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991.
An overview of device physics-oriented electrical modeling of thin-film transistors (TFTs) is presented. Four specific models are considered: (i) square-law, (ii) 3-layer, (iii) comprehensive depletion-mode, and (iv) discrete trap. For each model, a functional assessment of model equations is undertaken in terms of independent and dependent variables, model parameters, physical operating parameters, and constraining inequalities in order to facilitate mapping of model equations into a corresponding equivalent circuit. Channel mobility and “subthreshold” current trends are elucidated. Finally, a conductance integral equation based on Shockley's gradual channel approximation is introduced and is employed in model development and device assessment. 相似文献
992.
993.
M. Shen J. L. Shi Q. Wang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(2):215-219
The exact solutions for two color, Manakov vector
solitons in strongly nonlocal media are obtained. For such solitons
to exist, the ratio of the square of the beam widths must be
inversely proportional to the ratio of the wave numbers. The sum of
the incident powers must also be equal to a critical value. The
evolution of the beam widths is also discussed when the two-color,
Manakov vector solitons undergo periodic oscillations. 相似文献
994.
995.
将高量子效率的磷光材料fac-tris-2-phenylpyridine iridium(III) (Ir(ppy)3)按不同的比例掺杂到具有载流子传输能力的主体材料poly(N-vinylcarbazole) (PVK)中作为发光层制备磷光电致发光器件。通过对器件发光机制的研究,发现光致发光过程中起主导作用的是Fo¨ster能量转移机制;而在电致发光过程中,器件的发光性能受Dexter能量转移和电荷陷获2种能量传递形式的影响。器件的I-V-L特性表明:Ir(ppy)3的掺杂比例为5%时,器件的光功率效率最大,能量转移最充分。 相似文献
996.
E. Kirilov S. Putterman 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(3):683-691
We describe an efficient way to photoionize strontium atoms in a linear radio-frequency trap. We use a 2-photon second order
process to excite the autoionization resonance (4d2+5p2) 1D2 in neutral strontium (Sr). A doubled Ti:sapphire laser system is used at 431 nm to provide 100 fs pulses at 82 MHz. The fabrication
of the laser systems for addressing the Sr+ transitions necessary for laser cooling and excitation of quantum jumps, vacuum system and ion trap structure are also described.
With the current setup a easy and repeatable trapping of linear ion chains is readily achieved at very low Sr vapor pressures. 相似文献
997.
Xin-ye XU Wen-li WANG Qing-hong ZHOU Guo-hui LI Hai-ling JIANG Lin-fang CHEN Jie YE Zhi-hong ZHOU Yin CAI Hai-yao TANG Min ZHOU 《Frontiers of Physics in China》2009,4(2):160-164
The experiments on the laser cooling and trapping of ytterbium atoms are reported, including the two-dimensional transversal
cooling, longitudinal velocity Zeeman deceleration, and a magneto-optical trap with a broadband transition at a wavelength
of 399 nm. The magnetic field distributions along the axis of a Zeeman slower were measured and in a good agreement with the
calculated results. Cold ytterbium atoms were produced with a number of about 107 and a temperature of a few milli-Kelvin. In addition, using a 556-nm laser, the excitations of cold ytterbium atoms at 1S0-3P1 transition were observed. The ytterbium atoms will be further cooled in a 556-nm magneto-optical trap and loaded into a three-dimensional
optical lattice to make an ytterbium optical clock.
相似文献
998.
为了研究吸收双层球形微粒的横向光俘获,基于几何光学模型提出了双层带吸收球形微粒的光俘获模型,对TEM00模式高斯光束照射下外层有光吸收的双层电介质球形微粒受到的横向光俘获力进行了数值模拟,取得了光俘获力特性的一系列结果.结果显示,双层球形微粒的外层吸收系数对包括稳态俘获位置,峰值强度,稳态俘获的刚度等光俘获特性有很大影响.此外,内外径的比率对吸收双层球形微粒的光俘获特性也有调制性的影响.在一定条件下,带吸收的双层球形微粒可以被俘获在光轴上,也可能被俘获在中心在光轴上的圆环上.
关键词:
光俘获
几何光学模型
高斯光束
吸收双层球 相似文献
999.
利用亚纳焦量级、脉冲宽度为100 fs的激光脉冲在双折射光子晶体光纤中获得了450—1050 nm 的超连续光谱,且超连续光谱具有明显的分立峰状结构.分析了光谱中分立峰状结构产生的物理机制,抽运光波长处于接近零色散波长的反常色散区,形成高阶光孤子,由于高阶非线性和高阶色散的影响,高阶孤子分裂成多个基孤子,使初始光谱上演化出红移的光孤子成分和蓝移的色散波成分.理论模拟了飞秒激光脉冲在光纤中的色散特性和传输特性,较好地解释了实验结果.
关键词:
光子晶体光纤
超连续光谱产生
孤子分裂
脉冲俘获 相似文献
1000.
Optical forces acting on a sphere were experimentally analyzed to investigate the single-beam fiber optic trap using a cleaved optical fiber or a lensed optical fiber. A stable optical trap could be created at the point where the x-directed (horizontal) optical forces were precisely balanced, and the vector sum of axial and transverse forces acting on a sphere gave a restoring force directed back to the stable point. As compared with other embodiments, such as a single-beam gradient trap (optical tweezers) and dual-beam fiber optical traps, this single-beam fiber optic trapping was most economical, much simpler to operate, and required relatively low optical power to capture an object. Furthermore, a lensed optical fiber could easily trap and manipulate a micro object in comparison with a cleaved optical fiber because of the strong transverse optical confinement. 相似文献