Plasmon-enhancement of optical near-field of metal nanoaperture surface-emitting laser

We propose a double-aperture structure to enhance the optical near-field in metal nanoaperture vertical-cavity surface-emitting lasers (VCSELs). We fabricated 850 nm GaAs VCSELs with subwavelength-sized double metal apertures closed to each other. The optical near-field localized in the metal apertures is strongly enhanced by the excitation of localized plasmon around the metal apertures. The far-field power radiated from the apertures is enhanced to be 16 times larger than that from a single aperture VCSEL. The peak power density is as large as 2.5 mW/mum(2) with a spot size of 260 nm. The obtained power density is even larger than that of a conventional single-mode VCSEL without nanoapertures, which is very encouraging for use in high-density data storages. (C) 2004 American Institute of Physics.