金属—介质—半导体复合纳米结构光波导分束器设计和制备
发布时间：2019-01-21 09:16
【摘要】：对于集成光子芯片而言,微小型的光学部件是必要的基础元件。分束器是一种非常重要的光学元件,并经常被使用在光信息处理,光学计算,全息摄影和计量学中。表面等离激元(surface plasmons,SPs)——由电磁辐射激发的金属表面的自由电子的集体连续振荡所形成的电磁波,具有一系列的光学特性,例如对光的超强限域性,电磁场增强特性,对光的偏振敏感性等。因此低维的贵金属纳米结构,例如纳米颗粒,纳米线和纳米薄膜,在众多领域具有广阔的应用,其中包括表面增强光谱,光化学传感,光信息处理等。但是由于金属本身所固有的内在损耗很大,单纯地依靠表面等离激元来传递光学信号似乎并不是一个理想的选择。而低维的半导体纳米结构由于其特殊的光学性质和在纳/微米级光学器件中潜在的应用前景而成为装配紧凑型光学元件的重要的结构单元。尤其是通过化学气相沉积法(CVD)合成的一维的纳米线和纳米带,具有良好的单晶结构,高折射率和大的光学非线性性等特殊性质,为实现在亚波长的尺度上限域和波导光提供了良好的平台。利用低维半导体纳米材料内的波导光与低维金属纳米材料耦合产生表面等离激元的作用或许能产生新颖或者更丰富的光学效应,为制备具有更优良性能的光学元件开辟新的道路。当然,一些将半导体纳米材料与金属纳米颗粒相结合的混合纳米结构已经被一些科研人员所制备出来,但是关于结合一维半导体材料和金属纳米颗粒的光波导分束器却还未见报道。因此,我们设计和制备了一种基于新型的类似于三明治纳米结构的金属-电介质-半导体复合纳米结构,实现了通过金属纳米颗粒调制半导体纳米带中波导光的功能。1.用化学气相沉积法(CVD)生长出高质量的硫化镉(Cd S)纳米带,将生长的Cd S纳米带分散在刻有数字标记的Si O2/Si衬底上,随后用原子层沉积法在样品表面镀一层Hf O2层,再用电子束曝光(EBL)在样品表面制备一定尺寸的金纳米圆盘阵列,光学测试结果表明这种复合纳米结构使得Cd S纳米带中的波导光在纳米带的端部出射时被分裂成多个光点,且出射光点的数量可由这种复合纳米结构的尺寸和结构参数来控制。2.用基于有限元方法的数值模拟软件(COMSOL Multiphysics)进行了一系列相应的数值模拟,模拟结果表明Cd S纳米带中的波导光激发纳米带上方的金纳米圆盘阵列产生局域表面等离激元,由于局域表面等离激元具有较大的欧姆损耗,因此金纳米圆盘阵列下方的波导光被减弱,从而使得纳米带中的波导光相当于沿着被金纳米圆盘分开的狭缝传播形成多个波导光束,当这些被分裂的波导光束传播至没有金纳米圆盘覆盖的空白纳米带区域时,由于多光束之间的干涉效应,波导光可以进一步被调制,最终在纳米带端部以多个光点的形式出射,出射光点的数目与实验很好地符合。
[Abstract]:Micro optical components are essential for integrated photonic chips. Beam splitter is a very important optical element, and is often used in optical information processing, optical computing, holography and metrology. Surface isotherm (surface plasmons,SPs)-an electromagnetic wave formed by the collective continuous oscillation of free electrons on a metal surface excited by electromagnetic radiation. It has a series of optical properties, such as superlimation of light, enhancement of electromagnetic field, Polarization sensitivity to light, etc. Therefore, low dimensional noble metal nanostructures, such as nanoparticles, nanowires and nanocrystals, have been widely used in many fields, including surface enhanced spectroscopy, photochemical sensing, optical information processing and so on. However, due to the inherent loss of metal itself, it seems that it is not an ideal choice to rely solely on surface isotherms to transmit optical signals. Because of their special optical properties and potential applications in nanometer-scale optical devices, low-dimensional semiconductor nanostructures have become important structural units for assembling compact optical elements. In particular, one-dimensional nanowires and nanobelts synthesized by chemical vapor deposition (CVD) have good single crystal structure, high refractive index and large optical nonlinearity. It provides a good platform for the realization of the upper bound domain of subwavelength and waveguide light. Using the coupling of waveguide light in low-dimensional semiconductor nanomaterials with low-dimensional metal nanomaterials to produce surface isoexcitators may produce novel or more abundant optical effects. It opens up a new way for the fabrication of optical elements with better performance. Of course, some of the mixed nanostructures that combine semiconductor nanomaterials with metal nanoparticles have been prepared by some researchers. However, optical waveguide beam splitters combined with one-dimensional semiconductor materials and metal nanoparticles have not been reported. Therefore, we design and fabricate a novel metal-dielectric semiconductor composite nanostructure based on sandwich nanostructures, which can modulate waveguide light in semiconductor nanobelts by metal nanoparticles. 1. High quality cadmium sulfide (Cd S) nanobelts were grown by chemical vapor deposition (CVD) method. The grown Cd S nanoliths were dispersed on digitally labeled Si O2/Si substrates. Then a layer of Hf O 2 was deposited on the surface of the samples by atomic layer deposition. Then (EBL) was used to fabricate the gold nanometer-disk array on the surface of the sample. The optical test results showed that the waveguide light in the Cd S nanobelts was split into a number of light spots when the end of the Cd S nanobelts was emitted. And the number of emitting light points can be controlled by the size and structure parameters of the composite nanostructures. 2. A series of corresponding numerical simulations have been carried out with the finite element method (FEM) based numerical simulation software (COMSOL Multiphysics). The simulation results show that the waveguide in the Cd S nanowires excites the gold nanodisk arrays above the nanobelts to produce local surface isoexcitators. Due to the large ohmic loss of the local surface isopherons, the waveguide light under the gold nanodisk array is weakened. So that the waveguide light in the nanobelts is equivalent to propagating along the slit separated by the gold nanorods to form a plurality of waveguide beams, when these splintered waveguide beams propagate to the blank nanbbons that are not covered by the gold nanorods, Because of the interference effect between the multi-beam, the waveguide light can be further modulated, and finally, the number of the light points in the end of the nanobanth is in the form of a number of light dots, which is in good agreement with the experiment.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN252
