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Sample records for rael artel gallery

  1. Heritage Gallery

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Marshall Space Flight Center's (MSFC's) building 4200 hosts a new spaceflight history museum referred to as the Heritage Gallery, allowing employees and visitors alike to have the opportunity to experience history first hand. On display are many models of launch vehicles and spacecraft that have made the center famous. It features a full-scale mockup of the lunar roving vehicle, three built-in multimedia displays, a large theater screen, and two glass cases that house memorabilia such as personal items belonging to Wernher von Braun, MSFC's first Center Director. The new Heritage Gallery features the accomplishments of several past and present members of the Marshall team. Attending the ribbon cutting ceremony are: (left to right) Gerhard Reisig; Cort Durocher, executive director of the American Institute of Aeronautics and Astronautics; Ernst Stuhlinger; Konrad Darnenburg; Werner Dahm; Walter Jacobi; and host of event, Center Director Art Stephenson.

  2. West Indian Gallery

    ERIC Educational Resources Information Center

    Ramsaran, J. A.

    1975-01-01

    Reviews the poetry of Derek Walcott, a native of the West Indies, whose new volume 'Another Life' more resembles the poet-artists commentary on a gallery of scenes and portraits in Melvin Tolson's 'The Harlem Gallery' than anything else that has come from the English speaking Caribbean in the post-war period. (Author/JM)

  3. Pompton Lakes Photo Gallery

    EPA Pesticide Factsheets

    This gallery provides representative photographs of the soil removal and dredging operations within the Pompton Lake Study Area (PLSA) performed starting in 2016 through the present. It will be periodically updated in conjunction with the progress of the

  4. Whispering Gallery Pulse Compressor

    SciTech Connect

    Hirshfield, J.; Kuzikov, S.V.; Petelin, M.I.; Pavelyev, V.G.

    2004-12-07

    A barrel-like cavity resonant at a whispering gallery mode is known as capable to provide a SLED-like rf pulse compression. To enhance the power handling capacity of the compressor, we propose to use a coupler based on a wave tunneling through a continuous slot. A modeling low power 11.4 GHz experiment proved to be consistent with theory. A preliminary technical design for an evacuated high-power compressor has also been developed. According to a theory, a twin-cavity version of the device can efficiently compress microwave pulses produced with sources of limited bandwidth, in particular frequency-chirped pulses.

  5. Whispering Gallery Mode Thermometry.

    PubMed

    Corbellini, Simone; Ramella, Chiara; Yu, Lili; Pirola, Marco; Fernicola, Vito

    2016-10-29

    This paper presents a state-of-the-art whispering gallery mode (WGM) thermometer system, which could replace platinum resistance thermometers currently used in many industrial applications, thus overcoming some of their well-known limitations and their potential for providing lower measurement uncertainty. The temperature-sensing element is a sapphire-crystal-based whispering gallery mode resonator with the main resonant modes between 10 GHz and 20 GHz. In particular, it was found that the WGM around 13.6 GHz maximizes measurement performance, affording sub-millikelvin resolution and temperature stability of better than 1 mK at 0 °C. The thermometer system was made portable and low-cost by developing an ad hoc interrogation system (hardware and software) able to achieve an accuracy in the order of a few parts in 10⁸ in the determination of resonance frequencies. Herein we report the experimental assessment of the measurement stability, repeatability and resolution, and the calibration of the thermometer in the temperature range from -74 °C to 85 °C. The combined standard uncertainty for a single temperature calibration point is found to be within 5 mK (i.e., comparable with state-of-the-art for industrial thermometry), and is mainly due to the employed calibration setup. The uncertainty contribution of the WGM thermometer alone is within a millikelvin.

  6. Whispering Gallery Mode Thermometry

    PubMed Central

    Corbellini, Simone; Ramella, Chiara; Yu, Lili; Pirola, Marco; Fernicola, Vito

    2016-01-01

    This paper presents a state-of-the-art whispering gallery mode (WGM) thermometer system, which could replace platinum resistance thermometers currently used in many industrial applications, thus overcoming some of their well-known limitations and their potential for providing lower measurement uncertainty. The temperature-sensing element is a sapphire-crystal-based whispering gallery mode resonator with the main resonant modes between 10 GHz and 20 GHz. In particular, it was found that the WGM around 13.6 GHz maximizes measurement performance, affording sub-millikelvin resolution and temperature stability of better than 1 mK at 0 °C. The thermometer system was made portable and low-cost by developing an ad hoc interrogation system (hardware and software) able to achieve an accuracy in the order of a few parts in 109 in the determination of resonance frequencies. Herein we report the experimental assessment of the measurement stability, repeatability and resolution, and the calibration of the thermometer in the temperature range from −74 °C to 85 °C. The combined standard uncertainty for a single temperature calibration point is found to be within 5 mK (i.e., comparable with state-of-the-art for industrial thermometry), and is mainly due to the employed calibration setup. The uncertainty contribution of the WGM thermometer alone is within a millikelvin. PMID:27801868

  7. Whispering gallery mode sensors

    PubMed Central

    Foreman, Matthew R.; Swaim, Jon D.; Vollmer, Frank

    2015-01-01

    We present a comprehensive overview of sensor technology exploiting optical whispering gallery mode (WGM) resonances. After a short introduction we begin by detailing the fundamental principles and theory of WGMs in optical microcavities and the transduction mechanisms frequently employed for sensing purposes. Key recent theoretical contributions to the modeling and analysis of WGM systems are highlighted. Subsequently we review the state of the art of WGM sensors by outlining efforts made to date to improve current detection limits. Proposals in this vein are numerous and range, for example, from plasmonic enhancements and active cavities to hybrid optomechanical sensors, which are already working in the shot noise limited regime. In parallel to furthering WGM sensitivity, efforts to improve the time resolution are beginning to emerge. We therefore summarize the techniques being pursued in this vein. Ultimately WGM sensors aim for real-world applications, such as measurements of force and temperature, or alternatively gas and biosensing. Each such application is thus reviewed in turn, and important achievements are discussed. Finally, we adopt a more forward-looking perspective and discuss the outlook of WGM sensors within both a physical and biological context and consider how they may yet push the detection envelope further. PMID:26973759

  8. MoMLA: From Panel to Gallery

    ERIC Educational Resources Information Center

    Vitanza, Victor, Ed.; Kuhn, Virginia, Ed.

    2013-01-01

    The work presented here in this "Panel to Gallery" was originally produced and assembled for the 2012 Modern Language Association Conference in Seattle, Washington. Similar to "From Gallery to Webtext", the event Victor curated for the 2006 College Composition and Communication Conference, this "Panel to Gallery" event at MLA set aside the…

  9. Whispering gallery optical parametric oscillators

    NASA Astrophysics Data System (ADS)

    Breunig, Ingo; Buse, Karsten

    2013-12-01

    Whispering gallery optical parametric oscillators (WGR OPOs) are monolithic sources for tunable coherent and non-classical light. They are based on total internal reflection. Since reflection losses are negligible, their oscillation threshold can be far below one milliwatt. With sub-millimeter diameters, they are the most compact OPOs demonstrated so far. Recent experimental results demonstrate that WGR OPOs emit coherent light tunable over hundreds of nanometers. Operation in the visible as well as in the near-infrared has been demonstrated with up to 30 % conversion efficiency. These results indicate a great potential of WGR OPOs for spectroscopic and sensing applications.

  10. Graded-index whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor); Ilchenko, Vladimir (Inventor); Matsko, Andrey B. (Inventor)

    2005-01-01

    Whispering gallery mode optical resonators which have spatially-graded refractive indices. In one implementation, the refractive index spatially increases with a distance from an exterior surface of such a resonator towards an interior of the resonator to produce substantially equal spectral separations for different whispering gallery modes. An optical coupler may be used with such a resonator to provide proper optical coupling.

  11. Nonlinear optical whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Ilchenko, Vladimir (Inventor); Matsko, Andrey B. (Inventor); Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor)

    2005-01-01

    Whispering gallery mode (WGM) optical resonators comprising nonlinear optical materials, where the nonlinear optical material of a WGM resonator includes a plurality of sectors within the optical resonator and nonlinear coefficients of two adjacent sectors are oppositely poled.

  12. Whispering-gallery-mode-based seismometer

    DOEpatents

    Fourguette, Dominique Claire; Otugen, M Volkan; Larocque, Liane Marie; Ritter, Greg Aan; Meeusen, Jason Jeffrey; Ioppolo, Tindaro

    2014-06-03

    A whispering-gallery-mode-based seismometer provides for receiving laser light into an optical fiber, operatively coupling the laser light from the optical fiber into a whispering-gallery-mode-based optical resonator, operatively coupling a spring of a spring-mass assembly to a housing structure; and locating the whispering-gallery-mode-based optical resonator between the spring-mass assembly and the housing structure so as to provide for compressing the whispering-gallery-mode-based optical resonator between the spring-mass assembly and the housing structure responsive to a dynamic compression force from the spring-mass assembly responsive to a motion of the housing structure relative to an inertial frame of reference.

  13. Gallery of Portraits and Other Pictures

    NASA Astrophysics Data System (ADS)

    Velarde, M. G.

    Colleagues, scientific collaborators and visitors, and places… of significance in the life of Prof. M.G. Velarde. The gallery also illustrates the cosmopolitan life at Instituto Pluridisciplinar of Universidad Complutense of Madrid. Science is part of Culture.

  14. Seepage to Collection Gallery Near Seacoast

    NASA Astrophysics Data System (ADS)

    Hunt, B.

    1985-03-01

    Conformal mapping is used to obtain a solution for seepage to a collection gallery (a horizontal ditch or slotted pipe) that is parallel to a seacoast. The solution permits calculation of the gallery drawdown that is required to withdraw any given flow rate and also allows calculation of the maximum flow rate that can be abstracted without causing sea water intrusion. The results are applied to a numerical example.

  15. Thermal Properties of Whispering Gallery Mode Resonators

    DTIC Science & Technology

    2014-12-22

    F01m 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 ABSTRACT Number of Papers published in peer-reviewed journals: Thermal Properties of Whispering...Gallery Mode Resonators Report Title In this project, we studied the thermal properties of ultra-high-quality whispering-gallery-mode microtoroid...resonators. More specifically, we measured the thermal relaxation time of the resonator to estimate the response time of the resonator based infrared (IR

  16. Whispering Gallery Mode Optomechanical Resonator

    NASA Technical Reports Server (NTRS)

    Aveline, David C.; Strekalov, Dmitry V.; Yu, Nan; Yee, Karl Y.

    2012-01-01

    Great progress has been made in both micromechanical resonators and micro-optical resonators over the past decade, and a new field has recently emerged combining these mechanical and optical systems. In such optomechanical systems, the two resonators are strongly coupled with one influencing the other, and their interaction can yield detectable optical signals that are highly sensitive to the mechanical motion. A particularly high-Q optical system is the whispering gallery mode (WGM) resonator, which has many applications ranging from stable oscillators to inertial sensor devices. There is, however, limited coupling between the optical mode and the resonator s external environment. In order to overcome this limitation, a novel type of optomechanical sensor has been developed, offering great potential for measurements of displacement, acceleration, and mass sensitivity. The proposed hybrid device combines the advantages of all-solid optical WGM resonators with high-quality micro-machined cantilevers. For direct access to the WGM inside the resonator, the idea is to radially cut precise gaps into the perimeter, fabricating a mechanical resonator within the WGM. Also, a strategy to reduce losses has been developed with optimized design of the cantilever geometry and positions of gap surfaces.

  17. Landslide Caused Damages in a Gallery

    NASA Astrophysics Data System (ADS)

    Poisel, R.; Mair am Tinkhof, K.; Preh, A.

    2016-06-01

    On October 5th, 2010, cracks were found in a gallery 1.8 m high and 1.4 m wide. The gallery is 100 years old, runs parallel to a valley flank and was excavated in a tectonically strongly stressed, weathered and slightly dipping sandwich of clayey shales, sandstones and marls. The cracks in the roof as well as in the invert ran parallel to the axis of the gallery. Monitoring showed that crack widths were increasing 1.5 mm per year, sidewall distances were increasing 3.5 mm per year, whereas the height of the gallery was decreasing 2.5 mm per year. After eliminating several possible causes of cracking, a landslide producing the damages had to be taken into consideration. Monitoring of the valley flank surface as well as inclinometer readings revealed that a landslide was occurring, loading the gallery lining. Most probably the landslide had been reactivated by excessive rainfall in 2009 as well as by works for the renewal of a weir in the valley bottom. As stabilization of the slope was not an option for several reasons, it was decided to replace the gallery by a new one deeper inside the slope, which will be ready for operation in 2017. Thus the old gallery has to be kept in operation till then and it was decided to reinforce the old gallery by a heavily reinforced shotcrete lining 10 cm thick. As slope displacements went on, cracks in the shotcrete lining developed with a completely different pattern: in the section where the gallery lies completely in the landslide shear zone no cracks formed until now due to heavy reinforcement, whereas in the transition sections stable ground-landslide and landslide-stable ground diagonal tension cracks in the roof due to shear by the landslide developed. Numerical models showed that cracking and spalling of the shotcrete lining would occur only after some centimetres of additional displacements of the slope, which hopefully will not occur before 2017.

  18. 13. Historic American Building Survey Crocker Art Gallery Collection Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Historic American Building Survey Crocker Art Gallery Collection Original 1875 Rephoto 1960 DINING ROOM (IN SERVICE WING) LOOKING EAST TO HALL & DOUBLE PARLOURS - Crocker Art Gallery, 216 O Street, Sacramento, Sacramento County, CA

  19. 7. Historic American Building Survey Crocker Art Gallery Collection Stero ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Building Survey Crocker Art Gallery Collection Stero Photo of 1875 Rephoto 1960 INTERIOR STAIRHALL MAIN FLOOR TO WEST - Crocker Art Gallery, 216 O Street, Sacramento, Sacramento County, CA

  20. At 1150 Gallery, Block 5, view of spiral stairway leading ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1150 Gallery, Block 5, view of spiral stairway leading to 1200 Gallery, looking south. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  1. 19. MAIN MEETING ROOM LOOKING SOUTH FROM GALLERY. Note coved ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. MAIN MEETING ROOM LOOKING SOUTH FROM GALLERY. Note coved extension of gallery, erected when offices were built on gallery for the use of the Friends Service Committee in 1936. Note also the short stair balusters resulting from the wide modesty stair stringer provided for the women's side. - Twelfth Street Meeting House, 20 South Twelfth Street, Philadelphia, Philadelphia County, PA

  2. Shooting Gallery Notes. Working Paper #22. Preliminary.

    ERIC Educational Resources Information Center

    Bourgois, Philippe

    This paper contains ethnographic participant-observation field notes taken on a one-night visit to a "shooting gallery" in East Harlem (New York City) along with background information and commentary. East Harlem, also referred to as "El Barrio" or Spanish Harlem, is a 200-square block neighborhood on the upper East Side of…

  3. Portrait Gallery Illuminates--Grant's Triumphs, Failures.

    ERIC Educational Resources Information Center

    Lambert, Robert G., Jr.

    The 100th anniversary of Ulysses S. Grant's death was observed on July 23, 1985. The Smithsonian National Portrait Gallery featured an exhibit of Grant portraiture, which covered his life, from its humble beginnings to military and political triumphs and to failures and disappointment. The exhibit included pictures, artifacts, and momentos from…

  4. The Empirical Spectator and Gallery Education

    ERIC Educational Resources Information Center

    Fulkova, Marie; Straker, Alison; Jaros, Milan

    2004-01-01

    This paper examines the onto-epistemic status and understanding of contemporary material culture and of visual art, particularly in the context of gallery education. It does so through a case study of the response of 15 year-old school students in the Czech Republic and in England to a recent photographic exhibition, I.N.R.I., created by artists…

  5. The Empirical Spectator and Gallery Education

    ERIC Educational Resources Information Center

    Fulkova, Marie; Straker, Alison; Jaros, Milan

    2004-01-01

    This paper examines the onto-epistemic status and understanding of contemporary material culture and of visual art, particularly in the context of gallery education. It does so through a case study of the response of 15 year-old school students in the Czech Republic and in England to a recent photographic exhibition, I.N.R.I., created by artists…

  6. Whispering gallery modes in coated silica microspheres

    NASA Astrophysics Data System (ADS)

    Ristic, Davor; Chiasera, Alessandro; Moser, Enrico; Feron, Patrice; Cibiel, Gilles; Ivanda, Mile; Righini, Giancarlo C.; Ferrari, Maurizio

    2012-06-01

    Silica microspheres were made by melting the tip of a standard telecom fiber and were coated with a 70SiO2 - 30 HfO2 sol-gel derived glass activated by 0.3 mol % of Er3+ ions. The samples were coated using a dip coating apparatus. The thickness of the coating was estimated to be around 1 μm. The whispering gallery modes of the coated resonator were studied using a full taper - microsphere coupling setup. Upon excitation at 1480 nm sharp peaks at wavelengths 1540- 1565 nm were observed. They were attributed to the whispering gallery modes of the microsphere falling in the wavelength range of the erbium emission.

  7. Optimized polaritonic modes in whispering gallery microcavities

    NASA Astrophysics Data System (ADS)

    Hu, Tao; Xie, Wei; Wu, Lin; Wang, Yafeng; Zhang, Long; Chen, Zhanghai

    2017-08-01

    We study both theoretically and experimentally the quality factor characteristic and the optimized polaritonic modes in a whispering gallery microcavity. The quality factors (Q-factors) of the resonant modes are determined by two main factors, i.e., the so called cavity loss and media loss. These two factors determine the final Q-factor and spontaneously lead to an optimized wavelength range for polariton modes. By using finite element analysis (FEA), we present the numerical simulation of resonant frequencies, field distributions and quality factors of the TE polarized whispering gallery modes (WGMs), which agree well with the experimental results. The control of optimized resonance in polaritonic system will be very useful for the development of semiconductor lasers with low threshold.

  8. 18. INTERIOR OF CIVIL RIGHTS INSTITUTE, MILESTONE GALLERY EXHIBITION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. INTERIOR OF CIVIL RIGHTS INSTITUTE, MILESTONE GALLERY EXHIBITION OF THE SIXTEENTH STREET CHURCH, LOOKING NORTHWEST - Sixteenth Street Baptist Church, 1530 Sixth Avenue North, Birmingham, Jefferson County, AL

  9. Whispering-gallery waves in optical fibres

    SciTech Connect

    Sychugov, V A; Torchigin, V P; Tsvetkov, M Yu

    2002-08-31

    The process of excitation of whispering-gallery waves (WGWs) in optical fibres (microcavities) with the help of a bitapered fibre is analysed. It is shown that useful information on the WGW modes can be obtained from the spectrograms recorded by scanning the exciting-radiation frequency. Based on the geometrical-optic approximation, the longitudinal sizes of the WGW modes are estimated and it is shown that the ultimate diameter of the fibre exists for optical fibres (microcavities) where a mode can be still excited with the help of a bitapered fibre. (fibre optics. optical fibres)

  10. Science Outreach through Art: A Journal Article Cover Gallery

    ERIC Educational Resources Information Center

    McCullough, Ian

    2015-01-01

    Research faculty journal covers were used to create a gallery in the Science & Technology branch library at the University of Akron. The selection, presentation, and promotion process is shared along with copyright considerations and a review of galleries used for library outreach. The event and display was a great success attracting faculty…

  11. At 750 Gallery, (sump level) view of drain to sump ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 750 Gallery, (sump level) view of drain to sump pumps, looking north. This level contains the "art gallery" which features graffiti from the 1940s-1990s. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  12. 20. Historic American Building Survey Crocker Art Gallery Collection Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Historic American Building Survey Crocker Art Gallery Collection Drawing by N.D. Goodell, Architect C 1879 NORTH ELEVATION, SOUTH HOUSE (Property of Mrs. E. B. Crocker, 3rd & P Sts.) - Crocker Art Gallery, 216 O Street, Sacramento, Sacramento County, CA

  13. 19. Historic American Building Survey Crocker Art Gallery Collection Copy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Historic American Building Survey Crocker Art Gallery Collection Copy from N. P. Goodell, Architect C1879 NORTHWEST CORNER (EAST ELEVATION?) OF 3RD & P ST. (property of Mrs. E. B. Crocker) - Crocker Art Gallery, 216 O Street, Sacramento, Sacramento County, CA

  14. View just east of Block 31, 1150 Gallery, looking west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View just east of Block 31, 1150 Gallery, looking west showing change in ceiling height; in foreground is transverse gallery used for drum gate cord storage. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  15. From Analog Prototypes to Digital Drawing in the Gallery

    ERIC Educational Resources Information Center

    Nelson, Karen G.

    2011-01-01

    The "You Are Here" digital drawing interactive is one of the most successful interpretive elements in the renovated Oakland Museum of California Gallery of California Art. This interactive grew from considering how visitors could see themselves in the gallery and how visitor awareness of the creative process could be increased. The…

  16. Places to Go: New York Public Library Digital Gallery

    ERIC Educational Resources Information Center

    Downes, Stephen

    2005-01-01

    This article features the New York Public Library's (NYPL) recently opened Digital Gallery. Containing more than 275,000 images digitized from primary sources and printed rarities, the Digital Gallery offers unparalleled access to the past for educators and interested visitors alike. Organization and navigation present a challenge with any…

  17. Science Outreach through Art: A Journal Article Cover Gallery

    ERIC Educational Resources Information Center

    McCullough, Ian

    2015-01-01

    Research faculty journal covers were used to create a gallery in the Science & Technology branch library at the University of Akron. The selection, presentation, and promotion process is shared along with copyright considerations and a review of galleries used for library outreach. The event and display was a great success attracting faculty…

  18. The Authors Gallery: A Meaningful Integration of Technology and Writing

    ERIC Educational Resources Information Center

    Martin, Deb

    2008-01-01

    In this article, the author first explains what an authors gallery is and suggests additional uses and modifications. Next, readers are taken through a day-by-day description of creating the gallery while having the theory behind this pedagogical choice explained. The step-by-step discussion is supported with student examples and concepts drawn…

  19. Coral Reefs: A Gallery Program, Grades 7-12.

    ERIC Educational Resources Information Center

    National Aquarium in Baltimore, MD. Dept. of Education.

    Gallery classes at the National Aquarium in Baltimore give the opportunity to study specific aquarium exhibits which demonstrate entire natural habitats. The coral reef gallery class features the gigantic western Atlantic coral reef (325,000 gallons) with over 1,000 fish. The exhibit simulates a typical Caribbean coral reef and nearby sandy…

  20. Coral Reefs: A Gallery Program, Grades 7-12.

    ERIC Educational Resources Information Center

    National Aquarium in Baltimore, MD. Dept. of Education.

    Gallery classes at the National Aquarium in Baltimore give the opportunity to study specific aquarium exhibits which demonstrate entire natural habitats. The coral reef gallery class features the gigantic western Atlantic coral reef (325,000 gallons) with over 1,000 fish. The exhibit simulates a typical Caribbean coral reef and nearby sandy…

  1. Promoting Discussion in the Science Classroom Using Gallery Walks

    ERIC Educational Resources Information Center

    Francek, Mark

    2006-01-01

    A gallery walk is a discussion technique that gets students out of their chairs and actively involved in synthesizing important science concepts, writing, and public speaking. The technique also cultivates listening and team-building skills. This paper provides guidance for conducting, managing, and assessing gallery walks. (Contains 4 tables and…

  2. On the stress monitoring problem for parallel gallery regions

    NASA Astrophysics Data System (ADS)

    Babeshko, V. A.; Babeshko, O. M.; Evdokimova, O. V.

