Grating-coupled external-cavity quantum-cascade lasers were studied for temperatures from 80 to 230 K. At 80 K, a tuning range of ∼65–88 nm are obtained for 4.5 and 5.1 μm laser amplifiers, respectively. The tuning ranges for both narrowed substantially with increasing temperature, to ∼23 nm at 203 K. The threshold varied slowly versus wavelength, while the efficiency appeared to be close to optimum toward wavelengths shorter than the free running wavelength.

Articles you may be interested inReliability of strain-balanced Ga 0.331 In 0.669 As ∕ Al 0.659 In 0.341 As ∕ In P quantum-cascade lasers under continuous-wave room-temperature operation High-temperature operation of distributed feedback quantum-cascade lasers at 5.3 μm Appl. Phys. Lett. 78, 396 (2001); 10.1063/1.1340865 Design considerations and analytical approximations for high continuous-wave power, broad-waveguide diode lasers Appl. Phys. Lett. 74, 3102 (1999); 10.1063/1.124075 High-temperature continuous-wave operation of λ8 μm quantum cascade lasers

It was previously reported that spectrally matched n-SiC and n-GaN-based MIS Schottky barrier diode structures exhibited optical emission and photosensitivity in the near-ultraviolet (UV) range of the spectrum and rectification at elevated temperatures. However, such structures were not practical due to the low mechanical and thermal stability of the semitransparent Au contacts. In addition, we experienced difficulties in achieving stable optical emission from the n-GaN-based structures. In this work various Schottky barrier diode structures based on p-type GaN layers grown on sapphire with silicon (Si), boron nitride (BN), and silicon dioxide (SiO2) interfacial layers were investigated. Blue and wide-spectrum optical emissions at forward and reverse bias, respectively, and photosensitivity were observed from these structures. A spectral match in the range of 365–400 nm between the light emitting diode (LED) and photodetector structures fabricated on the same substrate was achieved. A total Lambertian radiant UV power of ∼466 μW was measured from a blue/UV LED at 22 V. UV-transparent and electrically conductive SnOx layers were fabricated, characterized, and employed for fabrication of p-GaN-based photodiode structures.

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Articles you may be interested in2 μm laterally coupled distributed-feedback GaSb-based metamorphic laser grown on a GaAs substrate Appl. Phys. Lett. 102, 231101 (2013); 10.1063/1.4808265 Molecular beam epitaxy of InP-based alloys for long-wavelength vertical cavity lasers