Silver Nanoparticles under Nanosecond Pulsed Laser Excitation as an Intensity Sensitive Saturable Absorption to Reverse Saturable Absorption Switching Material

Abstract

Optical nonlinearity involved switching draws an important consideration in nonlinear optical studies. Based on that, we explored nonlinear absorption processes in silver nanoparticles synthesized by liquid phase laser ablation technique employing a second harmonic wavelength (532 nm) of Q switched Nd:YAG laser pulses with 7 ns pulse width and 10 Hz repetition rates. The typical surface plasmon resonance induced absorption (~418 nm) confirmed the formation of Ag NPs. The Z-scan technique was used to study the nonlinear optical processes, employing the same laser system used for ablation. Our study reveals that there is an occurrence of a saturable to reverse saturable absorption switching activity in the Ag nanoparticles, which is strongly on-axis input intensity dependent as well. The closed aperture Z-scan analysis revealed the self-defocusing nature of the sample.

Nonlinear optical properties of polyaniline doped with cardanol based dye

“…The graph plotting normalized transmittance against input intensity of the laser beam (Figure 6) shows that the transmission through the sample is constant at higher intensities and decreases as input intensity increases. This is a clear indicator that the PANI S sample shows optical limiting [25]. The pure nonlinear refraction curves reveal the self-defocusing nature of the sample and a negative nonlinear refractive index n2.…”