The optical properties of semiconductor pseudomorphic multilayer systems (AlGaAs/GaAs/InGaAs multilayers) are investigated with Jone's matrix method. The theoretical calculation for VCSEL structure agrees with experimental results. In addition, the effect of strain-induced anisotropy of reflectance spectrum (RAS) in a multiplayer structure is analyzed. Furthermore, polarization dependent photoreflectance (PR) spectrum resulting from strain related electron state variation is reviewed. Potential applications of both methods to the diagnosis of optoelectronic materials and devices are discussed.