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 70 degrees C 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 similar to 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 100 degrees C.