本文编号：2412512
[Abstract]:Micro optical components are essential for integrated photonic chips. Beam splitter is a very important optical element, and is often used in optical information processing, optical computing, holography and metrology. Surface isotherm (surface plasmons,SPs)-an electromagnetic wave formed by the collective continuous oscillation of free electrons on a metal surface excited by electromagnetic radiation. It has a series of optical properties, such as superlimation of light, enhancement of electromagnetic field, Polarization sensitivity to light, etc. Therefore, low dimensional noble metal nanostructures, such as nanoparticles, nanowires and nanocrystals, have been widely used in many fields, including surface enhanced spectroscopy, photochemical sensing, optical information processing and so on. However, due to the inherent loss of metal itself, it seems that it is not an ideal choice to rely solely on surface isotherms to transmit optical signals. Because of their special optical properties and potential applications in nanometer-scale optical devices, low-dimensional semiconductor nanostructures have become important structural units for assembling compact optical elements. In particular, one-dimensional nanowires and nanobelts synthesized by chemical vapor deposition (CVD) have good single crystal structure, high refractive index and large optical nonlinearity. It provides a good platform for the realization of the upper bound domain of subwavelength and waveguide light. Using the coupling of waveguide light in low-dimensional semiconductor nanomaterials with low-dimensional metal nanomaterials to produce surface isoexcitators may produce novel or more abundant optical effects. It opens up a new way for the fabrication of optical elements with better performance. Of course, some of the mixed nanostructures that combine semiconductor nanomaterials with metal nanoparticles have been prepared by some researchers. However, optical waveguide beam splitters combined with one-dimensional semiconductor materials and metal nanoparticles have not been reported. Therefore, we design and fabricate a novel metal-dielectric semiconductor composite nanostructure based on sandwich nanostructures, which can modulate waveguide light in semiconductor nanobelts by metal nanoparticles. 1. High quality cadmium sulfide (Cd S) nanobelts were grown by chemical vapor deposition (CVD) method. The grown Cd S nanoliths were dispersed on digitally labeled Si O2/Si substrates. Then a layer of Hf O 2 was deposited on the surface of the samples by atomic layer deposition. Then (EBL) was used to fabricate the gold nanometer-disk array on the surface of the sample. The optical test results showed that the waveguide light in the Cd S nanobelts was split into a number of light spots when the end of the Cd S nanobelts was emitted. And the number of emitting light points can be controlled by the size and structure parameters of the composite nanostructures. 2. A series of corresponding numerical simulations have been carried out with the finite element method (FEM) based numerical simulation software (COMSOL Multiphysics). The simulation results show that the waveguide in the Cd S nanowires excites the gold nanodisk arrays above the nanobelts to produce local surface isoexcitators. Due to the large ohmic loss of the local surface isopherons, the waveguide light under the gold nanodisk array is weakened. So that the waveguide light in the nanobelts is equivalent to propagating along the slit separated by the gold nanorods to form a plurality of waveguide beams, when these splintered waveguide beams propagate to the blank nanbbons that are not covered by the gold nanorods, Because of the interference effect between the multi-beam, the waveguide light can be further modulated, and finally, the number of the light points in the end of the nanobanth is in the form of a number of light dots, which is in good agreement with the experiment.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN252
【参考文献】
相关期刊论文 前2条
1 S.Karthick Raja Namasivayam;Gnanendra Kumar E;Reepika R;;Synthesis of silver nanoparticles by Lactobaciluus acidophilus 01 strain and evaluation of its in vitro genomic DNA toxicity[J];Nano-Micro Letters;2010年03期
2 X.Y.Han;Y.H.Gao;X.H.Zhang;;One-dimensional Ga N nanomaterials transformed from one-dimensional Ga_2O_3 and Ga nanomaterials[J];Nano-Micro Letters;2009年01期
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