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Claire F. Gmachl - One of the best experts on this subject based on the ideXlab platform.
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Mid-infrared Quantum Cascade Lasers
Nature Photonics, 2012Co-Authors: Anthony J. Hoffman, Claire F. GmachlAbstract:Mid-infrared Quantum Cascade Lasers are semiconductor injection Lasers whose active core implements a multiple-Quantum-well structure. Relying on a designed staircase of intersubband transitions allows free choice of emission wavelength and, in contrast with diode Lasers, a low transparency point that is similar to a classical, atomic four-level laser system. In recent years, this design flexibility has expanded the achievable wavelength range of Quantum Cascade Lasers to ∼3–25 μm and the terahertz regime, and provided exemplary improvements in overall performance. Quantum Cascade Lasers are rapidly becoming practical mid-infrared sources for a variety of applications such as trace-chemical sensing, health monitoring and infrared countermeasures. In this Review we focus on the two major areas of recent improvement: power and power efficiency, and spectral performance. The design flexibility of Quantum Cascade Lasers has enabled their expansion into mid-infrared wavelengths of 3–25 μm. This Review focuses on the two major areas of recent improvement: power and power efficiency, and spectral performance.
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Mid-infrared Quantum Cascade Lasers
Nature Photonics, 2012Co-Authors: Yu Yao, Anthony J. Hoffman, Claire F. GmachlAbstract:The design flexibility of Quantum Cascade Lasers has enabled their expansion into mid-infrared wavelengths of 3–25 μm. This Review focuses on the two major areas of recent improvement: power and power efficiency, and spectral performance.
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Substrate emission of ring cavity surface emitting Quantum Cascade Lasers
Conference on Lasers and Electro-Optics 2012, 2012Co-Authors: Clemens Schwarzer, Claire F. Gmachl, Jian-zhang Chen, E Mujagic, Werner Schrenk, Gottfried StrasserAbstract:We report studies on bidirectional emission of ring cavity surface emitting Quantum Cascade Lasers. Special attention is put on substrate emission and methods for favoring one single emission direction.
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Highly power-efficient Quantum Cascade Lasers
Nature Photonics, 2010Co-Authors: Anthony J. Hoffman, Kale J. Franz, Matthew D. Escarra, Jacob B. Khurgin, Yamac Dikmelik, Xiaojun Wang, Claire F. GmachlAbstract:Quantum Cascade Lasers^ 1 are promising mid-infrared semiconductor light sources for molecular detection in applications such as environmental sensing or medical diagnostics. For such applications, researchers have been striving to improve device performance^ 2 . Recently, improvements in wall plug efficiency have been pursued with a view to realizing compact, portable, power-efficient and high-power Quantum Cascade laser systems^ 3 , 4 . However, advances have largely been incremental, and the basic Quantum design has remained unchanged for many years, with the wall plug efficiency yet to reach above 35%. A crucial factor in Quantum Cascade laser performance is the efficient transport of electrons into the laser active regions. We recently theoretically described this transport process as limited by the interface-roughness-induced detuning of resonant tunnelling^ 5 . Here, we report that an ‘ultrastrong coupling’ design strategy overcomes this limiting factor and leads to the experimental realization of Quantum Cascade Lasers with 40–50% wall plug efficiency when operated in pulsed mode at temperatures of 160 K or lower. A Quantum Cascade laser with a wall-plug efficiency of up to 50% is experimentally realized when operated at low temperatures and in pulsed mode. The high-efficiency performance is achieved by implementing an ultrastrong coupling between the injector and active regions.
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Quantum Cascade Lasers in chemical physics
Chemical Physics Letters, 2010Co-Authors: Robert F. Curl, Claire F. Gmachl, Federico Capasso, Anatoliy A. Kosterev, Barry Mcmanus, Rafal Lewicki, Michael Pusharsky, Gerard Wysocki, Frank K. TittelAbstract:In the short space of 15 years since their first demonstration, Quantum Cascade Lasers have become the most useful sources of tunable mid-infrared laser radiation. This Letter describes these developments in laser technology and the burgeoning applications of Quantum Cascade Lasers to infrared spectroscopy. We foresee the potential application of Quantum Cascade Lasers in other areas of chemical physics such as research on helium droplets, in population pumping, and in matrix isolation infrared photochemistry.
