Threshold gain properties of lasing modes in ID disordered media optically pumped by femtosecond-lasing pulse
Yong LIU, Jinsong LIU
Threshold gain properties of lasing modes in ID disordered media optically pumped by femtosecond-lasing pulse
By numerically solving Maxwell’s equations and rate equations, a comprehensive calculation on spectrum intensity and spectral widths of three localized modes via different pumping rates in one-dimensional (1D) disordered medium is investigated, in which pumping rate is described by a time function with duration of 80 fs. The spectral intensities varying with the peak value of femtosecond (fs) pumping pulse are calculated in the same disordered medium, and the calculated spectral intensities are compared with those with fixed pumping (simulation time is 6 ps). These results show that excited modes with fs pulse pumping rates are only slightly different from those with fixed pumping (picosecond (ps) pulse), which suggests the excited modes largely depend on the medium rather than the pumping rate at least for those of which pumping rates are fs and ps. At last, lifetimes of three excited modes are calculated. It is found that there is a certain corresponding relation between the mode’s lifetime and its threshold-pumping rate, which is the longer lifetime with lower threshold.
one-dimensional (1D) disordered medium / lasing pumping rates / localized modes
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