    2016-09-01

    We consider the problem of estimating the stress-strain state in underground hard mineral mines where long parallel underground galleries are formed. There are a number of papers dealing with local causes of gallery accidents due to variations in the medium stress-strain state occurring as the minerals are withdrawn. At the same time, the authors' theory of hidden effects shows that gallery fracture can be caused both by local actions on the defect region and by some long-range factors that can affect these defects remotely by localizing the stress-strain state in the defect region. It should be noted that the stress in the gallery region is redistributed each time a new gallery is formed or the dimensions of the existing galleries are changed. In this paper, a theory for estimating the stress-strain state in underground mines with arbitrarily many parallel galleries of various dimensions is developed. It is shown that the stresses due to remote factors can be monitored in all gallery regions. The study is based on factorization methods, the block element method, and the topological approach.

  3. 44. MAIN MEETING ROOM, SOUTH SIDE GALLERY. Under the flooring ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. MAIN MEETING ROOM, SOUTH SIDE GALLERY. Under the flooring were sleepers used to elevate the 1812 raised floor sections. These sleepers were fashioned from the 1755 Greater Meeting House salvaged gallery railing. Note the initials and date: 'EB 1788'. Other graffiti has dates as early as the 1760s. - Twelfth Street Meeting House, 20 South Twelfth Street, Philadelphia, Philadelphia County, PA

  4. Detecting light in whispering-gallery-mode resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor); Mohageg, Makan (Inventor); Le, Thanh M. (Inventor)

    2012-01-01

    An optical device including a whispering gallery mode (WGM) optical resonator configured to support one or more whispering gallery modes; and a photodetector optically coupled to an exterior surface of the optical resonator to receive evanescent light from the optical resonator to detect light inside the optical resonator.

  5. 36. MACHINERY CHAMBER FOR SLUICE GATE OUTLET WORKS ON GALLERY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. MACHINERY CHAMBER FOR SLUICE GATE OUTLET WORKS ON GALLERY 1 (LOCATED AT A ON SITE PLAN), SHOWING HYDRAULIC GATE HOIST (SIX, TOTAL, MANUFACTURED BY JOSHUA HENDRY IRON WORKS, SAN FRANCISCO) ON LEFT AND INSPECTION GALLERY ON RIGHT. VIEW TO NORTHEAST. - Owyhee Dam, Across Owyhee River, Nyssa, Malheur County, OR

  6. View north of west gallery of inside machine shop 36; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View north of west gallery of inside machine shop 36; the gallery housed turret, engine and toolroom lathes, small milling machines and drill presses used for machining small parts. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  7. Designing whispering gallery modes via transformation optics

    NASA Astrophysics Data System (ADS)

    Kim, Yushin; Lee, Soo-Young; Ryu, Jung-Wan; Kim, Inbo; Han, Jae-Hyung; Tae, Heung-Sik; Choi, Muhan; Min, Bumki

    2016-10-01

    In dielectric cavities with a rotational symmetry, whispering gallery modes (WGMs) with an extremely long lifetime (that is, a very high Q factor) can be formed by total internal reflection of light around the rim of the cavities. The ultrahigh Q factor of WGMs has enabled a variety of impressive photonic systems, such as ultralow threshold microlasers, bio-sensors with unprecedented sensitivity and cavity optomechanical devices. However, the isotropic emission of WGMs, which is due to the rotational symmetry, is a serious drawback in applications that require directional light sources. Considerable efforts have thus been devoted to achieving directional emission by intentionally breaking the rotational symmetry. However, all of the methods proposed so far have suffered from substantial Q-spoiling. Here, we show how the mode properties of dielectric whispering gallery cavities, such as the Q factor and emission directionality, can be tailored at will using transformation optics. The proposed scheme will open a new horizon of applications beyond the conventional WGMs.

  8. Whispering-Gallery Mode-Locked Lasers

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey; Iltchenko, Vladimir; Savchenkov, Anatoly; Maleki, Lute

    2003-01-01

    Mode-locked lasers of a proposed type would incorporate features of the design and operation of previously demonstrated miniature electro-optical modulators and erbium-doped glass lasers that contain whispering-gallery-mode (WGM) resonators. That is to say, WGM lasers and WGM electro-optical modulators would be integrated into monolithic units that, when suitably excited with pump light and microwaves, would function as mode-locked lasers. The proposed devices are intended to satisfy an anticipated demand for compact, low-power devices that could operate in the optical-communication wavelength band centered at a wavelength of 1.55 m and could generate pulses as short as picoseconds at repetition rates of multiple gigahertz.

  9. Aptasensors Based on Whispering Gallery Mode Resonators.

    PubMed

    Nunzi Conti, Gualtiero; Berneschi, Simome; Soria, Silvia

    2016-07-16

    In this paper, we review the literature on optical evanescent field sensing in resonant cavities where aptamers are used as biochemical receptors. The combined advantages of highly sensitive whispering gallery mode resonator (WGMR)-based transducers, and of the unique properties of aptamers make this approach extremely interesting in the medical field, where there is a particularly high need for devices able to provide real time diagnosis for cancer, infectious diseases, or strokes. However, despite the superior performances of aptamers compared to antibodies and WGMR to other evanescent sensors, there is not much literature combining both types of receptors and transducers. Up to now, the WGMR that have been used are silica microspheres and silicon oxynitride (SiON) ring resonators.

  10. Aptasensors Based on Whispering Gallery Mode Resonators

    PubMed Central

    Nunzi Conti, Gualtiero; Berneschi, Simome; Soria, Silvia

    2016-01-01

    In this paper, we review the literature on optical evanescent field sensing in resonant cavities where aptamers are used as biochemical receptors. The combined advantages of highly sensitive whispering gallery mode resonator (WGMR)-based transducers, and of the unique properties of aptamers make this approach extremely interesting in the medical field, where there is a particularly high need for devices able to provide real time diagnosis for cancer, infectious diseases, or strokes. However, despite the superior performances of aptamers compared to antibodies and WGMR to other evanescent sensors, there is not much literature combining both types of receptors and transducers. Up to now, the WGMR that have been used are silica microspheres and silicon oxynitride (SiON) ring resonators. PMID:27438861

  11. Interior hallway at 1250 Gallery, Block 11, which leads from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior hallway at 1250 Gallery, Block 11, which leads from Left Powerhouse to Pump-Generating Plant, looking southwest. - Columbia Basin Project, Grand Coulee Dam Powerplant Complex, Grand Coulee, Grant County, WA

  12. At 1150 Gallery, Block 5, view of top of spiral ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1150 Gallery, Block 5, view of top of spiral stairway, looking west. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  13. At 1150 Gallery, Block 5, between spiral stairways, looking southwest. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1150 Gallery, Block 5, between spiral stairways, looking southwest. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  14. At 1150 Gallery, Block 7, looking east, the length of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1150 Gallery, Block 7, looking east, the length of the dam. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  15. 15. GENERAL INTERIOR VIEW LOOKING EAST TOWARDS GALLERY AND FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. GENERAL INTERIOR VIEW LOOKING EAST TOWARDS GALLERY AND FRONT ENTRY (NOTE DOORWAY TO BELL TOWER AT TOP AND CONFESSIONAL BOOTHS TO LEFT REAR) - Sacred Heart Church at Whitemarsh, 16101 Annapolis Road, Bowie, Prince George's County, MD

  16. 10. VIEW WITHIN THE EAST OPERATING GALLERY OF WORK STATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW WITHIN THE EAST OPERATING GALLERY OF WORK STATION WITH MANIPULATOR ARMS. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV

  17. 14. VIEW IN THE WEST OPERATING GALLERY OF POSTMORTEM CELL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW IN THE WEST OPERATING GALLERY OF POST-MORTEM CELL WORK STATION AND MANIPULATOR ARMS. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV

  18. 16. VIEW OF FIRST FLOOR EAST OPERATING GALLERY. NOTE THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VIEW OF FIRST FLOOR EAST OPERATING GALLERY. NOTE THE SERIES OF MANIPULATOR ARMS ALONG THE LEFT WALL. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV

  19. 8. INTERIOR VIEW, LOOKING SOUTH, OF MUSEUM GALLERY WITH EUGENE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. INTERIOR VIEW, LOOKING SOUTH, OF MUSEUM GALLERY WITH EUGENE ALLEN SMITH'S VEHICLE WITH WHICH HE AS STATE GEOLOGIST (FROM 1873 TO 1927) CONDUCTED SURVEYS OF DISTRICT MINERAL RESOURCES - Smith Hall, Capstone Drive at Sixth Avenue, Tuscaloosa, Tuscaloosa County, AL

  20. Photo Gallery from the Los Angeles River Watershed (California)

    EPA Pesticide Factsheets

    Photo gallery of the Los Angeles River Watershed area of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

  1. 72. Credit FM. Overview of powerhouse from gallery. Notice cooling ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. Credit FM. Overview of powerhouse from gallery. Notice cooling duct on generator (now removed) and spare gate valve in far corner. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  2. 74. Credit TCL. General overview of interior from gallery looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    74. Credit TCL. General overview of interior from gallery looking east. Note air duct on generator (now removed). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  3. Nonlinear optics and crystalline whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey; Savchenkov, Anatoliy; Ilchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We report on our recent results concerning fabrication of high-Q whispering gallery mode crystalline resonaors, and discuss some possible applications of lithium niobate WGM resonators in nonlinear optics and photonics.

  4. 28. Conveyor gallery between elevators no. 2 and 3: conveyor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. Conveyor gallery between elevators no. 2 and 3: conveyor belt rollers and sampling apparatus, facing southeast - Washburn Crosby Company Elevators No. 2 & 3, 900 & 1000 Second Avenue, South, Minneapolis, Hennepin County, MN

  5. Optical rogue waves in whispering-gallery-mode resonators

    NASA Astrophysics Data System (ADS)

    Coillet, Aurélien; Dudley, John; Genty, Goëry; Larger, Laurent; Chembo, Yanne K.

    2014-01-01

    We report a theoretical study showing that rogue waves can emerge in whispering-gallery-mode resonators as the result of the chaotic interplay between Kerr nonlinearity and anomalous group-velocity dispersion. The nonlinear dynamics of the propagation of light in a whispering-gallery-mode resonator is investigated using the Lugiato-Lefever equation, and we give evidence of a range of parameters where rare and extreme events associated with non-Gaussian statistics of the field maxima are observed.

  6. Whispering Gallery Optical Resonator Spectroscopic Probe and Method

    NASA Technical Reports Server (NTRS)

    Anderson, Mark S. (Inventor)

    2014-01-01

    Disclosed herein is a spectroscopic probe comprising at least one whispering gallery mode optical resonator disposed on a support, the whispering gallery mode optical resonator comprising a continuous outer surface having a cross section comprising a first diameter and a second diameter, wherein the first diameter is greater than the second diameter. A method of measuring a Raman spectrum and an Infra-red spectrum of an analyte using the spectroscopic probe is also disclosed.

  7. Reconfigurable Liquid Whispering Gallery Mode Microlasers

    NASA Astrophysics Data System (ADS)

    Yang, Shancheng; Ta, Van Duong; Wang, Yue; Chen, Rui; He, Tingchao; Demir, Hilmi Volkan; Sun, Handong

    2016-06-01

    Engineering photonic devices from liquid has been emerging as a fascinating research avenue. Reconfigurably tuning liquid optical micro-devices are highly desirable but remain extremely challenging because of the fluidic nature. In this article we demonstrate an all-liquid tunable whispering gallery mode microlaser floating on a liquid surface fabricated by using inkjet print technique. We show that the cavity resonance of such liquid lasers could be reconfigurably manipulated by surface tension alteration originated from the tiny concentration change of the surfactant in the supporting liquid. As such, remarkable sensing of water-soluble organic compounds with a sensitivity of free spectral range as high as 19.85 THz / (mol · mL‑1) and the detectivity limit around 5.56 × 10‑3 mol · mL‑1 is achieved. Our work provides not only a novel approach to effectively tuning a laser resonator but also new insight into potential applications in biological, chemical and environmental sensing.

  8. Reconfigurable Liquid Whispering Gallery Mode Microlasers

    PubMed Central

    Yang, Shancheng; Ta, Van Duong; Wang, Yue; Chen, Rui; He, Tingchao; Demir, Hilmi Volkan; Sun, Handong

    2016-01-01

    Engineering photonic devices from liquid has been emerging as a fascinating research avenue. Reconfigurably tuning liquid optical micro-devices are highly desirable but remain extremely challenging because of the fluidic nature. In this article we demonstrate an all-liquid tunable whispering gallery mode microlaser floating on a liquid surface fabricated by using inkjet print technique. We show that the cavity resonance of such liquid lasers could be reconfigurably manipulated by surface tension alteration originated from the tiny concentration change of the surfactant in the supporting liquid. As such, remarkable sensing of water-soluble organic compounds with a sensitivity of free spectral range as high as 19.85 THz / (mol · mL−1) and the detectivity limit around 5.56 × 10−3 mol · mL−1 is achieved. Our work provides not only a novel approach to effectively tuning a laser resonator but also new insight into potential applications in biological, chemical and environmental sensing. PMID:27256771

  9. Experiences from full-scale rockfall testing of protection gallery

    NASA Astrophysics Data System (ADS)

    Volkwein, Axel; Fergg, Daniel; Hess, Reto; Schellenberg, Kristian

    2017-04-01

    Vertical drop tests have been performed at the Swiss Oberalppass road. The planned deconstruction of two avalanche protection galleries enabled a precedent evaluation of one gallery (Parde 1} regarding its capacity against rockfall. The background for this evaluation was also to evaluate an existing model for predicting the protection capacity of a rockfall gallery. Based on this model existing galleries can be evaluated whether their residual capacity is sufficient or if it is necessary to strengthen the structureaccording to the current guidelines. This contribution focusses the conduction of the experiments and the experiences obtained from. The presentation gives details on experimental setup, impact characterization, gallery performance, weather implications, data retrieval and data analysis.According to the limited time span for testing and the resources available, a compact testing series has been setup. Three fields of the gallery were tested with drop weights of 800, 1600 and 3200 kg falling from up to 25 m height. The blocks were lifted by a mobil crane. The concrete roof is supported by columns on the valley side and on the mountainside simply supported on the retention wall. The roof slabspans approximately 6x5 m with a thickness of about 0.60 m and is covered by a soil cushion, which has been unified to 0.40 m thickness previous to the test. Additional wooden columns have been installed at the roof's valleyside to avoid a failure of the concrete columns and to favorize a failure of the roof itself due to bending or punching. The measurements performed consist of high speed video records, accelerations within the impactors and on the bottom surface of the gallery roof.

  10. Whispering-Gallery-Mode Tunable Narrow-Band-Pass Filter

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Iltchenko, Vladimir; Matsko, Andrey; Maleki, Lute

    2004-01-01

    An experimental tunable, narrow-band-pass electro-optical filter is based on a whispering-gallery resonator. This device is a prototype of tunable filters needed for the further development of reconfigurable networking wavelength-division multiplexers and communication systems that utilize radio-frequency (more specifically, microwave) subcarrier signals on optical carrier signals. The characteristics of whispering-gallery resonators that make them attractive for such applications include high tuning speed, compactness, wide tuning range, low power consumption, and compatibility with single-mode optical fibers. In addition, relative to Fabry-Perot resonators, these devices offer advantages of greater robustness and lower cost. As described in several prior NASA Tech Briefs articles, a whispering-gallery resonator is a spheroidal, disk-like, or toroidal body made of a highly transparent material. It is so named because it is designed to exploit whispering-gallery electromagnetic modes, which are waveguide modes that propagate circumferentially and are concentrated in a narrow toroidal region centered on the equatorial plane and located near the outermost edge. The experimental whispering-gallery tunable filter (see figure) is made from a disk of Z-cut LiNbO3 of 4.8-mm diameter and 0.17-mm thickness. The perimeter of the disk is rounded to a radius of curvature of 100 m. Metal coats on the flat faces of the disk serve as electrodes for exploiting the electro-optical effect in LiNbO3 for tuning. There is no metal coat on the rounded perimeter region, where the whispering-gallery modes propagate. Light is coupled from an input optical fiber into the whispering-gallery modes by means of a diamond prism. Another diamond prism is used to couple light from the whispering-gallery modes to an output optical fiber. This device is designed and operated to exploit transverse magnetic (TM) whispering- gallery modes, rather than transverse electric (TE) modes because the

  11. Ringing phenomenon based whispering-gallery-mode sensing

    NASA Astrophysics Data System (ADS)

    Ye, Ming-Yong; Shen, Mei-Xia; Lin, Xiu-Min

    2016-01-01

    Highly sensitive sensing is one of the most important applications of whispering-gallery-mode (WGM) microresonators, which is usually accomplished through a tunable continuous-wave laser sweeping over a whispering-gallery mode with the help of a fiber taper in a relative slow speed. It is known that if a tunable continuous-wave laser sweeps over a high quality whispering-gallery mode in a fast speed, a ringing phenomenon will be observed. The ringing phenomenon in WGM microresonators is mainly used to measure the Q factors and mode-coupling strengths. Here we experimentally demonstrate that the WGM sensing can be achieved based on the ringing phenomenon. This kind of sensing is accomplished in a much shorter time and is immune to the noise caused by the laser wavelength drift.

  12. Ringing phenomenon based whispering-gallery-mode sensing

    PubMed Central

    Ye, Ming-Yong; Shen, Mei-Xia; Lin, Xiu-Min

    2016-01-01

    Highly sensitive sensing is one of the most important applications of whispering-gallery-mode (WGM) microresonators, which is usually accomplished through a tunable continuous-wave laser sweeping over a whispering-gallery mode with the help of a fiber taper in a relative slow speed. It is known that if a tunable continuous-wave laser sweeps over a high quality whispering-gallery mode in a fast speed, a ringing phenomenon will be observed. The ringing phenomenon in WGM microresonators is mainly used to measure the Q factors and mode-coupling strengths. Here we experimentally demonstrate that the WGM sensing can be achieved based on the ringing phenomenon. This kind of sensing is accomplished in a much shorter time and is immune to the noise caused by the laser wavelength drift. PMID:26796871

  13. Portion of Enhanced 360-degree Gallery Pan

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a sub-section of the 'geometrically improved, color enhanced' version of the 360-degree panorama heretofore known as the 'Gallery Pan', the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.

    The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. In this geometrically improved version of the panorama, distortion due to a 2.5 degree tilt in the IMP camera mast has been removed, effectively flattening the horizon.

    The IMP has color capability provided by 24 selectable filters -- twelve filters per 'eye'. Its red, green, and blue filters were used to take this image. The color was digitally balanced according to the color transmittance capability of a high-resolution TV at the Jet Propulsion Laboratory (JPL), and is dependent on that device. In this color enhanced version of the panorama, detail in surface features are brought out via changes to saturation and intensity, holding the original hue constant. A threshold was applied to avoid changes to the sky.

    At left is a Lander petal and a metallic mast which is a portion of the low-gain antenna. Misregistration in the antenna and other Lander features is due to parallax in the extreme foreground. Another Lander petal is at the right, showing the fully deployed forward ramp.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University

  14. Portion of Enhanced 360-degree Gallery Pan

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a sub-section of the 'geometrically improved, color enhanced' version of the 360-degree panorama heretofore known as the 'Gallery Pan', the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.

    The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. In this geometrically improved version of the panorama, distortion due to a 2.5 degree tilt in the IMP camera mast has been removed, effectively flattening the horizon.

    The IMP has color capability provided by 24 selectable filters -- twelve filters per 'eye'. Its red, green, and blue filters were used to take this image. The color was digitally balanced according to the color transmittance capability of a high-resolution TV at the Jet Propulsion Laboratory (JPL), and is dependent on that device. In this color enhanced version of the panorama, detail in surface features are brought out via changes to saturation and intensity, holding the original hue constant. A threshold was applied to avoid changes to the sky.

    At left is a Lander petal and a metallic mast which is a portion of the low-gain antenna. Misregistration in the antenna and other Lander features is due to parallax in the extreme foreground. Another Lander petal is at the right, showing the fully deployed forward ramp.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University

  15. Whispering Gallery Mode Spectroscopy as a Diagnostic for Dusty Plasmas

    SciTech Connect

    Thieme, G.; Basner, R.; Ehlbeck, J.; Roepcke, J.; Maurer, H.; Kersten, H.; Davies, P. B.

    2008-09-07

    Whispering-gallery-mode spectroscopy is being assessed as a diagnostic method for the characterisation of size and chemical composition of spherical particles levitated in a plasma. With a pulsed laser whispering gallery modes (cavity resonances) are excited in individual microspheres leading to enhanced Raman scattering or fluorescence at characteristic wavelengths. This method can be used to gain specific information from the particle surface and is thus of great interest for the characterisation of layers deposited on microparticles, e.g. in molecular plasmas. We present investigations of different microparticles in air and results from fluorescent particles levitated in an Argon rf plasma.

  16. Theory of anisotropic whispering-gallery-mode resonators

    SciTech Connect

    Ornigotti, Marco

    2011-07-15

    An analytic solution for a uniaxial spherical resonator is presented using the method of Debye potentials. This serves as a starting point for the calculation of whispering gallery modes (WGMs) in such a resonator. Suitable approximations for the radial functions are discussed in order to best characterize WGMs. The characteristic equation and its asymptotic expansion for the anisotropic case is also discussed, and an analytic formula with a precision of the order O[{nu}{sup -1}] is also given. Our careful treatment of both boundary conditions and asymptotic expansions makes the present work a particularly suitable platform for a quantum theory of whispering gallery resonators.

