OPTICAL GAIN AND ENERGY BAND STRUCTURE OF PHOTONIC CRYSTAL VCSELs WITH HIGH-INDEX-CONTRAST SUBWAVELENGTH GRATINGS

Photonic crystal vertical-cavity surface-emitting laser structure with incorporation of high-index-contrast subwavelength gratings is fabricated and the three quantum well active region of the structure is investigated with 8 band k.p model. The dispersion of energy sub-bands and wave functions in the conduction bands and valence bands indicate that effective overlapping and interactions between electrons and holes can be realized in the quantum wells and that the maximum spontaneous emission rate and optical gain occurs at the expected wavelength, which is confirmed by the measured photoluminescence spectrum.