A new concept for tunable long wavelength VCSEL

We present a novel two-chip concept for micro-electro-mechanically tunable vertical cavity surface emitting lasers (VCSELs) for the 1.55 μm wavelength range. The VCSEL is composed of two chips: one mirror membrane chip with a movable curved mirror membrane that can be displaced by electro-thermal actuation to adjust the cavity length and one "half-VCSEL" chip consisting of a fixed bottom mirror and an amplifying active region. The possibility of separate optimization of the micro-mechanical part and the VCSEL amplifier is the main advantage of that concept, which is appropriate for photo-pumping as well as for an electrical pumping scheme. The measurement results of an optically pumped VCSEL with more than 0.5 mW continuous wave (CW) single mode output power at room temperature over a 24 nm tuning range prove the feasibility of the proposed concept.