  17. 8. MAIN INLET FROM FILTER GALLERY AND CANAL INTO HINDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. MAIN INLET FROM FILTER GALLERY AND CANAL INTO HINDS PLANT. VIEW LOOKING DUE WEST OF HINDS COMPLEX IN BACKGROUND OF SAND FILTERS. - Hinds Pump Plant, East of Joshua Tree National Monument, 5 miles north of Route 10, Hayfield, Riverside County, CA

  18. 18. Photocopy of photo engraving (from August Spies' Spies' Gallery ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Photocopy of photo engraving (from August Spies' Spies' Gallery of Photo Engravings, Soldiers' and Sailors' Home, Sandusky, Ohio, (August Spies), 1902) FIRST FLOOR, READING ROOM, LOOKING WEST (INSET NORTHEAST FRONT) - Ohio Soldiers' & Sailors' Home, Library, U.S. Route 250 at DeWitt Avenue, Sandusky, Erie County, OH

  19. 20. Photocopy of photo engraving (from August Spies' Spies' Gallery ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Photocopy of photo engraving (from August Spies' Spies' Gallery of Photo Engravings, Soldiers' and Sailors' Home, Sandusky, Ohio, (August Spies), 1902) SECOND FLOOR, GRAND ARMY HALL, LOOKING SOUTH - Ohio Soldiers' & Sailors' Home, Library, U.S. Route 250 at DeWitt Avenue, Sandusky, Erie County, OH

  20. 13. Photocopy of photo engraving (from August Spies' Spies' Gallery ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Photocopy of photo engraving (from August Spies' Spies' Gallery of Photo Engravings, Soldiers' and Sailors' Home, Sandusky, Ohio, (August Spies), 1902) VIEW SOUTHEAST, NORTHWEST FRONT - Ohio Soldiers' & Sailors' Home, Cottage M, U.S. Route 250 at DeWitt Avenue, Sandusky, Erie County, OH

  1. 40. CONSTRUCTION OF GALLERY NO. 3, SHOWING INCLINED PLANE USED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. CONSTRUCTION OF GALLERY NO. 3, SHOWING INCLINED PLANE USED TO TRANSPORT MATERIALS, ALSO SPOIL FROM TUNNEL INTERIOR. POWDER HOUSE AND TOOL SHED VISIBLE TO RIGHT OF BASE INCLINE - Zion-Mount Carmel Highway, Tunnel, Two miles east of Zion Canyon Scenic Drive, Springdale, Washington County, UT

  2. 90. Photocopied August 1978. SWITCHBOARD AT CENTRAL GALLERY, SEPTEMBER 21, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    90. Photocopied August 1978. SWITCHBOARD AT CENTRAL GALLERY, SEPTEMBER 21, 1914. THE SLIM CONTROL PANELS (9 INCHES PER GENERATOR UNIT) BUILT BY WESTINGHOUSE FOR MICHIGAN NORTHERN TAKE CENTER STAGE. (912) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  3. 5. INTERIOR VIEW OF LAUNDRY ROOM ON GALLERY LEVEL, NEAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. INTERIOR VIEW OF LAUNDRY ROOM ON GALLERY LEVEL, NEAR SOUTHWEST CORNER OF BUILDING 149; WORKERS' UNIFORMS AND BEEF SHROUDS WERE LAUNDERED HERE; CLEAN BEEF SHROUDS WERE RETURNED TO DISASSEMBLY LINE ON LEVEL 4 THROUGH FUNNEL-SHAPED CHUTE AT LOWER LEFT - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  4. At 1050 Gallery, Block 16, view of access port down ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1050 Gallery, Block 16, view of access port down to top of penstock (this is a service hatch into penstock for turbine-generator unit No. 2), looking north. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  5. At 1200 Gallery, Block 63, looking west, showing 230 kv ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1200 Gallery, Block 63, looking west, showing 230 kv cables. These lines were installed in the 1960s and are no longer used. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  6. At 1200 Gallery, Block 63, looking down tunnel that extends ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1200 Gallery, Block 63, looking down tunnel that extends to the Right Powerhouse, showing 230 kva lines. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  7. At 1050 Gallery, Block 55, view of gate control and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1050 Gallery, Block 55, view of gate control and motor, looking west, (Westinghouse Gearmotor, ca. 1939, type CS induction motor, 440 volts, 43 rpm, 60 cycle). - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  8. From GUI to Gallery: A Study of Online Virtual Environments.

    ERIC Educational Resources Information Center

    Guynup, Stephen Lawrence

    This paper began as an attempt to clarify and classify the development of Web3D environments from 1995 to the present. In that process, important facts came to light. A large proportion of these sites were virtual galleries and museums. Second, these same environments covered a wide array of architectural interpretations and represented some of…

  9. Herbert Hoover Library & Museum: A Guide to the Exhibit Galleries.

    ERIC Educational Resources Information Center

    Smith, Richard Norton; And Others

    This guide book is used to accompany the exhibits at the Herbert Hoover Presidential Library and Museum. The guide provides a basic overview of the life and contributions of Herbert Hoover and can be read independent of a tour of the galleries. The book contains the following chapters: (1) "Years of Adventure"; (2) "The Great…

  10. 13. VIEW OF EAST OPERATING GALLERY ALONG THE POSTMORTEM CELLS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW OF EAST OPERATING GALLERY ALONG THE POST-MORTEM CELLS. A NUMBER OF MANIPULATOR ARMS COVERED WITH PLASTIC ARE ON THE LEFT WALL. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV

  11. 27. Emplacement no. 1, view to east from shot gallery. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Emplacement no. 1, view to east from shot gallery. At left is passage to entrance; at right is corridor to magazines and projectile hoist - Fort Wadsworth Battery Romeyn B. Ayers, South side of Ayers Road, Staten Island, Rosebank, Richmond County, NY

  12. At 1295 Gallery, Block 31, view of truck for hauling ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1295 Gallery, Block 31, view of truck for hauling coaster gates; note track at perpendicular; the elevator at Block 31 is to the left. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  13. At 1050 Gallery, Block 65, view of coaster gate bypass ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1050 Gallery, Block 65, view of coaster gate bypass valve (for turbine-generator unit G-10, this bypass-valve unit manufactured by Western Koppers Co., Fort Wayne, Ind., 1938), looking southeast. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  14. 45. MAIN MEETING ROOM COLUMNS. Ends of gallery columns identified ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. MAIN MEETING ROOM COLUMNS. Ends of gallery columns identified at the time of removal for transfer to the George School for re-erection. The stamp reads, 'REMOVED FROM 12th ST. MTG HSE PHILA 1972'. - Twelfth Street Meeting House, 20 South Twelfth Street, Philadelphia, Philadelphia County, PA

  15. Whisper gallery mirrors reflectivities from 100 [angstrom] to 500 [angstrom

    SciTech Connect

    Hung, Tsen-Yu; Hagelstein, P.L.

    1990-01-01

    We have examined optical constants and predicted reflectivities of candidate surface coatings for whisper gallery mirrors in the extreme ultraviolet (100 [Angstrom] to 500 [Angstrom]). Previous work of Vinogradov and coworkers have identified the spectral regime near 100-150 [Angstrom] as particularly promising due to the high whisper gallery mirror reflectivities of the noble metals in the vicinity of their Cooper minima in this regime. We confirm this basic result using newer optical data, and we have sought surface materials which would extend the range over which the whisper gallery mirrors may be used: between 100 to 500 [Angstrom]. We find that substantial whisper gallery mirror reflectivities (near or greater than 50%) are predicted for a variety of elements, and that the TE peak reflection is larger than TM peak reflection by on the order of 10%. However, most of the elements which do reflect well have surfaces that are vulnerable to oxygen contamination, which seriously degrades mirror performance. A cryogenic mirror design using a dynamic solid rare gas surface which has the potential to defeat such surface contaminations is described: it has peak reflectivity of more than 50% centered near 280 [Angstrom]. 8 figs, 18 refs.

  16. Whisper gallery mirrors reflectivities from 100 {angstrom} to 500 {angstrom}

    SciTech Connect

    Hung, Tsen-Yu; Hagelstein, P.L.

    1990-12-31

    We have examined optical constants and predicted reflectivities of candidate surface coatings for whisper gallery mirrors in the extreme ultraviolet (100 {Angstrom} to 500 {Angstrom}). Previous work of Vinogradov and coworkers have identified the spectral regime near 100-150 {Angstrom} as particularly promising due to the high whisper gallery mirror reflectivities of the noble metals in the vicinity of their Cooper minima in this regime. We confirm this basic result using newer optical data, and we have sought surface materials which would extend the range over which the whisper gallery mirrors may be used: between 100 to 500 {Angstrom}. We find that substantial whisper gallery mirror reflectivities (near or greater than 50%) are predicted for a variety of elements, and that the TE peak reflection is larger than TM peak reflection by on the order of 10%. However, most of the elements which do reflect well have surfaces that are vulnerable to oxygen contamination, which seriously degrades mirror performance. A cryogenic mirror design using a dynamic solid rare gas surface which has the potential to defeat such surface contaminations is described: it has peak reflectivity of more than 50% centered near 280 {Angstrom}. 8 figs, 18 refs.

  17. An Old-Growth Definition for Western Hardwood Gallery Forests

    Treesearch

    Kelly Kindscher; Jenny Holah

    1998-01-01

    Western hardwood gallery forests are found across an extremely large, diverse geographical area that encompasses the Great Plains in the United States and Canada. Remnant forests of this type still exist in the "Prairie Peninsula," which historically projected an eastern finger into Ohio. The forests are restricted to floodplains of major rivers and are in...

  18. 4. LOOKING WEST FROM THE VISITORS' GALLERY ABOVE THE SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. LOOKING WEST FROM THE VISITORS' GALLERY ABOVE THE SOUTH END OF LEVEL 4; SAWTOOTH MONITORS PROVIDED AMPLE NATURAL LIGHT FOR KILLING OPERATIONS; STEEL SUBSTRUCTURE NEAR BOTTOM OF PHOTO SUPPORTED CHAIN CONVEYOR SYSTEM - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  19. VLF/LF/MF Whispering Gallery Propagation Studies.

    DTIC Science & Technology

    1981-09-09

    October 10, 1980, pp. 5416-5422. S. K. G. Budden and H. G. Martin, "The Ionosphere as a Whispering Gallery," Proceedings Royal Society, vol. A265...Los Angeles, CA 90009 1 Dr. Albert Essmann, Hoogewinkel 46, 23 Kiel 1, West Germany I Glenn S. Smith, School of Elec. Eng. Georgia Tech. Atlanta, GA 1

  20. Beyond Art Waitressing: Meaningful Engagement in Interactive Art Galleries

    ERIC Educational Resources Information Center

    Kothe, Elsa Lenz

    2012-01-01

    The metaphor of "art waitressing" is a valuable tool for educators who seek guidance in enacting many of the new roles in museums, particularly the role of facilitator in an open-ended interactive gallery. Though this metaphor provides a valuable model for engaging visitors, the question quickly arises of how educators can go beyond "serving" an…

  1. Optical filter having coupled whispering-gallery-mode resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy (Inventor); Ilchenko, Vladimir (Inventor); Maleki, Lutfollah (Inventor); Handley, Timothy A. (Inventor)

    2006-01-01

    Optical filters having at least two coupled whispering-gallery-mode (WGM) optical resonators to produce a second order or higher order filter function with a desired spectral profile. At least one of the coupled WGM optical resonators may be tunable by a control signal to adjust the filtering function.

  2. 56. Photographic copy of historic photograph, interior gallery on southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. Photographic copy of historic photograph, interior gallery on southwest ward wing, ca. 1914. (Department of the Navy, Officer-in-Charge of Construction, Naval Facilities Engineering Command Contracts, Portsmouth Naval Hospital, Portsmouth, VA) - Portsmouth Naval Hospital, Hospital Building, Rixey Place, bounded by Williamson Drive, Holcomb Road, & The Circle, Portsmouth, Portsmouth, VA

  3. Whispering gallery resonator from lithium tetraborate for nonlinear optics

    NASA Astrophysics Data System (ADS)

    Fürst, Josef Urban; Buse, Karsten; Breunig, Ingo; Becker, Petra; Liebertz, Josef; Bohaty, Ladislav

    2015-02-01

    For second-order nonlinear-optical processes in the ultraviolet, appropriate materials with a sufficiently large band-gap typically exhibit smaller nonlinear coefficients than materials with comparably smaller band-gap. Whispering gallery resonators, with their outstanding quality factors, provide field enhancement and can compensate for these small coefficients. We report on the successful fabrication of a whispering gallery resonator made of lithium tetraborate, a suitable material for ultraviolet applications with a small nonlinear coefficient of d31 = 0:073 pm/V. Quality factors of the order of 108 are observed from the ultraviolet to the near-infrared spectrum. The inferred absorption coefficients of lithium tetraborate are below 0.2 m-1 in the visible and near-infrared. Continuous-wave second harmonic generation from 490 nm light to 245 nm is observed with conversion efficiencies up to 2.2 %.

  4. Phased-array optical whispering gallery mode modulation and method

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry V. (Inventor)

    2009-01-01

    A whispering gallery mode (WGM) resonator device and method capable of filtering sidebands of optical modulators are provided. The method includes providing an optical resonator adapted to support whispering gallery modes and forming a first field and a second field from a first location and a second location, respectively, at the circumference of the optical resonator and being separated by an arc angle, .alpha.. The method includes adjusting relative phase between the first field and the second field in accordance to a differential phase, .beta., and combining the first and the second fields into an output. Particular selection of the arc angle, .alpha., and the differential phase, .beta., can determine the function of the output.

  5. Museums and art galleries as partners for public health interventions.

    PubMed

    Camic, Paul M; Chatterjee, Helen J

    2013-01-01

    The majority of public health programmes are based in schools, places of employment and in community settings. Likewise, nearly all health-care interventions occur in clinics and hospitals. An underdeveloped area for public health-related planning that carries international implications is the cultural heritage sector, and specifically museums and art galleries. This paper presents a rationale for the use of museums and art galleries as sites for public health interventions and health promotion programmes through discussing the social role of these organisations in the health and well-being of the communities they serve. Recent research from several countries is reviewed and integrated into a proposed framework for future collaboration between cultural heritage, health-care and university sectors to further advance research, policy development and evidence-based practice.

  6. Phone-sized whispering-gallery microresonator sensing system

    NASA Astrophysics Data System (ADS)

    Xu, Xiangyi; Jiang, Xuefeng; Zhao, Guangming; Yang, Lan

    2016-11-01

    We develop a compact whispering-gallery-mode (WGM) sensing system by integrating multiple components, including a tunable laser, a temperature controller, a function generator, an oscilloscope, a photodiode detector, and a testing computer, into a phone-sized embedded system. We demonstrate a thermal sensing experiment by using this portable system. Such a system successfully eliminates bulky measurement equipment required for characterizing optical resonators and will open up new avenues for practical sensing applications by using ultra-high Q WGM resonators.

  7. 29. At 1050 Gallery, Block 12, two centrifugal pumps, Buffalo ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. At 1050 Gallery, Block 12, two centrifugal pumps, Buffalo Pumps, Buffalo, NY, driven by Allis Chalmers motors (size 3 HSO, head 230, 120 cpm, 1750, rpm, Impulse dia. 15) installed in the 1960s and used for water-cooling system for 230-kv cable; the cables have been removed and the pumps are not currently used. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  8. Whispering gallery mode resonators based on radiation-sensitive materials

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor); Ilchenko, Vladimir (Inventor); Handley, Timothy A. (Inventor)

    2005-01-01

    Whispering gallery mode (WGM) optical resonators formed of radiation-sensitive materials to allow for permanent tuning of their resonance frequencies in a controlled manner. Two WGM resonators may be cascaded to form a composite filter to produce a second order filter function where at least one WGM resonator is formed a radiation-sensitive material to allow for proper control in the overlap of the two filter functions.

  9. Graded-Index "Whispering-Gallery" Optical Microresonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Maleki, Lute; Iltchenko, Vladimir; Matsko, Andrey

    2006-01-01

    Graded-index-of-refraction dielectric optical microresonators have been proposed as a superior alternative to prior dielectric optical microresonators, which include microspheres and microtori wherein electromagnetic waves propagate along circumferential paths in "whispering-gallery" modes. The design and method of fabrication of the proposed microresonators would afford improved performance by exploiting a combination of the propagation characteristics of the whisperinggallery modes and the effect of a graded index of refraction on the modes.

  10. At 1050 Gallery, Block 55, view of motors for operating ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1050 Gallery, Block 55, view of motors for operating gates of diversion tubes, looking west (Note: the gate control unit to the far right is the one mistakenly left open in 1952 and this led to the flood inside the dam) - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  11. Nonlinear optics and crystalline whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey B.; Savchenkov, Anatoliy A.; Ilchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We report on our recent results concerning fabrication of high-Q whispering gallery mode (WGM) crystalline resonators, and discuss some possible applications of lithium niobate WGM resonators in nonlinear optics and photonics. In particular, we demonstrate experimentally a tunable third-order optical filter fabricated from the three metalized resonators; and report observation of parametric frequency dobuling in a WGM resonator made of periodically poled lithium niobate (PPLN).

  12. Enhancement of Optical Nonlinearities Via Whispering Gallery Mode Splitting

    NASA Technical Reports Server (NTRS)

    Chang, Hongrok; Smith, David D.; Fuller, Kirk A.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    An iterative method is applied to the analysis of N coupled ring-resonators, and the results are compared with multilayered spheres. Splitting of the whispering gallery modes into N higher-Q modes occurs when the round-trip phase shifts in each ring (or layer) are equal, in agreement with results for planar resonators. This mode-splitting is, therefore, a universal phenomenon for resonant structures, and can lead to reduced thresholds for nonlinear optical effects.

  13. Beyond the Gallery: Integrating Outreach into an Exhibition

    NASA Astrophysics Data System (ADS)

    Stephenson, C.; DeVorkin, D.

    2002-12-01

    This poster will display the types of outreach mechanisms we are using to engage the public in the process of discovery within Explore the Universe, a new astronomy and cosmology exhibition at the Smithsonian National Air and Space Museum. In keeping with the Smithsonian Institution's educational mission, the gallery was designed to attract and inform, but the high level of complexity of the subject matter has proven intimidating for many visitors. The Museum's Space History and Education divisions have collaborated to develop a number of initiatives to help a diverse, multigenerational audience explore and understand the gallery's message that as humanity has invented new tools with which to study the cosmos, we have revealed new Universes. Outreach initiatives underway and planned in Explore the Universe include mobile "Discovery Stations," updatable electronic kiosks, a lecture series, a college-level internship in the public interpretation of research, and an online astrophotography contest. These activities have helped a wide range of visitors make a memorable connection with a sophisticated subject area, while also eliciting a positive response from funders. The presentation will discuss program objectives, outline steps in developing each project, and review feedback received during the exhibition's first year. Principal funding for the Explore the Universe gallery is from TRW and NSF. NSF as well as Jaylee and Gilbert Mead are supporting the outreach programs described here.

  14. Whispering gallery resonators with broken axial symmetry: Theory and experiment.

    PubMed

    Fürst, J; Sturman, B; Buse, K; Breunig, I

    2016-09-05

    Axial symmetry is the cornerstone for theory and applications of high-Q optical whispering gallery resonators (WGRs). Nevertheless, research on birefringent crystalline material persistently pushes towards breaking this symmetry. We show theoretically and experimentally that the effect of broken axial symmetry, caused by optical anisotropy, is modest for the resonant frequencies and Q-factors of the WGR modes. Thus, the most important equatorial whispering gallery modes can be quantitatively described and experimentally identified. At the same time, the effect of broken axial symmetry on the light field distribution of the whispering gallery modes is typically very strong. This qualitatively modifies the phase-matching for the χ(2) nonlinear processes and enables broad-band second harmonic generation and optical parametric oscillation. The effect of weak geometric ellipticity in nominally symmetric WGRs is also considered. Altogether our findings pave the way for an extensive use of numerous birefringent (uniaxial and biaxial) crystals with broad transparency window and large χ(2) coefficients in nonlinear optics with WGRs.

  15. A gallery approach for off-angle iris recognition

    NASA Astrophysics Data System (ADS)

    Karakaya, Mahmut; Yoldash, Rashiduddin; Boehnen, Christopher

    2015-05-01

    It has been proven that hamming distance score between frontal and off-angle iris images of same eye differs in iris recognition system. The distinction of hamming distance score is caused by many factors such as image acquisition angle, occlusion, pupil dilation, and limbus effect. In this paper, we first study the effect of the angle variations between iris plane and the image acquisition systems. We present how hamming distance changes for different off-angle iris images even if they are coming from the same iris. We observe that increment in acquisition angle of compared iris images causes the increment in hamming distance. Second, we propose a new technique in off-angle iris recognition system that includes creating a gallery of different off-angle iris images (such as, 0, 10, 20, 30, 40, and 50 degrees) and comparing each probe image with these gallery images. We will show the accuracy of the gallery approach for off-angle iris recognition.

  16. A contribution to film coefficient estimation in piston cooling galleries

    SciTech Connect

    Torregrosa, A.J.; Broatch, A.; Olmeda, P.; Martin, J.

    2010-02-15

    The need to reduce fuel consumption and exhaust emissions in internal combustion engines has been drastically increased during last years. One of the most important processes affecting these parameters is heat transfer from the in-cylinder gas to the surrounding walls, as this mechanism has a direct influence on the combustion process. Regarding the different walls (liner, cylinder head and piston surfaces), heat flow to the piston is especially important, as it is essential to avoid excessively high temperatures that could result in material damage and/or oil cracking. With this purpose different cooling strategies are used, among which the improvement of the piston cooling system by using oil galleries is preferred. In this work, the heat flow through the oil gallery in a Diesel piston was investigated on a dedicated test bench. This bench consists of a controlled heat source and a piston oil cooling system in which different test conditions were evaluated in order to obtain a correlation for the film coefficient associated with piston oil cooling. These experimental results were then incorporated into a lumped model for engine heat transfer. Finally, in order to evaluate the accuracy of this model and the effects of the correlation for oil gallery coefficient on engine heat flows, results obtained on a conventional engine test bench equipped with a Diesel engine, in which two piston temperatures had been measured, were used. The results show an improvement in piston temperature predictions when compared with those obtained using a previously reported expression for the calculation of the oil film coefficient. (author)

  17. Hollow Cylinder Simulation Experiments of Galleries in Boom Clay Formation

    NASA Astrophysics Data System (ADS)

    Labiouse, Vincent; Sauthier, Claire; You, Shuang

    2014-01-01

    In the context of nuclear waste disposal in clay formations, laboratory experiments were performed to study at reduced scale the excavation damaged zone (EDZ) induced by the construction of galleries in the Boom clay formation. For this purpose, thick-walled hollow cylindrical samples were subjected (after recovery of in situ stress conditions) to a decrease in the inner confining pressure aiming at mimicking a gallery excavation. X-ray computed tomography (XRCT) scans of the specimens were carried out through the testing cell before and after the mechanical unloading and allowed to quantify the displacements undergone by the clay as a result of the mechanical unloading. The deformation of the hollow cylinders and the inferred extent of the damaged zone around the central hole are found to depend on the orientation of the specimen with respect to the bedding planes and show a great similarity with in situ observations around galleries and boreholes at Mol URL in the Boom clay formation. In the experiments performed on samples cored parallel to the bedding, the damaged zone is not symmetrical with respect to the hole axis and extends more in the direction parallel to the bedding. It is the same for the radial convergence of the hole walls which is larger in the direction parallel to bedding than in the perpendicular one. In contrast, a test on a sample cored perpendicularly to the bedding did not show any ovalisation of the central hole after the mechanical unloading. These observations confirm the significance of the pre-existing planes of weakness (bedding planes) in Boom clay and the need for a correct consideration of the related mechanical anisotropy.

  18. Observation of whispering gallery modes in microtube-microspheres system

    NASA Astrophysics Data System (ADS)

    Li, Hanyang; Hao, Sue; Qiang, Liangsheng; Li, Jin; Zhang, Yundong

    2013-06-01

    We proposed that a fluorescent microsphere with diameter of 6 μm was manipulated into a microtube with inner diameter of 6.2 μm. The whispering gallery modes (WGMs) of fluorescence resonance were observed by 532 nm laser pumping the microspheres-mircotube system. Another microsphere with the same diameter was manipulated into the microtube and mode splitting in the system of two spheres in contact in the mircotube was demonstrated. We also discussed relationship between WGMs peak intensity and the excitation power. The scheme will bring more insight into the applications of WGMs for biomedical diagnostics and microfluidics.

