Quantum dot nanostructures have been already used to realize a lot of innovative and/or improved devices based on QD unique properties: low threshold and temperature independent lasers, mode-locked lasers, tunable lasers, single photon emitter. The combination of QD with optically pumped vertical –external-cavity-surface-emitting lasers (VECSEL) are also very promising to realize high power laser with a larger wavelength tunability, and even for a new class of dual wavelength laser based on single axis VECSEL. This QD/VECSEL association is still very challenging. To reach this objective, we performed material development on the QD growth. We have been able to control the QD density (improving the gain), and compensate the natural redshift of the QD emitted wavelength to get QD emitting at 1.5 μm (Fig.1).
With this improvement, we have been able to realize the first QD VECSEL emitting at 1.5 μm (Fig.2). A very high output power of 2.2 W is obtained; a 60 nm tuning range is demonstrated. Further investigations are conducted to evaluate QD-VECSEL potentials for dual frequency operation.
Article publié dans: Applied Physics Letters