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An indirectly pumped terahertz quantum cascade laser with low injection coupling strength operating above 150 K

JOURNAL OF APPLIED PHYSICS 2013年第20期113卷 203107-203107-14页

作者： Razavipour, S. G. Dupont, E. Fathololoumi, S. Chan, C. W. I. Lindskog, M. Wasilewski, Z. R. Aers, G. Laframboise, S. R. Wacker, A. Hu, Q. Ban, D. Liu, H. C. CNR Ottawa ON K1A 0R6 Canada Univ Waterloo Waterloo Inst Nanotechnol Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada MIT Elect Res Lab Dept Elect Engn & Comp Sci Cambridge MA 02139 USA Lund Univ Div Math Phys S-22100 Lund Sweden Shanghai Jiao Tong Univ Dept Phys Key Lab Artificial Struct & Quantum Control Shanghai 200240 Peoples R China

We designed and demonstrated a terahertz quantum cascade laser based on indirect pump injection to the upper lasing state and phonon scattering extraction from the lower lasing state. By employing a rate equation formalism and a genetic algorithm, an optimized active region design with four-well GaAs/Al0.25Ga0.75As cascade module was obtained and epitaxially grown. A figure of merit which is defined as the ratio of modal gain versus injection current was maximized at 150 K. A fabricated device with a Au metal-metal waveguide and a top n(+) GaAs contact layer lased at 2.4 THz up to 128.5 K, while another one without the top n(+) GaAs lased up to 152.5 K (1.3 (h) over bar omega/k(B)). The experimental results have been analyzed with rate equation and nonequilibrium Green's function models. A high population inversion is achieved at high temperature using a small oscillator strength of 0.28, while its combination with the low injection coupling strength of 0.85 meV results in a low current. The carefully engineered wavefunctions enhance the quantum efficiency of the device and therefore improve the output optical power even with an unusually low injection coupling strength. (C) 2013 AIP Publishing LLC.

关键词： aluminium compounds gallium arsenide genetic algorithms Green's function methods iii-V semiconductors modules optical design techniques optical pumping oscillator strengths population inversion quantum cascade lasers wave functions

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New detectors and detector architectures for high resolution optical sensor systems

New detectors and detector architectures for high resolution...

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7th International Conference on Sensing Technology (ICST)

作者： Eckardt, Andreas Reulke, Ralf DLR German Aerosp Ctr Inst Opt Sensor Syst Berlin Germany

ISBN: (纸本)9781467352215;9781467352208

The Institute of optical Sensor Systems (OS) as member of the Robotics and Mechatronics Cluster of the German Aerospace Center (DLR) has more than 30 years experiences with high-resolution imaging technology. The technology changes in the development of detectors, as well as the significant change of the manufacturing accuracy in combination with the engineering research define the next generation of spaceborne sensor systems focusing on Earth observation and remote sensing. The combination of large TDI (time delay and integration) lines, intelligent synchronization control, fastreadable sensors and new focal-plane concepts open the door to new remote-sensing instruments. This class of instruments is feasible for high-resolution sensor systems regarding geometry and radiometry and their data products like 3D virtual reality. Systemic approaches are essential for such designs of complex sensor systems for dedicated tasks. The system theory of the instrument inside a simulated environment is the beginning of the optimization process for the optical, mechanical and electrical designs. Single modules and the entire system have to be calibrated and verified. Suitable procedures must be defined on component, module and system level for the assembly test and verification process. This kind of development strategy allows the hardware-in-the-loop design. The paper gives an overview about the current developments at DLR OS in the field of innovative sensor systems design for spatial and spectral high resolution remote sensing instruments.

关键词： Focal plane technology large TDI BTDI sensors sCMOS Focal Plane Earth observation instrument geometric accuracy radiometric accuracy instrument optimization process large focal plane high mechanical accuracy

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Recent developments with a prototype fan-beam optical CT scanner

Recent developments with a prototype fan-beam optical CT sca...

