光的干涉衍射综合实验仪

根据传统的光的干涉衍射实验装置存在的不足,研制出了光的干涉衍射综合实验仪．将光学元件放置在同一小型光学平台上,按照实验需要组合成相应仪器．该实验仪既可以用于光学演示实验,也可以作为光学专用的实验仪器。     

Polarization-independent wavelength conversion using a single semiconductor optical amplifier

Polarization-independent wavelength conversion is demonstrated by using four-wave mixing (FWM) in a single semiconductor optical amplifier (SOA). In this scheme, all the incident fields are split into two orthogonal-polarized parts by polarizing beam splitters (PBS). Each of the two parts is then transmitted into one facet of the SOA and they are counter-propagating through the same amplifier. Wavelength conversion with the polarization sensitivity less than 1.3 dB is obtained over a range from 1510 to 1620 nm.     

窄带Faraday反常色散光学滤波器

研究Faraday反常色散光学滤波器,给出其理论计算过程和模拟结果.结果表明,Faraday反常色散光学滤波器有线翼和线芯透过两种工作方式,其中线翼透过单峰谱线线宽约为600MHz,透过率约为25%,线芯透过谱线线宽约为700MHz,透过率约为100%.实验结果与理论结果相符.     

Generation and storage of double slow light pulses in a solid

We experimentally study the generation and storage of double slow light pulses in a Pr³⁺:Y₂SiO₅ crystal. Under electromagnetically induced transparency, a single signal pulse is stored in the spin coherence of the crystal. By simultaneously switching on two control fields to recall the stored information, the spin coherence is converted into two slow light pulses with distinct frequencies. Furthermore, the storage and controlled retrieval of double slow light pulses are obtained by manipulating the control fields. This study of double slow light pulses may have practical applications in information processing and all-optical networks. vspace2mm     

直流电纵向激励机械调Q CO2激光器的动力学分析

用一种快速斩波器实现简单直流电纵向激励CO₂激光的机械Q调制. 产生了峰值功率为1~2 kW、 重复频率为740 Hz、 单脉冲宽度为200~300 ns的激光脉冲. 用六温度模型模拟该机械调Q CO₂激光器Q调制的动力学过程, 分析了CO₂分子分解为CO分子比率、 腔内放电电子密度(放电电流)对输出脉冲强度的影响, 并计算了Q转换输出脉冲线形、 脉冲峰值功率及脉冲宽度, 理论计算分析与实验结果相符.      

Ultrabroad-band wavelength converter with high flattening conversion efficiency in a semiconductor optical amplifier

The efficiency of ultrabroad-band wavelength conversion using orthogonal-pump four-wave mixing in a semiconductor optical amplifier is measured for the wavelength shifts from 1500 to 1640 nm. The variation of conversion efficiency is < 0.9 dB over the wavelength range from 1530 to 1560 nm (C-band), and < 4.5 dB over the wavelength range from 1560 to 1610 nm (L-band). The maximum conversion efficiency is about -8.7 dB.     

热原子系综中双暗共振及亚多普勒吸收谱的实现

分别通过实验和数值模拟给出了在四能级倒Y模型原子系统中的双窗口电磁感应透明现象. 结果表明,    通过调解2个耦合场的失谐可控制透明窗口的位置. 双窗口电磁感应透明现象的物理本质是由于2个耦合场同时作用于原子系统中而形成的双暗共振,   同时双暗共振间的相互作用将探测场在目标频率处的吸收谱线压窄, 并在实验上得到频谱宽度（半高宽）约为30 MHz的探测场共振吸收谱线.     

Scanning the energy dissipation process of energetic materials based on excited state relaxation and vibration–vibration coupling

The energy dissipation mechanism of energetic materials(EMs) is very important for keeping safety. We choose nitrobenzene as a model of EM and employ transient absorption(TA) spectroscopy and time-resolved coherent anti-stokes Raman scattering(CARS) to clarify its energy dissipation mechanism. The TA data confirms that the excited nitrobenzene spends about 16 ps finishing the twist intramolecular charge transfer from benzene to nitro group, and dissipates its energy through the rapid vibration relaxation in the initial excited state. And then the dynamics of vibrational modes(VMs) in the ground state of nitrobenzene, which are located at 682 cm~(-1)(v_1), 854 cm~(-1)(v_2), 1006 cm~(-1)(v_3), and 1023 cm~(-1)(v_4),is scanned by CARS. It exhibits that the excess energy of nitrobenzene on the ground state would further dissipate through intramolecular vibrational redistribution based on the vibrational cooling of vi and v_2 modes, v_1 and v_4 modes, and v_3 and v_4 modes. Moreover, the vibration-vibration coupling depends not only on the energy levels of VMs, but also on the spatial position of chemical bonds relative to the VM.     

固体材料中原子相干效应的研究进展

原子相干效应是光与物质相互作用的结果,它导致了一系列重要的物理现象。目前原子相干的实验研究工作主要在原子气体中开展,而与之相比固体材料中的相关实验研究具有更实际的应用前景。本文系统介绍了近年来固体材料中原子相干效应的研究进展,主要涉及电磁感应光透明、光速减慢与相干存储、存储光信息的可控制擦除、基于光存储的全光路由、双光脉冲的速度减慢和可逆存储和基于原子相干的增强四波混频等基本内容,最后还讨论了其在相关领域的应用。     

QAPVA/PMPVA复合物膜对95%乙醇脱水的IR研究

季铵化聚乙烯醇(QAPVA)与磷酸单酯化聚乙烯醇(PMPVA)自组装成聚离子复合物(PIC)膜。PIC膜用95%乙醇中浸泡48 h, 在20～120 ℃(间隔20 ℃)下测定吸水后PIC膜的IR,分析了>3 000 cm-1OH伸缩振动基频(ν_OH)随温度变化情况,探讨了水与膜中OH的氢键作用。由于ν_OH在3 000 cm-1以上重叠严重,结合1 300～1 700 cm-1水与PIC膜中离子键的静电作用,采用二维相关分析提高分辨率,定性描述了95%乙醇中水与PIC膜之间的结合方式。结果表明：>3 000 cm-1νOH的重叠谱带得到了分辨, 证明了水与膜内OH缔合优先吸附渗透,随温度变化早于膜内的OH自缔合被解吸与乙醇分离;确认了水和PIC膜内聚电解质基团的吸收, 证明了水与聚电解质基团靠静电作用被吸附, 随温度升高被解吸与乙醇分离。文章为PIC膜用于有机物脱水研究提供了一种简便高效的方法。