Cw Tunable Lasers for Quantum Applications Expertise
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A Tunable Mode-Locked Ytterbium-Doped Fiber Laser Based on Nonlinear Kerr Beam Clean-Up Effect
A tunable mode-locked ytterbium-doped fiber laser based on nonlinear Kerr beam clean-up effect Shanchao Ma,1 Baofu Zhang,2,* Qiurun He,1 Jing Guo,3 and Zhongxing Jiao1,* 1School of Physics, Sun Yat-sen University, Guangzhou 510275, China 2School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, China 3School of Opto-Electronics, Beijing Institute of Technology, Beijing 100081, China *Corresponding author: [email protected], [email protected] Abstract:We demonstrate a novel approach to achieve tunable ultrashort pulses from an all-fiber mode-locked laser with a saturable absorber based on nonlinear Kerr beam clean-up effect. This saturable absorber was formed by a single-mode fiber spliced to a commercial graded-index multimode fiber, and its tunable band-pass filter effect has been studied by an original numerical model. By adjusting the bending condition of graded-index multimode fiber, the laser could produce dissipative soliton pulses with their central wavelength tunable from1033 nm to 1063 nm. The pulse width of output laser could be compressed externally to 791 fs, and the signal to noise ratio of its radio frequency spectrum was measured to be 75.5 dB. This work provides a new idea for the design of tunable mode-locked laser which can be used as an attractive light source in optical communication system. 1. Introduction Wavelength tunable lasers are widely used in optical communication [1], detection [2], and remote sensing [3]. Compared to tunable continuous-wave lasers, tunable mode-locked lasers can generate ultra-short pulses with high peak power and wide bandwidth that enable many important advances, such as high-sensitivity optical absorption measurement [4], multi photon microscopy [5], and super-continuum light source used in dense wavelength division multiplexing [6]. -
Tunable Laser Absorption Spectroscopy for Human Spaceflight
49th International Conference on Environmental Systems ICES-2019-358 7-11 July 2019, Boston, Massachusetts Tunable Laser Absorption Spectroscopy for Human Spaceflight Christopher M Matty1 and Lance E Christensen2 National Aeronautics and Space Administration, Houston Texas 77058 and Pasadena California 91109 Human Spaceflight consistently has need for measurement of the major constituent gasses in a habitable cabin environment. Traditionally, this measurement has been performed using a mixture of mass spectrometry, electrochemical, and other traditional sensing methods. Tunable laser spectroscopy has been used in industry and research applications since the 1970s but has not been used in primary operational human spaceflight systems aside from a handful of experimental applications. Meanwhile, recent advances in the quality, size, and cost of semiconductor lasers has had a significant impact on the range of feasible applications for tunable laser spectroscopy. In 2018, work started on the Orion Laser Air Monitor (LAM), which is designed to be the primary major constituency monitoring system for the Orion Spacecraft. This paper covers the history leading up to the selection, design, and build of the Orion Laser Air Monitor as a primary major constituent analyzer for human spaceflight. Nomenclature TLDAS = Tunable Laser Diode Absorption Spectroscopy QC = Quantum Cascade IC = Interband Cascade TEC = Thermo Electric Cooler TRL = Technology Readiness Level SWAP = System Size Weight and Power IR = Infrared MCA = International Space Station Major Constituent Analyzer CAMS = Submarine Central Atmosphere Monitoring System AGA = Anomaly Gas Analyzer MGM = Multi Gas Monitor CPM = Combustion Product Monitor LAM = Laser Air Monitor SAFFIRE = Spacecraft Fire Experiement GaSb = Gallium Antimodide I. Introduction UNABLE Laser Diode Absorption Spectroscopy (TLDAS) is currently enjoying a period at the developmental Tforefront. -
Detection of Chemical Clouds Using Widely Tunable Quantum Cascade Lasers
