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61.
Hongjun Liu Hongying Wang Xiaoli Li Yishan Wang Wei Zhao Chi Ruan 《Optics Communications》2009,282(9):1858-1860
Stacking chirped pulse optical parametric amplification based on a home-built Yb3+-doped mode-locked fiber laser and an all-fiber pulse stacker has been demonstrated. Energic 11 mJ shaped pulses with pulse duration of 2.3 ns and a net total gain of higher than 1.1 × 107 at fluctuation less than 2% rms are achieved by optical parametric amplification pumped by a Q-switched Nd:YAG frequency-doubled laser, which provides a simple and efficient amplification scheme for temporally shaped pulses by stacking chirped pulse. 相似文献
62.
In this paper, the crystallization behaviour of amorphous Ge2Sb2Te5 thin films is investigated using differential scanning calorimetry), x-ray diffraction and optical transmissivity measurements. It is indicated that only the amorphous phase to face-centred-cubic phase transformation occurs during laser annealing of the normal phase-change structure, which is a benefit for raising the phase-change optical disk's carrier-to-noise ratio (CNR). For amorphous Ge2Sb2Te5 thin films, the crystallization temperature is about 200℃ and the melting temperature is 546.87℃. The activation energy for the crystallization, Ea, is 2.25eV. The crystallization dynamics for Ge2Sb2Te5 thin films obeys the law of nucleation and growth reaction. The sputtered Ge2Sb2Te5 films were initialized by an initializer unit. The initialization conditions have a great effect on the reflectivity contrast of the Ge2Sb2Te5 phase-change optical disk. 相似文献
63.
In this paper, we discuss the phase-change recording at a short-wavelength (514nm) and a high numerical aperture (0.85). Effects
of recording power and pulse width on the size of the recording
marks are studied. The minimum recording mark with a length of
approximately 220nm has been observed. The capacity of about 17GB
for a single-layer disc of a 12cm diameter can be obtained. The
maximum carrier-to-noise ratio reaches 45dB at a writing power of 13--14mW. 相似文献
64.
Ruan Jianmiao Zhu Xiangrong 《高校应用数学学报(英文版)》2005,20(4):448-454
It is shown that the maximal singular integral operator with kernels satisfying Ho rmander's condition is of weak type (1,1) and L^p (1〈p〈∞) bounded without assuming that the underlying measure p is doubling. Under stronger smoothness conditions,such estimates can be obtained by using a Cotlar's inequality. This inequality is not applicable here and it is noticeable that the Cotlar's inequality maybe fails under Hormander's condition. 相似文献
65.
We report an intracavity frequency-doubled Q-switched self-Raman yellow laser at 587 nm. A composite Nd:YVO4 crystal was utilized as self-Raman gain medium. The maximum average output power of yellow light obtained was 1.5 W at the incident pump power of 30 W and at a repetition rate of 50 kHz, corresponding to the optical conversion efficiency of 5%. The shortest pulse width, the maximum pulse energy and the highest peak power were measured to be 5.8 ns, 46.7 μJ and 5.9 kW, respectively. 相似文献
66.
67.
采用基于密度泛函理论的第一性原理赝势法对Ag-N共掺杂ZnO体 系以及间隙N和间隙H掺杂p型ZnO: (Ag, N)体系的缺陷形成能和离化能进行了研究. 结果表明, 在AgZn和NO所形成的众多受主复合体中, AgZn-NO受主对不仅具有较低的缺陷形成能同时其离化能也相对较小, 因此, AgZn-NO受主对的形成是Ag-N共掺ZnO体系实现p型导电的主要原因. 研究发现, 当ZnO: (Ag, N)体系有额外间隙N原子存在时, AgZn-NO受主对容易与Ni形成AgZn-(N2)m O施主型缺陷, 该施主缺陷的形成降低了Ag-N共掺ZnO的掺杂效率因而不利于p型导电. 当间隙H引入到ZnO: (Ag, N)体系时, Hi易与AgZn-NO受主对形成 受主-施主-受主复合结构(AgZn-Hi-NO), 此复合体的形成不仅提高了AgZn-NO受主对在ZnO中的固溶度, 同时还能使其受主能级变得更浅而有利于p型导电. 因此, H辅助Ag-N共掺ZnO可能是一种有效的p型掺杂手段.
关键词:
p型ZnO
缺陷形成能
受主离化能
第一性原理 相似文献
68.
Kui Wu Zhe Li Jing Guo Yongchuan Xiao Huajuan Qi Wei Dong Shengping Ruan Weiyou Chen Yu Chen 《Optik》2014
An integrated tunable optical filter (TOF) based on thermo-optic effect in silicon on insulator (SOI) rib waveguide is designed and simulated. The device is comprised of two high refractivity contrast Si/Air stacks, functioning as high reflectivity of DBRs (distributed Bragg reflectors) and separating by a variable refractive index polymer Fabry–Perot (F–P) cavity. The designed device exhibits Q = 24077, FWHM = 0.065 nm and finesse = 566. Wavelength tuning is achieved through thermal modulation of refractive variation of the cavity. As the cavity polymer is heated, the refractive index of the cavity decreases. When the temperature of cavity polymer changes within 105, the central wavelength gets a continuous 35 nm shift from 1530 nm to 1565 nm, which can operate the whole C-band in the WDM (wavelength division multiplexing) networks. Moreover, by calculating, the tuning sensitivity is about 0.33 nm/°C. Owing to the compact size and excellent characteristics of integration, the proposed component has a promising utilization in spectroscopy and optical communication. 相似文献
69.
In this paper, we present a generic mode theory for the three-layer cylindrical waveguides consisting of three arbitrary material mediums. Based on derived eigenvalue equations of the TE, TM, and hybrid modes, the mode conditions of metal/dielectric-coated terahertz hollow waveguides are extracted. In addition, we quantitatively describe both the effective refractive indexes and the loss characteristics of the aurum/polystyrene-coated terahertz hollow waveguides operating at the TE01, TM01, and HE11 modes. It is indicated that the loss coefficient of the TE01 mode can be much lower than that of the TM01, and HE11 modes, and, especially, can tend to that of the terahertz wave in air. So the TE01 mode is very significant for the hollow waveguides in term of low loss propagating of the terahertz wave. We expect these results to enable a variety of new long-distance THz applications in sensing, detecting and communicating. 相似文献
70.
时间频率基准装置——铯原子喷泉钟, 在标准时间产生和保持、基础物理研究中发挥了重要的作用. 介绍了铯原子喷泉钟的工作原理, 对影响其性能的各项噪声源和频移项给出了分析, 影响频率稳定度性能的主要因素为Dick 效应相关的原子团装载时间、微波激励源相位噪声和探测激光的频率噪声, 影响频率不确定性能主要频移项为: 黑体辐射频移、冷原子碰撞频移、腔相位分布频移和微波泄露频移; 总结和比较了当前具有先进性能的铯原子喷泉钟采用的技术; 介绍了铯原子喷泉钟的主要应用方向、空间冷原子铯钟的研制情况和光学频率原子钟进展. 相似文献