  19. Whispering gallery mode aptasensors for detection of blood proteins

    NASA Astrophysics Data System (ADS)

    Pasquardini, L.; Berneschi, S.; Barucci, A.; Cosi, F.; Insinna, M.; Lunelli, L.; Nunzi Conti, G.; Pederzolli, C.; Salvadori, S.; Soria, S.

    2013-03-01

    Whispering gallery mode resonators (WGMR), as silica microspheres, have been recently proposed as an efficient tool for the realisation of optical biosensors. In this work we present a functionalization procedure based on the DNA-aptamer sequence immobilization on WGMR, able to recognize specifically thrombin or VEGF protein, preserving a high Q factor. The protein binding was numerically modelled and optically characterized in terms of specificity in buffer solution or in 10% diluted human serum. The aptasensor was also chemically regenerated and tested again, demonstrating the reusability of our system.

  20. Whispering Gallery Mode Resonators as Optical Reference Cavities

    NASA Technical Reports Server (NTRS)

    Baumgartel, Lukas; Thompson, Rob; Strekalov, Dmitry; Grudinin, Ivan; Yu, Nan

    2011-01-01

    Highly stabilized lasers are an increasingly valuable tool for metrology. For many applications, however, existing Fabry Perot systems are too bulky and cumbersome. We are investigating the use of miniature monolithic whispering gallery mode resonators as reference cavities for laser stabilization. We seek to exploit the benefit of small size and vibration resistance by suppressing thermally induced frequency fluctuations. We have theoretically investigated the viability of using a thin-film coating to achieve temperature compensation. We have experimentally investigated an active temperature stabilization scheme based on birefringence in a crystalline resonator. We also report progress of laser locking to the resonators.

  1. STAR Images: Image gallery from the Solenoidal Tracker at RHIC

    DOE Data Explorer

    The primary physics task of STAR is to study the formation and characteristics of the quark-gluon plasma (QGP), a state of matter believed to exist at sufficiently high energy densities. STAR consists of several types of detectors, each specializing in detecting certain types of particles or characterizing their motion. These detectors allow final statements to be made about the collision. The gallery of STAR images makes available a small collection of event-generated images from Gold-Beam experiments, a simulation of TCP Drift, and a library of STAR instrument and construction photos.

  2. Method of fabricating a whispering gallery mode resonator

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy A. (Inventor); Matkso, Andrey B. (Inventor); Iltchenko, Vladimir S. (Inventor); Maleki, Lute (Inventor)

    2011-01-01

    A method of fabricating a whispering gallery mode resonator (WGMR) is provided. The WGMR can be fabricated from a particular material, annealed, and then polished. The WGMR can be repeatedly annealed and then polished. The repeated polishing of the WGMR can be carried out using an abrasive slurry. The abrasive slurry can have a predetermined, constant grain size. Each subsequent polishing of the WGMR can use an abrasive slurry having a grain size that is smaller than the grain size of the abrasive slurry of the previous polishing iteration.

  3. Using Sense to Make Sense of Art: Young Children in Art Galleries

    ERIC Educational Resources Information Center

    MacRae, Christina

    2007-01-01

    This paper reflects on a collaborative project between Manchester City Art Gallery and Manchester Metropolitan University (2003-2004). The project's aim was to attract very young children and their families to the gallery. This paper will not report directly on the research methods used or the outcomes of the project but, rather, will explore…

  4. Whispering gallery modes in a spherical microcavity with a photoluminescent shell

    SciTech Connect

    Grudinkin, S. A. Dontsov, A. A.; Feoktistov, N. A.; Baranov, M. A.; Bogdanov, K. V.; Averkiev, N. S.; Golubev, V. G.

    2015-10-15

    Whispering-gallery mode spectra in optical microcavities based on spherical silica particles coated with a thin photoluminescent shell of hydrogenated amorphous silicon carbide are studied. The spectral positions of the whispering-gallery modes for spherical microcavities with a shell are calculated. The dependence of the spectral distance between the TE and TM modes on the shell thickness is examined.

  5. Traveling in the Snite Museum: A Gallery Game for Families and Young Children.

    ERIC Educational Resources Information Center

    Matthias, Diana C. J.; Grey, Richard

    This game, designed for use in the Snite Museum of Art, Knott Beckman Gallery, Indiana, focuses on some of the different types of travel depicted in gallery paintings from 16th and 17th century Europe. The questions, with multiple choice answers, encourage viewers to find details of every day life, and to consider whether their meaning is…

  6. The Art Gallery/La Galeria de Arte: An Exhibition of Transformation.

    ERIC Educational Resources Information Center

    Biagi, Juliet

    2001-01-01

    Describes the development of an art gallery within an urban elementary school, examining its impact on diverse students and their social interactions at school and home. The gallery had a positive impact on students (improved self-esteem, motivation, and appreciation of others); the school (transformation of the physical space and appreciation of…

  7. Teaching Students to Teach: A Case Study from the Yale University Art Gallery

    ERIC Educational Resources Information Center

    Manekin, Elizabeth; Williams, Elizabeth

    2015-01-01

    The way the Yale University Art Gallery engages students and the adult public has shifted profoundly over time, a change reflected in the evolution of the museum's signature Gallery Guide program. Founded in 1998 as an organic, experimental way to better engage Yale students to give lecture-based tours, it is now a structured, well-articulated…

  8. The Portable Art Gallery: Fostering Student Ownership and Meaningful Artmaking through Exhibiting Student Artwork

    ERIC Educational Resources Information Center

    Gillespie, Jethro

    2014-01-01

    This article describes how High School Visual Arts Teacher Jethro Gillespie built a portable art gallery for his students--essentially an 8-foot cube made from plywood and lightweight boards that can be assembled with bolts and taken apart in sections. The ceiling pieces of the gallery have track lights, the interior walls have been painted gray,…

  9. The Art Gallery/La Galeria de Arte: An Exhibition of Transformation.

    ERIC Educational Resources Information Center

    Biagi, Juliet

    2001-01-01

    Describes the development of an art gallery within an urban elementary school, examining its impact on diverse students and their social interactions at school and home. The gallery had a positive impact on students (improved self-esteem, motivation, and appreciation of others); the school (transformation of the physical space and appreciation of…

  10. The Portable Art Gallery: Fostering Student Ownership and Meaningful Artmaking through Exhibiting Student Artwork

    ERIC Educational Resources Information Center

    Gillespie, Jethro

    2014-01-01

    This article describes how High School Visual Arts Teacher Jethro Gillespie built a portable art gallery for his students--essentially an 8-foot cube made from plywood and lightweight boards that can be assembled with bolts and taken apart in sections. The ceiling pieces of the gallery have track lights, the interior walls have been painted gray,…

  11. Using Sense to Make Sense of Art: Young Children in Art Galleries

    ERIC Educational Resources Information Center

    MacRae, Christina

    2007-01-01

    This paper reflects on a collaborative project between Manchester City Art Gallery and Manchester Metropolitan University (2003-2004). The project's aim was to attract very young children and their families to the gallery. This paper will not report directly on the research methods used or the outcomes of the project but, rather, will explore…

  12. Perceptions of Pre-Service Teachers Value of Art Museums and Galleries

    ERIC Educational Resources Information Center

    Lemon, Narelle; Garvis, Susanne

    2014-01-01

    Art museums and galleries provide many educational opportunities for generalist classroom teachers to engage in learning experiences with students. Beliefs about engagement with art museums and galleries can begin in teacher education programs. This paper explores the beliefs of pre-service teachers in a Bachelor of Education (primary) program in…

  13. Poetry in the Gallery: Introducing Poetry through the Visual Arts. A Handbook for Educators.

    ERIC Educational Resources Information Center

    Getzler, Anita, Ed.; Kanatani, Kim, Ed.

    A handbook designed to explain the educational approach and outcomes of a year-long arts program which integrated art gallery tours with poetry writing is divided into four sections. Section 1, "Abstracts of the Evaluation" presents an overview of the philosophy of the program, background and organization, the participatory gallery tour which…

  14. Gallery productivity, emergence, and flight activity of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)

    Treesearch

    M. Lake Maner; James Hanula; S. Kristine Braman

    2013-01-01

    Flight and emergence of the redbay ambrosia beetle, Xyleborus glabratus Eichhoff, were monitored from March 2011 through August 2012 using Lindgren funnel traps baited with manuka oil and emergence traps attached over individual beetle galleries on infested redbay (Persea borbonia (L.) Sprengel) trees. Of the 432 gallery entrances...

  15. Voice, Choice, Equity and Access: Young Children Capture Their Art Gallery Education Experiences

    ERIC Educational Resources Information Center

    Lemon, Narelle

    2013-01-01

    Introducing a digital camera in the art gallery space is somewhat confrontational. Most museums have strict protocols on what can and cannot be captured. From the educational perspective it does, however, offer a new and innovative way of working that supports young people's ability to record what they see and how they experience the gallery, the…

  16. Changes of shape of the whispering gallery modes resonators due to their movement in inertial space

    NASA Astrophysics Data System (ADS)

    Filatov, Yuri V.; Kukaev, Alexander S.; Shalymov, Egor V.; Venediktov, Vladimir Yu.

    2016-11-01

    Influence of the centrifugal forces on angular velocity sensors that measure a spectral shift of whispering gallery modes is investigated. Spherical whispering gallery mode resonators of different materials are considered as sensing elements. The study is based on the results of the simulation in OOFELIE::Multiphysics software.

  17. Inclusive Art Gallery Practices: Exploring Collaborative Processes and Pedagogy in Outreach Community Programming

    ERIC Educational Resources Information Center

    Reid, Natasha

    2011-01-01

    Currently, many museums and galleries are attempting to create more welcoming and meaningful experiences for individuals who tend to be reluctant to enter and participate in these institutions. Art galleries and museums are examining and experimenting with ways to connect diverse publics through socially inclusive community outreach programs. This…

  18. Flow sensor using a hollow whispering gallery mode microlaser

    NASA Astrophysics Data System (ADS)

    Ward, Jonathan M.; Yang, Yong; Chormaic, Síle N.

    2016-03-01

    Flow sensing using the concept of a hot whispering gallery microlaser is presented. Silica microcapillaries or microbubbles, coated with a layer of erbium:ytterbium (Er:Yb) doped phosphate laser glass, result in a hollow, microbottle-shaped laser geometry. The Er:Yb doped glass outer layer is pumped at 980 nm via a tapered optical fiber and whispering gallery mode (WGM) lasing is recorded at 1535 nm. When gas passes through the capillary, the WGMs shift toward shorter wavelengths due to the cooling effect of the fluid flow. In this way, thermal tuning of the lasing modes over 70 GHz can be achieved. The output end of the capillary is connected to a mass flow sensor and the WGM shift rate as a function of flow rate and pump laser power is measured, with the results fitted using hot wire anemometry theory. Flow sensing can also be realized when the cavity is passively probed at 780 nm, with the estimated Q-factor of the WGMs being in excess of 105.

  19. Effects of whispering gallery mode in microsphere super-resolution imaging

    NASA Astrophysics Data System (ADS)

    Zhou, Song; Deng, Yongbo; Zhou, Wenchao; Yu, Muxin; Urbach, H. P.; Wu, Yihui

    2017-09-01

    Whispering Gallery modes have been presented in microscopic glass spheres or toruses with many applications. In this paper, the possible approaches to enhance the imaging resolution by Whispering Gallery modes are discussed, including evanescent waves coupling, transformed and illustration by Whispering Gallery modes. It shows that the high-order scattering modes play the dominant role in the reconstructed virtual image when the Whispering Gallery modes exist. Furthermore, we find that the high image resolution of electric dipoles can be achieved, when the out-of-phase components exist from the illustration of Whispering Gallery modes. Those results of our simulation could contribute to the knowledge of microsphere-assisted super-resolution imaging and its potential applications.

  20. Convergent structure and function of mycelial galleries in two unrelated Neotropical plant-ants.

    PubMed

    Mayer, V E; Lauth, J; Orivel, J

    2017-01-01

    The construction process and use of galleries by Azteca brevis (Myrmicinae: Dolichoderinae) inhabiting Tetrathylacium macrophyllum (Salicaceae) were compared with Allomerus decemarticulatus (Myrmicinae: Solenopsidini) galleries on Hirtella physophora (Chrysobalanaceae). Though the two ant species are phylogenetically distant, the gallery structure seems to be surprisingly similar and structurally convergent: both are pierced with numerous holes and both ant species use Chaetothyrialean fungi to strengthen the gallery walls. Al. decemarticulatus is known to use the galleries for prey capture and whether this is also the case for Az. brevis was tested in field experiments. We placed Atta workers as potential prey/threat on the galleries and recorded the behaviour of both ant species. We found considerable behavioural differences between them: Al. decemarticulatus was quicker and more efficient at capture than was Az. brevis. While most Atta workers were captured after the first 5 min by Al. decemarticulatus, significantly fewer were captured by Az. brevis even after 20 min. Moreover, the captured Atta were sometimes simply discarded and not taken to the nest by Az. brevis. As a consequence, the major function of the galleries built by Az. brevis may, therefore, be defense against intruders in contrast to Al. decemarticulatus which uses them mainly for prey capture. This may be due to a higher need for protein in Al. decemarticulatus compared to coccid-raising Az. brevis.

  1. Human Genome Program Image Gallery (from genomics.energy.gov)

    DOE Data Explorer

    This collection contains approximately 240 images from the genome programs of DOE's Office of Science. The images are divided into galleries related to biofuels research, systems biology, and basic genomics. Each image has a title, a basic citation, and a credit or source. Most of the images are original graphics created by the Genome Management Information System (GMIS). GMIS images are recognizable by their credit line. Permission to use these graphics is not needed, but please credit the U.S. Department of Energy Genome Programs and provide the website http://genomics.energy.gov. Other images were provided by third parties and not created by the U.S. Department of Energy. Users must contact the person listed in the credit line before using those images. The high-resolution images can be downloaded.

  2. Analysis of whispering-gallery superconducting dielectric resonator modes

    SciTech Connect

    Zhou Shiping; Jabbar, A. )

    1991-06-01

    The whispering-gallery (WG) modes of a superconducting dielectric resonator (SDR) based on a sapphire cylindrical dielectric resonator and a YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} shielding cylinder were studied. A method for the determination of the resonant frequencies and the maximum quality factor of such modes is presented. Calculations have shown that most of the mode energy could be confined between the caustic surface of the WG modes provided the dimensions of the SDR are properly selected, and a magnitude of 10{sup 9} for Q of the SDR could be estimated. A phenomenal explanation is given to account for such outstanding microwave behavior.

  3. Elementary modes of coupled oscillators as whispering-gallery microresonators

    NASA Astrophysics Data System (ADS)

    Banerjee, Rabin; Mukherjee, Pradip

    2015-10-01

    We obtain the elementary modes of a system of parity-time reversal (PT)-symmetric coupled oscillators with balanced loss and gain. These modes are used to give a physical picture of the phase transition recently reported [C. M. Bender, M. Gianfreda, B. Peng, S. K. Özdemir and L. Yang, Phys. Rev. A 88, 062111 (2013); L. Yang, S. K. Özdemir and B. Peng, 12th Int. Workshop and Conf. Pseudo-Hermitian Hamiltonians in Quantum Physics, Istanbul, Turkey, July 2013; B. Peng, S. K. Özdemir, F. Lei, F. Monifi, M. Gianfreda, G. L. Long, S. Fan, F. Nori, C. M. Bender and L. Yang, Nat. Phys. 10, 394 (2014)] in experiments with whispering-gallery microresonators.

  4. Staging scientific controversies: a gallery test on science museums' interactivity.

    PubMed

    Yaneva, Albena; Rabesandratana, Tania Mara; Greiner, Birgit

    2009-01-01

    The "transfer" model in science communication has been addressed critically from different perspectives, while the advantages of the interactive model have been continuously praised. Yet, little is done to account for the specific role of the interactive model in communicating "unfinished science." The traditional interactive methods in museums are not sufficient to keep pace with rapid scientific developments. Interactive exchanges between laypeople and experts are thought mainly through the lens of a dialogue that is facilitated and framed by the traditional "conference room" architecture. Drawing on the results of a small-scale experiment in a gallery space, we argue for the need for a new "architecture of interaction" in museum settings based on art installation and simulation techniques, which will enhance the communication potentials of science museums and will provide conditions for a fruitful even-handed exchange of expert and lay knowledge.

  5. Nonlinear and quantum optics with whispering gallery resonators

    NASA Astrophysics Data System (ADS)

    Strekalov, Dmitry V.; Marquardt, Christoph; Matsko, Andrey B.; Schwefel, Harald G. L.; Leuchs, Gerd

    2016-12-01

    Optical whispering gallery modes (WGMs) derive their name from a famous acoustic phenomenon of guiding a wave by a curved boundary observed nearly a century ago. This phenomenon has a rather general nature, equally applicable to sound and all other waves. It enables resonators of unique properties attractive both in science and engineering. Very high quality factors of optical WGM resonators persisting in a wide wavelength range spanning from radio frequencies to ultraviolet light, their small mode volume, and tunable in- and out- coupling make them exceptionally efficient for nonlinear optical applications. Nonlinear optics facilitates interaction of photons with each other and with other physical systems, and is of prime importance in quantum optics. In this paper we review numerous applications of WGM resonators in nonlinear and quantum optics. We outline the current areas of interest, summarize progress, highlight difficulties, and discuss possible future development trends in these areas.

  6. All-polymer whispering gallery mode sensor system.

    PubMed

    Petermann, Ann Britt; Varkentin, Arthur; Roth, Bernhard; Morgner, Uwe; Meinhardt-Wollweber, Merve

    2016-03-21

    Sensors based on whispering gallery modes have been extensively investigated with respect to their possible application as physical or biological sensors. Instead of using a single resonator, we use an all polymer resonator array as sensing element. A tunable narrowband laser is coupled into a PMMA plate serving as an optical wave guide. PMMA spheres are placed in the evanescent field on the surface of the plate. Due to small size variations, some spheres are in resonance at a given wavelength while others are not. We show that this device is well suited for the determination of an unknown wavelength or for temperature measurements. Moreover, we discuss several general aspects of the sensor concept such as the number and size of sensing elements which are necessary for a correct measurement result, or the maximum acceptable linewidth of the laser.

  7. Whispering-Gallery Mode Resonators for Detecting Cancer

    PubMed Central

    Pongruengkiat, Weeratouch; Pechprasarn, Suejit

    2017-01-01

    Optical resonators are sensors well known for their high sensitivity and fast response time. These sensors have a wide range of applications, including in the biomedical fields, and cancer detection is one such promising application. Sensor diagnosis currently has many limitations, such as being expensive, highly invasive, and time-consuming. New developments are welcomed to overcome these limitations. Optical resonators have high sensitivity, which enable medical testing to detect disease in the early stage. Herein, we describe the principle of whispering-gallery mode and ring optical resonators. We also add to the knowledge of cancer biomarker diagnosis, where we discuss the application of optical resonators for specific biomarkers. Lastly, we discuss advancements in optical resonators for detecting cancer in terms of their ability to detect small amounts of cancer biomarkers. PMID:28902169

  8. Brillouin lasing in whispering gallery micro-resonators

    NASA Astrophysics Data System (ADS)

    Sturman, B.; Breunig, I.

    2015-12-01

    Thresholds of stimulated Brillouin scattering (SBS) in solid-state whispering gallery mode (WGM) microresonators are analyzed. It is shown that the SBS interaction is substantially different here from that known in the bulk case and in the case of water droplet resonators. The reason is the absence of pure longitudinal acoustic WGMs owing to strong coupling of the longitudinal (l) and transverse (t) acoustic displacements at the surface of the resonator. As a result, a considerable increase of the SBS thresholds takes place, and the lowest thresholds correspond to the hybrid tl-modes with very large radial indices. Nevertheless, the thresholds lie in the μW range of the pump power. Dependence of the SBS power thresholds on the modal numbers and the possibility of self-tuning to the SBS resonance are analyzed.

  9. Whispering-gallery nanocavity plasmon-enhanced Raman spectroscopy

    PubMed Central

    Zhang, Jing; Li, Jinxing; Tang, Shiwei; Fang, Yangfu; Wang, Jiao; Huang, Gaoshan; Liu, Ran; Zheng, Lirong; Cui, Xugao; Mei, Yongfeng

    2015-01-01

    The synergy effect in nature could enable fantastic improvement of functional properties and associated effects. The detection performance of surface-enhanced Raman scattering (SERS) can be highly strengthened under the cooperation with other factors. Here, greatly-enhanced SERS detection is realized based on rolled-up tubular nano-resonators decorated with silver nanoparticles. The synergy effect between whispering-gallery-mode (WGM) and surface plasmon leads to an extra enhancement at the order of 105 compared to non-resonant flat SERS substrates, which can be well tuned by altering the diameter of micron- and nanotubes and the excitation laser wavelengths. Such synchronous and coherent coupling between plasmonics and photonics could lead to new principle and design for various sub-wavelength optical devices, e.g. plasmonic waveguides and hyperbolic metamaterials. PMID:26443526

  10. Genome Structure Gallery from the Mycobacterium Tuberculosis Structual Genomics Consortium

    DOE Data Explorer

    The TB Structural Genomics Consortium works with the structures of proteins from M. tuberculosis, analyzing these structures in the context of functional information that currently exists and that the Consortium generates. The database of linked structural and functional information constructed from this project will form a lasting basis for understanding M. tuberculosis pathogenesis and for structure-based drug design. The Consortium's structural and functional information is publicly available. The Structures Gallery makes more than 650 total structures available by PDB identifier. Some of these are not consortium targets, but all are viewable in 3D color and can be manipulated in various ways by Jmol, an open-source Java viewer for chemical structures in 3D from http://www.jmol.org/

  11. Light scattering by magnons in whispering gallery mode cavities

    NASA Astrophysics Data System (ADS)

    Sharma, Sanchar; Blanter, Yaroslav M.; Bauer, Gerrit E. W.

    2017-09-01

    Brillouin light scattering is an established technique to study magnons, the elementary excitations of a magnet. Its efficiency can be enhanced by cavities that concentrate the light intensity. Here, we theoretically study inelastic scattering of photons by a magnetic sphere that supports optical whispering gallery modes in a plane normal to the magnetization. Magnons with low angular momenta scatter the light in the forward direction with a pronounced asymmetry in the Stokes and the anti-Stokes scattering strength, consistent with earlier studies. Magnons with large angular momenta constitute Damon-Eschbach modes which are shown to inelastically reflect light. The reflection spectrum contains either a Stokes or anti-Stokes peak, depending on the direction of the magnetization, a selection rule that can be explained by the chirality of the Damon-Eshbach magnons. The controllable energy transfer can be used to manage the thermodynamics of the magnet by light.

  12. Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

    PubMed Central

    Coillet, Aurélien; Henriet, Rémi; Phan Huy, Kien; Jacquot, Maxime; Furfaro, Luca; Balakireva, Irina; Larger, Laurent; Chembo, Yanne K.

