Temperature dependence of lasing characteristics of irregular-shaped-microparticle ZnO laser

We investigate the temperature dependence of the lasing characteristics (lasing peak energy spontaneous emission factor β, and lasing threshold) of an irregular-shaped-ZnO-microparticle laser. The shift of the lasing peak energy with temperature is very small in the range of 120-300 K, thus, indicating that the peak is determined mainly by the resonance energy position of a given cavity mode, and not by the gain spectral peak. On the other hand, β and lasing threshold are strongly dependent on temperature; β reaches a maximum at a particular temperature, whereas the lasing threshold exhibits a minimum. In comparison with the theoretical calculations, it is found that β and lasing threshold are optimum at the temperature at which the spontaneous emission spectral peak is in resonance with the peak of the cavity mode.