Two- and three-photon absorption in a novel fluorene-based compound

A novel symmetrical charge transfer fluorene-based compound 2,7-bis (4-methoxystyryl)-9, 9-bis (2-ethylhexyl)-9H-fluorene (abbreviated as BMOSF) was synthesized and its nonlinear absorption was investigated using two different laser systems: a 140-fs, 800-nm Ti:sapphire laser operating at 1-kHz repetition rate and a 38-ps, 1064-nm Nd:YAG pulsed laser operating at 10-Hz repetition rate, respectively. Unique nonlinear absorption properties in this new compound were observed that rise from multiphoton absorption. The nonlinear absorption coefficients were measured to be 6.02×10-3 cm/GW (due to two-photon absorption, exciting wavelength is 800 nm) and 3.6×10-20 cm3/W2 (due to three-photon absorption, exciting wavelength is 1064 nm). This new compound possesses strong fluorescence induced by two-photon absorption and obvious three-photon absorption optical limiting effects.     

一种新的亚酞菁的共振三阶非线性光学性质

用简并四波混频技术研究了一种新的亚酞菁(三新戊氧基溴硼亚酞菁)的三阶非线性光学性质.测得纯固体三新戊氧基溴硼亚酞菁的三阶非线性极化率χ(3)pure和分子二阶超极化率〈γ〉分别为69×10-10esu和30×10-31esu.χ(3)pure的响应时间为20ps.并对这些结果进行了讨论     

绿敏光致聚合物的制备及其光全息存储性能研究

报导了一种新型的对绿光敏感的光致聚合物材料。该材料以丙烯酰胺为单体，由光引发剂，共引发剂，成膜物等组成。本材料记录的全息图衍射效率可达55％。在光聚物上采用角度复用技术存储了10幅图像，得到的再现像信噪比较高。说明该材料适合于大容量体全息存储。     

Low-Power Super-resolution Readout with Antimony Bismuth Alloy Film as Mask layer

Sb-Bi alloy flms are proposed as a new kind of super-resolution mask layer with low readout threshold power. Using the Sb-Bi alloy film as a mask layer and SiN as a protective layer in a read-only memory disc, the superresolution pits with diameters of 380 nm are read out by a dynamic setup, the laser wavelength is 780 nm and the numerical aperture of pickup lens is 0.45. The effects of the Sb-Bi thin film thickness, laser readout power and disc rotating velocity on the readout signal are investigated. The results show that the threshold laser power of super-resolution readout of the Sb-Bi mask layer is about 0.5 m W, and the corresponding carrier-to-noise ratio is about 20 dB at the film thickness of 50nm. The super-resolution mechanism of the Sb-Bi alloy mask layer is discussed based on its temperature dependence of reflection.     

用Z扫描方法测量掺C60有机改良介质的非线性折射率

用Ｚ扫描方法和波长１．０６４μｍ、脉宽１５０ｐｓ的锁模激光测定了Ｃ６０／ＮＨ２－（ＣＨ２）３－Ｓｉ（ＯＣ２Ｈ５）３（简称Ｃ６０／ＫＨ５５０）溶胶和凝胶的三阶光学非线性系数。理论拟合曲线计算得出，溶胶复合材料的非线性折射率ｎ２＝５．６×１０－１２ｅｓｕ，经两天凝结之后的凝胶复合材料的ｎ２＝６．２×１０－１２ｅｓｕ。在相同的激光强度下溶胶和凝胶的不同透过率归因于溶胶液体对激光的非线性散射。     

磷酸盐、锗酸盐和碲酸盐玻璃中Ce3+、Tb3+、Er3+和Tm3+离子的发光和敏化作用的研究——Ⅱ.辐射跃迁、无辐射跃迁和能量转移

对不同玻璃基质中的Tb3+、Er3+和Tm3+离子的辐射跃迁和无辐射跃迁速率进行了计算和测量,并讨论了基质玻璃对跃迁特性的影响。研究了Ce3+对Er3+、Tm3+,Tb3+的敏化作用,得出Ce3+对Er3+离子的敏化作用是弱的,而Ce3+对Tm3+和Tb3+是较强的,并对敏化机理进行了讨论。     

磁光极克尔转角θK温度特性的计算方法

本文提出了一种新的易于评价磁光极克尔转角θ_K和温度T的关系的计算方法,并给出了四层膜优化结构的计算实例。其结果和已知的实验规律相符,从而能导出最佳读出激光功率,使磁光盘信噪比达到最佳值。 关键词：     

玻璃中CuCl微晶的尺寸量子化激子

通过对尺寸分布非均匀加宽的激子吸收带选择激发的方法,研究了玻璃中几个nm量级的CuCl微晶的激子发光光谱.发现尺寸量子化的激子态劈裂形成多个分量.通过对尺寸量子化所产生的球形微晶中激光跃迁能级劈裂的分析,得到CuCl的z_(1.2)激子跃迁质量,Luttinger参数以及x线性项系数等数据.     

掺铬钛酸锶晶体的氧化还原诱导吸收及发光的退火效应和浓度效应

制备了纯的、掺0.005、0.01、0.2和0.5wt％Cr_2O_3的钛酸锶单晶.测量了不同退火条件下的室温透射光谱及6.5K以上的荧光光谱.对晶体的氧化和还原热处理诱导吸收及退火和掺杂浓度对晶体发光的影响进行了较为详细的研究.     

γ-LiAlO2晶体的生长缺陷研究

γ-LiAlO2晶体是一种非常有前途的GaN衬底材料,本文利用化学腐蚀光学显微术和同步辐射X射线形貌术研究了LiAlO2晶体的缺陷.结果表明,提拉法生长的γ-LiAlO2晶体中的缺陷主要为位错、包裹物和亚晶界.并发现在其(100)晶片上的腐蚀形貌两面有较大差异.