    2013-01-01

    Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency. PMID:23963358

  13. Microwave photonics systems based on whispering-gallery-mode resonators.

    PubMed

    Coillet, Aurélien; Henriet, Rémi; Phan Huy, Kien; Jacquot, Maxime; Furfaro, Luca; Balakireva, Irina; Larger, Laurent; Chembo, Yanne K

    2013-08-05

    Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

  14. Fungus symbionts colonizing the galleries of the ambrosia beetle Platypus quercivorus.

    PubMed

    Endoh, Rikiya; Suzuki, Motofumi; Okada, Gen; Takeuchi, Yuko; Futai, Kazuyoshi

    2011-07-01

    Isolations were made to determine the fungal symbionts colonizing Platypus quercivorus beetle galleries of dead or dying Quercus laurifolia, Castanopsis cuspidata, Quercus serrata, Quercus crispula, and Quercus robur. For these studies, logs from oak wilt-killed trees were collected from Kyoto Prefecture, Japan. Fungi were isolated from the: (1) entrances of beetle galleries, (2) vertical galleries, (3) lateral galleries, and (4) the larval cradle of P. quercivorus in each host tree. Among the fungus colonies which appeared on YM agar plates, 1,219 were isolated as the representative isolates for fungus species inhabiting in the galleries based on their cultural characteristics. The validity of the visual classification of the fungus colonies was checked and if necessary properly corrected using microsatellite-primed PCR fingerprints. The nucleotide sequence of the D1/D2 region of the large subunit nuclear rRNA gene detected 38 fungus species (104 strains) of which three species, i.e., Candida sp. 3, Candida kashinagacola (both yeasts), and the filamentous fungus Raffaelea quercivora were isolated from all the tree species. The two yeasts were most prevalent in the interior of galleries, regardless of host tree species, suggesting their close association with the beetle. A culture-independent method, terminal restriction fragment length polymorphism (T-RFLP) analysis was also used to characterize the fungus flora of beetle galleries. T-RFLP patterns showed that yeast species belonging to the genus Ambrosiozyma frequently occurred on the gallery walls along with the two Candida species. Ours is the first report showing the specific fungi inhabiting the galleries of a platypodid ambrosia beetle.

  15. The Cosmology Gallery: Unity through diversity in a vast and awe-inspiring universe.

    NASA Astrophysics Data System (ADS)

    Goldsmith, John

    2011-06-01

    Scientists, artists, religious and cultural leaders have come together to create the Cosmology Gallery at the Gravity Discovery Centre (GDC) located 70 km north of Perth, Western Australia. The Cosmology Gallery exhibitions include the multicultural cosmology artworks, Celestial Visions astronomical photography exhibition and the Timeline of the Universe. The multicultural cosmology artworks are new artworks inspired by Australian Indigenous, Christian, Buddhist, Islamic, Hindu, scientific and technological perspectives of the universe. The Celestial Visions exhibition features astronomical events above famous landmarks, including Stonehenge and the Pyramids. The AUD 400,000+ project was funded by Lotterywest, Western Australia and the Cosmology Gallery was officially opened in July 2008 by the Premier of Western Australia.

  16. Highly Efficient Integrated Generator of Tripartite Entanglement from χ (2) Whispering Gallery Microresonator

    NASA Astrophysics Data System (ADS)

    He, Guangqiang; Hu, Linxi; Li, Rongyu

    2017-08-01

    Whispering gallery microresonator (WGM) filled with nonlinear material has proven to be valuable for enhancing nonlinear optical effects. Here we explore the production of the pump-signal-idler tripartite entanglement based on the integrated high-Q whispering gallery mode cavities filled with lithium niobate. Our theoretical analysis about the entanglement condition when the van Loock and Furusawa criteria are violated paves the way for future investigation of integrated entanglement based on nonlinear high-Q microresonator. In addition, we present parameters used in our designed generator and our theoretical model is highly expansible to further exploration of entanglement over general χ (2) whispering gallery microresonator.

  17. Species composition, community and population dynamics of two gallery forests from the Brazilian Cerrado domain

    PubMed Central

    Almado, Roosevelt P; Miazaki, Angela S; Diniz, Écio S; Moreira, Luis C B; Meira-Neto, João A.A.

    2016-01-01

    Abstract Background To understand the impacts of global changes on future community compositions, knowledge of community dynamics is of crucial importance. To improve our knowledge of community composition, biomass stock and maintenance of gallery forests in the Brazilian Cerrado, we provide two datasets from the 0.5 ha Corrego Fazendinha Gallery Forest Dynamics Plot and the Corrego Fundo Gallery Forest Dynamics Plot situated in the Bom Despacho region, Minas Gerais, Southeastern Brazil. New information We report diameter at breast height, basal area and height measurements of 3417 trees and treelets identified during three censuses in both areas. PMID:27660529

  18. The Junior Gallery: A Hands-On Space for Learning and Creating.

    ERIC Educational Resources Information Center

    Podhurst, Jamie

    2001-01-01

    Describes an educational program focusing on workshops at the Junior Gallery, a part of the Everhart Museum (Scranton, Pennsylvania). Explains that the museum's collection is integrated with lessons in art appreciation, production, natural history, and other subject areas. (CMK)

  19. The influence of the whispering gallery modes resonators shape on their sensitivity to the movement

    NASA Astrophysics Data System (ADS)

    Filatov, Yuri V.; Govorenko, Ekaterina V.; Kukaev, Alexander S.; Shalymov, Egor V.; Venediktov, Vladimir Yu.

    2017-05-01

    The optical whispering gallery modes resonators are axially symmetrical resonators with smooth edges, supporting the existence of the whispering gallery modes by the total internal reflection on the surface of the resonator. For today various types of such resonators were developed, namely the ball-shaped, tor-shaped, bottle-shaped, disk-shaped etc. The movement of whispering gallery modes resonators in inertial space causes the changes of their shape. The result is a spectral shift of the whispering gallery modes. Optical methods allow to register this shift with high precision. It can be used in particular for the measurement of angular velocities in inertial orientation and navigation systems. However, different types of resonators react to the movement on a miscellaneous. In addition, their sensitivity to movement can be changed when changing the geometric parameters of these resonators. This work is devoted to a research of these aspects.

  20. 6. TROLLEY WASHER/OILER IN SOUTHWEST CORNER OF GALLERY LEVEL; LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. TROLLEY WASHER/OILER IN SOUTHWEST CORNER OF GALLERY LEVEL; LOOKING NORTHEAST - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  1. Interior hallway, at 1250 Gallery, showing entrance into PumpGenerating Plant ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior hallway, at 1250 Gallery, showing entrance into Pump-Generating Plant from Left Powerhouse, looking southwest. - Columbia Basin Project, Grand Coulee Dam Powerplant Complex, Grand Coulee, Grant County, WA

  2. The Junior Gallery: A Hands-On Space for Learning and Creating.

    ERIC Educational Resources Information Center

    Podhurst, Jamie

    2001-01-01

    Describes an educational program focusing on workshops at the Junior Gallery, a part of the Everhart Museum (Scranton, Pennsylvania). Explains that the museum's collection is integrated with lessons in art appreciation, production, natural history, and other subject areas. (CMK)

  3. 67. SUBSTATION 15, 606 WEST 143RD STREET, GALLERY EQUIPMENT. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. SUBSTATION 15, 606 WEST 143RD STREET, GALLERY EQUIPMENT. NOTE ADDITION OF MIMIC BOARD BETWEEN D. C. CIRCUIT BREAKER SWITCHES AND G. E. INSTRUMENT PANEL. - Interborough Rapid Transit Subway (Original Line), New York County, NY

  4. Direct electrical-to-optical conversion and light modulation in micro whispering-gallery-mode resonators

    NASA Technical Reports Server (NTRS)

    Maleki, Lute (Inventor); Levi, Anthony F. J. (Inventor)

    2005-01-01

    Techniques for directly converting an electrical signal into an optical signal by using a whispering gallery mode optical resonator formed of a dielectric material that allows for direct modulation of optical absorption by the electrical signal.

  5. Tunable Optical Filters Having Electro-optic Whispering-gallery-mode Resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy (Inventor); Ilchenko, Vladimir (Inventor); Matsko, Andrey B. (Inventor); Maleki, Lutfollah (Inventor)

    2006-01-01

    Tunable optical filters using whispering-gallery-mode (WGM) optical resonators are described. The WGM optical resonator in a filter exhibits an electro-optical effect and hence is tunable by applying a control electrical signal.

  6. GPR investigations in galleries buried inside a karstified limestone formation

    NASA Astrophysics Data System (ADS)

    Rousset, D.; Sénéchal, G.; Gaffet, S.

    2009-04-01

    A large scientific program of geophysical investigations is presently performed inside the Low-Noise Underground Laboratory (Laboratoire Souterrain à Bas Bruit / LSBB, Rustrel, France) which is an decomissioned underground missile control center, buried in a karstified limestone formation. One of the goals of this project is the understanding of the water circulation inside the structure. This experimental site offers a unique opportunity of perfoming measurements within an unweathered limestone massif. The tunnel has been dug in lower cretaceous limestone which is characterized by a low clay content, high electrical resistivity. The dip is around 25 degrees and vertical faults locally affect the structure. The studied zone is located in south-eastern France (Provence) and is characterized by a mediterranean climate with long dry periods and strong, short events of rain. This phenomenon induces large variations of water content within the karstified limestone from dry to saturated conditions. Analysis of the spatial and temporal variations of the water flow in a karstified limestones needs to define the geological context and the adequate geophysical methods. GPR offers a good tradeoff between resolution and ease of use on one hand and investigation depth on the other hand. We present some GPR profiles which have been acquired in April 2008 after a quite long and strong period of rain, inducing a complete water saturation inside the karstified massif. We used several RAMAC shielded antennas from 100 to 500 MHz. The longest profile is around 600 m long, with a 20 cm spacing, running from a raw to a concrete gallery. These data sets are characterized by a very good signal to noise ratio and a signal penetration, up to 18 meters. Signal processing includes very low frequency filtering, amplitude compensation, keeping lateral relative attenuation and ringing suppression. Final sections includes migration and time to depth conversion or depth migration. The estimated

  7. Late Holocene history of savanna gallery forest from Carimagua area, Colombia.

    PubMed

    Berrio; Hooghiemstra; Behling; van der Borg K

    2000-09-01

    The pollen record of a 65cm long core Laguna Carimagua-Bosque (4 degrees 04'N, 70 degrees 13'W) shows the late Holocene environmental history from a lake located within the gallery forest of the savannas of the Llanos Orientales of Colombia. Nine AMS radiocarbon dates of the organic deposits show that the core represents the period from ca. 1300(14)CyrBP to the present. The lake evolved from an active drainage system.During the period from ca. 1300 to 875(14)CyrBP (zone CMB-Ia), Mauritia-dominated swamp and gallery forest was present, dominated by Cecropia, and later also Acalypha and Alchornea. From 875 to 700(14)CyrBP (zone CMB-Ib), the lake was completely surrounded by gallery forest. Mauritiella and Cecropia occurred around the lake. Cecropia pioneer forest reached its greatest abundance and became gradually replaced by a more species-rich gallery forest, including Acalypha, Alchornea, Euterpe/Geonoma, Moraceae/Urticaceae, Piperaceae, and Virola. From 700 to 125(14)CyrBP (zone CMB-II), Cecropia lost its dominant role, and Mauritiella palms became more frequent. The main vegetation categories were swamp forest, gallery forest, understory elements, savanna shrubs and trees, and grass savanna. From 125(14)CyrBP to recent (zone CMB-III), the plant diversity in the gallery forest became highest, Mauritiella became very abundant, and among the savanna elements, woody Didymopanax increased.Comparison of four pollen records from savanna sites shows that pollen of savanna vegetation is markedly underrepresented in lake sediments when the lake lies within the gallery forest. As most of the drainage system of a savanna is hidden by gallery forest, we also expect a significant underrepresentation of the savanna ecosystem in river-transported pollen assemblages.

  8. Photonic whispering-gallery resonators in new environments

    NASA Astrophysics Data System (ADS)

    Ostby, Eric Paul

    Optical whispering-gallery devices, like the microtoroid or microdisk, confine light at resonant frequencies and in ultra-small volumes for long periods of time. Such ultra-low loss resonators have been applied in diverse areas of scientific research, including low-threshold lasers on-chip, biological sensing, and quantum computing. In this thesis, novel ultra-low loss microstructures are studied for their unique characteristics and utility. The author investigates the interaction between microcavities and various environments in order to quantify the results and lay the foundation for future applications. The first optical cavity studied is the microtoroid, which possesses ultra-high quality factor (Q) on account of its nearly atomic smooth surface, produced by surface-tension induced laser reflow. Ytterbium-doped silica microtoroids are fabricated by a sol-gel technique. The ytterbium microtoroid laser achieves record-low laser threshold (2 microW) in air, and produces the first laser output for a solid-state laser in water. This laser in water can be developed as an ultra-sensitive biological sensor, with potentially record sensitivity enabled by gain-narrowed linewidth. Also, a novel CO 2 laser reflow and microtoroid testing vacuum system is demonstrated. Fabrication and testing of microtoroids is performed in a vacuum chamber to study the effect of atmospheric water and upper limit of Q in microtoroids. The selective reflow of microtoroids presents difficulties for integration of on-chip optical waveguides. As an alternative, dimension-preserving low-loss optical structures are researched for their unique applications. A gold-coated silica microdisk is fabricated, and demonstrates record and nearly-ideal quality factor (1,376) as a surface-plasmon polariton resonator. The hybrid optical-plasmonic mode structure is studied in simulation and experiment. The plasmonic resonator has ultra-low mode volume and high field confinement, making it suitable for short

  9. Whispering Gallery Modes in Hexagonal Zinc Oxide Micro- and Nanocrystals

    NASA Astrophysics Data System (ADS)

    Nobis, Thomas; Kaidashev, Evgeni M.; Rahm, Andreas; Lorenz, Michael; Grundmann, Marius

    The resonator properties of zinc oxide (ZnO) micro- and nanocrystals grown by a novel high pressure pulsed laser deposition process have been investigated at room temperature by cathodoluminescence (CL), spatially resolved CL-imaging and polarization resolved micro-photoluminescence (μ-PL) within the visible spectral range. The spectra exhibit a series of comparatively sharp and almost equidistant resonance lines. Using a simple plane wave interference model and taking into account the spectral characteristic n(ω) of the refractive index of ZnO, we can unambiguously attribute those lines to whispering gallery modes (WGMs) of a two dimensional hexagonal resonator. The predicted resonator diameters agree well with the measured crystal sizes. Tapered, high aspect ratio ZnO nanoneedles furthermore allow systematic investigations of the WGMs as a function of cavity diameter D down to zero. Hence, the transition from a multi-mode to a single mode cavity is directly observed. μ-PL experiments demonstrate that the WGMs are mainly TM polarized.

  10. Optothermal transport behavior in whispering gallery mode optical cavities

    SciTech Connect

    Soltani, Soheil; Armani, Andrea M.

    2014-08-04

    Over the past century, whispering gallery mode optical cavities have enabled numerous advances in science and engineering, such as discoveries in quantum mechanics and non-linear optics, as well as the development of optical gyroscopes and add drop filters. One reason for their widespread appeal is their ability to confine light for long periods of time, resulting in high circulating intensities. However, when sufficiently large amounts of optical power are coupled into these cavities, they begin to experience optothermal or photothermal behavior, in which the optical energy is converted into heat. Above the optothermal threshold, the resonance behavior is no longer solely defined by electromagnetics. Previous work has primarily focused on the role of the optothermal coefficient of the material in this instability. However, the physics of this optothermal behavior is significantly more complex. In the present work, we develop a predictive theory based on a generalizable analytical expression in combination with a geometry-specific COMSOL Multiphysics finite element method model. The simulation couples the optical and thermal physics components, accounting for geometry variations as well as the temporal and spatial profile of the optical field. To experimentally verify our theoretical model, the optothermal thresholds of a series of silica toroidal resonant cavities are characterized at different wavelengths (visible through near-infrared) and using different device geometries. The silica toroid offers a particularly rigorous case study for the developed optothermal model because of its complex geometrical structure which provides multiple thermal transport paths.

  11. Conceptual Design Report. Footprint Gallery Upgrade - Civil Construction, May 1988

    SciTech Connect

    1988-05-01

    The Footprint Gallery Complex will be enlarged and modified. The basic outline of the project will be to add 68,100 square feet of new construction, remodel 20,600 square feet of existing space, and retire by removal 17 ,500 square feet. The principal items to be addressed are: the creation of larger Main Control Rooms and Central Control Computer Rooms, the replacement of several temporary structures with permanent facilities, the provision for a growth in population of 132 people, and the creation of an intermediate sized meeting/lecture room facility. Disjointed second floor areas will be connected and made accessible to the handicapped, secure and informative viewing for visitors will be provided, and parking will be increased to match the expected growth. The new construction will provide for a more centralized concentration of systems and support personnel of the Fermilab Accelerator Division, reflecting the growth of these organizations during the last 15 years. Experiments, such as the D-Zero detector and antiproton deceleration (E760), have been assigned to the Accelerator Division for support. The associated physicists and experimenters make up the most significant component of the growth in population for which this construction will provide additional space.

  12. Whispering galleries and the control of artificial atoms

    PubMed Central

    Forrester, Derek Michael; Kusmartsev, Feodor V.

    2016-01-01

    Quantum computation using artificial-atoms, such as novel superconducting circuits, can be sensitively controlled by external electromagnetic fields. These fields and the self-fields attributable to the coupled artificial-atoms influence the amount of quantum correlation in the system. However, control elements that can operate without complete destruction of the entanglement of the quantum-bits are difficult to engineer. Here we investigate the possibility of using closely-spaced-linear arrays of metallic-elliptical discs as whispering gallery waveguides to control artificial-atoms. The discs confine and guide radiation through the array with small notches etched into their sides that act as scatterers. We focus on π-ring artificial-atoms, which can generate their own spontaneous fluxes. We find that the micro-discs of the waveguides can be excited by terahertz frequency fields to exhibit whispering-modes and that a quantum-phase-gate composed of π-rings can be operated under their influence. Furthermore, we gauge the level of entanglement through the concurrence measure and show that under certain magnetic conditions a series of entanglement sudden-deaths and revivals occur between the two qubits. This is important for understanding the stability and life-time of qubit operations using, for example, a phase gate in a hybrid of quantum technologies composed of control elements and artificial-atoms. PMID:27122353

  13. Whispering galleries and the control of artificial atoms

    NASA Astrophysics Data System (ADS)

    Forrester, Derek Michael; Kusmartsev, Feodor V.

    2016-04-01

    Quantum computation using artificial-atoms, such as novel superconducting circuits, can be sensitively controlled by external electromagnetic fields. These fields and the self-fields attributable to the coupled artificial-atoms influence the amount of quantum correlation in the system. However, control elements that can operate without complete destruction of the entanglement of the quantum-bits are difficult to engineer. Here we investigate the possibility of using closely-spaced-linear arrays of metallic-elliptical discs as whispering gallery waveguides to control artificial-atoms. The discs confine and guide radiation through the array with small notches etched into their sides that act as scatterers. We focus on π-ring artificial-atoms, which can generate their own spontaneous fluxes. We find that the micro-discs of the waveguides can be excited by terahertz frequency fields to exhibit whispering-modes and that a quantum-phase-gate composed of π-rings can be operated under their influence. Furthermore, we gauge the level of entanglement through the concurrence measure and show that under certain magnetic conditions a series of entanglement sudden-deaths and revivals occur between the two qubits. This is important for understanding the stability and life-time of qubit operations using, for example, a phase gate in a hybrid of quantum technologies composed of control elements and artificial-atoms.

  14. Bacterial sensing using phage-functionalized whispering gallery microcavities

    NASA Astrophysics Data System (ADS)

    Ghali, Hala; Hibli, Hicham; Bianucci, Pablo; Nadeau, Jay; Peter, Yves-Alain

    2012-02-01

    Whispering gallery optical microcavities are structures which can efficiently confine light at the micro scale. This confinement is based on total internal reflection of light at the interface between the cavity and the surrounding medium. Devices based on optical microcavities have a wide range of applications, such as microlasers, quantum optical devices and much more. In this work, we describe a biosensing application of these optical microcavities for the label-free detection of bacteria. In order for the sensor to be specific to a particular species of bacteria, we need to properly functionalize its surface so that only that kind of bacteria will produce a signal. The microcavity surface is first functionalized using PEGylated aminosilane. We then introduce phage-derived proteins that are specific to the bacteria we want to detect. The binding between the bacteria and the phage proteins creates a perturbation to the cavity field that leads to a thermo-optic effect. This effect is then observed as a shift in the resonance features of the transmission spectrum. We performed experimental measurements using a tapered fiber to couple the light from red laser (635 nm) into the resonator.

  15. Interfacing whispering gallery mode microresonators for environmental biosensing

    NASA Astrophysics Data System (ADS)

    Hunt, Heather K.; Dahmen, Jeremy L.; Soteropulos, Carol E.

    2014-03-01

    Label-free biosensors that combine high sensitivity and high specificity characteristics have shown tremendous potential for applications in medical diagnostics, and have more recently been extended to the food safety and environmental monitoring arenas. A unique type of label-free, optical biosensor, based on Whispering Gallery Mode microresonators, has tremendous potential to revolutionize biodetection due to its extreme sensitivity. The primary limitation of these biosensors, however, is that they require the addition of biorecognition elements to specifically target a biological species of interest. Therefore, the ability to selectively functionalize the microresonator for a specific target molecule, without degrading device performance, is extremely important, and represents the next step in translating these devices from laboratory to field environments. Here, we demonstrate a variety of straightforward bioconjugation strategies that not only impart specificity to optical microresonators, but also allow for the creation of multi-use platforms for complex environments. Of particular interest is the ability to detect harmful bacteria, insects, and fungi in crop and water systems. The resulting surface chemistries are illustrated with XPS, SEM, and fluorescence and optical microscopy, and the device sensitivity is determined via quantitative microcavity analysis. The ability to minimize non-specific adsorption and target unique molecules in complex environments is demonstrated via ellipsometry and in situ device testing. The resulting devices can be recycled several times without loss of sensitivity. By combining these high sensitivity biosensors with appropriate biochemistries, the resulting platforms can be extended to address broader issues in environmental biosensing that directly impact agriculture.

  16. Whispering-gallery-bottle microcavities: the three-dimensional etalon.

    PubMed

    Sumetsky, M

    2004-01-01

    In a tapered optical fiber there exist localized light structures that, in analogy to the magnetic bottles used in plasma fusion, can be called whispering-gallery bottles (WGBs). These essentially three-dimensional structures are formed by the spiral rays that experience total internal reflection at the fiber surface and that also bounce along the fiber axis in response to reflection from the regions of tapering. It is shown that the Wentzel-Kramers-Brillouin quantization rules for the strongly prolate WGBs can be inversed exactly, thus determining the cavity shape from its spectrum. The approximation considered allows one to find the shape of the etalon bottle, which, similar to the one-dimensional Fabry-Perot etalon, contains an unlimited number of equally spaced wave-number eigenvalues. The problem of determining such a non-one-dimensional cavity is not trivial, because such a cavity does not exist among the uniformly filled cavities such as rectangular boxes, cylinders, and spheroids that allow separation of variables. The etalon cavity corresponds to the fiber radius variation p(z) = rho0/cos(deltakz)/, where deltak is the wave-number spacing. The latter result is in excellent agreement with ray-dynamics numerical modeling.

