THERMIONIC-TUNNELING-DIFFUSION MODEL OF THE LASER CURRENT-VOLTAGE AND POWER CHARACTERISTICS

An analytical model of the laser-diode current-voltage (I-V) characteristics based on the generalized thermionic-tunneling-diffusion mechanism of carrier transport through heterointerfaces has been proposed. It is valid for any degree of the carrier distribution degeneracy, not only in the laser active region but in the cladding layers as well. The model combines the laser rate equations with current flow equations and permits the evaluating of power-current and power-voltage characteristics. It is assumed that the temperature of the electron-hole gas in the active layer is different from the lattice temperatures. Under appropriate circumstances this allows one to consider the gas heating effect. In the present paper it is supposed that the temperature of the carriers in the laser active layer is proportional to the current in order to investigate the influence of heating on the laser I-V and power characteristics. The sequence of steps which must be carried out in the application of the model is described in detail. Analysis of the formation of different current components is carried out for lasing and unlasing laser diodes using as an example the 1.3 mum laser based on an InGaAsP compound. The influence of the heating effect and leakage current on the low-frequency linear response function is also presented.