Theory of the temperature dependence of the threshold current of an InGaAsP laser

The threshold current of an InGaAsP laser is calculated, where the radiative emission, reflection and absorption losses, and Auger recombination are considered. Moreover, the enhancement of the threshold carrier density at high temperatures is an important point. A mechanism for this enhancement is discussed. Then we obtain an excellent agreement with the measured temperature dependence of the threshold current, in particular the T
o
-values for T≷T
B
and the break point T
B
. The reason for this break point is that the radiative recombination dominates for T < T
B
, whereas the strongly temperature dependent valence band Auger process becomes more and more important for T > T
B
. It is this process which causes the strong increase of the threshold current in the room temperature range.