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1.
Low-loss single-mode waveguides form at the surface of glass in contact with liquid tin during the float process. Theoretical and experimental studies have demonstrated that float-glass can serve as an industrial substrate for integrated optics.  相似文献   

2.
The coordinate transformation approach is applied for the design of an optical mode adaptor between two different width waveguides in the near IR telecom optical domain. The control of the mode profile in the adaptor is achieved by considering a composite waveguide consisting of a thin metamaterial (MM) layer intercalated between 2???m thick SU8 photoresist slab and a glass substrate. We demonstrate that intercalated metafilm enables the realization of a space coordinate transformation and allows a precise control of the light propagation in the composite waveguide. Numerical simulations and experimental realizations of the metamaterial layer are performed in order to validate the device concept and realization feasibility.  相似文献   

3.
印建平 《物理》2006,35(1):69-75
文章首先简单介绍了冷原子操纵与控制的基本原理。然后,重点介绍了几何与波动原子光学及其器件的研究内容、潜在应用和最新进展,其中包括:原子束的反射和原子反射镜;原子束偏转(折射)、聚焦成像和原子透镜;原子衍射和原子光栅;原子干涉和原子干涉仪;原子全息学及其技术等。  相似文献   

4.
魏荣  周子超  史春艳  赵剑波  李唐  王育竹 《中国物理 B》2011,20(8):89501-089501
A fold optical path is utilized to capture and launch atoms in the atomic fountain.This improved technique reduces the laser power needed by 60 percent,facilitates suppression of the laser power fluctuations,and leads to a more simple and stable system.  相似文献   

5.
We demonstrate theoretically as well as experimentally that a four-layer polymeric waveguide structure can be used to produce a mode and a polarization filter. Various optical properties such as refractive index, birefringence and propagation constant of polycarbonate, polystyrene and a commercially available photoresist (from Shipley) are presented. The thin film structures consisting of glass/polycarbonate/polystyrene/air are used for demonstrating polarization filter action and glass/photoresist/polystyrene/air structure for mode filter. Expressions for the electric field intensity spatial distribution for the structure are used to calculate the intensity profiles to support the observed behavior. The experimental values were in good agreement with the one obtained theoretically.  相似文献   

6.
In this contribution we describe and discuss a series of challenges and questions relating to understanding extreme wave phenomena in optics. Many aspects of these questions are being studied in the framework of the MANUREVA project: a multidisciplinary consortium aiming to carry out mathematical, numerical and experimental studies in this field. The central motivation of this work is the 2007 results from optical physics [D. Solli et al., Nature 450, 1054 (2007)] that showed how a fibre-optical system can generate large amplitude extreme wave events with similar statistical properties to the infamous hydrodynamic rogue waves on the surface of the ocean. We review our recent work in this area, and discuss how this observation may open the possibility for an optical system to be used to directly study both the dynamics and statistics of extreme-value processes, a potential advance comparable to the introduction of optical systems to study chaos in the 1970s.  相似文献   

7.
A modified version of the signal flow graphs method can be applied to reveal the topological structure of physical models describing the operation of optoelectronic devices based on heterostructures comprising AIIIBV semiconductor compounds. In particular, this kind of analysis is apt to reveal the presence of closed paths (feedback loops) in the causal make-up of the phenomena underlying function of the devices. The analytical apparatus associated with the diagrams affords a new formulation of criteria for the occurrence of such physical conditions as the bistability or the threshold behaviour. The approach is illustrated on the instances of injection semiconductor laser, nonlinear Fabry-Perot resonator, self-electro-optic effect device and semiconductor laser optical amplifier. Presented at the 1st Czech-Chinese Workshop “Advanced Materials for Optoelectronics”, Prague, Czech Republic, June 13–17, 1998 Support of the Grant Agency of the Czech Republic (project No. 102/99/0341) is gratefully acknowledged.  相似文献   

8.
Sanjay Kumar Sharma 《Optik》2012,123(22):2068-2071
Complex materials are of increasing interest in Finite-Difference Time-Domain (FDTD) modeling. For example, when the particle density becomes large, collisional fluid models of plasmas are an attractive alternative to particle in cell methods. Further, frequency dispersive meta-materials are of increasing interest. Thus, Finite-Difference Time-Domain (FDTD) models are derived for magnetized plasmas and for the Lorentz and Drude material models. This paper models the Lorentz material using the FDTD tool. The modal analysis and various types of simulation results are also presented for these materials.  相似文献   

9.
Nearly closed rhombus-shaped channels in micromachined silicon with very high accuracy for fibre array assemblies are presented. The fabrication and the assembly of fibres are described. The achieved accuracy is comparable with conventional V-groove assemblies. Additionally, rhombus-shaped channels allow new applications such as monitor pigtails with integrated photodiodes or buried fibre supplies in optical MEMS. Received: 22 May 2001 / Revised version: 7 September 2001 / Published online: 30 October 2001  相似文献   

