A way of analyzing the data in a variable stripe length method gain experim
ent is presented. We confirm that the stripe length dependence of the gain
in In0.02Ga0.98N/In0.16Ga0.84N multiple quantum wells is caused by the chan
ge of the chemical potential along the excited stripe due to the interactio
n of the carrier and photon densities, and the gain threshold density is es
timated. A trial function assuming a Lorentzian line shape for the stripe l
ength dependence of the gain is compared with the edge emission intensity a
s a function of the stripe length. This is found to fit very well with our
data, even beyond the saturation region. (C) 2001 American Institute of Phy
sics.