1,721,078 research outputs found
Proprietà ottiche e vibrazionali dei punti quantici nei vetri: spettroscopia Raman e fotoacustica
No full textMid-IR Quantum cascade lasers: thermal properties and their application in optoacoustic sensors
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Spettroscopia micro-Raman per lo studio di nanostrutture e diodi laser a buca quantica in InGaAs
No full textFilling the terahertz gap
No full textRecent breakthroughs in nanotechnologies are pushing up the efficiency of compact semiconductor laser sources
and detectors of radiation in the terahertz (THz) range of the electromagnetic spectrum. At these frequencies, many
molecules have their spectroscopic fingerprints due to rotational and vibrational transitions. Hence, long-dreamed
killer applications of THz photonics such as sensing, imaging, diagnostics, coherent spectroscopy in strategic fields
like medicine, microelectronics, petrochemical industry, forensic science, cultural heritage are coming true
Demonstration of high wall plug efficiency THz QCLs: investigation of the optical, electronic and thermal performance
No full textHigh-performance terahertz quantum cascade lasers operating at 106 μm: analysis of the thermal and electronic properties
No full textWe report on the investigation of the electronic and thermal properties of high performance terahertz (THz) quantum cascade lasers (QCLs) based on a bound-to-continuum scheme and grown by molecular beam epitaxy (MBE) by a commercial provider. The local lattice temperatures, the subband electronic temperatures and the electron-lattice coupling constant have been extracted from the analysis of microprobe band-to-band photoluminescence spectra measured on devices operating in continuous wave (cw). We found that the electronic distributions in both the active region and the injector are thermalized and that all the subbands share the same electronic temperatures. The measured device thermal conductance C(*) = 4.6 W/(Kxm) reflects the good thermal management of the investigated devices. The electron-lattice coupling constant alpha = 78.5 Kcm(2)/kA is a factor 1.65 higher than in mid-IR QCLs thus indicating the inefficient cooling of the electronic ensemble caused by the strong reduction of electron-LO phonons scattering channels
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