Thermal diffusivity of 2,3-Pyridinediamine determination by thermal blooming

The nonlinear optical properties, optical limiting and self diffraction of 2,3-pyridinediamine in the solvent DMSO have been studied. The measurements were performed using a low power continuous wave (CW) from solid state laser (SDL) at 473 nm wavelength. The effect of the pH in 2,3-pyridinediamine solution on nonlinear optical properties, optical limiting and self diffraction pattern have been investigated. The results show the dependence of the nonlinear refractive index, nonlinear absorption coefficient, optical limiting threshold and number of diffraction rings on the pH values. This 2,3-pyridinediamine solution exhibit an interesting optical limiting performance with CW laser. Thermal blooming technique was applied to investigate the thermo-optical properties and the nonlinear refractive index. In this technique a pump beam was aligned collinearly. A localized change in the refractive index of the sample due to the thermal heating produced a thermal lens that was then detected by the study of the focusing and defocusing of the pump beam. With excellent nonlinear optical coefficient, the sample is expected to have potential applications in optical devices.