μ-Stripes high power quantum cascade lasers arrays

Summary form only given. For optical countermeasures application, the efficiency of the sources, the beam quality and the power are the crucial points. In the field of quantum cascade lasers, those three parameters give trade off values on the geometry of the laser limiting seriously the capability of the technology. For instance, one has to use ridges with width below 8μm to have a M2 suitable for DIRCM application. It limits the power to 5W up to now [1]. We will introduce a new way to improve the power of the laser while keeping a good beam quality: μ-stripes array technology (see fig 2) [2]. These buried arrays are very appealing because they offer both lateral dissipation enhancement and beam quality control in large active region lasers.We will present the numerical modeling of this μ-stripes approach analyzing the beam quality and the thermal properties. We will show that the thermal resistance is not any more limited by the active regions materials and demonstrate thermal resistances below 2 K/W, as shown on figure 1. Comparison between experimental and theoretical results show excellent agreement allows us to make prediction on the possibility of this technology. Thermal resistance decreases with both number and width of emitters. Furthermore we have also shown in previous work phase-locking provided by evanescent coupling between adjacent ridges and singlemode emission up to 32 emitters [3]. By analyzing the beam quality we show that the laser is 100% coherent and spatially mono-mode.