We have investigated efficient light outcoupling from light-emitting diodes (LEDs) by introducing lateral tapers. The concept is based on light generation in the very central area of a circularly symmetric structure. After propagating between two highly reflecting mirrors light is outcoupled in a tapered mesa region. By proper processing we achieve quantum and waliplug efficiencies of almost 30% for outcoupling via a planar surface or, respectively, 45% and 44% for encapsulated devices.

No abstract

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 parasitics 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 nm emission wavelength are investigated for use in perfluorinated graded-index plastic-optical 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 m diameter GI-POF. We investigate data transmission over standard 1300 nm, 9 m 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 m 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 = 850 nm. Longer wavelength InGaAs VCSELs with emission at = 1130 nm are used to transmit 2.5 Gb/s signals over 10 km of 9 m 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.

No abstract

No abstract