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Effect of thickness variations of lithium niobate on insulator waveguide on the frequency spectrum of spontaneous parametric down-conversion 下载免费PDF全文
Guang-Tai Xue 《中国物理 B》2021,30(11):110313-110313
We study the effect of waveguide thickness variations on the frequency spectrum of spontaneous parametric down-conversion in the periodically-poled lithium niobate on insulator (LNOI) waveguide. We analyze several variation models and our simulation results show that thickness variations in several nanometers can induce distinct effects on the central peak of the spectrum, such as narrowing, broadening, and splitting. We also prove that the effects of positive and negative variations can be canceled and thus lead to a variation-robust feature and an ultra-broad bandwidth. Our study may promote the development of on-chip photon sources in the LNOI platform, as well as opens up a way to engineer photon frequency state. 相似文献
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Plasmon-Assisted Phase-Matched Second- and Third-Harmonic Generation in Single-Negative Heterostructures 下载免费PDF全文
Dispersion relations of surface plasmon polaritons (SPPs) in sandwiched optical systems are studied. The system is actually a kind of SPP waveguides, with two kinds of single negative material (SNG) as core and cladding layers, respectively. Since both TM and TE polarized SPPs can be excited in the structure, the dispersion of SPPs becomes more abundant and leads to colorful nonlinear opticM properties. The authors demonstrate the effective phase-matched second and third-harmonic generation (SHG, THG) assisted by the coupled SPPs. A cascaded second-order nonlinear process can Mso be achieved in the structure when the thickness of the core layer is properly selected, leading to the simultaneous SHG and THG. Further investigations show that much easier phase-matching can be fulfilled in the SNG waveguide array. Our results would be of potential use for surface-enhanced frequency conversion device such as light emitters or lasers. 相似文献
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用测量电阻法,在等温条件下在544℃至810℃温区研究了 YBa_2Cu_3O_(7-x)失氧过程中氧的扩散.当T>700℃时扩散激活能为1.47_eV/atom;当 T<700℃时为0.90_eV/atom.两温区的差异可能与氧在四方和正交两种结构中扩散机制不同有关. 相似文献
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High-sensitivity Bloch surface wave sensor with Fano resonance in grating-coupled multilayer structures 下载免费PDF全文
A new type of device consisting of a lithium niobate film coupled with a distributed Bragg reflector (DBR) was theoretically proposed to explore and release Bloch surface waves for applications in sensing and detection. The film and grating made of lithium niobate (LiNbO3) were placed on both sides of the DBR and a concentrated electromagnetic field was formed at the film layer. By adjusting the spatial incidence angle of the incident light, two detection and analysis modes were obtained, including surface diffraction detection and guided Bloch detection. Surface diffraction detection was used to detect the gas molecule concentrations, while guided Bloch detection was applied for the concentration detection of biomolecule-modulated biological solutions. According to the drift of the Fano curve, the average sensor sensitivities from the analysis of the two modes were 1560 °/RIU and 1161 °/RIU, and the maximum detection sensitivity reached 2320 °/RIU and 2200 °/RIU, respectively. This study revealed the potential application of LiNbO3 as a tunable material when combined with DBR to construct a new type of biosensor, which offered broad application prospects in Bloch surface wave biosensors. 相似文献
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使用一块准周期LiTaO3光学超晶格晶体,利用准相位匹配技术,通过光参变产生与和频两个非线性过程,将一束532nm绿色抽运光转变成666nm红光与443nm蓝光。具体过程为,通过参变过程获得红色信号光和红外闲频光,再通过绿色抽运光与红外闲置光和频获得蓝光,两个过程在同一块准周期光学超晶格中实现,准周期超晶格的两个倒易矢量分别补偿这两个过程中的相位失配。抽运光的脉宽为40ps,重复频率为10Hz,在平均功率为0.5mW时,测得红光和蓝光功率分别0.15mW和16.6μW,转换效率达到34%和3%。这一方法,提供了一种用一块超晶格晶体同时获得三原色输出的有效途径。 相似文献
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We provide an overview of quantum photonic network on chip. We begin from the discussion of the pros and cons of several material platforms for engineering quantum photonic chips. Then we introduce and analyze the basic building blocks and functional units of quantum photonic integrated circuits. In the main part of this review, we focus on the generation and manipulation of quantum states of light on chip and are particularly interested in some applications of advanced integrated circuits with different functionalities for quantum information processing, including quantum communication, quantum computing, and quantum simulation. We emphasize that developing fully integrated quantum photonic chip which contains sources of quantum light, integrate circuits, modulators, quantum storage, and detectors are promising approaches for future quantum photonic technologies. Recent achievements in the large scale photonic chips for linear optical computing are also included. Finally, we illustrate the challenges toward high performance quantum information processing devices and conclude with promising perspectives in this field. 相似文献
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We design and demonstrate a type of multiplexed hologram by nanoscatterers inside a dielectric-loaded plasmonic waveguide with guided-wave illuminations. The mode division multiplexed hologram(MDMH) is fulfilled by the scattering of guided waves to free space with respect to different modes. According to different mode numbers, these guided modes have different responses to the multiplexed hologram, and then give rise to different holographic images in reconstructions. In experiments, we show two kinds of MDMHs based on TM_0∕TE_0 and TE_0∕TE_1 modes as examples. Our approach could enrich the holography method that favors on-chip integration. 相似文献