zhongshan University, Guangzhou 510275
Experimental results demonstrate that the band gap of colloidal suspension crystal changes with both the thickness of crystal and the dispersity of micro-spheres. As the thickness decreases, a red shift of band gap is observed, and there is a maximum of red shift. The values of the maximum red shifts are dependent on the standard deviations of micro-spheres. The experimental results are consistent with theoretical calculation. As the colloidal suspension crystal is assembled from micro-spheres with a standard deviation of 8.4% in a thick cell, an incident angles independent broadband is observed, which is explained as an amorphous structure. Two amorphous models are discussed.
160.0160 materials 300.0300 spectroscopy 300.6170 spectra Chinese Optics Letters
2004, 2(8): 08471
