Temperature Dependence of Optical Gain and Loss in $\lambda \approx$ 8.2–10.2 $\mu$m Quantum-Cascade Lasers

Liu, Zhijun; Gmachl, Claire F.; Cheng, Liwei; Choa, Fow-Sen; Towner, Fred; Wang, Xiaojun; Fan, Jen-Yu

doi:10.1109/jqe.2008.917273

Cited by 15 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The latter directly transforms into a larger carrier-tophoton lifetime ratio. Assuming the photon lifetime is slowly varying compared to the upper state lifetime between 290 K and 77 K, [26] the carrier-to-photon lifetime is thus expected to increase from 0.13 to 0.26 on average. This largely explains the increased sensitivity to the external optical feedback of the QCL in this study, as underlined in the Lang and Kobayashi model for semiconductor lasers under external optical feedback [27] in which the carrier-to-photon lifetime ratio plays a predominant role.…”

Section: Resultsmentioning

confidence: 99%

Low-frequency fluctuations of a mid-infrared quantum cascade laser operating at cryogenic temperatures

Spitz

Carras

et al. 2018

Laser Phys. Lett.

View full text Add to dashboard Cite

This work demonstrates that mid-infrared quantum cascade lasers operating under external optical feedback can output a chaotic dynamics through low-frequency fluctuations close to 77 K. Results also show that the birth of chaotic dynamics is not limited to near-threshold pumping levels. In addition, when the semiconductor material is cooled down from room temperature to 77 K, it is found that the laser destabilization takes place at a lower feedback ratio which proves that quantum cascade lasers are sensitive to temperatures, likely due to changes in the upper state lifetime. These examinations are meaningful for chaotic operation of quantum cascade lasers in secure atmospheric transmission lines and optical countermeasure systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Low-frequency fluctuations of a mid-infrared quantum cascade laser operating at cryogenic temperatures

Spitz

Carras

et al. 2018

Laser Phys. Lett.

View full text Add to dashboard Cite

show abstract

“…(6). The experimental FWHM of the luminescence, i.e ., $2\gamma _{{\rm UL}}$ , was assumed as 16 meV at RT 19. The effective refractive index η eff and optical confinement Γ of the reference QCL structure and the QCS1, QCS2, and QCL3 structures were respectively obtained by simulating their waveguide structures 5 with different active cores using finite element method.…”

Section: Resultsmentioning

confidence: 99%

Design optimization of quantum cascade laser structures at λ ∼ 11–12 µm

2010

Physica Status Solidi (a)

View full text Add to dashboard Cite

By a simulation optimization technique, we design In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As quantum cascade laser (QCL) structures, based on a four-quantum well (QW) active region. The design of QCL structures is performed by maximizing an objective function, i.e., z 2 UL ð1 À t L =t UL Þt U , related to the optical gain, including dipole matrix element (z UL ) and population inversion between subbands. For a specific lasing wavelength, each barrier/well layer in the active region can be optimized to maximize the objective function, which results from the increase in the dipole matrix element and the reduction in the lifetime ratio of t L =t UL , by an iterative procedure. The optimized QCL structures are obtained for the target wavelengths from 11 to 12 mm by a step of 0.5 mm. For a QCL structure operating at l ¼ 11.98, it exhibits the maximized objection function of 6.30 ps-nm 2 with a large dipole matrix element under an electric field of 45 kV/cm. The influence of the percent variation of thickness in In 0.53 Ga 0.47 As and In 0.52 Al 0.48 As layers by the change in growth rate on the lasing wavelength and objective function is also investigated.

show abstract

“…Alternatively, fewer carriers will be captured in the multiplication region by limiting the total charge flow during an avalanche event to the minimum value required to achieve accurate counts or by developing materials technologies to significantly reduce the number of trap centers. Recently, we have developed a new quenching circuit, passive quenching with active reset (PQAR) [14]. A schematic diagram of the PQAR circuit is shown in Fig.…”

Section: Invitedmentioning

confidence: 99%