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Quantum cascade lasers (QCLs) are high-power coherent light sources in the midinfrared and terahertz parts of the electromagnetic spectrum. They are devices in which the electronic and lattice systems are far from equilibrium, strongly…

Mesoscale and Nanoscale Physics · Physics 2021-06-16 Y. B. Shi , S. Mei , O. Jonasson , I. Knezevic

Quantum Cascade Lasers (QCL) are increasingly being used to probe the mid-infrared "molecular fingerprint" region. This prompted efforts towards improving their spectral performance, in order to reach ever-higher resolution and precision.…

We report on our study of the luminescence spectra of a quantum cascade laser in the presence of an external magnetic field tilted from the direction perpendicular to the electron plane. The effect of the tilted field is to allow novel…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 V. M. Apalkov , T. Chakraborty

Quantum cascade lasers are unipolar semiconductor lasers covering a wide range of the infrared and terahertz spectrum. Lasing action is achieved by using optical intersubband transitions between quantized states in specifically designed…

Mesoscale and Nanoscale Physics · Physics 2014-12-12 Christian Jirauschek , Tillmann Kubis

The first global quantum simulation of semiconductor-based quantum-cascade lasers is presented. Our three-dimensional approach allows to study in a purely microscopic way the current-voltage characteristics of state-of-the-art unipolar…

Condensed Matter · Physics 2009-11-07 Rita Claudia Iotti , Fausto Rossi

The link between the inversion gain of quantum cascade structures and the Bloch gain in periodic superlattices is presented. The proposed theoretical model based on the density matrix formalism is able to treat the gain mechanism of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Harald Willenberg , Gottfried H. Dohler , Jerome Faist

We present a viewpoint of the transport process in quantum cascade laser structures in which spatial transport of charge through the structure is a property of coherent quantum-mechanical wavefunctions. In contrast, scattering processes…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. -C. Lee , F. Banit , M. Woerner , A. Wacker

The first global simulation of semiconductor-based quantum-cascade lasers is presented; Our fully three-dimensional approach allows to study in a purely microscopic way -without resorting to phenomenological parameters- the current-voltage…

Materials Science · Physics 2007-05-23 Rita Claudia Iotti , Fausto Rossi

Interband cascade lasers (ICLs) stand out due to their low threshold current and minimal power consumption, rendering them viable sources for compact and mobile devices in the mid-infrared. Since their first demonstration, they experienced…

Optics · Physics 2024-06-03 Andreas Windischhofer , Nikola Opačak , Benedikt Schwarz

Quantum cascade lasers can be modeled within a hierarchy of different approaches: Standard rate equations for the electron densities in the levels, semiclassical Boltzmann equation for the microscopic distribution functions, and quantum…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 A. Wacker , S. -C. Lee , M. F. Pereira

The linewidth in intersubband transitions can be significantly reduced below the sum of the lifetime broadening for the involved states, if the scattering environment is similar for both states. This is studied within a nonequilibrium Green…

Other Condensed Matter · Physics 2007-05-23 F. Banit , S. -C. Lee , A. Knorr , A. Wacker

Ring quantum cascade lasers (QCLs) proved to be a versatile tool for generating tunable and stable frequency combs in the mid infrared range in the form of quantum walk combs. By homogeneously integrating a racetrack QCL with a passive…

A quantum cascade laser where the quantum wells in the active regions are replaced by quantum dots with their atom-like discrete energy levels is an interesting system to study novel features in optical spectroscopy. We study structures…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Vadim Apalkov , Tapash Chakraborty

The transfer of charge between different regions of a phase-coherent mesoscopic sample is investigated. Charge transfer from a side branch quantum dot into a ring changes the persistent current through a sequence of plateaus of diamagnetic…

Condensed Matter · Physics 2007-05-23 M. Büttiker , C. A. Stafford

In this work, a design for a mid-infrared quantum cascade laser (QCL) frequency comb source that enhances the high frequency response and the comb characteristics of the device is presented . A state-of-the-art active region (AR), grown on…

Quantum cascade lasers (QCL) have revolutionized the generation of mid-infrared light. Yet, the ultrafast carrier transport in mid-infrared QCLs has so far constituted a seemingly insurmountable obstacle for the formation of ultrashort…

In this work, control over the precise state emitted by quantum cascade laser frequency combs through strong radio-frequency current modulation close to their repetition frequency is demonstrated. In particular, broadening of the spectrum…

A model of sequential resonant tunneling transport between two-dimensional subbands that takes into account explicitly elastic scattering is investigated. It is compared to transport measurements performed on quantum cascade lasers where…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Romain Terazzi , Tobias Gresch , Andreas Wittmann , Jérôme Faist

We show that the free carrier absorption in Quantum Cascade Lasers is very small and radically different from the classical Drude result on account of the orthogonality between the direction of the carrier free motion and the electric field…

Mesoscale and Nanoscale Physics · Physics 2012-08-30 F. Carosella , C. Ndebeka-Bandou , R. Ferreira , E. Dupont , K. Unterrainer , G. Strasser , A. Wacker , G. Bastard

The intensity noise of a laser source represents one of the key factors limiting the ultimate sensitivity in laser-based systems for sensing and telecommunication. For advanced applications based on interferometry, the availability of a…

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