准波导结构染料薄膜中荧光和放大自发辐射的泄漏模特性

Properties of Leaky-Modes of Fluorescence and Amplified Spontaneous Emission in Dye Film with Quasi-Waveguide Structure

通过理论分析和实验测量,研究准波导结构染料薄膜中荧光和放大自发辐射(ASE)的泄漏模特性。理论上,考虑薄膜传输损耗及染料吸收损耗对准波导结构中泄漏模特性的影响,通过计算准波导结构中泄漏模的光强分布,给出了相应的物理机制分析;实验上,以棱镜为衬底制备染料薄膜,根据棱镜耦合法测量不同出射角对应的泄漏模的荧光与ASE光谱,验证理论的正确性。此外,采用光束分析仪探测各泄漏模式对应的荧光及ASE的光强分布,研究了准波导结构中ASE的激励特性。结果证明,荧光峰及ASE峰的红移以及泄漏模的激发是界面反射率、薄膜传输损耗及染料吸收损耗等共同作用的结果,而界面反射率对ASE泄漏模激发特性有重要影响,染料的自吸收是荧光峰及ASE峰产生红移的主要因素。

The properties of leaky modes of the fluorescence and the amplified spontaneous emission （ASE） in the dye film with quasi-waveguide structure are theoretically and experimentally investigated. Theoretically, considering the propagation loss and dye absorption loss, the physical mechanism of leaky-modes characteristics of the fluorescence and ASE are analyzed by calculating the field intensity distributions of the leaky-modes in the dye film with quasi-waveguide structure. Experimentally, the dye films are spin coated on the prism substrate, and the spectra of fluorescence and ASE of leaky modes of the dye films with quasi-waveguide structure are measured by the prism coupling method at different wavelengths and different output angles. The results show the consistence of theoretic analysis and experimental measurement. In addition, a beam analyzer is used to obtain the intensity distribution of fluorescence and ASE of leaky modes to understand the ASE exciting characteristic in the dye film with quasi-waveguide structure. It shows the redshifts of the fluorescence peaks and the ASE peak as well as the exciting leaky modes come from the interaction of the interface reflectivity, the propagation loss and the dye absorption loss, while the interface reflectivity is the dominate factor for exciting the leaky-modes, and the dye self-absorption is the dominate factor for the redshift of fluorescence peaks and the ASE peaks.