双坩埚三维温度梯度法蓝宝石晶体生长炉设计

在已有的三维温度梯度法(3DGF)蓝宝石晶体生长炉基础上,设计了一种双坩埚蓝宝石晶体生长炉。设计的三维温度梯度法蓝宝石晶体生长炉主要针对蓝宝石手机面板市场,将坩埚设计成长方体型,增加了材料利用率,并简化了晶体切割工艺。采用双坩埚技术,可进一步提高晶体的生产效率,节约能耗,降低成本。本设计的双坩埚3DGF蓝宝石晶体生长炉可单炉获得2个300 mm×100 mm×100 mm的蓝宝石晶体。     

遗传算法在检测耦合腔链各单腔频率中的应用

利用遗传算法来诊断耦合腔链的各单腔频率,不需插入活塞探针进入耦合腔链,由计算机通过微波网络分析仪,从腔链的输入波导获取通带特性数据,便可求解各单腔频率.这种方法可以简化调谐过程,并可以用来诊断密封腔链.此问题可以看作是一个非线性最优化问题,我们选择遗传算法来解决此问题,并且在遗传算法中加入了最小二乘的变异算子,使遗传算法的收敛速度和精度都得到显著改善.数值实验证实了这种算法的优越性,并且与传统的遗传算法进行了比较.     

Optimization of holey fiber for dispersion compensation

Hermite-Gaussian functions were used to calculate the dispersion of holey fibers, when pitch was more than 0.6 μm, there was dispersion inflexion at 1.55 μm (wavelength), and the relation of the dispersion inflexion versus fiber structure was given. Calculations show that the dispersion of holey fiber could reach -2300 ps/(nm·km), or they could compensate (to within ±4%) the dispersion of 120 times of their length of standard single mode fiber over a 100-nm range.     

一种新的多阶只读光存储方法的仿真分析和实验验证

提出了一种波形调制的方法,在原有记录符中加入一个短坑或短岸,在读出信号上产生一个可辨识的"扰动",从而对读出信号波形产生调制.用简化的光刻模型和基于角谱分解的读出模型,对该方法在DVD系统上的坑形和读出信号进行了仿真.仿真结果确定了各个游程可实现的阶次和各个阶次的刻写参量.对典型游程6T和11T进行了实验,读出信号与仿真结果相吻合,并分别得到了小于1×104和1×10-5的阶次误码率.实验结果验证了该方案的实际可行性.     

Restriction of shot noise and material noise in a multilevel photochromic memory on signal-to-noise ratio

The recording density of multilevel photochromic memory is limited by the signal-to-noise ratio （SNR） of the readout signal. In this paper, shot noise and material noise are investigated through theoretical analysis of SNR. When the bandwidth of a system is less than 1MHz, the material noise takes a prominent position; when the bandwidth of the system is more than 10MHz, the shot noise becomes dominant. The thickness of recording layer can be optimized to maximize the SNR and reduce the influence of the bandwidth of the system on SNR.     

基于凹面光栅的特定蛋白分析仪结构设计及性能分析

为解决罗兰光栅光谱成像不易直接读取、平面场凹面光栅成像算法复杂等问题,设计了一种基于全息凹面光栅原理的用于特定蛋白分析仪生化检测的分光光度计。该结构以罗兰光栅为基底,采用双透镜作为过渡元件,将罗兰光栅的曲面成像过渡成平场光谱,同时采用光学设计软件Zemax对该结构进行模拟和优化。优化结果表明,分光光度计能够实现光谱平场化,工作波段为320～800 nm,最高分辨率可达0.5 nm,整体分辨率优于1.7 nm,可被光电二极管阵列直接读取,结构特性满足特定蛋白分析仪的测量要求。样机实验结果与模拟结果一致,仪器重复性、准确度、稳定性及线性度均达到行业标准。     

Packaging multi-wavelength DFB laser array using REC technology

Packaging of Distributed feedback （DFB） laser array based on reconstruction=equivalent-chirp （REC） tech- nology is a bridge from chip to system, and influences the practical process of REC chip. In this letter, DFB laser arrays of 4 channel @1 310 nm and 8 channel @1 550 nm are packaged. Experimental results show that both 4 channel @1 310 nm and 8 channel @1 550 nm have uniform wavelength spacing and average side mode suppression ratio （SMSR）〉35 dB. When I=35 mA, we get the total output power 1 mW of 4 channel @1 310 nm, and 227 μW of 8 channel @1 550 nm, respectively. The high frequency characteristic of the packaged chips is also demonstrated, and the requirements of 4× 10 G or even 8× 10 G system can be reached, we demonstrate the practical and low cost performance of REC technology and indicates its potential application in the future fiber-to-the-home （FTTH）.     

Photonic angle-of-arrival and time-difference-of-arrival measurement based on dual drive 1 × 2 MZM

We propose and experimentally demonstrate a photonic approach to estimate the time-difference-of-arrival (TDOA) and the angle-of-arrival (AOA) of a microwave signal. TDOA and AOA are estimated from the carrier power difference of the two outputs of the Mach-Zehnder modulator (MZM) using only one dualdrive 1 × 2 MZM. Experimentally, the TDOA of a microwave signal at 3 GHz from 27.78 to 166.67 ps is measured with maximum measurement errors of ± 2.24 ps; correspondingly, the AOA from 60°to 85.2°is measured with maximum measurement errors of ± 0.4° .     

Theoretical and experimental analyses of recording mark microstructures in signal waveform modulation optical disc

In this paper,we propose a dynamic mastering process model for signal waveform modulation (SWM) optical disc.To form the ideal microstructures and solve the problems in the SWM master manufacturing process,we use this model to simulate the three-dimensional mark profiles in the SWM read-only disc.The simulated micro-patterns of recording pits and lands are employed to optimize the writing strategy and provide a quantitative basis for manufacturing the sub-pits and sub-lands.The simulation mark profiles are compared with the experimental ones,which are produced with the optimized writing strategy parameters.Comparison results demonstrate that the simulated profiles are highly consistent with the actual ones.