Qusay M. Ali Hassan

Physical origin of observed nonlinearities in Poly (1-naphthyl methacrylate): Using a single transistor?transistor logic modulated laser beam

A thermal lens technique is adopted using a single modulated continuous wave (cw) 532-nm laser beam to evaluate the nonlinear refractive index n2, and the thermo-optic coefficient dn/dT, in polymer Poly (1-naphthyl methacrylate) (P-1-NM) dissolved in chloroform, tetrahydrofuran (THF), and dimethyl sulfoxide (DMSO) solvents. The results are compared with Z-scan and diffraction ring techniques. The comparison reveals the effectiveness and the simplicity of the TTL modulation technique. The physical origin is discussed for the obtained results.

Self diffraction and nonlinear optical properties for 2, 3- Diaminopyridine under cw illumination

The nonlinear absorption and refraction indices for 2,3-Diaminopyridine solution were measured using open-and closed- aperture z-scan techniques, with continuous wave (cw) irradiation. Furthermore, diffraction rings pattern as a result of nonlinear refraction was observed. The effect of concentration, wavelength and laser intensity on the nonlinear absorption, nonlinear refraction and diffraction rings are studied experimentally. It is found that the nonlinear refraction and absorption indexes in order of 10 -8 cm 2 /W and10 -3 cm/W, respectively. We suggested an opportunity to form a new nonlinear-optical media for nonlinear optical application.