
179Optical Direct and External Modulation
5.2.4.10 Effects
due to the Gain Compression Factor (ε)
The
inclusion of gain compression factor ε in the laser rate equations (5.2) and (5.3) is a phe-
nomenological
approach, which can represent a number of mechanisms, including spatial
hole burning and lateral carrier diffusion [2.33], [2.34], spectral hole burning, and other
nonlinearities [2.35] (Figure 5.29).
From
Figure 5.27 and Figure 5.29, it is clear that a good damping effect (less relaxation
oscillations) and a small overshoot can be achieved by having a larger value of ε. For
instance, oscillations of four cycles with overshoot o ...