Kimiyoshi Fukatsu

High-speed 1.1-μm-range InGaAs VCSELs

We have developed 1.1-μm-range high-speed VCSELs based on InGaAs-QWs for high-speed and highly reliable optical interconnections. 3-dB bandwidth up to 20 GHz and error-free 30-Gbps 100 m operations were demonstrated with oxide confined VCSELs. We also developed buried tunnel junction VCSELs to further improve the relaxation oscillation frequency limit. 3-dB bandwidth up to 24 GHz and error-free 40-Gbps operations were demonstrated with these VCSELs.

Highly Reliable High-Speed 1.1-

In this paper, we describe high-speed 1.1-μm-range oxide-confined vertical-cavity surface-emitting lasers (VCSELs) for large-scale optical interconnection applications. For achieving high data rates up to 25 Gbit/s under high temperature, we applied InGaAs/GaAsP strain-compensated multiple quantum wells (SC-MQWs) as the active layer. The developed device showed 25 Gbit/s error-free operation at 100°C. We also examined reliability of the VCSELs through accelerated life tests. The result showed an extremely long lifetime of about 10 thousand hours in MTTF under an ambient temperature of 150°C and a current density of about 19 kA/cm2. The level of reliability either equaled or surpassed that of conventional 0.85-μm VCSELs. Moreover, we revealed a typical failure mode of the device, which was caused by ≪110≫ dark line defects (DLDs) generated in the n-DBR layers under the current aperture area.

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In this work, 1.1-mum-range VCSELs based on InGaAs/GaAs quantum wells with high modulation bandwidth up to 20 GHz were developed. Error-free 25-Gbps operations were achieved for the first time using directly modulated multimode VCSELs

m-Range VCSELs With InGaAs/GaAsP-MQWs

We have developed vertical-cavity surface-emitting lasers for optical interconnections operating at 1.07 mum. The active layers of the devices are InGaAs-GaAs multiple quantum-wells, which are suitable for high-speed operation and high reliability. The devices exhibit -3-dB modulation bandwidths up to 19 GHz and no degradation under 70degC, 1000-h automatic power control tests. Error-free 20-Gb/s operations were also achieved

25-Gbps operation of 1.1-/spl mu/m-range InGaAs VCSELs for high-speed optical interconnections

We have developed novel 1.1-mum-range buried type-II tunnel junction vertical-cavity surface-emitting lasers (VCSELs) with a dielectric mirror for high-speed optical interconnections. A relaxation oscillation frequency of 27 GHz was achieved. The maximum 3-dB bandwidth was over 24 GHz. Error-free 30-Gb/s operation using a 27 -1-length pseudorandom bit sequence was demonstrated using directly modulated multimode VCSELs.

1.1-/spl mu/m-range InGaAs VCSELs for high-speed optical interconnections

We have developed novel 1.1-μm-range InGaAs VCSELs with buried type-II tunnel junctions for high-speed optical interconnections. A relaxation oscillation frequency of 27 GHz was achieved. Error-free 30-Gbps operations were demonstrated using directly modulated multi-mode VCSELs.

1.1-

We developed 1.1-mum-range vertical-cavity surface-emitting lasers based on InGaAs-GaAs quantum wells, back-illuminated InGaAs photodiodes, and transimpedance amplifiers (InP heterojunction bipolar transistor) for high-speed optical interconnection. Clear eye opening operation and error-free transmission at 30 Gb/s over 100-m multimode fibers (GI32) were successfully achieved for the first time.

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We developed VCSELs based on InGaAs-QWs for high-speed optical interconnections. Error-free operations were achieved up to 25 Gbps. We also proposed VCSELs with type-II tunnel junctions to reduce electrical resistance for higher speed operation

m-Range High-Speed Tunnel Junction Vertical-Cavity Surface-Emitting Lasers

We demonstrate 30-Gb/s transmission using 1.1 μm-range VCSELs based on InGaAs/GaAs quantum wells, back-illuminated InGaAs PDs, and TIAs (InP-HBT). Error-free 30-Gbps transmission with 100 m-MMFs (GI32) is achieved for the first time.

1.1-μm-range tunnel junction VCSELs with 27-GHz relaxation oscillation frequency

We propose 1.1-µm-range InGaAs quantum-well (QW) vertical-cavity surface-emitting lasers (VCSELs) with a buried type-II tunnel junction (BTJ). Because of the low electrical resistance of the type-II tunnel junction, the chip resistance was reduced by over 40% compared with conventional oxide-confined VCSELs with the same-size aperture. In an aging test, stable operation at 85 °C was maintained in terms of optical and electrical characteristics for over 1000 h without early failure. The introduction of the type-II TJ structure can suppress self-heating caused by the chip resistance and may be a practical approach to achieving high-speed VCSELs for advanced optical interconnection.