Random laser emission from dye-doped gain media with optically trapped scattering particles

In this study, an optical trapping technique is employed to manipulate the scatterer distribution within a random laser medium. By focusing the trapping beams into small regions within the three-dimensional scattering medium, the scattering particles around them are concentrated in those regions, resulting in an inhomogeneous scatterer distribution. The experimental results show that optical trapping increases the maximum spike intensity in the emission spectrum. Furthermore, the spectral spike intensity depends on the power of the trap spots. The relationship between the maximum and average spike intensities in the emission spectra exhibits a characteristic observed in other random lasers with inhomogeneous scatterer distributions.