The recent Swiss start up, BeamExpress S.A., has demonstrated 1.5 µm waveband optically pumped tunable VCSELs with 38 nm tunability at tuning voltage values below 4 V. Devices with 5µm apertures show 1 mW continuous-wave single-mode output power with a 40 dB side mode suppression ratio. Manufacturing is based on a proprietary technology including a modified wafer fusion technique.
A simple and efficient process allows a high perfor-mance VCSEL to be monolithically integrated with a micro-electro-mechanical system (MEMS) tuning structure that can be electrostatically activated at a very low tuning voltage using standard low cost electronics. This demonstration of widely tunable VCSELs that can cover the whole C or L WDM bands at tuning voltage values below 4 V opens new perspectivesin the quest for cost-effective, high performance tunable lasers for METRO optical net-works.