Quantum Dynamical Approach to Predicting the Optical Pumping Threshold for Lasing in Organic Materials

The quantum dynamic (QD) study of organic lasing (OL) is a challenging issue in organic optoelectronics. Previously, the phenomenological method has achieved success in describing experimental observation. However, it cannot directly bridge the laser threshold (LT) with microscopic parameters, which is the advantage of the QD method. In this paper, we propose a microscopic OL model and apply time-dependent wave packet diffusion to reveal the microscopic QD process of optically pumped lasing. LT is obtained from the onset of output as a function of optical input pumping. We predict that the LT has an optimal value as a function of the cavity volume and depends linearly on the intracavity photon leakage rate. The calculated structure-property relationships between molecular parameters and the LT are in qualitative agreement with the experimental results, confirming the reliability of our approach. This work is beneficial for understanding the OL mechanism and optimizing the design of organic laser materials.