Packaged 850 nm vertical-cavity surface-emitting lasers as low-cost optical sources for transparent fibre-optic links

Experimental results of microwave modulation characteristics of high-speed oxide-confined 850 nm VCSELs are presented. First, SFDRs of unpackaged VCSELs measured at various drive currents and frequencies for VCSELs having various oxide apertures are reported, with peak values of approximately 110 dBHz²3/. In order to investigate their implementation as low-cost optical sources in analog systems, the fibre length dependence of the SFDR is then measured for a multimode packaged VCSEL. The SFDR remains above 95 dBHz²3/ after 800 m of 50 μm laser-optimized multimode fibre for both frequencies of 900 and 1800 MHz. This SFDR still fulfills the requirements of analog applications. VCSELs are shown to be insensitive to optical feedback when using absorptive and reflective ball lenses.