High performance selectively oxidized VCSELs and arrays for parallel high-speed optical interconnects

We introduce a new layout for high-bandwidth single-mode selectively oxidized vertical-cavity surface-emitting laser (VCSEL) arrays operating at 980 nm or 850 nm emission wavelength for substrate or epitaxial side emission. Coplanar feeding lines and polyimide passivation are used to reduce electrical parasities in top-emitting GaAs and bottom-emitting InGaAs VCSELs. In order to enhance fundamental single-mode emission for larger devices of reduced series resistance a surface relief transverse mode filter is employed. Fabricated VCSELs are applied in various interconnect schemes. In detail, InGaAs quantum-well based VCSELs at 935 mu emission wavelength are investigated for use in perfluorinated graded-index plastic-opticaI fiber (GI-POF) links. We obtain a 7 Gb/s pseudo random bit sequence (PRBS) nonreturn-to-zero (NRZ) data transmission over 80 m long 155 mum diameter GI-POF. We investigate data transmission over standard 1300 mum, 9 mum core diameter single-mode fiber with selectively oxidized single-mode GaAs and InGaAs VCSELs. We achieve biased 3 Gb/s and bias-free 1 Gb/s pseudo-random data transmission over 4.3 km at 830 nm emission wavelength where a simple fiber mode filter is used to suppress intermodal dispersion caused by, the second order fiber mode. For the first time, we demonstrate 12.5 Gb/s data rate transmission of PRBS signals over 100 in graded-index multimode fiber or 1 km single-mode fiber using high performance single-mode GaAs VCSELs of 12.3 GHz modulation bandwidth emitting at gimel = 850 nm. Longer wavelength InGaAs VCSELs with emission at gimel = 1130 nm are used to transmit 2.5 Gb/s signals over 10 kin of 9 mum standard single-mode fiber. For all data transmission experiments bit-error rates (BER) remain better than 10(-11) for transmission of PRBS signals for back-to-back (BTB) testing as well as for fiber transmission.