Effect of the thickness of the active region on the temperature dependence of the threshold current in homojunction lasers

Calculations are made of the temperature dependence of the threshold current allowing for losses caused by electron leakage from the active region of homojunction lasers. An exponential model of the density of upper states is used in the calculations. It is shown that the temperature dependence of the threshold current depends on the degree of spatial overlap of the carrier injection region (having the parameter $L$) by the field (having the parameter $S$), which is characterized by $R=S/\pi L$. If $R\ll1$, the temperature dependence is close to a power function, whereas for $R>1$, it is superexponential.