1.54-μm vertical-cavity laser transmission at 2.5 Gbit/s

Vertical cavity surface-emitting lasers (VCSELs) are potentially low-cost sources for optical communications and interconnections because of their advantages in low-cost packaging and testing. The transmission of lasers with wavelengths shorter than 1 μm is strongly limited by dispersion and the loss of the fiber. The reported longest single-mode fiber transmission with short wavelength VCSELs was 4.3 km. On the other hand, 1.5 μm VCSELs are excellent candidates for fiber-optic communications not only because the wavelength matches the low-loss window of the fiber but also because the use of erbium-doped fiber amplifiers (EDFAs) makes possible long-distance applications and broadcasting systems. We have recently demonstrated 35°C CW operation of VCSELs operating at 1.54 μm and the single-mode fiber transmission over 200 km at 622 Mbit/s using optical amplifiers. In the paper, the incorporation of lateral oxidation in the laser fabrication increases the output optical power from several microwatts to about 1 mW which allows us to transmit at high bit rates and to investigate systems without optical amplification