Application of High-Speed Quantum Cascade Detectors for Mid-Infrared, Broadband, High-Resolution Spectroscopy.

Broadband, high-resolution, heterodyne, mid-infrared absorption spectroscopy was performed with a high-speed quantum cascade (QC) detector. By strictly reducing the device capacitance and inductance via air-bridge wiring and a small mesa structure, a 3-dB frequency response over 20 GHz was obtained for the QC detector, which had a 4.6-μm peak wavelength response.

Ultra-broadband room-temperature terahertz quantum cascade laser sources based on difference frequency generation.

We present ultra-broadband room temperature monolithic terahertz quantum cascade laser (QCL) sources based on intra-cavity difference frequency generation, emitting continuously more than one octave in frequency between 1.6 and 3.8 THz, with a peak output power of ~200 μW.

Broadband tuning of continuous wave quantum cascade lasers in long wavelength (> 10 μm) range.

Broadband spectral tuning in the long wavelength range (greater than 10 μm) was demonstrated with an external-cavity quantum cascade laser. The tunable wavelength of the laser ranged from 9.5 to 11.

Broad-gain (Δλ/λ0

Broad-gain operation of λ~8.7 μm quantum cascade lasers based on dual-upper-state to multiple-lower-state transition design is reported. The devices exhibit surprisingly wide (~500 cm(-1)) electroluminescence spectra which are very insensitive to voltage and temperature changes above room temperature.