激光二极管泵浦的高效、单频Nd:YVO4激光器

对激光二极管端面泵浦的单频Nd:YVO4激光器进行了研究,研究了不同输出耦合率情况下输出功率随泵浦功率的变化曲线及光-光转化效率随输出耦合率的变化曲线,实验结果与理论分析结果基本一致.当泵浦功率为2.2 W时,得到瓦级单频1064 nm激光输出,最高光-光转化效率为47.2%.     

双共振准相位匹配光学参量振荡器的调谐特性

利用全固化单频Nd：YVO4激光器泵浦双共振难相位匹配铌酸锂连续光学参量振荡器，实验研究了该光学参量振荡器下转换光的调谐特性。通过改变PPLN晶体的温度及OPO的腔长，下转换光的调谐范围分别为189nm和175nm，通过改变泵浦光频率，信号光频率连续调谐375MHz。实验结果与理论计算值基本吻合。     

利用PPKTP晶体半整块光学参量放大器产生1.5μm光通信波段明亮正交振幅压缩光

利用周期极化磷酸氧钛钾(PPKTP)晶体构成的半整块结构简并光学参量放大器获得了连续变量1.5μm光通信波段的明亮正交振幅压缩态光场。光学参量放大器工作于阈值以下反放大状态,阈值功率为220 mW。当780nm抽运光场功率为110 mW,1.5μm注入信号光场功率为115 mW时,下转换光场输出功率为80μW,实测的连续变量1.5μm明亮正交振幅压缩态光场的压缩度达3.0dB。     

FeCl_3催化合成新型烯丙基醚类化合物

以烯丙基醇类化合物(1a~1i)和乙醇为起始原料,FeCl_3为催化剂,经分子间亲核取代反应合成了9个烯丙基醚类化合物(2a~2i,其中2c,2e~2i为新化合物),收率80%~95%,其结构经1H NMR,13C NMR和HRESI-MS表征。研究了催化剂,溶剂,反应温度和反应时间对2a产率的影响。结果表明:在最优反应条件[1a 0.5mmol,Fe Cl34 mg,Et OH 2.5 mmol,CH2Cl2为溶剂,于室温反应0.8 h]下,2a收率95%。     

输出功率5.2 W的全固态连续单横模671 nm红光激光器

设计了全固态连续单横模671 nm红光激光器.利用880 nm LD双端端面泵浦Nd:YVO4复合晶体,实现了均匀泵浦并改善了激光晶体热效应;考虑到影响倍频转化效率的各种因素,优化设计了Z字形四镜激光谐振腔,采用I类临界相位匹配晶体LBO作为腔内倍频晶体;当泵浦功率为42.5W时,获得了5.2W的连续单横模671 nm红光输出,光-光转化效率达到12.2％,激光器长期功率稳定性优于±2.5％(1 h).     

Quantum Dynamics of Entanglement and Single Excitation Transfer in LH1-RC-Type Trimer

In this paper,we study quantum dynamics of entanglement and single excitation transfer(SET) in an LH1-RC-type trimer which can describe a basic unit cell in the LH1-RC complex in the photosynthetic process.It is shown that there exists a sudden change of entanglement at the critic point of quantum phase transition(QPT) of the system at low temperatures,the entanglement sudden change caused by the QPT is suppressed at higher temperatures.We investigate the influence of environment on entanglement and SET.We show the generation of the dephasing-assisted entanglement between a donor and an acceptor and the existence of the steady-state entanglement,and demonstrate the entanglement transfer from donor-donor entanglement to donor-acceptor entanglement in the dynamic evolution.We reveal the close relation between the SET probability and donor-acceptor entanglement.Especially,we find that the SET probability is proportional to the amount of donor-acceptor entanglement under certain conditions.     

输出功率12W的全固态连续单横模1.34μm激光器

设计了全固态连续单横模1.34μm激光器。利用880nm激光二极管双端纵向泵浦Nd:YVO4复合晶体,在泵浦功率为51W时,获得12.4W的连续单横模1.34μm激光输出,光-光转换效率达到24.3%,激光器长期功率稳定性优于±1.2%(3h)。     

Exciton transfer dynamics in a trimer system

We study exciton transfer dynamics in a trimer system by investigating excitation transfer probability (ETP). We calculate ETP in the zero-temperature limit and theoretically predict the environment-assisted quantum critical effect, in which ETP exhibits a sudden change at the critical point of quantum phase transition for the trimer. In particular, we find that the steady-state ETP can be observed in the presence of the environment interaction.     

Study of the structure of borromean nucleus 17Ne

The ¹⁷Ne nucleus is a possible candidate with a two-proton borromean halo structure. Since the theoretical model is difficult to handle the three-body system, it is difficult to determine the two-proton halo structure in ¹⁷Ne. In the present research, we try to study the breakup reaction of ¹⁷Ne. For the Borromean nuclei, one-proton knockout results in an unstable nucleus which is decaying further by proton emission. This process will result in an angular correlation between the direction of the aligned recoiling unstable nucleus and its decay products. The angular correlations can give us information about the configuration of the valence proton in the ¹⁷Ne. Furthermore, theoretical calculations indicate that the momentum distributions of ¹⁶F c.m are sensitive to the structure of the halo in ¹⁷Ne. Thus the measurement of momentum distributions of ¹⁶F c.m may also give us conclusive information on the structure of ¹⁷Ne. The present experiment has been done at IMP in Lanzhou using the radioactive beam ¹⁷Ne at 30.8 MeV/u on a 43mg/cm^{2 12}C target. The data analysis is under procedure and the primary results are provided.     

Investigation on Characteristics and the Improving Method of Double Loop Optical Buffer

We establish an equivalent cascaded semiconductor optical amplifier system model to analyze the characteristics of the double loop optical buffer （DLOB）. The theoretical analysis finds that the performance of the DLOB can be improved by inserted amplifying process in an interval of some cycles. The experiment demonstrates that the buffered cycles can be improved from 20 to 50 and the bit error rate is less than 10-9 by inserting amplifying process in an interval of about 10 cycles.