Jérôme Faist - One of the best experts on this subject based on the ideXlab platform.
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Short pulse generation and high power emission of Quantum Cascade Lasers
2017 42nd International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2017Co-Authors: Dominic Bachmann, Jérôme Faist, Mattias Beck, Markus Rösch, Giacomo Scalari, Martin A. Kainz, Sebastian Schönhuber, M. Brandstetter, M. Andrews, Gottfried StrasserAbstract:A unique feature of Quantum Cascade Lasers is the possibility to stack active regions. Using a three stack heterogeneous Quantum Cascade laser ultra broadband amplification and short pulse generation is demonstrated. High power output is achieved by two stacked symmetric active regions.
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Design of Dirac-point photonic crystal Quantum Cascade Lasers
Conference on Lasers and Electro-Optics, 2017Co-Authors: Yong Liang, Zhixin Wang, Xuefan Yin, Chao Peng, Jérôme FaistAbstract:We design photonic-crystals enabling laser operation at the Dirac-point, based on three-dimensional simulations of realistic Quantum Cascade laser structures. We demonstrate the feasibility of using the Dirac-point mode for higher-power single-mode photonic-crystal Quantum Cascade Lasers.
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Strain-Compensated InGaAs Terahertz Quantum Cascade Lasers
ACS Photonics, 2016Co-Authors: Keita Ohtani, Mattias Beck, Jérôme FaistAbstract:Strain-compensated InGaAs/AlInGaAs terahertz Quantum Cascade Lasers grown by molecular beam epitaxy are reported. A choice of a moderate amount of strain in the wells (−0.24%) and in the quaternary barriers (+1.07%) makes it possible to coherently grow an active region as thick as 10 μm. Lasers based on a four Quantum well design emit at 3.3 THz with a maximum operation temperature of 149 K, which is among the highest temperatures of InGaAs-based THz Quantum Cascade Lasers.
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Negative free carrier absorption in terahertz Quantum Cascade Lasers
Applied Physics Letters, 2016Co-Authors: Camille Ndebeka-bandou, Mattias Beck, Keita Ohtani, Markus Rösch, Jérôme FaistAbstract:We analyze the peculiar case where the free carrier absorption arising from LO phonon absorption-assisted transitions becomes negative and therefore turns into a gain source for Quantum Cascade Lasers. Such an additional source of gain exists when the ratio between the electronic and the lattice temperatures is larger than one, a condition that is usually fulfilled in Quantum Cascade Lasers. We find a gain of few cm$^{-1}$'s at 200K. We report the development of a terahertz Quantum Cascade laser operating in the negative free carrier absorption regime.
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singlemode Quantum Cascade Lasers with power dissipation below 1 w
Electronics Letters, 2012Co-Authors: Borislav Hinkov, Mattias Beck, Stéphane Blaser, Alfredo Bismuto, Y Bonetti, Jérôme FaistAbstract:Presented are narrow-ridge, singlemode (λ=4.49 µm) Quantum Cascade Lasers with low power consumption in continuous-wave operation. Episide up mounted 3 µm-wide and 1 mm-long devices with high-reflectivity backside coating show an electrical dissipation at laser threshold as low as 840 mW at 20°C. The devices can be tuned singlemode and mode-hop free between −30°C and +50°C and in a range of injected electrical power of 0.7 and 1.3 W with a sidemode suppression ratio better than 27 dB.
Carlo Sirtori - One of the best experts on this subject based on the ideXlab platform.
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Room temperature operation of InAs/AlSb Quantum Cascade Lasers
Applied Physics Letters, 2017Co-Authors: Roland Teissier, Alekseevich Nikolai Baranov, David Barat, Aurore Vicet, Dmitry G. Revin, Charlotte Alibert, Xavier Marcadet, M. Garcia, Carlo Sirtori, Catherine Renard, John W. CockburnAbstract:The room temperature operation of InAs/AlSb Quantum Cascade Lasers is reported. The structure, grown by molecular beam epitaxy on an InAs substrate, is based on a vertical transition design and a low loss n+-InAs plasmon enhanced waveguide. The Lasers emitting near 4.5 μm operate in pulse regime up to 300 K. The threshold current density of 3.18-mm-long Lasers is 1.5 kA/cm2 at 83 K and 9 kA/cm2 at 300 K.