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7th International Conference on 3D Radiation Dosimetry (IC3DDose)

作者： Campbell, W. G. Jirasek, A. Wells, D. Univ Victoria Dept Phys & Astron Victoria BC Canada BC Canc Agcy Vancouverisland Ctr Victoria BC Canada

The latest design of a prototype fan-beam optical computed tomography scanner is presented. A new beam creation system consists of a 635 nm laser diode module with variable, DC voltage-controlled beam intensity. A change in scanner alignment allows for the elimination of ring artefacts caused by data corruption that is spaced symmetrically across the detector array. These artefacts, as well as a pair of streaking artefacts caused by flask seams, are removed in sinogram space. A flask registration technique has been developed that allows for accurate, reproducible dosimeter placement. Protocol investigations with gel dosimeters have indicated the importance of: i) proper cooling techniques during gel manufacture, and ii) scanning the dosimeter while it is at room temperature. Latest reconstructions of a normoxic polymer gel dosimeter are presented as an indicator of current system performance.

关键词： Dosimeters

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current developments in Lens design and optical engineering Xiii

Current Developments in Lens Design and Optical Engineering ...

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current developments in Lens design and optical engineering Xiii

ISBN: (纸本)9780819492036

The proceedings contain 41 papers. The topics discussed include: novel global optimization algorithms: binary construction and the saddle-point method;finding starting points analytically for optical system optimization;reflaxicon objectives for imaging;digital optical microscope as a sampled imaging system: mathematical description, camera selection and focusing;graphically selecting optical components and housing material for color correction and passive athermalization;design and implementation of multi-layer and multi-bit micro holographic optical data storage employing blue lasers;using micro-projectors to realize large screen head-up display;fly-cutting and testing of freeform optics with sub-μm shape deviations;hybrid polishing of fused silica glass with bound-abrasive polishers in conjunction with vibration;and ultrastable mirrors made from diamond reinforced SiC composites for high precision and power applications.

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engineering Challenges for Instrumenting and Controlling Integrated Organ-on-Chip Systems

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IEEE TRANSACTIONS ON BIOMEDICAL engineering 2013年第3期60卷 682-690页

作者： Wikswo, John P. Block, Frank E., iii Cliffel, David E. Goodwin, Cody R. Marasco, Christina C. Markov, Dmitry A. McLean, David L. McLean, John A. McKenzie, Jennifer R. Reiserer, Ronald S. Samson, Philip C. Schaffer, David K. Seale, Kevin T. Sherrod, Stacy D. Vanderbilt Univ Dept Biomed Engn Nashville TN 37235 USA Vanderbilt Univ Dept Mol Physiol & Biophys Nashville TN 37235 USA Vanderbilt Univ Dept Phys & Astron Nashville TN 37235 USA Vanderbilt Univ Dept Chem Nashville TN 37235 USA Vanderbilt Univ Dept Canc Biol Nashville TN 37232 USA

The sophistication and success of recently reported microfabricated organs-on-chips and human organ constructs have made it possible to design scaled and interconnected organ systems that may significantly augment the current drug development pipeline and lead to advances in systems biology. Physiologically realistic live microHuman (mu Hu) and milliHuman (mHu) systems operating for weeks tomonths present exciting and important engineering challenges such as determining the appropriate size for each organ to ensure appropriate relative organ functional activity, achieving appropriate cell density, providing the requisite universal perfusion media, sensing the breadth of physiological responses, and maintaining stable control of the entire system, while maintaining fluid scaling that consists of similar to 5 mL for the mHu and similar to 5 mu L for the mu Hu. We believe that successful mHu and mu Hu systems for drug development and systems biology will require low-volume microdevices that support chemical signaling, microfabricated pumps, valves and microformulators, automated optical microscopy, electrochemical sensors for rapid metabolic assessment, ion mobility-mass spectrometry for real-time molecular analysis, advanced bioinformatics, and machine learning algorithms for automated model inference and integrated electronic control. Toward this goal, we are building functional prototype components and are working toward top-down system integration.