Detection of chemical clouds using widely tunable quantum cascade lasers Anish K. Goyal*, Petros Kotidis, Erik R. Deutsch, Ninghui Zhu, Mark Norman, Jim Ye, Kostas Zafiriou, and Alex Mazurenko Block Engineering/MEMS, 377 Simarano Drive, Marlborough, MA 01752 ABSTRACT Widely tunable quantum cascade lasers (QCLs) spanning the long-wave infrared (LWIR) atmospheric transmission window and an HgCdTe detector were incorporated into a transceiver having a 50-mm-diameter transmit/receive aperture. The transceiver was used in combination with a 50-mm-diameter hollow retro-reflector for the open-path detection of chemical clouds. Two rapidly tunable external-cavity QCLs spanned the wavelength range of 7.5 to 12.8 m. Open-path transmission measurements were made over round-trip path-lengths of up to 562 meters. Freon-132a and other gases were sprayed into the beam path and the concentration-length (CL) product was measured as a function of time. The system exhibited a noise-equivalent concentration (NEC) of 3 ppb for Freon-132a given a round-trip path of 310 meters. Algorithms based on correlation methods were used to both identify the gases and determine their CL- products as a function of time. Keywords: atmospheric sensing, open-path spectroscopy, gas detection, vibrational spectroscopy, infrared spectroscopy, quantum cascade lasers, chemical detection 1. INTRODUCTION Open-path atmospheric spectroscopy is used to measure the gas concentration along an optical path. There are many such systems and they operate within one or more of the atmospheric transmission bands that exist between the ultraviolet (UV) and mid-infrared (MIR) portions of the optical spectrum [1-4]. -
NS14 ASSOCIATION NATIONAL BOAT REGISTER Sail No. Hull
NS14 ASSOCIATION NATIONAL BOAT REGISTER Boat Current Previous Previous Previous Previous Previous Original Sail No. Hull Type Name Owner Club State Status MG Name Owner Club Name Owner Club Name Owner Club Name Owner Club Name Owner Club Name Owner Allocated Measured Sails 2070 Midnight Midnight Hour Monty Lang NSC NSW Raced Midnight Hour Bernard Parker CSC Midnight Hour Bernard Parker 4/03/2019 1/03/2019 Barracouta 2069 Midnight Under The Influence Bernard Parker CSC NSW Raced 434 Under The Influence Bernard Parker 4/03/2019 10/01/2019 Short 2068 Midnight Smashed Bernard Parker CSC NSW Raced 436 Smashed Bernard Parker 4/03/2019 10/01/2019 Short 2067 Tiger Barra Neil Tasker CSC NSW Raced 444 Barra Neil Tasker 13/12/2018 24/10/2018 Barracouta 2066 Tequila 99 Dire Straits David Bedding GSC NSW Raced 338 Dire Straits (ex Xanadu) David Bedding 28/07/2018 Barracouta 2065 Moondance Cat In The Hat Frans Bienfeldt CHYC NSW Raced 435 Cat In The Hat Frans Bienfeldt 27/02/2018 27/02/2018 Mid Coast 2064 Tiger Nth Degree Peter Rivers GSC NSW Raced 416 Nth Degree Peter Rivers 13/12/2017 2/11/2013 Herrick/Mid Coast 2063 Tiger Lambordinghy Mark Bieder PHOSC NSW Raced Lambordinghy Mark Bieder 6/06/2017 16/08/2017 Barracouta 2062 Tiger Risky Too NSW Raced Ross Hansen GSC NSW Ask Siri Ian Ritchie BYRA Ask Siri Ian Ritchie 31/12/2016 Barracouta 2061 Tiger Viva La Vida Darren Eggins MPYC TAS Raced Rosie Richard Reatti BYRA Richard Reatti 13/12/2016 Truflo 2060 Tiger Skinny Love Alexis Poole BSYC SA Raced Skinny Love Alexis Poole 15/11/2016 20/11/2016 Barracouta -
On the Instabilities of Tropical Cyclones Generated by Cloud Resolving Models
SERIES A DYANAMIC METEOROLOGY Tellus AND OCEANOGRAPHY PUBLISHED BY THE INTERNATIONAL METEOROLOGICAL INSTITUTE IN STOCKHOLM On the instabilities of tropical cyclones generated by cloud resolving models By DAVID A. SCHECTERÃ, NorthWest Research Associates, Boulder, CO, USA (Manuscript received 30 May 2018; in final form 29 August 2018) ABSTRACT An approximate method is developed for finding and analysing the main instability modes of a tropical cyclone whose basic state is obtained from a cloud resolving numerical simulation. The method is based on a linearised model of the perturbation dynamics that distinctly incorporates the overturning secondary circulation of the vortex, spatially inhomogeneous eddy diffusivities, and diabatic forcing associated with disturbances of moist convection. Although a general formula is provided for the latter, only parameterisations of diabatic forcing proportional to the local vertical velocity perturbation and modulated by local cloudiness of the basic state are implemented herein. The instability analysis is primarily illustrated for a mature tropical cyclone representative of a category 4 hurricane. For eddy diffusivities consistent with the fairly conventional configuration of the simulation that generates the basic