We demonstrate a measurement technique fur determining the contributio
n of carrier transport effect on the maximum modulation bandwidth in q
uantum well lasers. This technique independently measures the ratio of
the effective carrier capture to escape times, as well as the contrib
ution from intraband damping mechanisms, in an operating laser. Every
single parameter in the present model for modulation dynamics of quant
um well lasers can now be determined experimentally, which enables a c
onsistency check on its validity. (C) 1996 American Institute of Physi
cs.