  17. Whispering galleries and the control of artificial atoms.

    PubMed

    Forrester, Derek Michael; Kusmartsev, Feodor V

    2016-04-28

    Quantum computation using artificial-atoms, such as novel superconducting circuits, can be sensitively controlled by external electromagnetic fields. These fields and the self-fields attributable to the coupled artificial-atoms influence the amount of quantum correlation in the system. However, control elements that can operate without complete destruction of the entanglement of the quantum-bits are difficult to engineer. Here we investigate the possibility of using closely-spaced-linear arrays of metallic-elliptical discs as whispering gallery waveguides to control artificial-atoms. The discs confine and guide radiation through the array with small notches etched into their sides that act as scatterers. We focus on π-ring artificial-atoms, which can generate their own spontaneous fluxes. We find that the micro-discs of the waveguides can be excited by terahertz frequency fields to exhibit whispering-modes and that a quantum-phase-gate composed of π-rings can be operated under their influence. Furthermore, we gauge the level of entanglement through the concurrence measure and show that under certain magnetic conditions a series of entanglement sudden-deaths and revivals occur between the two qubits. This is important for understanding the stability and life-time of qubit operations using, for example, a phase gate in a hybrid of quantum technologies composed of control elements and artificial-atoms.

  18. Optofluidic whispering gallery mode microcapillary lasers for refractive index sensing

    NASA Astrophysics Data System (ADS)

    François, Alexandre; Riesen, Nicolas; Gardner, Kristy; Monro, Tanya M.; Meldrum, Al

    2016-12-01

    Whispering gallery modes (WGMs) allow for remarkable refractive index sensing performance with extremely low detection limits, and thus have found use in various emerging label free biosensing applications. Among the different types of resonators which have been studied, microcapillaries have the unique property of having the evanescent fields extend into and sample the medium inside the resonator, which is particularly interesting because the resonator itself serves as a microfluidic channel. Here, lasing of the WGMs in fluorescent microcapillaries is demonstrated for the first time, and their application to refractive index sensing is investigated. The laser gain medium used here is embedded inside a high refractive index polymer coating deposited onto the inner surface of the capillary. Lasing can only be realized for thick polymer coatings (in this case >= 800 nm), with higher Q factor but also stronger confinement of the propagating wave, which lowers the refractive index sensitivity compared to non-lasing capillaries which can have thinner polymer coatings. We however find that the large improvement in signal-to-noise ratio and Q factor realized upon lasing more than compensates for the reduced sensitivity, resulting in an order-of-magnitude improvement in the detection limit for refractive index sensing.

  19. High-Q whispering-gallery mode sensor in liquids

    NASA Astrophysics Data System (ADS)

    Nadeau, Jay L.; Ilchenko, Vladimir S.; Kossakovski, Dmitri; Bearman, Gregory H.; Maleki, Lute

    2002-06-01

    Optical sensing of biomolecules on microfabricated glass surfaces requires surface coatings that minimize nonspecific binding while preserving the optical properties of the sensor. Microspheres with whispering-gallery (WG) modes can achieve quality factor (Q) levels many orders of magnitude greater than those of other WG-based microsensors: greater than 1010 in air, and greater than 109 in a variety of solvents, including methanol, H2O and phosphate buffered saline (PBS). The presence of dyes that absorb in the wavelength of the WG excitation in the evanescent zone can cause this Q value to drop by almost 3 orders of magnitude. Silanization of the surface with mercapto-terminal silanes is compatible with high Q (>109), but chemical cross-linking of streptavidin reduces the Q to 105-106 due to build-up of a thick, irregular layer of protein. However, linkage of biotin to the silane terminus preserves the Q at a ~2x107 and yields a reactive surface sensitive to avidin-containing ligands in a concentration-dependent manner. Improvements in the reliability of the surface chemistry show promise for construction of an ultrasensitive biosensor.

  20. Phase-Array Approach to Optical Whispering Gallery Modulators

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry

    2010-01-01

    This technology leverages the well-defined orbital number of a whispering gallery modulator (WGM) to expand the range of applications for such resonators. This property rigidly connects the phase variation of the field in this mode with the azimuthal angle between the coupling locations. A WGM with orbital momentum L has exactly L instant nodes around the circumference of the WGM resonator supporting such a mode. Therefore, in two locations separated by the arc alpha, the phase difference of such a field will be equal to phi= alpha L. Coupling the field out of such locations, and into a balanced interferometer, once can observe a complete constructive or distractive interference (or have any situation in between) depending on the angle alpha. Similarly, a mode L + delta L will pick up the phase phi + alpha delta L. In all applications of a WGM resonator as a modulator, the orbital numbers for the carrier and sidebands are different, and their differences delta L are known (usually, but not necessarily, delta L = 1). Therefore, the choice of the angle alpha, and of the interferometer arms difference, allows one to control the relative phase between different modes and to perform the conversion, separation, and filtering tasks necessary.

  1. Dispersion and polarization conversion of whispering gallery modes in nanowires

    SciTech Connect

    Pavlovic, G.; Malpuech, G.; Gippius, N. A.

    2010-11-15

    We investigate theoretically the optical properties of nano-wires (NWs) with cross sections having either discrete or cylindrical symmetry. The material forming the wire is birefringent, showing a different dielectric response in the plane and along the axis of the wire, which is typically the case for wires made of wurtzite materials, such as ZnO or GaN. We look for solutions of Maxwell's equations having the proper symmetry. The dispersions and the linewidths versus angle of incident light for the modes having high momentum in the cross-section plane, so called whispering gallery modes, are calculated. We put a special emphasis on the case of hexagonal cross sections. The energy positions of the modes for a set of azimuthal quantum numbers are shown. We demonstrate the dependence of the energy splitting between TE and TM modes versus birefringence. The polarization conversion from TE to TM with increase in the axial wave vector is discussed for both cylindrical and discrete symmetries.

  2. Protein-based flexible whispering gallery mode resonators

    NASA Astrophysics Data System (ADS)

    Yilmaz, Huzeyfe; Pena-Francesch, Abdon; Xu, Linhua; Shreiner, Robert; Jung, Huihun; Huang, Steven H.; Özdemir, Sahin K.; Demirel, Melik C.; Yang, Lan

    2016-02-01

    The idea of creating photonics tools for sensing, imaging and material characterization has long been pursued and many achievements have been made. Approaching the level of solutions provided by nature however is hindered by routine choice of materials. To this end recent years have witnessed a great effort to engineer mechanically flexible photonic devices using polymer substrates. On the other hand, biodegradability and biocompatibility still remains to be incorporated. Hence biomimetics holds the key to overcome the limitations of traditional materials in photonics design. Natural proteins such as sucker ring teeth (SRT) and silk for instance have remarkable mechanical and optical properties that exceed the endeavors of most synthetic and natural polymers. Here we demonstrate for the first time, toroidal whispering gallery mode resonators (WGMR) fabricated entirely from protein structures such as SRT of Loligo vulgaris (European squid) and silk from Bombyx mori. We provide here complete optical and material characterization of proteinaceous WGMRs, revealing high quality factors in microscale and enhancement of Raman signatures by a microcavity. We also present a most simple application of a WGMR as a natural protein add-drop filter, made of SRT protein. Our work shows that with protein-based materials, optical, mechanical and thermal properties can be devised at the molecular level and it lays the groundwork for future eco-friendly, flexible photonics device design.

  3. Optical Whispering Gallery Modes in Chalcogenide Arsenic Selenide Microspheres

    NASA Astrophysics Data System (ADS)

    Yue, Hong-Quan

    Anisotropic chalcogenide microsphere is introduced for coupling theoretical analyzing and coupling experiment. Whispering Gallery Modes (WGMs) of isotropic microsphere is introduced and the TE & TM WGMs dispersion relationship is derived from electromagnetic vector equations in the spherical coordinate. The Maxwell equations can be solved in 2D model for the 3D model of axisymmetric or Rotational symmetry isotropic microsphere. First 4 TE&TM WGMs are simulated in 2D model using finite-element weak method. The binding capability, mode volume V and quality factor Q depend on the refractive index and size of the microsphere. Plane wavefront light wave is assumed to propagate inside the microsphere; coupling coefficient is determined by WGMs numbers and the distance between the microsphere and the micro-taper. Coupling related Q factor is analyzed; TE & TM nonlinear microsphere coupling is introduced with Matlab simulation. Chalcogenide coupling experiments for transmission, reflection and drop-port function are conducted. The light waves for coupling are broadband incoherent light source and narrowband tunable laser. Broadband light gave sensitive results while the coherent laser gave easy coupling capability. The chalcogenide microsphere was used as a feedback element of an amplifying medium. Comparing with silica microsphere, chalcogenide microsphere's response is more unstable due to free carriers perturbation and thermal activity

  4. Shooting gallery attendance among IDUs in Tijuana and Ciudad Juarez, Mexico: correlates, prevention opportunities, and the role of the environment.

    PubMed

    Philbin, Morgan; Pollini, Robin A; Ramos, Rebecca; Lozada, Remedios; Brouwer, Kimberly C; Ramos, Maria Elena; Firestone-Cruz, Michelle; Case, Patricia; Strathdee, Steffanie A

    2008-07-01

    We identified factors associated with shooting gallery attendance among injection drug users (IDUs) in two Mexico-US border cities. IDUs in Tijuana (n=222) and Ciudad Juarez (n=205), Mexico, who were >or=18 years and injected illicit drugs in the last month were recruited using respondent-driven sampling (RDS). An interviewer-administered survey collected sociodemographic and behavioral data. Logistic regression was used to examine correlates of shooting gallery attendance in each of the two cities. Homelessness and being arrested for syringe possession--both structural level factors--were associated with shooting gallery use in both cities. In Ciudad Juarez, younger age and having overdosed were also associated with shooting gallery use. Our study highlights the need for structural interventions that mitigate homelessness among IDUs and facilitate changes in law enforcement practices associated with shooting gallery use. Harm reduction interventions based within shooting galleries should also be considered to prevent transmission of blood-borne pathogens among IDUs.

  5. Whispering Gallery Modes in Standard Optical Fibres for Fibre Profiling Measurements and Sensing of Unlabelled Chemical Species

    PubMed Central

    Boleininger, Anna; Lake, Thomas; Hami, Sophia; Vallance, Claire

    2010-01-01

    Whispering gallery mode resonances in liquid droplets and microspheres have attracted considerable attention due to their potential uses in a range of sensing and technological applications. We describe a whispering gallery mode sensor in which standard optical fibre is used as the whispering gallery mode resonator. The sensor is characterised in terms of the response of the whispering gallery mode spectrum to changes in resonator size, refractive index of the surrounding medium, and temperature, and its measurement capabilities are demonstrated through application to high-precision fibre geometry profiling and the detection of unlabelled biochemical species. The prototype sensor is capable of detecting unlabelled biomolecular species in attomole quantities. PMID:22294898

  6. Acoustic whispering gallery modes within the theory of elasticity

    NASA Astrophysics Data System (ADS)

    Sturman, Boris; Breunig, Ingo

    2015-07-01

    Investigations of nonlinear phenomena in optical whispering gallery mode (WGM) microresonators are booming because of rich physics and applications. Stimulated Brillouin scattering is one of the strongest processes in these devices. Here, the optical WGMs interact with acoustic counterparts. The acoustic WGMs are well known for resonators based on liquids and gases, where the sound waves are longitudinal. The situation with solid-state resonators is different because of the presence of the longitudinal (l) and transverse (t) sound waves with substantially different velocities v l , t . Moreover, the l- and t-parts of the acoustic displacement are coupled at the resonator surface breaking the separation of modes into longitudinal and transverse. Investigation of the acoustic WGMs is of high priority. Here, analytically and numerically we investigate the resonant frequencies and the eigenfunctions (displacement vector distributions) for acoustic WGMs in microresonators made of isotropic solid-state materials. Cylindrical and spherical resonators are considered. Each mode has the azimuth, radial, and orbital (for sphere) numbers m, q, and ℓ; its properties are controlled also by the ratio v l / v t . All modes are either transverse (t) or hybrid transverse-longitudinal (tl). Pure l-modes, providing the strongest interaction with optical modes in fibers and bulk crystals, are absent. The tl-modes include distorted Rayleigh waves, the modes with q ˜ 1 and dominating t-part, and pseudo-longitudinal modes with q ≫ 1 , closely spaced frequencies, and weakly localized t-part. They have no analogies to the optical WGMs and are of high relevance for Brillouin lasing in optical microresonators. The actual values of ℓ and m are 10 2 - 10 5 , and the lasing thresholds lie in the μW range. Our findings include exact dispersion equations for acoustic WGMs, which can be solved numerically for ℓ , m ≲ 10 4 , asymptotic tools for ℓ , m ≳ 10 3 , and particular

  7. Volcano monitoring with a multiparametric station placed inside a subhorizontal gallery in Tenerife (Canary Islands)

    NASA Astrophysics Data System (ADS)

    Torres-González, Pedro; Moure-García, David; Luengo-Oroz, Natividad; Jiménez-Mejías, María; Jiménez-Abizanda, Ana Isabel; García-Fraga, Jose Manuel; Soler-Javaloyes, Vicente; Domínguez Cerdeña, Itahiza

    2017-04-01

    Measuring gaseous emissions from a volcano is one of the main tasks in volcano monitoring. These emissions can occur inside an active crater as fumaroles or plumes or along the whole volcanic area as diffuse emissions through porous soils or using preferential paths like dikes, faults or fractures. H2O, CO2, SO2 and H2S are the main species released by volcanoes. Among them, CO2 has received special attention in the last years. It has been used as an unrest and/or eruption early warning signal due to his low magma solubility and easily measurement. In the Canary Islands (oceanic volcanic islands) during the last century hundreds of galleries, subhorizontal drillings with lengths from few meters to kilometers and a 2x2 meters mean section, have been drilled to obtain groundwater. In the island of Tenerife there are about 1200. These infrastructures can cut across some preferential rising paths like dikes or fractures, so they turn to be optimum places to measure volcanic gas emissions. In addition, atmospheric parameters influence significantly decreases inside the galleries. In this work, we present data analysis from a three years registration period of a station placed at 1600 meters from the entrance of a gallery in Tenerife. This station measures several parameters like ambient and soil temperature and CO2 and Radon air concentrations inside the gallery. We also show how outside atmospheric parameters affect the microclimate inside the gallery.

  8. Stress Distribution on Blasting Gallery Barrier Pillar due to Goaf Formation During Extraction

    NASA Astrophysics Data System (ADS)

    Kumar Reddy, Sandi; Sastry, Vedala Rama

    2016-10-01

    Semi-mechanised blasting gallery mining is a sustainable option to achieve higher production and productivity from underground thick coal seams. Judicious design of underground blasting gallery panel requires understanding of stress distribution on barrier pillars during different stages of extraction. This paper presents a study of stress distribution in and around barrier pillar for the different stages of extraction in the blasting gallery panel. Finite difference analysis taken up for final excavation (depillaring) in the panel with different stages of extraction. Analysis revealed that the stress transferred on barrier pillar increased as progress of excavation increased. Maximum stress was observed at a distance of 10 and 12 m from the pillar edge for virgin and goaved out panel sideby respectively, which gradually decreased towards centre of the pillar.

  9. Topological Galleries: A High Level User Interface for Topology Controlled Volume Rendering

    SciTech Connect

    MacCarthy, Brian; Carr, Hamish; Weber, Gunther H.

    2011-06-30

    Existing topological interfaces to volume rendering are limited by their reliance on sophisticated knowledge of topology by the user. We extend previous work by describing topological galleries, an interface for novice users that is based on the design galleries approach. We report three contributions: an interface based on hierarchical thumbnail galleries to display the containment relationships between topologically identifiable features, the use of the pruning hierarchy instead of branch decomposition for contour tree simplification, and drag-and-drop transfer function assignment for individual components. Initial results suggest that this approach suffers from limitations due to rapid drop-off of feature size in the pruning hierarchy. We explore these limitations by providing statistics of feature size as function of depth in the pruning hierarchy of the contour tree.

  10. Using Whispering-Gallery-Mode Resonators for Refractometry

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey; Savchenkov, Anatoliy; Strekalov, Dmitry; Iltchenko, Vladimir; Maleki, Lute

    2010-01-01

    A method of determining the refractive and absorptive properties of optically transparent materials involves a combination of theoretical and experimental analysis of electromagnetic responses of whispering-gallery-mode (WGM) resonator disks made of those materials. The method was conceived especially for use in studying transparent photorefractive materials, for which purpose this method affords unprecedented levels of sensitivity and accuracy. The method is expected to be particularly useful for measuring temporally varying refractive and absorptive properties of photorefractive materials at infrared wavelengths. Still more particularly, the method is expected to be useful for measuring drifts in these properties that are so slow that, heretofore, the properties were assumed to be constant. The basic idea of the method is to attempt to infer values of the photorefractive properties of a material by seeking to match (1) theoretical predictions of the spectral responses (or selected features thereof) of a WGM of known dimensions made of the material with (2) the actual spectral responses (or selected features thereof). Spectral features that are useful for this purpose include resonance frequencies, free spectral ranges (differences between resonance frequencies of adjacently numbered modes), and resonance quality factors (Q values). The method has been demonstrated in several experiments, one of which was performed on a WGM resonator made from a disk of LiNbO3 doped with 5 percent of MgO. The free spectral range of the resonator was approximately equal to 3.42 GHz at wavelengths in the vicinity of 780 nm, the smallest full width at half maximum of a mode was approximately equal to 50 MHz, and the thickness of the resonator in the area of mode localization was 30 microns. In the experiment, laser power of 9 mW was coupled into the resonator with an efficiency of 75 percent, and the laser was scanned over a frequency band 9 GHz wide at a nominal wavelength of

  11. White-Light Whispering-Gallery-Mode Optical Resonators

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute

    2006-01-01

    Whispering-gallery-mode (WGM) optical resonators can be designed to exhibit continuous spectra over wide wavelength bands (in effect, white-light spectra), with ultrahigh values of the resonance quality factor (Q) that are nearly independent of frequency. White-light WGM resonators have potential as superior alternatives to (1) larger, conventional optical resonators in ring-down spectroscopy, and (2) optical-resonator/electro-optical-modulator structures used in coupling of microwave and optical signals in atomic clocks. In these and other potential applications, the use of white-light WGM resonators makes it possible to relax the requirement of high-frequency stability of lasers, thereby enabling the use of cheaper lasers. In designing a white-light WGM resonator, one exploits the fact that the density of the mode spectrum increases predictably with the thickness of the resonator disk. By making the resonator disk sufficiently thick, one can make the frequency differences between adjacent modes significantly less than the spectral width of a single mode, so that the spectral peaks of adjacent modes overlap, making the resonator spectrum essentially continuous. Moreover, inasmuch as the Q values of the various modes are determined primarily by surface Rayleigh scattering that does not depend on mode numbers, all the modes have nearly equal Q. By use of a proper coupling technique, one can ensure excitation of a majority of the modes. For an experimental demonstration of a white-light WGM resonator, a resonator disk 0.5-mm thick and 5 mm in diameter was made from CaF2. The shape of the resonator and the fiberoptic coupling arrangement were as shown in Figure 1. The resonator was excited with laser light having a wavelength of 1,320 nm and a spectral width of 4 kHz. The coupling efficiency exceeded 80 percent at any frequency to which the laser could be set in its tuning range, which was >100-GHz wide. The resonator response was characterized by means of ring

  12. Evaluating two infiltration gallery designs for managed aquifer recharge using secondary treated wastewater.

    PubMed

    Bekele, Elise; Toze, Simon; Patterson, Bradley; Fegg, Wolfgang; Shackleton, Mark; Higginson, Simon

    2013-03-15

    As managed aquifer recharge (MAR) becomes increasingly considered for augmenting water-sensitive urban areas, fundamental knowledge of the achievable scale, longevity and maintenance requirements of different options will become paramount. This paper reports on a 39 month pilot scale MAR scheme that infiltrated secondary treated wastewater through unsaturated sand into a limestone and sand aquifer. Two types of infiltration gallery were constructed to compare their hydraulic performance, one using crushed, graded gravel, the other using an engineered leach drain system (Atlantis Leach System(®)). Both galleries received 25 kL of nutrient-rich, secondary treated wastewater per day. The Atlantis gallery successfully infiltrated 17 ML of treated wastewater over three years. The slotted distribution pipe in the gravel gallery became clogged with plant roots after operating for one year. The infiltration capacity of the gravel gallery could not be restored despite high pressure cleaning, thus it was replaced with an Atlantis system. Reduction in the infiltration capacity of the Atlantis system was only observed when inflow was increased by about 3 fold for two months. The performance of the Atlantis system suggests it is superior to the gravel gallery, requiring less maintenance within at least the time frame of this study. The results from a bromide tracer test revealed a minimum transport time of 3.7 days for the recharged water to reach the water table below 9 m of sand and limestone. This set a limit on the time available for attenuation by natural treatment within the unsaturated zone before it recharged groundwater. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  13. The whispering gallery as an optical component in the X-ray region

    SciTech Connect

    Howells, M.R.

    1995-08-01

    The whispering gallery phenomenon in acoustics has been known and studied for more than a century, and the same effect has been observed to take place with waves other than sound waves. In this paper we review the theoretical basis and attractive features of the whispering gallery as a soft x-ray optical component and indicate some of its potential applications. We then describe what may be its most unique capability which, in favorable cases, is to provide a way. to manipulate the phase difference between the s and p polarization components and thus to generate circularly or elliptically polarized soft x-rays.

  14. Electro-pumped whispering gallery mode ZnO microlaser array

    SciTech Connect

    Zhu, G. Y.; Li, J. T.; Tian, Z. S.; Dai, J.; Wang, Y. Y.; Li, P. L.; Xu, C. X.

    2015-01-12

    By employing vapor-phase transport method, ZnO microrods are fabricated and directly assembled on p-GaN substrate to form a heterostructural microlaser array, which avoids of the relatively complicated etching process comparing previous work. Under applied forward bias, whispering gallery mode ZnO ultraviolet lasing is obtained from the as-fabricated heterostructural microlaser array. The device's electroluminescence originates from three distinct electron-hole recombination processes in the heterojunction interface, and whispering gallery mode ultraviolet lasing is obtained when the applied voltage is beyond the lasing threshold. This work may present a significant step towards future fabrication of a facile technique for micro/nanolasers.

  15. The influence of whispering gallery modes on the far field of ring lasers

    PubMed Central

    Szedlak, Rolf; Holzbauer, Martin; MacFarland, Donald; Zederbauer, Tobias; Detz, Hermann; Andrews, Aaron Maxwell; Schwarzer, Clemens; Schrenk, Werner; Strasser, Gottfried

    2015-01-01

    We introduce ring lasers with continuous π-phase shifts in the second order distributed feedback grating. This configuration facilitates insights into the nature of the modal outcoupling in an optical cavity. The grating exploits the asymmetry of whispering gallery modes and induces a rotation of the far field pattern. We find that this rotation can be connected to the location of the mode relative to the grating. Furthermore, the direction of rotation depends on the radial order of the whispering gallery mode. This enables a distinct identification and characterization of the mode by simple analysis of the emission beam. PMID:26573341

  16. In-fiber whispering-gallery-mode resonator fabricated by femtosecond laser micromachining.

    PubMed

    Shi, Leilei; Zhu, Tao; Huang, Dongmei; Liu, Min; Deng, Ming; Huang, Wei

    2015-08-15

    An in-fiber whispering-gallery-mode resonator fabricated by femtosecond laser micromachining is demonstrated. The cylinder resonator cavity is fabricated by scanning the D-fiber cladding with infrared femtosecond pulses along a cylindrical trace with a radius of 25 μm and height of 20 μm. Quality factor on the order of 10(3) is achieved by smoothing the cavity surface with an ultrasonic cleaner, which is mainly limited by the surface roughness of several hundred nanometers. Resonant characteristics and polarization dependence of the proposed resonator are also studied in detail. Our method takes a step forward in the integration of whispering-gallery-mode resonators.

