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Université de Neuchâtel

Frequency noise correlation between the offset frequency and the mode spacing in a mid-infrared quantum cascade laser frequency comb

Shehzad, Atif ; Brochard, Pierre ; Matthey, Renaud ; Kapsalidis, Filippos ; Shahmohammadi, Mehran ; Beck, Mattias ; Hugi, Andreas ; Jouy, Pierre ; Faist, Jérôme ; Südmeyer, Thomas ; Schilt, Stéphane

In: Optics Express, 2020, vol. 28, no. 6, p. 8200-8210

The generation of frequency combs in the mid-infrared (MIR) spectral range by quantum cascade lasers (QCLs) has the potential for revolutionizing dual-comb multi-heterodyne spectroscopy in the molecular fingerprint region. However, in contrast to frequency combs based on passively mode-locked ultrafast lasers, their operation relies on a completely different mechanism resulting from a four-wave...

Université de Neuchâtel

Continuous Wave Operation of a Mid-Infrared Semiconductor Laser at Room Temperature

Beck, Mattias ; Hofstetter, Daniel ; Aellen, Thierry ; Faist, Jérôme ; Oesterle, Ursula ; Ilegems, Marc ; Gini, Emilio ; Melchior, Hans

In: Science, 2002, vol. 295, no. 5553, p. 301-305

Continuous wave operation of quantum cascade lasers is reported up to a temperature of 312 kelvin. The devices were fabricated as buried heterostructure lasers with high-reflection coatings on both laser facets, resulting in continuous wave operation with optical output power ranging from 17 milliwatts at 292 kelvin to 3 milliwatts at 312 kelvin, at an emission wavelength of 9.1 micrometers. The...

Université de Neuchâtel

CO2 isotope sensor using a broadband infrared source, a spectrally narrow 4.4 μm quantum cascade detector, and a Fourier spectrometer

Hofstetter, Daniel ; Di Francesco, Joab F. ; Hvozdara, Lubos ; Herzig, Hans-Peter ; Beck, Mattias

In: Applied Physics B: Lasers and Optics, 2010, vol. 103, no. 4, p. 967-970

We report a prototype CO2 gas sensor based on a simple blackbody infrared source and a spectrally narrow quantum cascade detector (QCD). The detector absorption spectrum is centered at 2260 cm−1 (4.4 μm) and has a full width at half maximum of 200 cm−1 (25 meV). It covers strong absorption bands of two spectrally overlapping CO2 isotopomers, namely...

Université de Neuchâtel

Free-space optical data link using Peltier-cooled quantum cascade laser

Blaser, Stéphane ; Hofstetter, Daniel ; Beck, Mattias ; Faist, Jérôme

In: Electronics Letters, 2001, vol. 37, no. 12, p. 778-780

The authors demonstrate a free-space optical data link over 350 m using a Peltier-cooled 9.3 µm quantum cascade laser operating at a duty cycle of almost 50%. On the emitter side, a Ge lens was used for beam collimation and a flat mirror for beam steering, while on the receiver side, a fast room-temperature HgCdTe detector in combination with a Φ = 16 cm mirror telescope detected the incoming...

Université de Neuchâtel

Continuous-wave operation of far-infrared quantum cascade lasers

Ajili, Lassaad ; Scalari, Giacomo ; Hofstetter, Daniel ; Beck, Mattias ; Faist, Jérôme ; Beere, Harvey ; Davies, Giles ; Linfield, Edmund ; Ritchie, David

In: Electronics Letters, 2002, vol. 38, no. 25, p. 1675-1676

Continuous-wave operation of a terahertz quantum cascade laser is reported. Optical output powers ranging from 410 µW at 10 K to 124 µW at 35 K, at an emission wavelength of 66 µm are obtained.

Université de Neuchâtel

Continuous-wave operation of quantum cascade laser emitting near 5.6 µm

Yarekha, D. A. ; Beck, Mattias ; Blaser, Stéphane ; Aellen, Thierry ; Gini Emilio ; Hofstetter, Daniel ; Faist, Jérôme

In: Electronics Letters, 2003, vol. 39, no. 15, p. 1123-1125

Buried heterostructure quantum cascade lasers emitting at 5.64 µm are presented. Continuous-wave (CW) operation has been achieved at –30°C for junction down mounted devices with both facets coated. A 750 µm-long laser exhibited 3 mW of CW power with a threshold current density of 5.4 kA/cm2.

Université de Neuchâtel

Edge- and surface-emitting 10.1 μm quantum cascade distributed feedback lasers

Hofstetter, Daniel ; Faist, Jérôme ; Beck, Mattias ; Müller, Antoine ; Oesterle, Ursula

In: Physica E: Low-dimensional Systems and Nanostructures, 2000, vol. 7, no. 1-2, p. 25-28

We present measurement results on high-power low-threshold quantum cascade-distributed feedback lasers emitting infrared radiation at 10.16 μm. A lateral current injection scheme allowed the use of a strongly coupled surface grating without metal coverage and epitaxial re-growth. Although this design resulted in a simplified processing, the fabrication of high-performance edge- and...

Université de Neuchâtel

Continuous wave operation of quantum cascade lasers

Beck, Mattias ; Hofstetter, Daniel ; Aellen, Thierry ; Blaser, Stéphane ; Faist, Jérôme ; Oesterle, Ursula ; Gini Emilio

In: Journal of Crystal Growth, 2003, vol. 251, no. 1-4, p. 697-700

Continuous wave (CW) operation of quantum cascade lasers is reported up to temperatures of 312 K. The devices were fabricated as buried heterostructure lasers and episide-down mounted for improved heat dissipation. Fabry–Perot lasers emitted 17 mW of continuous optical power at 292 K and still 3 mW at 311 K at λ=9.12 μm. Distributed feedback quantum cascade lasers showed CW single-mode...

Université de Neuchâtel

Chemical sensing with pulsed QC-DFB lasers operating at 15.6 μm

Kosterev, A. A. ; Curl, R. F. ; Tittel, F. K. ; Rochat, Michel ; Beck, Mattias ; Hofstetter, Daniel ; Faist, Jérôme

In: Applied Physics B: Lasers and Optics, 2002, vol. 75, no. 2-3, p. 351-357

Pulsed thermoelectrically cooled QC-DFB lasers operating at 15.6 μm were characterized for spectroscopic gas sensing applications. A new method for wavelength scanning based on repetition rate modulation was developed. A non-wavelength-selective pyroelectric detector was incorporated in the sensor configuration giving the advantage of room-temperature operation and low cost. Absorption lines of...