Random laser action under picosecond laser pumping
R. A. Ejbarah, J. M. Jassim, S. M. Hamidi
This study was aimed to investigate the effect of scattering mean free path of different concentrations of silver nanoparticles in Rhodamine B (RhB) solution. To get the random lasing, the samples were exposed to Picosecond laser. Our results show a gradual increase in the random lasing emission by increase in the concentrations and thus scattering mean free path until the threshold amount. The emission intensity was enhanced by enhancing the laser power due to an increase in scattering, which cannot make a close loop path in the gain medium to reach the coherence random lasing. Our results showed efficient emission intensity due to the absorption of Rhodamine B with Ag NPs in the pumping wavelength where it has been observed that the lasing threshold is reduced from 0.68 A (without scatterer) to 0.62 A at Likewise, the lowest FWHM (full width at half maximum) for this concentration was 34nm, while without concentration it was 37nm, but the clear and important difference is that the first occurred at 72 A, while the second state at 80 A.