Performance of InGaAs/GaAs Microdisk Lasers with Improved Thermal Resistance

We discuss the static characteristics and high-frequency performance of microdisk lasers with an active region based on dense array of InGaAs/GaAs quantum well-dots having the improved thermal resistance. The decrease in thermal resistance of the microlasers is achieved by epi-side down bonding on a heat-conducting Si substrate. Compared to the characteristics of initial microlasers, the bonding results in a in thermal resistance decreasing by a factor of 2.3 (1.8) in microdisks with a diameter of 19 (31)µm, Further improvement of heat removal is achieved by a thinner epitaxial structure between the active region and the heatsink, realized by concept of two coupled resonant planar waveguides. Using this method, we managed to place the active region at a distance of only 870 nm from the surface of the heterostructure and achieve the record low thermal resistance of 0.17 K/mW in bonded lasers.