state, perturbation growth is dominated by a low azimuthal wavenumber instability having greatest asymmetric kinetic energy density in the lower tropospheric region of the inner core of the vortex. The characteristics of the instability mode are inadequately explained by nondivergent 2D dynamics. Moreover, the growth rate and modal structure are sensitive to reasonable variations of the diabatic forcing. A second instability analysis is conducted for a mature tropical cyclone generated under conditions of much weaker horizontal diffusion. In this case, the linear model predicts a relatively fast high-wavenumber instability that is insensitive to the parameterisation of diabatic forcing. -
Improved Laser Based Photoluminescence on Single-Walled Carbon Nanotubes
Improved laser based photoluminescence on single-walled carbon nanotubes S. Kollarics,1 J. Palot´as,1 A. Bojtor,1 B. G. M´arkus,1 P. Rohringer,2 T. Pichler,2 and F. Simon1 1Department of Physics, Budapest University of Technology and Economics and MTA-BME Lend¨uletSpintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary 2Faculty of Physics, University of Vienna, Strudlhofgasse 4., Vienna A-1090, Austria Photoluminescence (PL) has become a common tool to characterize various properties of single- walled carbon nanotube (SWCNT) chirality distribution and the level of tube individualization in SWCNT samples. Most PL studies employ conventional lamp light sources whose spectral dis- tribution is filtered with a monochromator but this results in a still impure spectrum with a low spectral intensity. Tunable dye lasers offer a tunable light source which cover the desired excitation wavelength range with a high spectral intensity, but their operation is often cumbersome. Here, we present the design and properties of an improved dye-laser system which is based on a Q-switch pump laser. The high peak power of the pump provides an essentially threshold-free lasing of the dye laser which substantially improves the operability. It allows operation with laser dyes such as Rhodamin 110 and Pyridin 1, which are otherwise on the border of operation of our laser. Our sys- tem allows to cover the 540-730 nm wavelength range with 4 dyes. In addition, the dye laser output pulses closely follow the properties of the pump this it directly provides a time resolved and tunable laser source. -
Electrically Tunable Mode-Locked Lasers Based on Time-To-Wavelength Mapping for Optical Communications
Laser Original Electrically Tunable Mode-Locked Lasers Based on Time-to-Wavelength Mapping for Optical Communications Kohichi R. TAMURA NTT Corporation, NTT Network Innovation Laboratories, 1-1 Hikari-no-oka, Yokosuka, Kanagawa 239-0847 (Received August 20, 2001) The tunable mode-locked laser based on time-to-wavelength mapping is a relatively unexplored alternative to tunable sources that can be applied to transmission and wavelength switching in optical networks. These lasers have the advantages of a simple tuning mechanism, good wavelength reproducibility, and simple cavity design. The state of research is discussed. Key Words: Tunable laser, Mode-locked laser, Fiber Bragg grating, Arrayed waveguide grating 1. Introduction ment to make a cavity with a length that depends on wavelength. The oscillation wavelength is selected by changing a single elec- Compact and tunable lasers are considered to be key compo- trical control signal - the RF frequency. The dependence of the nents for realizing advanced functionality in optical communi- oscillation wavelength on RF frequency is determined by the cation networks.1) A variety of designs exist, and, currently, sev- delay element and should be stable over time if a stable wave- eral of them are in the early stages of commercialization. The length-selective element is used. Inherent drawbacks to ETMLs first application of tunable lasers will be as temporary sources are the changing repetition rate with wavelength and the broad for DWDM terminals, which eliminates the need for stocking optical spectrum that results from mode-locking. Even so, as spare parts at each wavelength. While the tuning speed is not we describe below, these lasers may find applications in optical critical in this case, more advanced applications call for speeds switching within nodes or for short distance transmission in ranging from millisecond-to-nanosecond time scales. -
