聚合物复合薄膜DR13/PMMA的制备及其光学特性

薄膜的厚度、折射率和传输损耗等参数在电光系数的确定和光波导器件的设计和制作过程中都是重要的参考数据。采用旋涂法制备了三种不同质量比的偶氮化合物染料分散红13(DR13)与聚合物聚甲基丙烯酸甲酯(PMMA)复合薄膜;利用分光光度计测量样品的吸收光谱;利用棱镜耦合仪测量了薄膜的厚度和折射率,并对不同波长下的折射率进行拟合得到折射率色散曲线;采用视频摄像技术研究样品的光传输特性,利用自己编写的计算机程序来处理其实验结果。DR13/PMMA复合薄膜在300nm和500nm处有两个大的吸收峰,而在其他波段,尤其是在通信波段没有明显吸收。薄膜的膜厚大约为1~2μm,其折射率随着质量比的增加而增大,随着激光波长的增大而降低,膜厚和折射率的误差分别为3.2×10-1μm和1.5×10-3。三种质量比(10%,15%和20%)的薄膜传输损耗分别为1.5269dB/cm,2.7601dB/cm和3.6291dB/cm,可以看出随着DR13质量比的增大,光传输损耗也逐渐增大,即DR13的含量对于传输损耗的影响较大。

Preparation and Optical Characteristics of Polymer DR13/PMMA Composite Films

The thickness, refractive index and transmission loss of films are important parameters in determining electro-optical coefficients and designing optical waveguide devices. The guest-host polymer disperse red 13 (DR13)/poly-methylmethacrylate (PMMA) thin films with three different concentrations were prepared by the spin-coating method, whose absorption spectra were obtained using a spectrophotometer. Their refractive index and thickness were measured with a prism coupler and the dispersion curve was plotted by fitting their refractive indices at different wavelengths. The experimental apparatus for an imaging technique were set up, by which the films′ transmission losses were measured with the help of image processing program written by ourselves. From the absorption spectra, there are two large absorption peaks at about 300 nm and 500 nm and no absorption peak in the telecommunication wave band, so this material can potentially be used in telecommunication devices. Thicknesses of the films are about 1～2 μm. It can be seen that at the same input wavelength, the refractive index becomes greater as the mass ratio increases, and when the wavelength of the input laser increases, the refractive index of the same mass ratio reduces. The error values of thickness and refractive index of the films are about 3.2×10-1 μm and 1.5×10-3. The transmission losses of three different mass ratio (10%, 15%, 20%) are 1.5269 dB/cm, 2.7601 dB/cm and 3.6291 dB/cm, respectively. It is shown that the transmission loss increases as the mass fraction increases, that is, DR13 is more important for the transmission loss than PMMA.