The polarization dependent optical confinement factor of waveguide structure with mixed strained layer multi quantum well has been discussed in this paper. Since the barrier width is relative small

its variation doesn’t affect the optical confinement very much. If the refractive index of layers are fixed

the optimal widths of waveguiding layer （with the largest confinement factor） are the same for symmetry and unsymmetry waveguide structures. And near the optimal width

Γ TM /Γ TE is sensitive to waveguiding layer width. This can be used to design polarization insensitive semiconductor laser amplifiers.By adjusting the waveguiding layer width

we can change the ratio of gain between TM and TE modes.