High Speed VCSEL Transmission at 1310 nm and 1550 nm Transmission Wavelengths

Vertical cavity surface emitting lasers (VCSELs) operating at 1310 nm and 1550 nm are very promising sources for access and interconnections in telecommunication systems due to their technologically attractive properties such as low threshold currents and narrow spectral linewidth due to single mode operation. VCSELs are also being rapidly commercialized for single-mode fibre metropolitan area and wide area network applications. All these advantages leads to cost-effective wavelength-tunable lasers, which are essential for the future intelligent, all-optical networks. Direct modulation (DM) of VCSEL with separate optical and current apertures enables high modulation bandwidth operating at single mode at low current density. However, dispersion and attenuation is a major hurdle to VCSELs transmission at bit rate of 10 Gb/s and above. In this study, a 1310 and 1550 nm VCSELs were directly modulated with 10 Gb/s NRZ PRBS 2 7-1 and transmitted over 25 km ITU. T G.652 and ITU. T G.655 fibres and optimized for metro-access distances. A low dispersion penalty was realized when a 1550 nm VCSEL was used on a G.655 fibre and when a 1310 nm source was transmitted over a G.652 fibre. The transmission system has been analyzed on the basis of different parameters, which are (Bit error rate) BER, Quality (Q) factor and Output power.