Coupled-Ring-Resonator-Mirror-Based Heterogeneous III–V Silicon Tunable Laser Volume 7, Number 3, June 2015
Coupled-Ring-Resonator-Mirror-Based Heterogeneous III–V Silicon Tunable Laser Volume 7, Number 3, June 2015 S. Srinivasan M. Davenport T. Komljenovic J. Hulme D. T. Spencer J. E. Bowers, Fellow, IEEE DOI: 10.1109/JPHOT.2015.2428255 1943-0655 Ó 2015 IEEE IEEE Photonics Journal Heterogeneous III–V Silicon Tunable Laser Coupled-Ring-Resonator-Mirror-Based Heterogeneous III–V Silicon Tunable Laser S. Srinivasan, M. Davenport, T. Komljenovic, J. Hulme, D. T. Spencer, and J. E. Bowers, Fellow, IEEE Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106 USA DOI: 10.1109/JPHOT.2015.2428255 1943-0655 Ó 2015 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. Manuscript received February 6, 2015; revised April 21, 2015; accepted April 23, 2015. Date of current version May 26, 2015. This work was supported by the DARPA EPHI Program. The work of T. Komljenovic was supported by NEWFELPRO under Grant 25. Corresponding author: S. Srinivasan (e-mail: [email protected]). Abstract: We show theoretical and experimental results from a tunable laser, with its center wavelength in the C-band, designed using coupled-ring resonator mirrors. The effective cavity length enhancement and negativeopticalfeedbackobtainedfromtheres- onators helps to narrow the laser linewidth in a small form factor. We report a linewidth of 160 kHz and a side-mode suppression ratio of 9 40 dB over the full tuning range. Index Terms: Tunable lasers, coupled resonators, semiconductor lasers, silicon photonics. -
Numerical Simulations of a Surface Piercing A- Class Catamaran Hydrofoil and Comparison Against Model Tests
Journal of Sailing Technology, Article 2017-04. © 2017, The Society of Naval Architects and Marine Engineers. NUMERICAL SIMULATIONS OF A SURFACE PIERCING A- CLASS CATAMARAN HYDROFOIL AND COMPARISON AGAINST MODEL TESTS Thilo Keller TU Berlin, Berlin, Germany Juryk Henrichs DNV GL SE, Potsdam, Germany Dr. Karsten Hochkirch Downloaded from http://onepetro.org/jst/article-pdf/2/01/1/2205567/sname-jst-2017-04.pdf by guest on 27 September 2021 DNV GL SE, Potsdam, Germany Dr. Andrés Cura Hochbaum TU Berlin, Berlin, Germany Manuscript received March 1, 2017; accepted April 4, 2017. Abstract: Hydrofoil supported sailing vessels gained more and more importance within the last years. Due to new processes of manufacturing, it is possible to build slender section foils with low drag coefficients and heave stable hydrofoil geometries are becoming possible to construct. These surface piercing foils often tend to ventilate and cause cavitation at high speeds. The aim of this work is to define a setup to calculate the hydrodynamic forces on such foils with RANS CFD and to investigate whether the onset of ventilation and cavitation can be predicted with sufficient accuracy. Therefore, a surface piercing hydrofoil of an A-Class catamaran is simulated by using the RANS software FineMarine with its volume of fluid method. The C-shaped hydrofoil is analyzed for one speed at Froude Number 7.9 and various angles of attack (AoA) by varying rake and leeway angle in ranges actually used while sailing. In addition, model tests were carried out in the K27 cavitation tunnel of TU-Berlin, for the given hydrofoil and in the same conditions as simulated with CFD to provide data for validation. -
International Dredging Review JULY/AUGUST 2009 VOLUME 28, NUMBER 4
International Dredging Review JULY/AUGUST 2009 VOLUME 28, NUMBER 4 IN THIS ISSUE: Sand and Gravel Dredging A capping project is a major customer for Wisconsin producers. Page 6 The high-profile Hudson River cleanup project proceeds – carefully. Page 14 Recovery dredging projects are running full tilt. Contract Awards starting on page 17. Vortex Marine’s DB Vengeance working in the Richmond, California entrance channel on a misty July afternoon. Story on page 12. On the Cover: BUILDING THE PUMPOUT SYSTEM Description courtesy of Manson Construction Vortex Marine Construction Using DB Vengeance In recent years, in-water disposal has At Richmond Entrance Channel Maintenance become more and more of an environmental concern in the San Francisco Bay area, and all Dredged Material Is Used for Marsh Creation parties involved have been searching for alter- feet wide. Despite its size, the project