TE/TM polarization bistability in a lambda=1.3 mu m ridge-waveguide In
GaAsP/InP bulk laser is studied by near-field scanning optical microsc
opy with an optical resolution of better than lambda/8. The near-field
mode profiles of TE and TM emission show different lateral widths and
distinctly different mode center positions. This lateral shift is rel
ated to a nonuniform strain distribution along the active layer. Based
on this strain gradient, we present a model that accounts for the hys
teresislike current dependence of the polarization resolved laser outp
ut. (C) 1996 American Institute of Physics.