Time-dependent theory for random lasers in the presence of an inhomogeneous broadened gain medium such as PbSe quantum dots.
Time-dependent theory for random lasers in the presence of an inhomogeneous broadened gain medium such as PbSe quantum dots.
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DOI：
10.1364/ao.52.001317
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发表时间：
2013-02
期刊：
影响因子：
1.9
通讯作者：
A. G. Ardakani;S. Mahdavi;A. Bahrampour
中科院分区：
文献类型：
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作者：
A. G. Ardakani;S. Mahdavi;A. Bahrampour
本文提出了一种模拟非均匀增益介质中随机激光器的时变模型。具有任意尺寸分布的PbSe量子点被视为非均匀增益介质。通过在极化、速率和麦克斯韦方程中引入PbSe量子点的不均匀性，我们建立了一维无序系统的模型。采用时域有限差分法对控制方程进行了数值求解，计算了激光频谱和电场的空间分布。研究了提高抽运速率对激光器特性的影响。结果表明，随着抽运速率的增加，激光模式的数目和强度增加。它还表明，发射光谱依赖于高斯分布函数的标准偏差。增加标准偏差导致激光强度降低。
Time-dependent model is presented to simulate random lasers in the presence of an inhomogeneous gain medium. PbSe quantum dots (QDs) with an arbitrary size distribution are treated as an inhomogeneous gain medium. By introducing inhomogeneity of the PbSe QDs in polarization, rate, and Maxwell's equations, our model is constructed for a one-dimensional disordered system. By employing the finite difference time-domain method, the governing equations are numerically solved and lasing spectra and spatial distribution of the electric field are calculated. The effect of increasing the pumping rate on the laser characteristics is investigated. The results show that the number of lasing modes and their intensities increase with pumping rate. It is also demonstrated that the emission spectra depend on the standard deviation of the Gaussian distribution function. Increasing the standard deviation leads to reduction of the laser intensity.