• Lampin, Jean-Francois
• Lin, Quyang
• Hakl, Michael
• Lepillet, Sylvie
• Peytavit, Emilien
• Barbieri, Stefano

Abstract

<jats:p>Thanks to intrinsically short electronic relaxation on the ps time scale, III-V semiconductor unipolar devices are ideal candidates for ultrahigh-speed operation at mid-infrared frequencies. In this work, antenna-coupled, GaAs-based multi-quantum-well photodetectors operating in the 10–11 µm range are demonstrated, with a responsivity of 0.3 A/W and a 3-dB-cutoff bandwidth of 100 GHz at room temperature. The frequency response is measured up to 220 GHz: beyond 100 GHz we find a roll-off dominated by the 2.5-ps-long recombination time of the photo-excited electrons. The potential of the detectors is illustrated by setting up an experiment where the time dependent emission frequency of a quantum cascade laser operated in pulsed mode is measured electronically and in real time, over a frequency range &gt;60GHz. By exploiting broadband electronics, and thanks to its high signal-to-noise ratio, this technique allows the acquisition, in a single-shot, of frequency-calibrated, mid-infrared molecular spectra spanning up to 100 GHz and beyond, which is particularly attractive for fast, active remote sensing applications in fields such as environmental or combustion monitoring.</jats:p>

Topics

• impedance spectroscopy
• experiment
• combustion
• III-V semiconductor