Matsuda Hirohisa, Fujimoto Yousuke, Ito Syoji, Nagasawa Yutaka, Miyasaka Hiroshi, Asahi Tsuyoshi, Masuhara Hiroshi
Division of Frontier Materials Science, Graduate School of Engineering Science and Research Center for Material Science at Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan.
J Phys Chem B. 2006 Jan 26;110(3):1091-4. doi: 10.1021/jp0561165.
Femtosecond near-infrared laser microscope was developed with a home-built cavity-dumped chromium:forsterite laser as a light source centered at 1.26 microm. Optimization of the pulse duration achieved 35 fs fwhm at the sample position of the microscope after passing through a 100x objective. This system was applied to the detection of multiphoton fluorescence of some organic microcrystals. Excitation intensity dependence and the interferometric autocorrelation detection of the fluorescence clearly demonstrated that simultaneous three- and four-photon absorption processes are responsible for the production of the excited state for perylene and anthracene microcrystals, respectively. The spatial resolution along the optical axis and its dependence on the order of the multiphoton process were also discussed.
镁橄榄石激光器作为中心波长为1.26微米的光源研制而成的。在通过100倍物镜后，在显微镜的样品位置实现了脉冲持续时间的优化，半高宽为35飞秒。该系统被应用于一些有机微晶的多光子荧光检测。荧光的激发强度依赖性和干涉自相关检测清楚地表明，苝和蒽微晶分别通过同时的三光子和四光子吸收过程产生激发态。还讨论了沿光轴的空间分辨率及其对多光子过程阶数的依赖性。
