Quantum cascade laser technology

In the mid-infrared spectral region, where continuous wave room temperature operation of the QCL devices was achieved in the previous phase of the program, the main goal will be to further broaden the frequency range over which these high performances are achieved. Another important topic is the fabrication of devices with a very large frequency tuning capability, which will enable the spectroscopy of multi-component gases, solids, or liquids. An exciting new result is the achievement of large broadband tuning of such a device, based on the monolithic stacking of two broadband active regions, with a tuning range of over more than 250 cm-1 for a laser emission centered at about 1000 cm-1. As shown in the figure below, the tuning range in pulsed operation goes from about 8.2 to 10.4 μm). Tuning over 10% of the central wavelength (7.96-8.84 μm) was possible with the laser chip in continuous-wave (CW) operation at room temperature, with a side-mode suppression ratio (SMSR) > 30dB. It is worth noting that the tuning range observed is the largest ever demonstrated at these wavelengths in CW.