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wave engineering with thz Quantum Cascade Lasers
Nature Photonics, 2013Co-Authors: Carlo Sirtori, S Barbieri, R ColombelliAbstract:This article reviews state-of-the-art engineering of the spectral and spatial emission properties of terahertz Quantum Cascade Lasers by focusing on three key factors: photonic structures for extracting and confining light in a cavity, an upconversion technique based on nonlinear intracavity mixing and a frequency stabilisation technique based on femtosecond-laser combs.
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terahertz Quantum Cascade Lasers with large wall plug efficiency
Applied Physics Letters, 2007Co-Authors: Miriam Serena Vitiello, Gaetano Scamarcio, Vincenzo Spagnolo, S. S. Dhillon, Carlo SirtoriAbstract:Improved optical power performance of bound-to-continuum Quantum-Cascade Lasers operating at 2.83THz is reported. Peak optical powers of 100mW at 4K and power conversion-efficiencies as high as ηw=(5.5±0.4)% in continuous wave at 40K were measured. The ηw values were assessed via an experimental method based on the analysis of the local lattice temperature as extracted by microprobe photoluminescence versus electrical power. From the measured ηw values they extracted a slope efficiency value 0.41±0.11W∕A.
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High power spatial single-mode Quantum Cascade Lasers at 8.9 µm
Electronics Letters, 2005Co-Authors: Sebastien Forget, Jérôme Faist, Clement Faugeras, Jean Yves Bengloan, Michel Calligaro, Olivier Parillaud, Marcella Giovannini, Carlo SirtoriAbstract:High performance of InP-based Quantum Cascade Lasers emitting at $\lambda$ ~ 9µm are reported. Thick electroplated gold layer was deposited on top of the laser to improve heat dissipation. With one facet high reflection coated, the devices produce a maximum output power of 175mW at 40% duty cycle at room temperature and continuous-wave operation up to 278K.
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InAs/AlSb Quantum Cascade Lasers operating at 6.7 µm
Electronics Letters, 2003Co-Authors: Roland Teissier, David Barat, Aurore Vicet, Charlotte Alibert, Xavier Marcadet, A N Baranov, D. A. Yarekha, Carlo SirtoriAbstract:Quantum Cascade Lasers based on the InAs/AlSb material system have been realised. The optical confinement is obtained using a plasmon waveguide with n+-InAs cladding layers. In pulse mode the Lasers emit close to 6.7 μm with a threshold current density of 5 kA/cm2 at 90 K. The maximum operating temperature is 220 K.
Benjamin S. Williams - One of the best experts on this subject based on the ideXlab platform.
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Quantum Cascade Lasers 20 years of challenges
Optics Express, 2015Co-Authors: Miriam S Vitiello, Benjamin S. Williams, Giacomo Scalari, Paolo De NataleAbstract:We review the most recent technological and application advances of Quantum Cascade Lasers, underlining the present milestones and future directions from the Mid-infrared to the Terahertz spectral range. Challenges and developments, which are the subject of the contributions to this focus issue, are also introduced.
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Terahertz Quantum Cascade Lasers
Asia Optical Fiber Communication and Optoelectronic Exposition and Conference, 2008Co-Authors: Benjamin S. WilliamsAbstract:An overview of terahertz Quantum Cascade Lasers based on resonant-phonon depopulation is presented. Limiting mechanisms for high-temperature operation are discussed.
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terahertz Quantum Cascade Lasers
Nature Photonics, 2007Co-Authors: Benjamin S. WilliamsAbstract:Six years after their birth, terahertz Quantum-Cascade Lasers can now deliver milliwatts or more of continuous-wave coherent radiation throughout the terahertz range — the spectral regime between millimetre and infrared wavelengths, which has long resisted development. This paper reviews the state-of-the-art and future prospects for these Lasers, including efforts to increase their operating temperatures, deliver higher output powers and emit longer wavelengths.