关键词： Artificial biological organs biological systems biotechnology systems biology

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design of multi-functional GaInAsP/Si hybrid semiconductor optical amplifier array with AlInAs-oxide current confinement layer

Design of multi-functional GaInAsP/Si hybrid semiconductor o...

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Indium Phosphide and Related Materials Conference

作者： Yusuke Hayashi Keita Fukuda Ryo Osabe Jun-Ichi Suzuki Yuki Atsumi Joonhyun Kang Nobuhiko Nishiyama Shigehisa Arai Department of Electrical and Electronic Engineering Tokyo Institute of Technology Meguro Tokyo Japan Department of Electrical and Electronic Engineering Quantum Nanoelectronics Research Center Tokyo Institute of Technology Meguro Tokyo Japan

Novel configuration of multi-functional SOA array by iii-V/Si hybrid technique using one-time iii-V/Si wafer bonding is proposed. A iii-V/Si hybrid structure can realize multi-functional SOA array with different gain ... 详细信息

ISBN: (纸本)9781467361309

关键词： Silicon optical waveguides Semiconductor optical amplifiers optical device fabrication optical saturation

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Waveguide-coupled nanolasers in iii–V membranes on silicon

Waveguide-coupled nanolasers in III–V membranes on silicon

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International Conference on Transparent optical Networks

作者： V. Dolores-Calzadilla D. Heiss A. Fiore M. Smit Technische Universiteit Eindhoven Eindhoven Noord-Brabant NL Department of Electrical Engineering Photonic Integration USA Department of Applied Physics Photonics and Semiconductor Nanophysics USA

ISBN: (纸本)9781479906840

Semiconductor nanolasers provide an attractive route towards high density photonic integrated circuits in low power applications such as optical interconnects. In this paper we present the concept of a waveguide-coupled nanolaser for integration in a CMOS compatible photonic platform. We exploit metallic and dielectric confinement to provide high quality factors exceeding 500 in a wavelength-scale cavity, that provides efficient cooling and cross-talk immunity due to the metal coverage. We present simulations detailing the design considerations for high quality factors and efficient waveguide coupling. optical and electrical simulations predict room temperature operation at 1.55 μm with a threshold current of 120 μA and a differential quantum efficiency of 0.16. We also discuss briefly the challenges of fabricating these devices and integrating them in the photonic platform.

关键词： optical waveguides Cavity resonators Photonics Q-factor optical device fabrication Integrated optics Semiconductor lasers

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New detectors and detector architectures for high resolution optical sensor systems

New detectors and detector architectures for high resolution...

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International Conference on Sensing Technology, ICST

作者： Andreas Eckardt Ralf Reulke Institute of Optical Sensor Systems DLR German Aerospace Center Berlin Germany

The Institute of optical Sensor Systems (OS) as member of the Robotics and Mechatronics Cluster of the German Aerospace Center (DLR) has more than 30 years experiences with high-resolution imaging technology. The technology changes in the development of detectors, as well as the significant change of the manufacturing accuracy in combination with the engineering research define the next generation of spaceborne sensor systems focusing on Earth observation and remote sensing. The combination of large TDI (time delay and integration) lines, intelligent synchronization control, fast-readable sensors and new focal-plane concepts open the door to new remote-sensing instruments. This class of instruments is feasible for high-resolution sensor systems regarding geometry and radiometry and their data products like 3D virtual reality. Systemic approaches are essential for such designs of complex sensor systems for dedicated tasks. The system theory of the instrument inside a simulated environment is the beginning of the optimization process for the optical, mechanical and electrical designs. Single modules and the entire system have to be calibrated and verified. Suitable procedures must be defined on component, module and system level for the assembly test and verification process. This kind of development strategy allows the hardware-in-the-loop design. The paper gives an overview about the current developments at DLR OS in the field of innovative sensor systems design for spatial and spectral high resolution remote sensing instruments.

