Linewidth enhancement factor of terahertz quantum cascade lasers

Green, Richard P.; Xu, J.; Mahler, L.; Tredicucci, Alessandro; Beltram, Fabio; Giuliani, G.; Beere, Harvey E.; Ritchie, D. A.

doi:10.1063/1.2883950

Cited by 94 publications

(52 citation statements)

References 9 publications

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“…It has been demonstrated that thermal photons contribute significantly to linewidth broadening at elevated temperatures. For the investigated structure of 3 THz QCL, a linewidth enhancement factor of a % 0.5 is found, which is in excellent agreement with experimental results (Green et al 2008). Mátyás et al (2011) performed calculations of photon-induced transport in mid-infrared QCL structures (Bai et al 2010).…”

Section: Optical Gainsupporting

confidence: 63%

Monte Carlo modeling applied to studies of quantum cascade lasers

2017

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One of the commonly used approaches of solving electron transport problems in quantum cascade lasers (QCL) is the Monte Carlo (MC) method, based on semiclassical description in the framework of the Boltzmann Transport Equation. A major benefit of MC modeling is that it only relies on well-established material parameters and structure specification, in most cases without the need to use phenomenological parameters. The results of the modeling can be easily interpreted and they give microscopic insight of QCL operation. The goal of the present paper is to review the application of the MC technique to the studies of operation of QCL. The description of the components of the simulation algorithm is provided. Various physical mechanisms governing electron transport in QCL are described and their influence on the operation are reviewed.

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Section: Optical Gainsupporting

confidence: 63%

Monte Carlo modeling applied to studies of quantum cascade lasers

2017

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“…For example, variation of L ext (t) with time may represent a moving target or changes in surface relief during a raster scan over the object surface [16]; time variation of ε(t) or R(t) may represent an optical chopper in the collimated beam path; and the target reflectivity R may be a complex number for the purpose of a refractive index measurement [18]. The linewidth enhancement factor of THz QCLs, α in (2), is low and known to vary slightly with drive current and optical feedback [56]. In this work we use the value α = −0.1 [9].…”

Section: Incorporating Optical Feedbackmentioning

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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“…Consequently, QC lasers should display a symmetric differential gain and a zero α [16]. However, experiments determined nonzero values going from α = 0 to α = 2 [17]- [20].…”

Section: Formulationmentioning

confidence: 99%

“…It is also worthwhile to stress that Eqs. (18)- (20) are not the equations for a Class A injected laser. For a Class A laser (such as He-Ne and Ar + lasers), the carrier Z is adiabatically eliminated and α = 0 [1].…”

Section: Fast Escape Of Carriers At the Lower Levelmentioning

confidence: 99%

Nonlinear dynamics of an injected quantum cascade laser

2013

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The stability properties of an injected quantum cascade laser are investigated analytically on the basis of current estimates of the laser parameters. We show that in addition to stable locking, Hopf bifurcations leading to pulsating intensities are possible. We discuss the stability diagrams in terms of the detuning and the injection rate for different values of the linewidth enhancement factor. The analysis indicates domains of coexistence between two stable steady states (bistability) or between a stable steady state and stable periodic oscillations. All predictions are verified numerically by determining bifurcation diagrams from the laser rate equations.

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Linewidth enhancement factor of terahertz quantum cascade lasers

Cited by 94 publications

References 9 publications

Monte Carlo modeling applied to studies of quantum cascade lasers

Monte Carlo modeling applied to studies of quantum cascade lasers

Model for a pulsed terahertz quantum cascade laser under optical feedback

Nonlinear dynamics of an injected quantum cascade laser

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