Investigating the thermal diffusivity of Pyrromethene 567 in different solvents using dual beam thermal lens spectroscopy

The investigation of the thermo-optic characteristics of a material is vital in understanding the nonradiative relaxation processes occurring within the sample. Pyrromethene 567 a member of the laser dye family, has gained significant attention due to its excellent photo-physical characteristics, such as excellent laser efficiency, photostability, and quantum yield. The investigation of the photothermal studies in Pyrromethene 567 remains unexplored. Herein, a dual-beam thermal lens technique was performed to analyze the thermal lensing behaviour of Pyrromethene 567 in various solvents. The thermal diffusivity of Pyrromethene 567 in different solvents was calculated. There were no previous reports measuring the thermal diffusivity of Pyrromethene 567 dye. Thermal lens spectroscopy offers several advantages over conventional techniques because of its high sensitivity. The work also discusses the factors that influence the thermal lens signal in Pyrromethene 567. The influence of detector positioning, chopper frequency, and sample positioning, on thermal lens measurements was discussed. Additionally, the thermal lens experiments should be performed at intensities where diffraction patterns due to spatial self-phase modulation are absent to minimise experimental errors.