  We present a comparison of the band alignment of the Ga1-xInxNyAs1-y active
layers on GaAs and InP substrates in the case of conventionally strained and
strained-compensated quantum wells. Our calculated results present that the
band alignment of the tensiley strained Ga1-xInxNyAs1-y quantum wells on InP
substrates is better than than that of the compressively strained
Ga1-xInxNyAs1-y quantum wells on GaAs substrates and both substrates provide
deeper conduction wells. Therefore, tensiley strained Ga1-xInxNyAs1-y quantum
wells with In concentrations of x<=0.53 on InP substrates can be used safely
from the band alignment point of view when TM polarisation is required. Our
calculated results also confirm that strain compensation can be used to balance
the strain in the well material and it improve especially the band alignment of
dilute nitride Ga1-xInxNyAs1-y active layers on GaAs substrates. Our
calculations enlighten the intrinsic superiority of N-based lasers and offer
the conventionally strained and strain-compensated Ga1-xInxNyAs1-y laser system
on GaAs and InP substrates as ideal candidates for high temperature operation.