  17. Blending aesthetics and empirics: teaching health assessment in an art gallery.

    PubMed

    Pardue, Karen T

    2005-07-01

    An art gallery was used successfully as a clinical laboratory for nursing students studying health assessment. Art galleries provide students with a visually rich and stimulating environment that can support the development of astute visual inspection skills. Working in pairs, students examined artwork incorporating design elements common to both physical assessment and artistic inquiry. Students described new learning and clinical application through this innovative laboratory experience. Uniting traditionally empirical coursework with an aesthetic learning opportunity is important in the development of caring, humanistic professionals.

  18. At 1050 Gallery, Block 55, similar view as WA139A25. Joshua ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1050 Gallery, Block 55, similar view as WA-139-A-25. Joshua Hendy Ironworks, Sunnyvale, California, manufactured the mechanical components of this gate control unit. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  19. Artistic Sensibility in the Studio and Gallery Model: Revisiting Process and Product

    ERIC Educational Resources Information Center

    Thompson, Geoffrey

    2009-01-01

    This paper examines the cultivation of artistic sensibility and its impact on the art therapy process and product in a community mental health center. Artistic sensibility embodies the sense of self as an artist through the integration of artistic and aesthetic attributes of self and other. The formation of a gallery to exhibit patient art was…

  20. Durability of visitable concrete sewer gallery under the effect of domestic wastewater

    NASA Astrophysics Data System (ADS)

    Salhi, Aimed; Kriker, Abdelouahed; Tioua, Tahar; Abimiloud, Youcef; Barluenga, Gonzalo

    2016-07-01

    The durability of concrete structures for the disposal of wastewater depends on their behavior when faced to different aggressions such as mechanics, chemical and biological, causing a deterioration often cementing matrix. The deterioration of recent evacuations wastewater infrastructure, made of reinforced concrete less than 15 years ago, has become an important concern. The aim of this study was to investigate the degradation and the factors responsible for the deterioration of the concrete visitable gallery of sewage from the town of Touggourt (south-east of Algeria). Thus, samples from different parts of the gallery were extracted and unaltered samples were selected as a reference. A degraded sample exposed to H2S gas and another sample of the gallery submerged into wastewater were analyzed to characterize the internal and external damage to the gallery as well as the chemical and mineralogical changes. These tests were complemented by a physical and mechanical characterization of the samples. The experimental results showed the strong anisotropy of both internal and external damage.

  1. Linear and nonlinear behavior of crystalline optical whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy A.; Matsko, Andrey B.; Ilchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We demonstrate strong nonlinear behavior of high-Q whispering gallery mode (WGM) resonators made out of various crystals adn devices based on the resonators. The maximum WGM optical Q-fact or achieved at room temperature exceeds 2X10 to the tenth power.

  2. All-optical Photonic Oscillator with High-Q Whispering Gallery Mode Resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy A.; Matsko, Andrey B.; Strekalov, Dmitry; Mohageg, Makan; Iltchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We demonstrated low threshold optical photonic hyper-parametric oscillator in a high-Q 10(exp 10) CaF2 whispering gallery mode resonator which generates stable 8.5 GHz signal. The oscillations result from the resonantly enhanced four wave mixing occurring due to Kerr nonlinearity of the material.

  3. Retention of external and internal markers by southern pine beetles (Coleoptera: Scolytidae) during gallery

    Treesearch

    Douglas J. Rhodes; Jane Leslie Hayes; Chris Steiner

    1998-01-01

    If retained, markers used in mark-release-recapture studies of bark beetle dispersal could provide valuable tools in the determination of post-dispersal fate. Retention of the internal marker rubidium (Rb) and of the external marker fluorescent powder during egg gallery construction, oviposition, and feeding were quantified at intervals from 0 to 96 hours by allowing...

  4. The Spiral Gallery: Non-Market Creativity and Belonging in an Australian Country Town

    ERIC Educational Resources Information Center

    Waitt, Gordon; Gibson, Chris

    2013-01-01

    This paper seeks to explore creative practice in an Australian country town, and in so doing, to unsettle market-orientated interpretations of creativity that privilege the urban. Instead of focusing on creative practice as a means to develop industries, we focus on how creativity is a means to establish a cooperative gallery space that helps to…

  5. Morphology and ecology of Schizosthetus simulatrix (Acari, Mesotigmata) associated with galleries of bark beetles (Scolytidae)

    Treesearch

    Stanislav Klauz; Peter Masan; John C. Moser

    2003-01-01

    The deutonymphal stage and adults of Schizosthetus simulatrix Athias- Henriot, 1982 (Acari, Mesostigmata, Parasitidae), originally known from Canary Islands and Portugal, has been illustrated and described or redescribed, respectively. The subadults of S. simulatk have not previously been described. This very specialised subcorticolous species lives in galleries of...

  6. Contemporary Adult Education Philosophies and Practices in Art Galleries and Museums in Canada and the UK

    ERIC Educational Resources Information Center

    Clover, Darlene E.; Bell, Lorraine

    2013-01-01

    Public art galleries and museums have been mandated to become more relevant and useful to the lived experiences of the broad communities they claim to serve. Adult education has long been part of the work of these institutions, although historically the relationship has been uneasy, and they seldom feature in the adult education literature. To…

  7. A coaxial converter for transforming a whispering gallery mode to the HE sub 11 mode

    SciTech Connect

    Moeller, C.P.; Doane, J.L.

    1991-08-01

    A coaxial analogue of the Vlasov converter is described which transforms a whispering gallery mode into an oversize rectangular TE{sub 01} mode, which can in turn be transformed into the HE{sub 11} mode by standard techniques. 5 refs., 4 figs.

  8. Optical apparatus for conversion of whispering-gallery modes into a free space gaussian like beam

    DOEpatents

    Stallard, B.W.; Makowski, M.A.; Byers, J.A.

    1992-05-19

    An optical converter for efficient conversion of millimeter wavelength whispering-gallery gyrotron output into a linearly polarized, free-space Gaussian-like beam is described. The converter uses a mode-converting taper and three mirror optics. The first mirror has an azimuthal tilt to eliminate the k[sub [phi

  9. Lifelong Learning for People Aged 64+ within the Contemporary Art Gallery Context

    ERIC Educational Resources Information Center

    Goulding, Anna

    2012-01-01

    This paper reports the initial findings from Contemporary Visual Art and Identity Construction--Wellbeing Amongst Older People: a two-year research project that aims to understand how the lives of older people can be improved by examining their use of contemporary visual art in the art gallery and museum. It will focus on data relating to lifelong…

  10. A&M. Hot cell annex (TAN633) interior of operating gallery. Camera ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    A&M. Hot cell annex (TAN-633) interior of operating gallery. Camera probably facing south. At each side of the viewing windows are "master" manipulators which control "slaves" within hot cell. Date: March 2004. INEEL negative no. HD-39-2-3 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  11. Ratiometric detection of oligonucleotide stoichiometry on multifunctional gold nanoparticles by whispering gallery mode biosensing.

    PubMed

    Wu, F C; Wu, Y; Niu, Z; Vollmer, F

    2015-05-07

    A label-free method is developed to ratiometrically determine the stoichiometry of oligonucleotides attached to the surface of gold nanoparticle (GNP) by whispering gallery mode biosensing. Utilizing this scheme, it is furthermore shown that the stoichiometric ratio of GNP attached oligonucleotide species can be controlled by varying the concentration ratio of thiolated oligonucleotides that are used to modify the GNP.

  12. Bringing Image and Language Together: A Workshop at the Lehman College Art Gallery.

    ERIC Educational Resources Information Center

    Wexler, Alice

    2001-01-01

    Discusses a ten day workshop for kindergarten and fourth grade students that centered around the art exhibit "Contemporary Chinese Art and the Literary Culture of China" held at the Lehman College Art Gallery (Bronx, New York). Explains that students created accordion books based on Xing Fei's "Red Book." (CMK)

  13. The Artist-Led Pedagogic Process in the Contemporary Art Gallery: Developing a Meaning Making Framework

    ERIC Educational Resources Information Center

    Pringle, Emily

    2009-01-01

    Drawing on recent research which examined how selected artist educators perceive themselves as arts practitioners and analysed how these constructions inform their pedagogy, this article proposes a framework of meaning making in the art gallery. Art practice is defined as a process of conceptual and experiential enquiry which embraces inspiration,…

  14. The Spiral Gallery: Non-Market Creativity and Belonging in an Australian Country Town

    ERIC Educational Resources Information Center

    Waitt, Gordon; Gibson, Chris

    2013-01-01

    This paper seeks to explore creative practice in an Australian country town, and in so doing, to unsettle market-orientated interpretations of creativity that privilege the urban. Instead of focusing on creative practice as a means to develop industries, we focus on how creativity is a means to establish a cooperative gallery space that helps to…

  15. Active mode-locked lasers and other photonic devices using electro-optic whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey B. (Inventor); Ilchenko, Vladimir (Inventor); Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor)

    2006-01-01

    Techniques and devices using whispering gallery mode (WGM) optical resonators, where the optical materials of the WGM resonators exhibit an electro-optical effect to perform optical modulation. Examples of actively mode-locked lasers and other devices are described.

  16. Nest-Gallery Development and Caste Composition of Isolated Foraging Groups of the Drywood Termite, Incisitermes minor (Isoptera: Kalotermitidae)

    PubMed Central

    Himmi, S. Khoirul; Yoshimura, Tsuyoshi; Yanase, Yoshiyuki; Oya, Masao; Torigoe, Toshiyuki; Akada, Masanori; Imadzu, Setsuo

    2016-01-01

    An X-ray computed-tomographic examination of nest-gallery development from timbers naturally infested by foraging groups of Incisitermes minor colonies was conducted. This study documents the colonization process of I. minor to new timbers and how the isolated groups maintain their nest-gallery system. The results suggested that development of a nest-gallery within a suitable wood item is not random, but shows selection for softer substrate and other adaptations to the different timber environments. Stigmergic coordinations were expressed in dynamic changes of the nest-gallery system; indicated by fortification behavior in sealing and re-opening a tunnel approaching the outer edge of the timber, and accumulating fecal pellets in particular chambers located beneath the timber surface. The study also examines the caste composition of isolated groups to discover how I. minor sustains colonies with and without primary reproductives. PMID:27455332

  17. Nest-Gallery Development and Caste Composition of Isolated Foraging Groups of the Drywood Termite, Incisitermes minor (Isoptera: Kalotermitidae).

    PubMed

    Himmi, S Khoirul; Yoshimura, Tsuyoshi; Yanase, Yoshiyuki; Oya, Masao; Torigoe, Toshiyuki; Akada, Masanori; Imadzu, Setsuo

    2016-07-22

    An X-ray computed-tomographic examination of nest-gallery development from timbers naturally infested by foraging groups of Incisitermes minor colonies was conducted. This study documents the colonization process of I. minor to new timbers and how the isolated groups maintain their nest-gallery system. The results suggested that development of a nest-gallery within a suitable wood item is not random, but shows selection for softer substrate and other adaptations to the different timber environments. Stigmergic coordinations were expressed in dynamic changes of the nest-gallery system; indicated by fortification behavior in sealing and re-opening a tunnel approaching the outer edge of the timber, and accumulating fecal pellets in particular chambers located beneath the timber surface. The study also examines the caste composition of isolated groups to discover how I. minor sustains colonies with and without primary reproductives.

  18. [The gallery forests of the São Francisco river as corridors for Euglossine bees (Hymenoptera: Apidae) from tropical rainforests].

    PubMed

    Moura, Debora C; Schlindwein, Clemens

    2009-01-01

    Euglossini are typical bees of Neotropical rainforests and only a few species occur in the Caatinga. The São Francisco river, which is the only permanent river in the semi-arid NE-Brazil, is bordered by a gallery forest with evergreen leaves. This environment offers flooral rewards along the year. Surveys of euglossine bees by attracting males to scent baits showed that species of the Atlantic Rainforest like Euglossa imperialis Cockerel, E. truncata Moure and Eulaema cingulata Fabricius occur in the gallery forest of the São Francisco river under the semi-arid climate of the caatinga region. These bees are restricted to the gallery forests which function as bio-corridors, and are absent at places where the forests were cut down. This emphasizes the need to protect the threatened gallery forests to maintain biodiversity.

  19. Detection and identification of microparticles/nanoparticles and blood components using optical resonance of whispering-gallery modes in microspheres

    NASA Astrophysics Data System (ADS)

    Tcherniavskaia, E. A.; Saetchnikov, V. A.

    2010-11-01

    We present experimental data on the dependence of optical resonance spectra of whispering-gallery modes in dielectric microspheres on the constituent composition of solutions modeling blood plasma and also containing disease indicators and virus ghosts. We observe substantial changes in the optical resonance spectra of whispering-gallery modes, associated both with a change in the macroscopic parameters of the microsphere environment and with possible interaction between the microsphere surface and components of the solution.

  20. White-Light Whispering Gallery Mode Optical Resonator System and Method

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey B. (Inventor); Savchenkov, Anatoliy A. (Inventor); Maleki, Lute (Inventor)

    2009-01-01

    An optical resonator system and method that includes a whispering-gallery mode (WGM) optical resonator that is capable of resonating across a broad, continuous swath of frequencies is provided. The optical resonator of the system is shaped to support at least one whispering gallery mode and includes a top surface, a bottom surface, a side wall, and a first curved transition region extending between the side wall and the top surface. The system further includes a coupler having a coupling surface which is arranged to face the transition region of the optical resonator and in the vicinity thereof such that an evanescent field emitted from the coupler is capable of being coupled into the optical resonator through the first curved transition region

  1. Frequency Shift of Polar Whispering Gallery Modes Caused by Uniaxial Stress

    NASA Astrophysics Data System (ADS)

    Wagner, H.-P.; Schmitzer, H.; Lutti, J.; Borri, P.; Langbein, W.

    2010-03-01

    Optical whispering gallery modes in small spheres -so called microcavity optical resonators- have been investigated in the past years because they are promising as single virus or single bacterium detectors and as pressure sensors for microfluidic applications. Due to high Q-factors whispering gallery modes are very sensitive to changes of the shape and the refractive index of the sphere. Both can be caused by mechanical stress. A small exerted compressive force will therefore lead to an energy shift of the resonant modes. The relationship between this energy shift and the exerted force depends on the geometry of the experimental setup. We investigated the energy shift of polar modes in polystyrene beads of 45 micron diameter applying an uniaxial force. With increasing force we find a shift to higher energy for resonator modes with different mode order n and number l. The observed results will be compared with model calculations.

  2. From the galleries to the clinic: applying art museum lessons to patient care.

    PubMed

    Miller, Alexa; Grohe, Michelle; Khoshbin, Shahram; Katz, Joel T

    2013-12-01

    Increasingly, medical educators integrate art-viewing into curricular interventions that teach clinical observation-often with local art museum educators. How can cross-disciplinary collaborators explicitly connect the skills learned in the art museum with those used at the bedside? One approach is for educators to align their pedagogical approach using similar teaching methods in the separate contexts of the galleries and the clinic. We describe two linked pedagogical exercises--Visual Thinking Strategies (VTS) in the museum galleries and observation at the bedside--from "Training the Eye: Improving the Art of Physical Diagnosis," an elective museum-based course at Harvard Medical School. It is our opinion that while strategic interactions with the visual arts can improve skills, it is essential for students to apply them in a clinical context with faculty support-requiring educators across disciplines to learn from one another.

  3. Physics. Creating and probing electron whispering-gallery modes in graphene.

    PubMed

    Zhao, Yue; Wyrick, Jonathan; Natterer, Fabian D; Rodriguez-Nieva, Joaquin F; Lewandowski, Cyprian; Watanabe, Kenji; Taniguchi, Takashi; Levitov, Leonid S; Zhitenev, Nikolai B; Stroscio, Joseph A

    2015-05-08

    The design of high-finesse resonant cavities for electronic waves faces challenges due to short electron coherence lengths in solids. Complementing previous approaches to confine electronic waves by carefully positioned adatoms at clean metallic surfaces, we demonstrate an approach inspired by the peculiar acoustic phenomena in whispering galleries. Taking advantage of graphene's gate-tunable light-like carriers, we create whispering-gallery mode (WGM) resonators defined by circular pn junctions, induced by a scanning tunneling probe. We can tune the resonator size and the carrier concentration under the probe in a back-gated graphene device over a wide range. The WGM-type confinement and associated resonances are a new addition to the quantum electron-optics toolbox, paving the way to develop electronic lenses and resonators.

  4. Towards next-generation label-free biosensors: recent advances in whispering gallery mode sensors.

    PubMed

    Kim, Eugene; Baaske, Martin D; Vollmer, Frank

    2017-03-29

    Whispering gallery mode biosensors have been widely exploited over the past decade to study molecular interactions by virtue of their high sensitivity and applicability in real-time kinetic analysis without the requirement to label. There have been immense research efforts made for advancing the instrumentation as well as the design of detection assays, with the common goal of progressing towards real-world sensing applications. We therefore review a set of recent developments made in this field and discuss the requirements that whispering gallery mode label-free sensors need to fulfill for making a real world impact outside of the laboratory. These requirements are directly related to the challenges that these sensors face, and the methods proposed to overcome them are discussed. Moving forward, we provide the future prospects and the potential impact of this technology.

  5. Shooting Gallery Attendance among IDUs in Tijuana and Ciudad Juarez, Mexico: Correlates, Prevention Opportunities, and the Role of the Environment

    PubMed Central

    Philbin, Morgan; Pollini, Robin A.; Ramos, Rebecca; Lozada, Remedios; Brouwer, Kimberly C.; Ramos, Maria Elena; Firestone-Cruz, Michelle; Case, Patricia; Strathdee, Steffanie A.

    2009-01-01

    We identified factors associated with shooting gallery attendance among injection drug users (IDUs) in two Mexico–US border cities. IDUs in Tijuana (n = 222) and Ciudad Juarez (n = 205), Mexico, who were ≥18 years and injected illicit drugs in the last month were recruited using respondent-driven sampling (RDS). An interviewer-administered survey collected sociodemographic and behavioral data. Logistic regression was used to examine correlates of shooting gallery attendance in each of the two cities. Homelessness and being arrested for syringe possession—both structural level factors—were associated with shooting gallery use in both cities. In Ciudad Juarez, younger age and having overdosed were also associated with shooting gallery use. Our study highlights the need for structural interventions that mitigate homelessness among IDUs and facilitate changes in law enforcement practices associated with shooting gallery use. Harm reduction interventions based within shooting galleries should also be considered to prevent transmission of blood-borne pathogens among IDUs. PMID:18369723

  6. [Diversity of filamentous fungi associated with Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae) and its galleries in berries of Coffea canephora (Pierre)].

    PubMed

    Gama, Farah de C; Teixeira, César A D; Garcia, Alvanir; Costa, José N M; Lima, Daniela K S

    2006-01-01

    Field sampling was carried out in Ouro Preto d'Oeste - Rondônia (10 degrees 45'S and 62 degrees 15'W) to evaluate the mycobiota associated with Hypothenemus hampei Ferrari [cuticle, mouth, prothorax (mycangia), gut and feces] and its galleries on berries of Coffea canephora Pierre. Ten genera (201 isolates) were directly related with the insect while five genera (20 isolates) were related with galleries on berries. All the genera identified in the insects were also present in their galleries, what indicates that boring may be an active way of fungi inoculation by H. hampei. The fungi genera were more diverse in the mouth and prothorax of borers, and lower in feces. Fusarium, Penicillium and Geotrichum, with abundance of 55.7, 24.3 and 10.8%, respectively, were dominant genera. In the galleries Fusarium, Geotrichum, Trichoderma and Aspergillus with abundance of 33.3, 29.6, 18.5 and 14.8%, respectively, were dominant genera. The overall presence of Fusarium in coffee berry borer and its galleries) reinforces previous indications of a close interaction between H. hampei-Fusarium. The presence of Aspergillus and Penicillium emphasizes the possibility of "ochratoxin dispersion" by the borer. This work provides the first record of the mycobiota associated with H. hampei in C. canephora. Among the identified genera, Cephalosporium, Geotrichum and Oidiodendrum were recorded for the first time in association with H. hampei and its galleries in C. canephora.

  7. Nanostructuring of poly(diphenylamine) inside the galleries of montmorillonite organo clay through self-assembly approach.

    PubMed

    Gopalan, Anantha Iyengar; Lee, Kwang-Pill; Hong, Mung-Hwa; Santhosh, Padmanabhan; Manesh, Kalayil Manian; Kim, Sang-Ho

    2006-06-01

    Hollow spheres of poly(diphenylamine) (PDPA) was prepared by confining PDPA in the galleries of montmorillonite organo clay modified with organoammonium cations (MMT). At first instant, diphenylamine (DPA) was loaded into the galleries of MMT and subjected to subsequent oxidative polymerization to form PDPA. beta-naphthalene sulfonic acid (NSA) was used as medium to influence self-assembly of DPA inside the galleries of MMT. Polymerization of self assembled structure resulted hollow spheres of PDPA inside galleries of MMT. X-ray diffraction analysis (XRD), field emission transmission electron microscopy (FETEM), Fourier transform infra-red spectroscopy (FT-IR) and thermogravimetric analysis (TGA) were used to characterize the composites. Transmission emission microscopy of the composite shows the hollow spherical morphology of PDPA. FT-IR, UV-Visible spectroscopy, conductivity measurement and X-ray photoelectron spectroscopy were used to characterize the PDPA extracted from MMT galleries. PDPA extracted from MMT galleries was found to have difference in electronic property than PDPA formed by the conventional method, due to the confinement effect.

  8. A&M. TAN607. Interior view of operating gallery in hot shop. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    A&M. TAN-607. Interior view of operating gallery in hot shop. Shielded viewing windows are along right side of corridor. Cabinet on wheels at left of corridor is operating console for hot shop manipulators. When in use, it is stationed at window station and connected to appropriate control cables. note reserve bottles of zinc bromide above each station. Date: January 3, 1955. INEEL negative no. 55-0072 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  9. Semiochemical emission from individual galleries of the southern pine beetle, (Coleoptera: Curculionidae: Scolytinae), attacking standing trees.

