Saudi Journal of Engineering and Technology (SJEAT)
Volume-2 | Issue-01 | 32-48
Research Article
Study of Third Order Optical Nonlinearity in DASPB Dye-doped Polymer Films using CW Laser
Shubrajyotsna Aithal, Dr. P. S. Aithal, Dr. G. K. Bhat
Published : Jan. 31, 2017
Abstract
The optimum self-focussing materials with an intensity-dependent refractive index and the realization of the
ability of these materials to produce intensity dependent phase shift in all-optical photonic devices have become a topic
of continuous investigation. Many organic materials including dye-doped polymer films are creating interest due to their
advantages in terms of enhanced efficiency, and optimum mechanical properties to fabricate reliable devices. In this
paper, we have studied the nonlinear optical properties like nonlinear absorption and nonlinear refraction of a two-photon
fluorescent dye DASPB doped in Polymethyl methacrylate-methacrylic acid (PMMA-MA) polymer matrix using open
aperture and closed aperture Z-scan experimental methods by means of low power continuous wave (CW) laser beam.
The optical limiting properties of these films are also studied using Type 1 and Type 2 configurations at different input
powers using continuous wave (CW) laser beams of 532 nm wavelength. The nonlinear refractive index n2, nonlinear
absorption coefficient β, changes in refractive index with input intensity, and the magnitude of third-order optical
nonlinearity of the dye-doped film are experimentally determined. The saturated output power for type 1 and type 2
optical limiting are determined. The input limiting threshold and saturated output power level for both type 1 and type 2
optical limiting configurations are recorded. DASPB dye-doped in PMMA-MA polymer film has shown saturation
absorption at lower input irradiance and reverse saturation absorption along with two-photon absorption at higher input
irradiance and hence found to be a potential candidate for the third harmonic property based photonic devices.