2004 Volume 1 Issue 13 Pages 368-372
We propose a monolithic external-cavity vertical-cavity surface emitting laser (VCSEL) for achieving ultra-high speed direct modulation beyond the limit of a relaxation oscillation frequency. We present the modeling of small-signal and large signal modulation characteristics of VCSELs with optical feedback. It is predicted that a 3 dB-modulation bandwidth can be increased by 50% with optimizing an external cavity length. Also, better eye opening can be expected in 40Gbps direct modulation.