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Terahertz Quantum Cascade Lasers
2007 Conference on Lasers and Electro-Optics (CLEO), 2007Co-Authors: Benjamin S. Williams, Santosh Kumar, Qi Qin, Alan Wei Min Lee, John L. Reno, Z. R. Wasilewski, H. C. LiuAbstract:We provide an overview of terahertz Quantum Cascade Lasers based on resonant-phonon depopulation and metal-metal waveguides, including two-phonon resonant-phonon depopulation schemes, long wavelength operation, and real time terahertz imaging.
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high power terahertz Quantum Cascade Lasers
Quantum Electronics and Laser Science Conference, 2006Co-Authors: Benjamin S. Williams, Sushil Kumar, John L. RenoAbstract:We report the demonstration of Quantum-Cascade Lasers at ~4.4 THz (lambda ~ 68 mum) that emit 248 mW peak power in pulsed mode, and 138 mW continuous-wave power at heat-sink temperatures of 10 K.
Federico Capasso - One of the best experts on this subject based on the ideXlab platform.
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beam engineering of Quantum Cascade Lasers
Laser & Photonics Reviews, 2012Co-Authors: Qi Jie Wang, Federico CapassoAbstract:This paper reviews beam engineering of mid-infrared and terahertz Quantum Cascade Lasers (QCLs), based on two approaches: designer plasmonic structures and deformed microcavities. The plasmonic structures couple laser emission into surface waves and control the laser wavefront in the near-field, thereby greatly increasing beam collimation or introducing new functionalities to QCLs. The plasmonic designs overall preserve laser performance in terms of operating temperature and power output. The deformed microcavity QCLs operate primarily on whispering-gallery modes, which have much higher quality factors than other modes, leading to lower threshold current densities. Cavity deformations are carefully controlled to greatly enhance directionality and output power.
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high performance midinfrared Quantum Cascade Lasers
Optical Engineering, 2010Co-Authors: Federico CapassoAbstract:The design and operating principles of Quantum Cascade Lasers (QCLs) are reviewed along with recent developments in high-power cw and broadband devices. Cw power levels of several watts at room temperature have been achieved at 4.6-µm wavelength; broadband single-mode tuning (400 cm−1) has been achieved using an external-cavity QCL with a grating as a tuning element. An alternative approach, consisting of a monolithically integrated array of single-mode QCLs individually current-driven by a microcontroller, has led to broadband single-mode tuning over a range of 200 cm−1 without requiring the use of moving parts. This spectrometer on a chip holds promise for high-brightness compact trace-gas sensors capable of operating in harsh environments.
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Quantum Cascade Lasers in chemical physics
Chemical Physics Letters, 2010Co-Authors: Robert F. Curl, Claire F. Gmachl, Federico Capasso, Anatoliy A. Kosterev, Barry Mcmanus, Rafal Lewicki, Michael Pusharsky, Gerard Wysocki, Frank K. TittelAbstract:In the short space of 15 years since their first demonstration, Quantum Cascade Lasers have become the most useful sources of tunable mid-infrared laser radiation. This Letter describes these developments in laser technology and the burgeoning applications of Quantum Cascade Lasers to infrared spectroscopy. We foresee the potential application of Quantum Cascade Lasers in other areas of chemical physics such as research on helium droplets, in population pumping, and in matrix isolation infrared photochemistry.
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time domain measurements of group velocity dispersion in Quantum Cascade Lasers
Conference on Lasers and Electro-Optics, 2008Co-Authors: Hyunyong Choi, Federico Capasso, Laurent Diehl, Theodore B Norris, David P Bour, Scott W Corzine, Jintian Zhu, Gloria E HoflerAbstract:Time-resolved mid-infrared upconversion based on sum-frequency generation was applied to measure the group-velocity dispersion in Quantum Cascade Lasers; material, waveguide, and gain contributions were distinguished, and used to model the temporal pulse broadening.
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Nonlinear optics with Quantum Cascade Lasers
Laser Physics, 2007Co-Authors: Feng Xie, Federico Capasso, V. R. Chaganti, Don D. Smith, Alexey Belyanin, Claire F. GmachlAbstract:We discuss new approaches to monolithic integration of Quantum Cascade Lasers with resonant intersubband nonlinearities. We show that the proposed approaches can greatly enhance the performance of Quantum Cascade Lasers and give rise to new functionalities. Examples considered include extreme frequency up-or down-conversion and wide-range electric tuning.
