The quantum cascade laser (QCL) exploits optical transitions between quantized electron states in amulti-quantum-well active region.Consequently, the lasing wavelength is not determined by the material bandgap, but can be custom-tailoredover a wide range of the mid-infrared and terahertz spectral regions by quantum engineering.Formanyapplications,laser operating regimes are exploitedwhich generatespecial temporal or spectral waveforms. These includeperiodic trains of ultrashort pulsesas required, e.g., for time-resolved spectroscopy[1], andtime-periodic waveformsin general, where the resultingcomb-like spectraare widely used inmetrology and sensing[2,3].     «

The quantum cascade laser (QCL) exploits optical transitions between quantized electron states in amulti-quantum-well active region.Consequently, the lasing wavelength is not determined by the material bandgap, but can be custom-tailoredover a wide range of the mid-infrared and terahertz spectral regions by quantum engineering.Formanyapplications,laser operating regimes are exploitedwhich generatespecial temporal or spectral waveforms. These includeperiodic trains of ultra...     »