关键词： Detectors Signal to noise ratio Instruments optical sensors Wavelength measurement Extraterrestrial measurements

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Physics and Applications of Novel Gain Materials

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Physica Status Solidi (C) current Topics in Solid State Physics 2013年第4期10卷 554-555页

作者： Calvez, Stephane Rorison, Judy Guina, Mircea Alexandropoulos, Dimitris Balkan, Naci University of Strathclyde Institute of Photonics Wolfson Centre 106 Rottenrow Glasgow G4 0NW United Kingdom Department of Electrical and Electronic Engineering University of Bristol Merchant Venturers Building Woodland Rd Bristol BS8 1UB United Kingdom Tampere University of Technology Optoelectronics Research Centre Korkeakoulunkatu 3 FI-33720 Tampere Finland University of Patras Department of Materials Science Patras 26504 Greece University of Essex School of Computer Science and Electronic Engineering Colchester Essex United Kingdom

If silicon and its associated oxides are the enabling materials for mainstream micro-electronics, iii–V semiconductors have proven to be key alloys for opto-electronic devices and specialized electronics. Indeed, these semiconductor compounds are the basis of laser diodes and detectors used in optical communications (being for long-haul transmission or within datacenters), and of the high-frequency electronics embedded in wireless communication systems. Furthermore, they are also becoming of strategic importance in major emerging or future markets, namely through visible LEDs for solid-state lighting and concentrator-based multi-junction solar cells. All these developments critically depend on the availability of suitable materials and the ability to engineer their structural/electronic/optical properties to enable new functionalities or improve device performance. The introduction at the end of 1990s of the highly-mismatched iii–V alloys, in which a group iii or V element of very dissimilar size to the other elements of the compound is incorporated, offered new opportunities in that respect since these novel semiconductors permit the range of useful iii–V compositions and bandgaps to be extended in an unusual way. This deliberate choice to include a mismatched element resulted in growth challenges, but also gave rise to new physics to understand their unique opto-electronic properties and how to exploit these in full to make advanced and/or new devices. This active field research has been dominated by the reports on the iii–V nitrides. These can be either (Al)(In)GaN compounds, which present high nitrogen content and wide bandgap (1.1 eV (InN) < E g < 6.2 eV (AlN)) and are mostly studied for solid-state lighting applications, or the other iii–V–N alloys, which include a low nitrogen content (<10%) and possess a small bandgap ( E g < 1.4 eV) and whose primary drivers are telecommunication and more recently intermediate band solar-cell applications. If the activity o

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Basic optical Properties of the Photoelastic Modulator Part iii: Thermal Properties

Basic Optical Properties of the Photoelastic Modulator Part ...

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Conference on current developments in Lens design and optical engineering Xiii

作者： Hirschy, Linda Wang, Baoliang (Bob) Wolf, Jacob Lakanen, Bob Hartmann, Brittany Hinds Instruments Inc Hillsboro OR 97124 USA

ISBN: (纸本)9780819492036

Hinds Instruments has provided photoelastic modulators (PEMs) to the photonics industry for over 40 years. In the past Bob Wang, et al. from Hinds have made two presentations(,1,2) at SPIE meetings, Basic optical Properties of the Photoelastic Modulator Part I: Useful Aperture and Acceptance Angle and Part II: Residual Birefringence in the optical Element. This presentation, Part iii in the series, addresses the characteristics of the PEM that vary with temperature, highlighting effects on frequency and signal drift due to retardation changes. In addition, Part iii will introduce a new PEM with advanced thermal control (PEM-ATC (TM)). Data is presented that shows the increased stability of the PEM frequency and retardation signal using this new device.

关键词： photoelastic modulator PEM polarization modulation thermal stability modulation frequency

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