Study of third-order NLO properties of organic dye for optoelectronics applications

Third-order nonlinear optical properties of aqueous solutions of methylene blue dye with different concentrations were studied by Z-scan technique. The magnitude of nonlinear refractive index (n(2)), nonlinear absorption coefficient (beta) and third-order nonlinear optical susceptibility (chi((3))) were found to be the order of 10(-7) cm(2)/W, 10(-2) cm/W and 10(-5) esu, respectively. The dye sample possesses a large negative nonlinear index of refraction due to self-defocusing phenomena and saturable absorption behavior with significant nonlinear absorption coefficient. The experimental results revealed that the dye sample studied here may be a potential material for future photonics and optoelectronics applications.