only native disposal sites. More than 90 percent of includes 150,000 cubic yards of material and the Bay’s marsh and wetlands have disap- another 100,000 of possible overdepth materi- peared through development. al, because the depth of the siltation overall is The U.S. Army Corps of Engineers, in part- not that great, explained Dave Doak, San nership with the California State Coastal Francisco District Senior Project Manager for Conservancy and the Port of Oakland, have the Richmond job. developed the Hamilton Wetlands Restoration The dredge is loading into two 3000-cubic- Project (HWRP) to address these two environ- yard closed hopper barges for transport to the mental concerns. The project takes dredged Liberty Offloader, which is moored 10 miles material from the Ports of Oakland and from Richmond and five miles offshore from Richmond and deposits it for beneficial re-use the Hamilton Wetlands. -
Design of a Free-Rotating Wing Sail for an Autonomous Sailboat
DEGREE PROJECT IN VEHICLE ENGINEERING, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2017 Design of a free-rotating wing sail for an autonomous sailboat CLAES TRETOW KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ENGINEERING SCIENCES ! ! ! ! Design of a free-rotating wing sail for an autonomous sailboat Claes Tretow ! ! ! ! ! ! ! ! ! ! Degree Project in Naval Architecture (30 credits) Degree Programme in Naval Architecture (120 credits) Degree Programme in Vehicle Engineering (300 credits) The Royal Institute of Technology 2017 Supervisors: Jakob Kuttenkeuler, Mikael Razola Examiner: Jakob Kuttenkeuler ! ! 2 Abstract There is an accelerating need for ocean sensing where autonomous vehicles can play a key role in assisting engineers, researcher and scientists with environmental monitoring and colleting oceanographic data. This thesis is performed in collaboration with a research group at The Royal Institute of Technology that currently develops an autonomous sailboat to be used as a sensor carrying platform for autonomous data acquisition in the Baltic Sea. This type of vehicle has potentials to be a helpful and cheaper alternative to a commercial research vessel. The thesis presents the design, construction and experimental testing of a rigid free-rotating wing sail for this autonomous sailboat. The goal is to design a rig that can sustain under all occurring weather conditions in the Baltic sea while ensuring sailing performance, robustness, reliability and low power consumption, which are key aspects driving the design. The rig is designed through the utilization of analysis and design methods involving a Vortex Lattice Method combined with a Velocity Prediction Program in order to achieve best possible aerodynamic performance with respect to the application requirements. -
Portsmouth Yardstick 2010 2
Standard Portmouth Yardstick Numbers Complete Numerical Listing Valid from 9th March 2010. Class PY NO Pursuit Race No Class PY NO Pursuit Race No 18' Skiff a 675 68 Seafly c 1087 109 Foiling Moth 690 69 420 c 1087 109 49er a 744 74 405 a 1089 109 RS 800 a 822 82 Laser 2000 a 1090 109 International 14 * Non Foil 840 84 National 12 * o 1089 109 Laser 5000 a 846 85 Redwing c 1094 109 Boss a 847 85 Wayfarer c 1101 110 RS 700 a 857 86 Laser Vago SD S/H a 1100 110 Canoe International a 870 87 Laser Radial o 1104 110 B 14 a 874 87 OK o 1109 111 Musto Skiff a 875 88 Leader c 1115 112 Flying Dutchman c 879 88 Enterprise o 1116 112 505 c 902 90 Snipe o 1117 112 RS K6 a 903 90 GP 14 c 1127 113 Canoe International o 905 91 Wanderer c 1139 114 59er a 905 91 GP 14 o 1136 114 Laser 4000 a 908 91 Europe o 1140 114 RS 600 o 920 92 Byte CII o 1140 114 29er a 924 92 Lightening 368 o 1152 115 ISO a 926 93 Mercury c 1152 115 Javelin c 926 93 Solo o 1155 116 Cherub * 2005 a 930 93 Byte o 1165 117 Spice a 930 93 Firefly o 1165 117 Laser Vortex a 937 94 Streaker o 1162 116 Osprey c 940 94 Graduate o 1165 117 RS 400 a 950 95 British Moth o 1168 117 National 18 c 957 96 Comet o 1177 118 Laser Vortex o 960 96 Comet Duo o 1175 118 RS 500 a 972 97 Laser 4.7 o 1175 118 470 c 973 97 Miracle c 1185 119 Hornet c 973 97 Splash o 1184 118 Cherub * 1997 a 975 98 RS Feva XL a 1200 120 International Moth * Non Foil 980 98 Topaz Duo o 1190 119 Fireball c 982 98 Pacer o 1193 119 Contender o 993 99 Bosun c 1198 120 RS 300 o 1000 100 Challenger o 1200 120 Buzz a 1002 100 YW