2.4 W room temperature continuous wave operation of distributed feedback quantum cascade lasers

Abstract

We demonstrate high power continuous-wave room-temperature operation surface-grating distributed feedback quantum cascade lasers at 4.8 μm. High power single mode operation benefits from a combination of high-reflection and antireflection coatings. Maximum single-facet continuous-wave output power of 2.4 W and peak wall plug efficiency of 10% from one facet is obtained at 298 K. Single mode operation with a side mode suppression ratio of 30 dB and single-lobed far field without beam steering is observed.

Heterogeneously Integrated Distributed Feedback Quantum Cascade Lasers on Silicon

“…Distributed-feedback (DFB) lasers are attractive in many sensing applications, such as laser-based chemical bond spectroscopy, gas analysis [19], and explosive detection [20], which require a single frequency, narrow-linewidth source. Typically, gratings for QCLs are defined on the laser ridge sidewalls [21], as a surface grating on the top of the laser [22], or buried within a cladding layer [23]. Heterogeneous integration offers the additional option of etching a shallow surface grating into the silicon waveguide underneath the III-V mesa [24], to provide distributed feedback without the need for epitaxial regrowth.…”

All-optical wavelength shifting in a semiconductor laser using resonant nonlinearities

“…The wavelength shift can be engineered to any desired THz value 30 and can be equally applied to MIR QCLs, 31 where the wavelength shift is much greater and can be used to shift between different telecommunication bands 32 . As well as room temperature and high power output, 33 MIR QCLs are based on InGaAs/AlInAs quantum wells where the interband transition is directly in the telecommunication range. Further increases in efficiencies could be realised through a) adapted active region designs or the insertion of passive quantum wells to enhance the non-linearity through optimisation of the overlaps between the confined states;…”

Les lasers à cascade quantique : l’accès au moyen infrarouge

“…Le laser fonctionne en continu à température ambiante avec un rendement de conversion de 21 %, proche de la limite théorique de 30 % [4]. Une source mono-fréquence à 4,8 μm avec une puissance optique de 2,4 Watts a aussi été démontrée [5]. Ces résultats confirment le fort potentiel des lasers à cascade quantique.…”