10 Gb/s optically preamplified receiver using a vertical-cavity amplifying optical filter

We have demonstrated optical preamplification at 10 Gb/s using a vertical cavity semiconductor optical amplifier (VCSOA). The VCSOA has a narrow bandwidth of 37 GHz and functions as an amplifying filter. Operating the VCSOA at 11 dB fiber-fiber gain resulted in a 7 dB improvement in receiver sensitivity. These results suggest that VCSOAs are potential low-cost alternatives to more expensive preamplifiers; such as fiber amplifiers. The combined functionality preamplifier-filter is especially attractive for WDM applications where channel selection is needed. Our present device is optimized for reflection mode operation; better isolation of adjacent channels can be obtained using transmission mode operation. Interesting possibilities for future devices include integration of vertical-cavity amplifying filters with photodetectors, either as single devices or 2-dimensional arrays for parallel applications. Tunable receivers could be realized by employing micro electromechanical systems (MEMS), similar to what is being used for tunable VCSELs.