Frequency-stabilized semimonolithic frequency doubler with high output power

The frequency-doubled Nd:YAP laser with high out- put power is an important pumping source for quan- tum information, quantum optics, and nonlinear optics experiments[1-6]. Intracavity frequency-doubled[7-11] and external frequency-doubled lasers[12-18] are two usual methods to generate continuous second harmonic wave. For the former, the frequency-doubling nonlinear crystal and the active medium of the laser are put in the same resonant cavity, thus the process of frequency doubling possibly…     

Photon Statistics of Single-Photon Quantum States in Real Single Photon Detection

Single photon detection (SPD) with high quantum efficiency has been widely used for measurement of different quantum states with different photon distributions.Based on the direct single SPD and double-SPD of HBT configuration, we discuss the effect of a real SPD on the photon statistics measurement and it shows that the measured photon distributions for different quantum states are corrected in different forms.The results are confirmed by experiment with the strongly attenuated coherent light and thermal light.This system can be used to characterize the photon statistics of the fluorescence light from single atom or single molecular.     

Improving frequency stability of laser by means of temperature-controlled Fabry-Perot cavity

The frequency stability of an all-solid-state Nd:YVO4 laser is significantly improved by means of a specially designed Fabry-Perot (F-P) interferometer used for the frequency standard in the frequency-stabilizing system. The ten.peraturo of the F-P cavity is accurately controlled by a set of thermoelectric cooler (TEC) modules attached on th dy of the cavity and the electronic feedback circuit. We find that the long-term unidirectional frequency shift of the output laser, resulting from the slow increase of the cavity length under the effect of the temperature integration on the cavity body, is essentially eliminated. The frequency stability of the output laser with the power of 530 mW is better than ±200 kHz in 1 minute and ±2.3 MHz iu 40 minutes, respectively. The fluctuation of output power is smaller than ±0.5% over one hour.     

大规模数据场的并行可视化

计算机数值模拟已经成为一种主要的科学研究手段。随着计算机性能的不断提高和并行化技术的广泛使用，计算规模得到了大大的提高，不仅给数据存储带来了压力，也给数据可视化带来了挑战。可视化是—个交互的数据分析过程，当数据规模增大时，数据的读入和处理都因为数据庞大而难于实现交互，硬件性能的改进和串行算法的优化难以提供较大的性能改进空间，在目前的软硬件环境下，并行I/O和并行可视化处理是有效的解决途径。     

频率可调谐的非经典光场的产生及其在FM光谱中的应用

利用Ⅱ类相位匹配KTP晶体组成的双共振OPO,实现了可调谐连续OPO单频运转,最大输出功率360mW,波长调谐范围大于9nm.在此基础上,进一步利用α切割KTP晶体获得了输出波长可调谐的强度关联孪生光束,调谐范围大于5nm,最大量子关联大于5dB.将此非经典光场用于Cs2频率调制光谱测量,获得了突破散粒噪声极限4dB的测量结果,在室温下观测到了Cs2在1041nm、1065nm的吸收谱.     

用于BEC的Rb原子饱和吸收稳频半导体激光器系统

用于冷却和俘获原子的激光器要求窄线宽和稳定性好.为了满足要求,在实验上我们使用的半导体激光器采用主振荡器--功率放大 (Master-oscillator power amplifier: MOPA) 式单频半导体激光器TA100 (德国 Topicas).     

光压缩器的研制

目前,非经典光场已被成功应用于亚散粒噪声极限光学测量,量子非破坏测量,量子离物传态及量子保密通讯等领域.而且近年来随着以EPR纠缠态的非局域关联为基础的量子信息科学的迅速发展,使可以方便地产生连续变量的EPR关联的双模压缩态光场显示出它广泛的应用前景.但是目前压缩态光场产生系统装置庞大、操作复杂、稳定性不理想.因此实现实用化压缩光产生系统就成为一个重要的研究课题.     

光学偶极俘获及单量子测量

对目前的腔QED系统实现强耦合的条件进行了讨论.主要内容包括:获得强耦合的一般条件,我们目前的可能达到的最好结果分析:不同腔组合可能达到的参数,与量子点、光子晶体、纳米腔以及微球腔QED的比较;单原子(单光子)测量的基本过程:单原子辐射的基本特点,非经典性的测量,包括差拍测量,光子统计特性的分析.不同单光子量子态(或多光子量子态)在采用HBT实验测量中的修正等问题.对热光和相干光的初步实验对比证实了理论模型.原子操控的进展:铯原子光学偶极俘获,最近的实验结果,利用CCD荧光探测对偶极阱的测量结果.     

低于散离噪声极限的微小吸收测量

用量子相关孪生光束完成了低于散离噪声极限微小吸收测量 ,信噪比较散离噪声极限提高约 2 .5dB .实验结果证实了半经典理论预测. .