10.
Flow cytometry is widely used for analyzing micro-particles such as cells and bacteria. Microfabricated flow cytometers promise reduced instrument size and cost with increased robustness and have application in medicine, life sciences and environmental metrology. Further miniaturisation and robustness can be achieved if integrated optics are used instead of traditional free space optics. We present designs simulation and experimental characterisation of integrated optics for a microfabricated cytometer made from SU-8 resin on a glass substrate. The optics constructed from combinations of optical fibres (positioned with microgrooves), waveguides, and microlenses enable analysis of scattered light and fluorescence from particles positioned near the centre of a microchannel using one dimensional sheath flow. Four different methods for directing the incident light onto the particles are examined and the optimum design discussed.  相似文献   

11.
Holographic chirped gratings with parallel grating lines have been fabricated by recording the interference structure of a plane wave and a cylindrical wave in a photoresist layer on a monomode glass waveguide. These gratings will be useful elements for the imaging of guided waves in integrated optics. A theoretical approach for treating their imaging properties is presented. The experimental results are described theoretically.  相似文献   

12.
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14.
A perturbation method is described to analytically model the electrical behavior of submicron FETs for millimeter-wave circuit applications. The approach includes the determination of the two-dimensional potential distribution in a non-rectangular depletion region. The result is used to derive analytical expressions for the threshold voltage and transconductance of FETs.  相似文献   

15.
超导磁储能系统(SMES)因其响应速度快,能够灵活地对有功、无功功率进行独立控制等特点,在电力系统中具有良好的应用前景。简要介绍了超导磁储能装置的应用现状;从装置及系统两个层面分析了SMES应用的关键技术问题;结合新能源发电及新型用电负荷探讨了SMES未来的应用场景。  相似文献   

16.
高福斌  李丽娜  金锋 《光学学报》1989,9(9):823-829
由单侧和双侧漏模法,测量了液体和气体的折射率,将液体或气体滴入或充入棱镜和衬底之间,使这三层介质组成单侧或双侧漏波导.用棱镜耦合器测量共振漏模的模折射率,并由相应的模方程确定液体或气体的折射率.测量结果表明,折射率的误差为1~3×10~(-4).并在理论上对测量精度作了分析和讨论.  相似文献   

17.
A new route to grow an ensemble of indium phosphide single-crystal semiconductor nanowires is described. Unlike conventional epitaxial growth of single-crystal semiconductor films, the proposed route for growing semiconductor nanowires does not require a single-crystal semiconductor substrate. In the proposed route, instead of using single-crystal semiconductor substrates that are characterized by their long-range atomic ordering, a template layer that possesses short-range atomic ordering prepared on a non-single-crystal substrate is employed. On the template layer, epitaxial information associated with its short-range atomic ordering is available within an area that is comparable to that of a nanowire root. Thus the template layer locally provides epitaxial information required for the growth of semiconductor nanowires. In the particular demonstration described in this paper, hydrogenated silicon was used as a template layer for epitaxial growth of indium phosphide nanowires. The indium phosphide nanowires grown on the hydrogenerated silicon template layer were found to be single crystal and optically active. Simple photoconductors and pin-diodes were fabricated and tested with the view towards various optoelectronic device applications where group III–V compound semiconductors are functionally integrated onto non-single-crystal platforms.  相似文献   

18.
双异质结双极晶体管(DHBT)的性能与发射区-基区(E.B)异质结和基区.集电区(B.C)异质结的能带突变类型关系密切,本文基于热场发射.扩散模型,对两类不同能带结构类型的新型DHBT的性能做了比较分析.结论表明:与作为当今研究热点的E.B和B.C异质结构均为全交错II型能带结构的InP/GaSbAs/InPDHBT的性能相比,E.B异质结采用传统I型、B.C异质结采用交错II型的一类新型能带结构的InAlAs/GaSbAs/InPDHBT虽然在开启电压上更高,但具有更好的电流驱动能力、直流增益和高频性能.  相似文献   

19.
Theoretical analysis of the radiation effect on transient behavior of an optoelectronic integrated device composed of a heterojunction phototransistor and a light emitting diode is studied theoretically. First, the transient behavior and the rise time of this device before radiation are investigated based on the frequency response of the constituent devices and the optical feedback inside the device. Second, the effect of neutron irradiation flux on the transient behavior of this device is theoretically studied. The results show that, by increasing the optical feedback inside the device, the rise time in the amplification mode is increased along with an increasing output, while that in the switching mode can be reduced effectively, and the neutron irradiation reduces the transient response and the rise time in both the amplification and switching modes. This type of model can be exploited as optical amplifier, optical switching device, and other applications.  相似文献   

20.
A very simple and compact arrangement is proposed for generation of surface periodic structures for integrated optics using laser exposition and photolithographic technique. The method applied is based on the division of a laser beam into two “half-wavefronts” by a Fresnel mirror (90°) with one arm formed by an exposed sample, and on interference of divided wavefronts on the sample surface.  相似文献   

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