ANALYSIS OF METAL-INTERLACED-GRATING VERTICAL-CAVITY SURFACE-EMITTINGLASERS USING THE MODAL METHOD BY MODAL EXPANSION

It is analyzed by the modal method by modal expansion (MMME) that the strong polarization discrimination of a vertical-cavity surface-emitti ng laser (VCSEL) can be effectively obtained by using the metal-interl aced grating on the topmost layer of the VCSEL, The MMME is used to ov ercome the problems coming from the large permittivity discontinuities at GaAs-Al-air-Al interfaces, The analyses predict the correct direct ion of dominant polarization and the mode-suppression ratio, The calcu lated transmission efficiencies explain the characteristics of the VCS EL's below threshold, It is found that the difference in phase and amp litude between the two orthogonal polarization generated by the gratin g plays important roles for the selection of a dominant polarization t hrough mirror reflectivities and mirror losses. In addition, the influ ence of various thin metal layers on polarization stabilization Is dem onstrated.