基于单个推挽调制器产生矢量毫米波信号的光路方案,结合几何成形技术,研究了8PSK/GS-8PSK和8QAM/GS-8QAM调制格式下8/16-Gbaud 80 GHz的矢量毫米波信号的传输性能。结果表明,与传统调制格式相比,几何成形后的信号在背靠背和光纤传输条件下的误码率与光功率均有明显的改善,8-Gbaud GS-8PSK信号经过150 km光纤传输后,光功率约有1 dBm的提升;16-Gbaud GS-8QAM调制信号经过背靠背和80 km光纤传输后,光功率约有0.5 dBm的改善。
Metasurface provides miniaturized devices for integrated optics. Here, we design and realize a meta-converter to transform a plane-wave beam into multiple Laguerre-Gaussian (LG) modes of different orders at various diffraction angles. The metasurface is f
The visible and near-UV emission spectroscopy of methane (
CH4
Micro-deposition of an aluminum film of 500-nm thickness on a quartz substrate was demonstrated by laser-induced forward transfer (LIFT) using a femtosecond laser pulse. With the help of atomic force microscopy (AFM) and scanning electron microscopy (SEM)
We report an all-fiber high power, single frequency large-mode area (LMA) linearly polarized ytterbiumdoped fiber amplifiers (YDFA) module, which is based on the master oscillator multi-stage power amplifiers (MOPA). The maximum output power is 43.8 W at
利用光谱学手段研究了CH3NH3PbI3薄膜中的放大自发辐射效应。首先,从随温度变化的光致发光(Photoluminescence,PL)光谱中观察到了CH3NH3PbI3从正交相到四方相的相变。在低于相变温度时, PL过程优先发生在四方相上。在较高的激发光强下, 正交相的PL峰由于四方相上激子浓度的饱和而逐渐显现,导致了放大自发辐射现象。然而, 放置15天后的CH3NH3PbI3薄膜中激光效应却出现在了四方相上, 表明CH3NH3PbI3薄膜中的缺陷态能够自发湮灭, 从而增强了四方相在低温下的光辐射能力
美国加里福尼亚洲国际商用机器公司研究实验室的A. Tam提出了在固体中非破坏地获得超短超声脉冲(10-9M/sup
通过数值仿真, 研究了空间孤子在经过一个宇称-时间(PT)对称纵向势垒之后的动态传播特性。仿真结果表明, 空间孤子穿越势垒之后有一个横向的偏折。偏折角度与PT对称势垒的增益/损耗项、调制深度以及纵向宽度有关, 增益/损耗项对空间孤子的动态特性有重要的影响。此外, 空间孤子在经过一个PT对称势垒之后会得到能量上的增益, 增益大小与偏折角度有密切的关系。通过调整势垒参数可以控制偏折的角度, 这使得空间孤子在光开关、光通信等众多领域中具有巨大的应用前景。
A ring cavity fiber laser based on Fabry-Pérot interferometer (FPI) is proposed and demonstrated experimentally for micro-displacement sensing. Simulation results show that the dips of the FPI transmission spectrum are sensitive to the cavity length of th