Studies on thermal nonlinear optical effects on cyclododecanone crystals for IR optical switching application

A cyclic ketone, cyclododecanone (CDD) and its derivatives has been synthesized by direct aldol condensation reaction. CDD derivative (–CH₃, –OMe, –2Br, –2Cl, –4Cl, 2CF₃, –C₆H₆) crystals were grown in the mixture of solvent tetrahydrofuran and ethanol by Natural evaporation method. The linear optical property of CDD derivative crystals has been studied using UV–Vis–NIR spectroscopy. The optical constants are calculated theoretically in the wavelength range 190–1100 nm. The third order nonlinear optical property of CDD derivatives has investigated by using z-scan technique using He–Ne laser (632.8 nm). The saturation absorption and self-defocusing effect was observed in z-scan open and closed aperture methods respectively. The nonlinear optical effects were due to the thermal mechanism processes of the incident laser power passing through an optical material. The response time of CDD derivative has found to be in the order of milliseconds. The two figures of merit W > 1 and T < 1 are suitable for optical switching application. The refractive index of CDD crystals has been measured using Abbe’s refractometer.