Extended density-matrix model applied to silicon-based terahertz quantum cascade lasers

Dinh, Thanh Viet; Valavanis, Alexander; Lever, L.; Ikonić, Z.; Kelsall, R. W.

doi:10.1103/physrevb.85.235427

Cited by 39 publications

(41 citation statements)

References 47 publications

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“…The latter point was accounted for in Ref. [36], in which the coherent gain and transport characteristics were calculated in a proposed silicon-based terahertz QCL.…”

Section: Introductionmentioning

confidence: 99%

Density matrix model for polarons in a terahertz quantum dot cascade laser

Burnett

Williams

2014

Phys. Rev. B

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A density matrix based method is introduced for computation of steady-state dynamics in quantum cascade systems of arbitrary size, which incorporates an optical field coherently. The method is applied to a model terahertz quantum dot cascade laser system, where a means of treating coherent electron-optical-phonon coupling is also introduced. Results predict a strong increase in the upper state lifetime and operating temperature as compared to traditional well-based terahertz quantum cascade lasers. However, new complications also arise, including multiple peaks in the gain spectrum due to strong electron-phonon coupling, and strong parasitic subthreshold current channels that arise due to reduced dephasing. It is anticipated that novel design schemes will be necessary for such lasers to become a reality.

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“…The latter point was accounted for in Ref. [36], in which the coherent gain and transport characteristics were calculated in a proposed silicon-based terahertz QCL.…”

Section: Introductionmentioning

confidence: 99%

Density matrix model for polarons in a terahertz quantum dot cascade laser

Burnett

Williams

2014

Phys. Rev. B

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“…In contrast to more computationally demanding density-matrix or non-equilibrium Green's function formalism approaches [42][43][44], the static behavior of a THz QCL can be modeled efficiently using a full electron-scattering rate equation (RE) solver [45,46], including energy balance. However, modeling the dynamic behavior under thermal transients in the presence of optical feedback would present a significant computational challenge even with an RE approach.…”

Section: Laser-specific Rre Model Under Pulsed Operation and Optical mentioning

confidence: 99%

Model for a pulsed terahertz quantum cascade laser under optical feedback

Agnew¹,

Grier²,

Taimre³

et al. 2016

Opt. Express

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Abstract:Optical feedback effects in lasers may be useful or problematic, depending on the type of application. When semiconductor lasers are operated using pulsed-mode excitation, their behavior under optical feedback depends on the electronic and thermal characteristics of the laser, as well as the nature of the external cavity. Predicting the behavior of a laser under both optical feedback and pulsed operation therefore requires a detailed model that includes laser-specific thermal and electronic characteristics. In this paper we introduce such a model for an exemplar bound-to-continuum terahertz frequency quantum cascade laser (QCL), illustrating its use in a selection of pulsed operation scenarios. Our results demonstrate significant interplay between electro-optical, thermal, and feedback phenomena, and that this interplay is key to understanding QCL behavior in pulsed applications. Further, our results suggest that for many types of QCL in interferometric applications, thermal modulation via low duty cycle pulsed operation would be an alternative to commonly used adiabatic modulation.Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. 4, 631-633 (2014). 11. G. Giuliani, M. Norgia, S. Donati, and T. Bosch, "Laser diode self-mixing technique for sensing applications," J. Opt.A 1937-1942 (2016

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“…To analyze the parasitic paths and the temperature performance degradation, an extended density matrix (DM) approach was used to simulate the carrier transport [27]. This approach is capable of modelling QCLs with an arbitrary number of subbands, and there is no need to manually designate an injector subband in advance.…”

Section: Numerical Resultsmentioning

confidence: 99%

Extraction-controlled terahertz frequency quantum cascade lasers with a diagonal LO-phonon extraction and injection stage

Han¹,

Li²,

Grier³

et al. 2016

Opt. Express

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Abstract:We report an extraction-controlled terahertz (THz)-frequency quantum cascade laser design in which a diagonal LO-phonon scattering process is used to achieve efficient current injection into the upper laser level of each period and simultaneously extract electrons from the adjacent period. The effects of the diagonality of the radiative transition are investigated, and a design with a scaled oscillator strength of 0.45 is shown experimentally to provide the highest temperature performance. A 3.3 THz device processed into a double-metal waveguide configuration operated up to 123 K in pulsed mode, with a threshold current density of 1.3 kA/cm 2 at 10 K. The QCL structures are modeled using an extended density matrix approach, and the large threshold current is attributed to parasitic current paths associated with the upper laser levels. The simplicity of this design makes it an ideal platform to investigate the scattering injection process.

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Extended density-matrix model applied to silicon-based terahertz quantum cascade lasers

Cited by 39 publications

References 47 publications

Density matrix model for polarons in a terahertz quantum dot cascade laser

Density matrix model for polarons in a terahertz quantum dot cascade laser

Model for a pulsed terahertz quantum cascade laser under optical feedback

Extraction-controlled terahertz frequency quantum cascade lasers with a diagonal LO-phonon extraction and injection stage

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