1.3-μm GaInNAs surface-normal devices

The compatibility of GaInNAs/GaAs active regions with AlGaAs Bragg mirror technology opens up a range of surface-normal device formats for the spectral region around 1.3 μm. The authors report recent progress on the development of diode-pumped vertical external-cavity surface emitting lasers (VECSELs) and vertical cavity semiconductor optical amplifiers (VCSOAs) based on this technology. Pertinent performance characteristics are reported for GaInNAs 1.3-μm VECSELs capillary-bonded to diamond heatspreader platelets. In a conventional three-mirror air-spaced laser cavity up to 0.6 W of TEM₀₀ output power was obtained. With the outer surface of the diamond platelet coated to form a dielectric output coupler mirror, it was possible to obtain the first monolithic microchip operation of a GaInNAs VECSEL, where a Gaussian beam with output power up to 120 mW was obtained. The influence of temperature on the performance of a six-quantum-well VCSOA with on-chip gain values of up to 16 dB was also reported. It reveals that on-chip gain of 9 dB can be achieved over a range of 85°C, allowing the amplifier characteristics to be tuned over more than 9.5 nm. Further investigations of the influence of optical feedback on the performance of these vertical amplifiers demonstrate that a three-mirror analysis explains the observed phenomena.