Recent developments in long wavelength VCSELs based on localized wafer fusion

We review recent results on wafer fused long wavelength VCSELs emitting in the 1310 - 2000 nm range. This technology allows reaching fundamental mode output in excess of 4.5 mW at room temperature and close to 3 mW at 70degC for both the 1310 nm and 1550 nm wavebands-the highest values obtained so far. Emission wavelength can be tuned continuously with current with a tuning range as large as 15 nm. For 2000 nm emission wavelength, room temperature output is ~ 0.5 mW, limited so far by high optical absorption in the cavity. 1310 nm-VCSELs that are optimized for high speed operation yield excellent 10 Gbps operation both at room temperature and at 100degC.