3.2.3 Comparison Between Theory and DC-Measured
Experimental Data
To understand the dependence of the intrinsic parameters for high-speed modula-
tion of three lasers, steady-state characteristics of these lasers are studied. The net
modal gain spectra for three lasers are measured for several injection currents up to
the thr eshold and are plotted in Figure 3.1(a)–(c) in dashed lines. Also presented in
Figure 3.1(a)–(c) are our calculated (solid curves) optical gain spectra using the
many-body gain model for the three material systems. Through fitting the gain
spectra, we obtain the para meters, including the intraband relaxation time
in
, the
correlation time
c
, and a parameter C used in the formulation of the reference
[20], which contributes