Abstract: For epitaxial-side-down bonding of quantum cascade lasers (QCLs), it is important to optimize the heat transfer between the QCL chip and the heat sink to which the chip is mounted. This is achieved by using a heatsink with high thermal conductivity and by minimizing the thermal resistance between the laser active region and said heatsink. In the epi-down configuration concerned, the active region of the QCL is located only a few micrometers away from the heatsink, which is preferable from a thermal standpoint. However, this design is challenging to implement and often results in a low fabrication yield if no special precautions are taken. Since the active region is very close to the heatsink, solder material may ooze out on the sides of the chip during the bonding process and may short-circuits the device, rendering it unusable. To avoid this happening, the invention proposes to provide a trench all around the chip with the exception of the two waveguide facets, i.e. the ends of the active region.

Abstract: For epitaxial-side-down bonding of quantum cascade lasers (QCLs), it is important to optimize the heat transfer between the QCL chip and the heat sink to which the chip is mounted. This is achieved by using a heatsink with high thermal conductivity and by minimizing the thermal resistance between the laser active region and said heatsink. In the epi-down configuration concerned, the active region of the QCL is located only a few micrometers away from the heatsink, which is preferable from a thermal standpoint. However, this design is challenging to implement and often results in a low fabrication yield if no special precautions are taken. Since the active region is very close to the heatsink, solder material may ooze out on the sides of the chip during the bonding process and may short-circuits the device, rendering it unusable. To avoid this happening, the invention proposes to provide a trench all around the chip with the exception of the two waveguide facets, i.e. the ends of the active region.

Abstract: Semiconductor lasers, in particular Quantum Cascade Lasers (QCLs) are tuable especially in the mid-IR spectral range, e.g. in wavelengths of about 3-14 ?m, by precisely controlling the laser's temperature in the vicinity of the active region. The present invention introduces a novel design for locally heating the active region, thereby allowing fast heating and thus tuning a laser. It is generally applicable for lasers across the field, e.g. to QCLs with multi-color emitters or to Vertical-Cavity Single-Emitter Lasers (VCSELs) or to Distributed Feedback (DFB) lasers. Essentially, the invention consists of structurally integrating a heating resistor as part of the laser, placed close to the component to be temperature-controlled, i.e. the active region or the grating, etc., and feeding this resistor with a variable electrical current in order to locally control the thermal dissipation.

Abstract: Semiconductor lasers, in particular Quantum Cascade Lasers (QCLs) are tuable especially in the mid-IR spectral range, e.g. in wavelengths of about 3-14 ?m, by precisely controlling the laser's temperature in the vicinity of the active region. The present invention introduces a novel design for locally heating the active region, thereby allowing fast heating and thus tuning a laser. It is generally applicable for lasers across the field, e.g. to QCLs with multi-color emitters or to Vertical-Cavity Single-Emitter Lasers (VCSELs) or to Distributed Feedback (DFB) lasers. Essentially, the invention consists of structurally integrating a heating resistor as part of the laser, placed close to the component to be temperature-controlled, i.e. the active region or the grating, etc., and feeding this resistor with a variable electrical current in order to locally control the thermal dissipation.