电子束曝光机自动套准系统的研究

于2010-11-23批量导入

一种通用神经网络处理机设计及其VLSI集成化讨论

于2010-11-23批量导入

光交换中的半导体增益光开关门的研究

通过实验对双区共腔半导体增益光开关门的动态和静态光学特性(包括温度特性、偏振特性、光谱特性、偏置特性、开关特性及增益放大特性等)进行了分析研究,特别研究了其做为增益光开关门在光子交换系统中实现数据包交换功能的可行性,对半导体光开关门的数据包开光传输能力进行了原理性实验,文章最后提出了一种采用半导体增益光开关门的构成的新颖的光子交换系统网络结构.

量子阱激光器光增益温度关系及对激射特性的影响

计算了不同温度下GaAs/AlGaAs量子阱材料光增益与载流子密度的关系。根据B-D条件:ΔF＞hγ≥E_g+E_(c1)+E_(v1),得到了ΔF、峰值增益光子能量和E_g+E_(v1)与载流子密度的关系,并得到了不同增益的激光器阈值电流温度关系。计算结果解释了实验出现的阈值电流温度的反常特性和波长开关现象,并且与器件温度特性符合。

室温连续的新结构垂直腔面发射半导体激光器

报道了室温连续激射的GaAs/GaAlAS新结构垂直腔面发射半导体激光器的最新研究结果。该器件结构是采用钨丝掩膜四次质子轰击方法制备的,这种方法是目前报道的垂直腔面发射激光器制作工艺中最简单的。对于直径15μm的钨丝,器件的最低值电流为17mA,最大光输出功率达4mW,微分量子效率高达65％。

在脊形波导级联双区量子阱激光器中皮秒光脉冲的产生

讨论脊形波导级联双区增益(或Q)开放MBE生长量子阱皮秒激光器的工作原理和实验,测得的脉冲半峰宽WHM<60ps,与理论值符合很好.

低阈值脊形波导单量子阱级联双区激光器

国家863计划

高迁移率Si/Si（0.7）Ge（0.3）/Si调帛掺杂异质结构的生长和输运性质

863计划,国家攀登计划

用银膜作反射镜的垂直短腔面发射激光器

于2010-11-23批量导入

Design of Photonic Crystal Semiconductor Optical Amplifier With Polarization Independence

Slow-light effects in photonic crystal (PC) waveguides can enhance light-mater interaction near the photonic band edge, which can be used to design a short cavity length semiconductor optical amplifier (SOA). In this paper, a novel SOA based on slow-light effects in PC waveguides (PCSOA) is presented. To realize the amplification of the optical signal with polarization independence, a PCSOA is designed with a compensated structure. The cascaded structure leads to a balanced amplification to the TE and TM polarized light.

An Ameliorated Phase Generated Carrier Demodulation Algorithm With Low Harmonic Distortion and High Stability

A novel ameliorated phase generated carrier (PGC) demodulation algorithm based on arctangent function and differential-self-multiplying (DSM) is proposed in this paper. The harmonic distortion due to nonlinearity and the stability with light intensity disturbance (LID) are investigated both theoretically and experimentally. The nonlinearity of the PGC demodulation algorithm has been analyzed and an analytical expression of the total-harmonic-distortion (THD) has been derived. Experimental results have confirmed the low harmonic distortion of the ameliorated PGC algorithm as expected by the theoretical analysis. Compared with the traditional PGC-arctan and PGC-DCM algorithm, the ameliorated PGC algorithm has a much lower THD as well as a better signal-to-noise-and-distortion (SINAD). A THD of below 0.1% and a SINAD of 60 dB have been achieved with PGC modulation depth (value) ranges from 1.5 to 3.5 rad. The stability performance with LID has also been studied. The ameliorated PGC algorithm has a much higher stability than the PGC-DCM algorithm. It can keep stable operations with LID depth as large as 26.5 dB and LID frequency as high as 1 kHz. The system employing the ameliorated PGC demodulation algorithm has a minimum detectable phase shift of 5 mu rad/root Hz @ 1 kHz, a large dynamic range of 120 dB @ 100 Hz, and a high linearity of better than 99.99%.

The role of zinc dopant and the temperature effect on the controlled growth of InNnanorods in metal-organic chemical vapor deposition system

This work was supported by the National Science Foundation of China (60976008 and 60776015), the Special Funds for Major State Basic Research Project (973 program) of China (2006CB604907), and the 863 High Technology R&D Program of China (2007AA03Z402 and 2007AA03Z451). The authors express their appreciations to Prof. Yongliang Li (Analytical and Testing Center, Beijing Normal University) for FE-SEM measurements, to DrTieying Yang and Prof. Huanhua Wang (Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences) for XRD measurements and helpful discussions.

All-Optical Clock Recovery for 20 Gb/s Using an Amplified Feedback DFB Laser

We report all optical clock recovery based on a monolithic integrated four-section amplified feedback semiconductor laser (AFL), with the different sections integrated based on the quantum well intermixing (QWI) technique. The beat frequency of an AFL is continuously tunable in the range of 19.8-26.3 GHz with an extinction ratio above 8 dB, and the 3-dB linewidth is close to 3 MHz. All-optical clock recovery for 20 Gb/s was demonstrated experimentally using the AFL, with a time jitter of 123.9 fs. Degraded signal clock recovery was also successfully demonstrated using both the dispersion and polarization mode dispersion (PMD) degraded signals separately.

The growth of ZnO on bcc-In2O3 buffer layers and the valence band offset determined by X-ray photoemission spectroscopy

This work was supported by the 863 High Technology R&D Program of China (Grant Nos. 2007AA03Z402 and 2007AA03Z451), the Special Funds for Major State Basic Research Project (973 program) of China (Grant No. 2006CB604907), and the National Science Foundation of China (Grant Nos. 60506002 and 60776015). The authors express their appreciation to Dr. Tieying Yang and Prof. Huanhua Wang (Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences) for XRD measurements and helpful discussions.

Intersubband absorption energy shifts in 3-level system for asymmetric quantum well terahertz emitters

Intersubband absorption energy shifts in 3-level system stemming from depolarization and excitonlike effects are investigated. Analytically, the expressions we derive present good explanations to the conventional 2-level results and bare potential transition energy results; and numerical results show that they are more exact than the previous studies to describe the 3-level system depolarization and excitonlike shift (DES) character especially for higher carrier density (more than 8 x 10(11) cm(-2)). One interesting detail we find is that the "large blue" DES becomes "slight redshift" in the low doping limit (less than 1.9 x 10(11) cm(-2)), which may be neglected by the previous studies of intersubband transitions. Temperature character of DES in the step well structure is also numerically studied. Finally the above are applied to calculate asymmetric step quantum well structures. The two main functional aspects of terahertz (THz) emitters are discussed and several basic optimizing conditions are considered. By adjusting the well geometry parameters and material composition systematically, some optimized structures which satisfy all of the six conditions are recommended in tables. These optimizations may provide useful references to the design of 3-level-based optically pumping THz emitters.