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901.
以椭圆形平面反射镜实例为研究对象,介绍了轻质反射镜材料的选择以及反射镜在真空超低温环境中的应用。分析了各种轻量化孔的特点,设计了一种反射镜结构;在吊带支撑方式下,建立整体结构的有限元模型,对由于镜体自重及超低温环境引起的镜面变形进行了有限元分析。由数控系统在图形方式下控制实际轻量化加工,加工后的反射镜轻量化率达到33%;采用化学方法消除加工过程中产生的应力与微小裂纹;运用环形抛光机结合局部修磨进行光学抛光加工,抛光后面形精度达到0.022A(均方根,λ=633nm);在实验室进行小范围温度拉偏实验,实验结果表明,面形精度变化量为0.03nm。 相似文献
902.
给出了n次积分C半群的几个性质及其证明,讨论了它与一类抽象柯西问题存在强解的关系及强解的表示式. 相似文献
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906.
We propose a new scheme for realizing deterministic quantum state transfer (QST) between two spatially separated single molecule magnets (SMMs) with the framework of cavity quantum eleetrodynamics (QED). In the present scheme, two SMMs are trapped in two spatially separated optical cavities coupled by an optical fiber. Through strictly numerically simulating, we demonstrate that our scheme is robust with respect to the SMMs' spontaneous decay and fiber loss under the conditions of dispersive SMMs-field interaction and strong coupling of cavity fiber. In addition, we also discuss the influence of photon leakage out of cavities and show that our proposal is good enough to demonstrate the generation of QST with high fidelity utilizing the current experimental technology. The present investigation provides research opportunities for realizing QST between solid-state qubits and may result in a substantial impact on the progress of solid-state-based quantum communications network. 相似文献
907.
The resolution and the summing characteristics of an EXOGAM segmented Clover germanium detector has been studied for use it in y spectroscopic experiments. The measurements have been performed with standard radioactive sources of ^152Eu, ^133Ba and β-delayed γ-rays from 176Ir decay. The data analytic results, realized by software, are presented in this paper. 相似文献
908.
Narrow Linewidth Tm^3+-Doped Large Core Fiber Laser Based on a Femtosecond Written Fiber Bragg Grating 下载免费PDF全文
A diode laser (LD) clad-pumped narrow linewidth all-fiber Tm^3+-doped fiber laser is reported with a maximal output power of 27W at 1.947μm. By successively splicing an LD pigtail fiber, a single-mode Tm^3+-doped fiber, and a multi-mode Tm^3+-doped fiber, the fiber laser has 70pm narrow linewidth output, and a high slope efficiency of nearly 47.5% with respect to the launched pump power. The high reflectivity fiber Bragg gratings, which are directly written into the single-mode Tm^3+-doped fiber core by the 800nm femtosecond pulsed laser, act as the high reflectivity coupler. The output laser has diffraction-limited beam quality with a factor M^2 of 1.29, when the output laser power is nearly 27W. 相似文献
909.
Coupled THz Waveguide Utilizing Surface Plasmon Polaritons on Thin Dielectric Slab Sandwiched between Two Corrugated Metallic Claddings 下载免费PDF全文
We present a comprehensive experimental study of terahertz (THz) wave propagation utilizing surface plasmon polaritons (SPPs) on the interfaces of a thin dielectric core layer sandwiched between two corrugated metallic claddings. THz wave impinges on the structured surfaces at normal incidence. Long-lasting oscillation propagation features are observed in the temporal waveform after traveling through the periodic arrays. The enhanced THz transmission can be achieved due to the coupling between incident waves to SPPs at the bottom and top interfaces. The finite element method is used to simulate the field distribution and the transmission mode in the waveguide. The hybrid waveguide with low absorption has great potential applications in THz integrated devices. 相似文献
910.
Experiment of C-Band Wavelength Conversion in a Silicon Waveguide Pumped by Dispersed Femtosecond Laser Pulse 下载免费PDF全文
We experimentally demonstrate the C-band wavelength conversion using four-wave mixing in a 17-mm-long silicon-on-insulator waveguide pumped by a dispersed mode-locked femtosecond laser pulse. The idler can be observed with an incident average pump power lower than 4 dBm, and about 35 nm of conversion bandwidth from 1530nm to 1565nm is measured by using a 1550-nm pump wavelength. The pulse-pumped efficiency is demonstrated to be higher, by more than 22 dB, than the cw-pumped efficiency. The conversion efficiency variations with respect to the pump and signal powers are also investigated. 相似文献