The Department of Physics at the College of Education for Pure Sciences examined a master's thesis titled "A Study of Third-Order Nonlinear Properties in a Waveguide Configuration for Mumijo-Doped Polymethyl Methacrylate (PMMA)."
The thesis, presented by researcher Batoul Jassim Mohammed, aimed to investigate new materials possessing linear and nonlinear optical properties and to study the optical behavior of Mumijo under laser irradiation. It also sought to determine nonlinear optical parameters—specifically the nonlinear refractive index and nonlinear absorption coefficient—and to explore the material's potential for use in modern optical applications. The study utilized the Z-scan technique in both open-aperture and closed-aperture modes; the methodology involved preparing Mumijo in a chloroform solution and using it to dope PMMA polymer films.
The results demonstrated that Mumijo—whether dissolved in chloroform or used to dope PMMA films—exhibits a distinct nonlinear optical response characterized by a self-defocusing effect. The nonlinear refractive index values ​​were found to be negative, increasing in magnitude with higher concentrations. The study also identified thermal nonlinear effects resulting from laser radiation absorption, which led to heat redistribution within the sample, changes in the refractive index, the emergence of thermal lensing behavior, and distortion of the optical beam's phase.
Additionally, the study examined the optical power limiting properties of the solutions and polymer films, calculated threshold power levels, and compared the performance of the various samples. The results revealed an inverse relationship between threshold power and concentration; the power required for optical limiting decreases as concentration increases, confirming that Mumiyana exhibits an effective nonlinear response.
These findings indicate that Mumiyana is a promising material in the field of nonlinear optics, with potential applications in optical and optoelectronic devices, optical power limiters, and solar cells..