    PubMed

    Pureswaran, Deepa S; Sullivan, Brian T

    2012-02-01

    We collected, identified, and quantified volatiles arising from individual gallery entrances of the monogamous bark beetle Dendroctonus frontalis Zimmermann. Samples were collected while the insects were mass attacking mature loblolly pines (Pinus taeda L.) in an established infestation in western Mississippi, 1 August through 3 October 2005. Following volatile sample collection, the entrances were dissected and categorized according to those that 1) contained a solitary female (the gallery initiating sex), 2) contained a pair that had not yet produced an egg gallery, 3) led to an egg gallery with niches and/or eggs, or 4) represented failed attacks (either abandoned or containing dead beetles). The greatest mean release rate of the female-produced aggregation pheromone components frontalin (74 ng/h) and trans-verbenol (0.35 microg/h) was detected from entrances of solitary females, whereas the highest mean quantities of the male-produced multifunctional pheromone components endo-brevicomin (18 ng/h) and verbenone (0.15 microg/h) were detected from entrances of preoviposition beetle pairs. Alpha-pinene, a host-produced monoterpene that functions as a synergist for the aggregation attractant for D. frontalis, was detected from entrances of solitary females and preoviposition pairs at a rate of 0.6 mg/h, or 3-4 orders of magnitude greater than the insect-produced components of the attractant. Our results indicate that the release rates of pheromone components used in published field studies of the chemical ecology of D. frontalis (generally > 0.1 mg/h) represent thousands of 'attack equivalents' or production rates on the scale of a beetle mass attack on a single host. Additionally, our data suggest that the loss in attractiveness of host tissue fully colonized by D. frontalis is because of the disappearance of attractants rather than an increase in inhibitors.

  10. In situ tuning of whispering gallery modes of levitated silica microspheres

    NASA Astrophysics Data System (ADS)

    Minowa, Yosuke; Toyota, Yusuke; Ashida, Masaaki

    2017-06-01

    We demonstrated the tuning of whispering gallery modes (WGMs) of a silica microsphere during optical levitation through the annealing process. We determined the annealing temperature from the power balance between the CO2 laser light heating and several cooling processes. Cooling caused by heat conduction through the surrounding air molecules is the dominant process. We achieved a blue shift of the WGMs as large as 1 \\%, which was observed in the white-light scattering spectrum from the levitated microsphere.

  11. Dynamic Fano-like resonances in erbium-doped whispering-gallery-mode microresonators

    SciTech Connect

    Lei, Fuchuan; Peng, Bo; Özdemir, Şahin Kaya Yang, Lan; Long, Gui Lu

    2014-09-08

    We report Fano-like asymmetric resonances modulated by optical gain in a whispering-gallery-mode resonator fabricated from erbium-doped silica. A time-dependent gain profile leads to dynamically varying sharp asymmetric resonances with features similar to Fano resonances. Depending on the scan speed of the frequency of the probe laser and the pump-probe power ratio, transmission spectra of the active microcavity exhibit a resonance dip, a resonance peak, or a Fano-like resonance.

  12. Hyper-Parametric Oscillations in a Whispering Gallery Mode Fluorite Resonator

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Strekalov, Dmitry; Mohageg, Makan; Ilchenko, Vladimir; Matsko, Andrey; Maleki, Lute

    2004-01-01

    This viewgraph presentation summarizes the hyper-parametric oscillations observations of the fluorite resonator. The reporters have observed various nonlinear effects in ultra-high Q crystalline whispering gallery mode (WGM) resonators. In particular, it was demonstrated a low threshold optical hyper-parametric oscillations in a high-Q (Q=1010) CaF2 WGM resonator. The oscillations result from the resonantly enhanced four-wave-mixing occurring due to Kerr nonlinearity of the material.

  13. Temperature independent tuning of whispering gallery modes in a cryogenic environment.

    PubMed

    Henze, Rico; Ward, Jonathan M; Benson, Oliver

    2013-01-14

    A new tuning method for tuning whispering gallery modes (WGMs) in a cryogenic environment is presented. Within a home-made exchange gas cryostat the applicability of pressure tuning in microbubbles at liquid nitrogen (LN) temperature is shown. The general thermal shift and tuning behavior of borosilicate microbubbles is theoretically analyzed and compared to experimental data. We show that stress/strain tuning using compressed gas is widely unaffected by system temperature.

  14. Efficient frequency generation in phoXonic cavities based on hollow whispering gallery mode resonators

    PubMed Central

    Farnesi, Daniele; Righini, Giancarlo; Nunzi Conti, Gualtiero; Soria, Silvia

    2017-01-01

    We report on nonlinear optical effects on phoxonic cavities based on hollow whispering gallery mode resonators pumped with a continuous wave laser. We observed stimulated scattering effects such as Brillouin and Raman, Kerr effects such as degenerated and non-degenerated four wave mixing, and dispersive wave generation. These effects happened concomitantly. Hollow resonators give rise to a very rich nonlinear scenario due to the coexistence of several family modes. PMID:28266641

  15. Photorefractive tuning of whispering gallery modes of a spherical resonator integrated inside a microstructured optical fibre

    NASA Astrophysics Data System (ADS)

    Kosma, K.; Konidakis, I.; Pissadakis, S.

    2014-09-01

    We demonstrate the photorefractive tuning of the whispering gallery modes of a single BaTiO3 microsphere resonator integrated inside a grapefruit-shaped microstructured optical fibre, upon CW laser irradiation at 532 nm while using irradiation intensities up to 5.5 W/cm2. Temporal evolution results of the WGM spectra are provided with respect to the illumination and relaxation conditions applied.

  16. Tunability and synthetic lineshapes in high-Q optical whispering gallery modes

    NASA Technical Reports Server (NTRS)

    Ilchenko, Vladimir S.; Savchenkov, Anatoliy A.; Matsko, Andrey B.; Maleki, Lute

    2003-01-01

    We demonstrate novel techniques to manipulate spectral properties of high quality factor (Q>107) whispering-gallery modes (WGM) in optical dielectric microresonators. These include permanent frequency trimming of WGM frequencies by means of UV photosensitivity of germanium doped silica resonators electro-optical tuning of WGM in lithium niobate resonators, and cascading of microresonators for obtaining second-order filtering function. We present theoretical interpretation of experimental results, and application example of techniques for photonic microwave filtering.

  17. Presence and diversity of Streptomyces in Dendroctonus and sympatric bark beetle galleries across North America.

    PubMed

    Hulcr, Jiri; Adams, Aaron S; Raffa, Kenneth; Hofstetter, Richard W; Klepzig, Kier D; Currie, Cameron R

    2011-05-01

    Recent studies have revealed several examples of intimate associations between insects and Actinobacteria, including the Southern Pine Beetle Dendroctonus frontalis and the Spruce Beetle Dendroctonus rufipennis. Here, we surveyed Streptomyces Actinobacteria co-occurring with 10 species of Dendroctonus bark beetles across the United States, using both phylogenetic and community ecology approaches. From these 10 species, and 19 other scolytine beetles that occur in the same trees, we obtained 154 Streptomyces-like isolates and generated 16S sequences from 134 of those. Confirmed 16S sequences of Streptomyces were binned into 36 distinct strains using a threshold of 0.2% sequence divergence. The 16S rDNA phylogeny of all isolates does not correlate with the distribution of strains among beetle species, localities, or parts of the beetles or their galleries. However, we identified three Streptomyces strains occurring repeatedly on Dendroctonus beetles and in their galleries. Identity of these isolates was corroborated using a house-keeping gene sequence (efTu). These strains are not confined to a certain species of beetle, locality, or part of the beetle or their galleries. However, their role as residents in the woodboring insect niche is supported by the repeated association of their 16S and efTu from across the continent, and also having been reported in studies of other subcortical insects.

  18. Do isolated gallery-forest trees facilitate recruitment of forest seedlings and saplings in savannna?

    NASA Astrophysics Data System (ADS)

    Azihou, Akomian Fortuné; Glèlè Kakaï, Romain; Sinsin, Brice

    2013-11-01

    Facilitation is an ecological process that allows some species to establish in environments they can hardly afford in the absence of the process. This study investigated if the subcanopy of gallery-forest trees isolated in savanna is suitable for the early recruitment of forest woody species. We measured tree crown area as well as the density of seedlings and saplings of gallery-forest tree species beneath isolated trees and in the savanna matrix along 50 transects of 5-km long and 600 m wide located along four gallery forests. We then tested the nurse-plant effect and Janzen-Connell hypothesis beneath isolated trees. We also examined the relationships between the crown area and the density of seedlings and saplings. Among the eight identified tree species isolated in savanna, only Daniellia oliveri and Khaya senegalensis showed nurse-plant effect and promoted a significant, yet low early recruitment with a seedling-to-sapling survival of 0.044 and 0.578, respectively. The suitability of the subcanopy of isolated trees decreased with the recruitment progression and Janzen-Connell effects were absent. Seedlings had neutral association with the crown area of isolated trees which shifted to positive at the sapling stage. The species of the isolated tree and the crown area explained less than 20% of total variance, indicating that other predictive factors are important in explaining the nurse-plant effect observed in this study.

  19. High Contribution of Gallery Forests to Local Evaporation in Semi-Arid Burkina Faso

    NASA Astrophysics Data System (ADS)

    Ceperley, N. C.; Mande, T.; Tyler, S. W.; Van De Giesen, N.; Rinaldo, A.; Parlange, M. B.

    2014-12-01

    Management of the hydrologic cycle is critical to the primary livelihood of a large part of semi-arid West Africa's primary livelihood, rain-fed farming. We use flux measurements from an eddy-covariance station coupled with a dense network of small wireless meteorological stations to examine the relationship between land surface properties (albedo, soil moisture, and roughness) and evapotranspiration in a small (3.5 km2) catchment in Burkina Faso, West Africa. The catchment is a matrix of savanna and agricultural land maintained under various regimes, providing a comparison of multiple land use types of Sudanian Wooded Savanna including a canyon gallery forest, agroforestry parklands, occasionally grazed semi-open savanna, a semi-closed wooded slope, fallow fields, rice paddies, and ephemeral wetlands. By filtering out times when dry air was entrained, we demonstrate the small control of soil moisture and vegetation on the evaporative fraction, which was not initially visible. Additionally we document the high contribution of the gallery forest to the the catchment evaporation, despite its small size. These small meteorological stations could be paired with currently available satellite data to calculate evaporation over a much larger area, even when eddy-covariance equipment is not available. These findings reinforce local cultural beliefs of the importance of gallery forests for climate regulation and may provide tools to key local decision makers, rural farmers.

  20. High Diversity and Low Specificity of Chaetothyrialean Fungi in Carton Galleries in a Neotropical Ant–Plant Association

    PubMed Central

    Nepel, Maximilian; Voglmayr, Hermann; Schönenberger, Jürg; Mayer, Veronika E.

    2014-01-01

    New associations have recently been discovered between arboreal ants that live on myrmecophytic plants, and different groups of fungi. Most of the – usually undescribed – fungi cultured by the ants belong to the order Chaetothyriales (Ascomycetes). Chaetothyriales occur in the nesting spaces provided by the host plant, and form a major part of the cardboard-like material produced by the ants for constructing nests and runway galleries. Until now, the fungi have been considered specific to each ant species. We focus on the three-way association between the plant Tetrathylacium macrophyllum (Salicaceae), the ant Azteca brevis (Formicidae: Dolichoderinae) and various chaetothyrialean fungi. Azteca brevis builds extensive runway galleries along branches of T. macrophyllum. The carton of the gallery walls consists of masticated plant material densely pervaded by chaetothyrialean hyphae. In order to characterise the specificity of the ant–fungus association, fungi from the runway galleries of 19 ant colonies were grown as pure cultures and analyzed using partial SSU, complete ITS, 5.8S and partial LSU rDNA sequences. This gave 128 different fungal genotypes, 78% of which were clustered into three monophyletic groups. The most common fungus (either genotype or approximate species-level OTU) was found in the runway galleries of 63% of the investigated ant colonies. This indicates that there can be a dominant fungus but, in general, a wider guild of chaetothyrialean fungi share the same ant mutualist in Azteca brevis. PMID:25398091

  1. High diversity and low specificity of chaetothyrialean fungi in carton galleries in a neotropical ant-plant association.

    PubMed

    Nepel, Maximilian; Voglmayr, Hermann; Schönenberger, Jürg; Mayer, Veronika E

    2014-01-01

    New associations have recently been discovered between arboreal ants that live on myrmecophytic plants, and different groups of fungi. Most of the - usually undescribed - fungi cultured by the ants belong to the order Chaetothyriales (Ascomycetes). Chaetothyriales occur in the nesting spaces provided by the host plant, and form a major part of the cardboard-like material produced by the ants for constructing nests and runway galleries. Until now, the fungi have been considered specific to each ant species. We focus on the three-way association between the plant Tetrathylacium macrophyllum (Salicaceae), the ant Azteca brevis (Formicidae: Dolichoderinae) and various chaetothyrialean fungi. Azteca brevis builds extensive runway galleries along branches of T. macrophyllum. The carton of the gallery walls consists of masticated plant material densely pervaded by chaetothyrialean hyphae. In order to characterise the specificity of the ant-fungus association, fungi from the runway galleries of 19 ant colonies were grown as pure cultures and analyzed using partial SSU, complete ITS, 5.8S and partial LSU rDNA sequences. This gave 128 different fungal genotypes, 78% of which were clustered into three monophyletic groups. The most common fungus (either genotype or approximate species-level OTU) was found in the runway galleries of 63% of the investigated ant colonies. This indicates that there can be a dominant fungus but, in general, a wider guild of chaetothyrialean fungi share the same ant mutualist in Azteca brevis.

  2. Integration of Microsphere Resonators with Bioassay Fluidics for Whispering Gallery Mode Imaging

    PubMed Central

    Kim, Daniel C.; Armendariz, Kevin P.

    2013-01-01

    Whispering gallery mode resonators are small, radially symmetric dielectrics that trap light through continuous total internal reflection. The resonant condition at which light is efficiently confined within the structure is linked with refractive index, which has led to the development of sensitive label-free sensing schemes based on whispering gallery mode resonators. One resonator design uses inexpensive high index glass microspheres that offer intrinsically superior optical characteristics, but have proven difficult to multiplex and integrate with the fluidics for sample delivery and fluid exchange necessary for assay development. Recently, we introduced a fluorescence imaging approach that enables large scale multiplexing with microsphere resonators, thus removing one obstacle for assay development. Here we report an approach for microsphere immobilization that overcomes limitations arising from their integration with fluidic delivery. The approach is an adaptation of a calcium-assisted glass bonding method originally developed for microfluidic glass chip fabrication. Microspheres bonded to glass using this technique are shown to be stable with respect to fluid flow and show no detectable loss in optical performance. Measured Q-factors, for example, remain unchanged following sphere bonding to the substrate. The stability of the immobilized resonators is further demonstrated by transferring lipid films onto the immobilized spheres using the Langmuir-Blodgett technique. Bilayers of DOPC doped with GM1 were transferred onto immobilized resonators to detect the binding of cholera toxin to GM1. Binding curves generated from shifts in the whispering gallery mode resonance result in a measured Kd of 1.5 × 10−11 with a limit of detection of 3.3 pM. These results are discussed in terms of future assay development using microsphere resonators. PMID:23615457

  3. Laboratory and In Situ Simulation Tests of the Excavation Damaged Zone Around Galleries in Opalinus Clay

    NASA Astrophysics Data System (ADS)

    Labiouse, Vincent; Vietor, Tim

    2014-01-01

    In the context of nuclear waste disposal in clay formations, laboratory and in situ simulation experiments were performed to study at reduced scale the excavation damaged zone (EDZ) around tunnels in the indurated Opalinus Clay at Mont Terri, Switzerland. In the laboratory, thick-walled hollow cylindrical specimens were subjected to a mechanical unloading mimicking a gallery excavation. In samples cored parallel to bedding, cracks sub-parallel to the bedding planes open and lead to a buckling failure in two regions that extend from the borehole in the direction normal to bedding. The behaviour is clearly anisotropic. On the other hand, in experiments performed on specimens cored perpendicular to bedding, there is no indication of failure around the hole and the response of the hollow cylinder sample is mainly isotropic. The in situ experiment at Mont Terri which consisted in the overcoring of a resin-injected borehole that follows the bedding strike of the Opalinus Clay showed a striking similarity between the induced damaged zone and the fracture pattern observed in the hollow cylinder tests on samples cored parallel to bedding and such a bedding controlled "Excavation" Damaged Zone is as well consistent with the distinct fracture patterns observed at Mont Terri depending on the orientation of holes/galleries with respect to the bedding planes. Interestingly, the damaged zone observed in the hollow cylinder tests on samples cored parallel to bedding and in situ around URL galleries is found to develop in reverse directions in Boom Clay (Mol) and in Opalinus Clay (Mont Terri). This most probably results from different failure mechanisms, i.e. shear failure along conjugated planes in the plastic Boom Clay, but bedding plane splitting and buckling in the indurated Opalinus Clay.

  4. ZnO nanocone: application in fabrication of the smallest whispering gallery optical resonator.

    PubMed

    Yang, Y H; Zhang, Y; Wang, N W; Wang, C X; Li, B J; Yang, G W

    2011-02-01

    ZnO semiconductors at the micro- and nanometre scales are attractive in optical, magnetic, and electronic applications because of their particular features and excellent properties. The whispering gallery mode (WGM) is a general and effective type to amplify the intensity of the luminescence emission, and has gained extensive application in lasing and microcavities. In this contribution, we reported that the smallest whispering gallery optical resonator has been achieved in an individual ZnO nanocone whose diameter gradually reduces from bottom to top in the range of 700 to 50 nm. Using the monochromatic cathodoluminescence (CL) equipment attached at a scanning electron microscopy, we observed the alternating patterns of bright and dark rings from the monochromatic CL image of an individual ZnO nanocone, which is attributed to the WGM-like enhanced luminescence emission when the ZnO nanocone is considered as an optical resonator. The smallest mode number of WGM, N=0, was observed in the ZnO nanocone with a radius of 55 nm for the considered light wavelength of 380 nm, and with a radius of 81 nm for the considered light wavelength of 500 nm, respectively. These results showed that the smallest whispering gallery optical resonator from an individual ZnO nanocone has been fabricated. Experiments are in good agreement with both theoretical predictions and computer simulations based on the finite-difference time domain method with perfectly matched layer boundary conditions. These findings provided valuable information for applications of ZnO micro- and nanostructures in optoelectronic devices.

  5. Orchid bee (Hymenoptera: Apidae) community from a gallery forest in the Brazilian Cerrado.

    PubMed

    Silva, Francinaldo S

    2012-06-01

    The orchid bees are a very important group of pollinators distributed in the Neotropics. Although a lot of studies concerning male euglossine bees have been done in this region, few works have so far been carried out in the Cerrado biome. This manuscript has the main objective to present the orchid bee community from a Gallery Forest in the Northeastern Brazilian Cerrado landscape, taking account the species composition, abundance, seasonality and hourly distribution. Male euglossine bees were collected monthly from October 2007 to May 2009, in the Reserva Florestal da Itamacaoca belonging to the Companhia de Agua e Esgoto do Maranhão, in Chapadinha municipality, Maranhão State. The scents eucalyptol, eugenol and vanillin were utilized, between 07:00 and 17:00hr, to attract the euglossine males. Cotton balls were dampened with the scents and suspended by a string on tree branches 1.5m above soil level, set 8m from one another. The specimens were captured with entomological nets, killed with ethyl acetate and transported to the laboratory to be identified. A total of 158 individuals and 14 species of bees were recorded. The genus Eulaema was the most representative group of euglossine bees in relation to the total number of the sampled individuals, accounting for 50.6% of bees followed by Euglossa (26.6%), Eufriesea (15.2%) and Exaerete (7.6%). The most frequent species were Eulaema nigrita (27.8%), Eulaema cingulara (19%) and Euglossa cordata (18.3%). Many species typical of forested environments were found in samples, like Euglossa avicula, Euglossa violaceifrons and Eulaema meriana, emphasizing the role played by the Gallery Forests as bridge sites to connect the two great biomes of Amazonia and Atlantic Forest. The occurrence of Exaerete guaykuru represents the second record of this species for the Neotropical region, and both records coming from the Gallery Forest zones. The male euglossine bees were sampled mainly in the dry season, where 62.5% of the

  6. Experimental observation of Fano resonance in a single whispering-gallery microresonator

    NASA Astrophysics Data System (ADS)

    Li, Bei-Bei; Xiao, Yun-Feng; Zou, Chang-Ling; Liu, Yong-Chun; Jiang, Xue-Feng; Chen, You-Ling; Li, Yan; Gong, Qihuang

    2011-01-01

    We experimentally observe Fano resonance in a single silica toroidal microresonator, in which two whispering-gallery modes (WGMs) are excited simultaneously through a fiber taper. By adjusting the fiber-cavity coupling strength and the polarization of incident light, the Fano-like resonance line shape can be engineered and further convert to the electromagnetically induced transparency (EIT) like line shape. Our theoretical analysis reveals that both the Fano and EIT resonances originate from an indirect-coupling of two originally orthogonal WGMs, which is mediated by the common fiber taper waveguide. The sharp Fano line shape holds great potential in optical switching and sensitivity-enhanced biochemical sensing.

  7. Initial operation of a high-power whispering-gallery-mode gyrotron

    SciTech Connect

    Felch, K.; Ives, L.; Jongewaard, E.; Jory, H.; Spang, S.

    1987-10-01

    Varian has begun the development of a high-power gyrotron based on a whispering-gallery-mode interaction circuit. The first experimental tube has been designed to generate pulsed output powers up to 1 MW at a frequency of 140 GHz. The tube was also designed for CW operation at power levels of several hundred kilowatts. The overall design of the tube is discussed. Fabrication of the tube is nearing completion and initial tests on the tube will be carried out in the near future. 5 refs., 2 figs.

  8. Distribution, diversity, mesonotal morphology, gallery architecture, and queen physogastry of the termite genus Calcaritermes (Isoptera, Kalotermitidae)

    PubMed Central

    Scheffrahn, Rudolf H.

    2011-01-01

    Abstract An updated New World distribution of the genus Calcaritermes is given along with photographs and a key to the New World species outside Mexico. Calcaritermes recessifrons is found to be a junior synonym of Calcaritermes nigriceps. Except for Calcaritermes temnocephalus, pseudergates of the other seven studied Calcaritermes species possess a mesonotal rasp. The rasps suggest a role in propagation of microbes on gallery surfaces and microbial infusion below the wood surface. Calcaritermes temoncephalus is shown to have an unusually large physogastric queens for a kalotermitid and several species produce large eggs. PMID:22287890

  9. Calculation of the spectrum of whispering gallery modes in cylindrical resonators with perturbed boundary conditions

    SciTech Connect

    Dontsov, A A; Monakhov, A M; Averkiev, Nikita S

    2013-05-31

    The spectrum of whispering gallery modes for resonators with a small deformation of the boundary is calculated analytically. Cylindrical resonators with two different cross sections (segment close to a circle and segment close to a semicircle) are considered. The calculation is performed for resonators with metal boundaries, but the obtained result is a good approximation for dielectric resonators as well. The applicability limits of the found expressions for the spectra are analysed. It is shown that the spectra calculated using the obtained expressions coincide well with computer-calculated spectra. The perturbation-induces changes in the field distribution are qualitatively studied using numerical simulation. (semiconductor lasers. physics and technology)

  10. Formation of whispering gallery modes by scattering of an electromagnetic plane wave by two cylinders

    NASA Astrophysics Data System (ADS)

    Abramov, Arnold; Kostikov, Alexander

    2017-03-01

    We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder.

  11. Strong coupling between whispering gallery modes and chromium ions in ruby

    NASA Astrophysics Data System (ADS)

    Farr, Warrick G.; Goryachev, Maxim; Creedon, Daniel L.; Tobar, Michael E.

    2014-08-01

    We report the study of interactions between cavity photons and paramagnetic Cr3+ spins in a ruby (Cr3+:Al2O3) whispering gallery mode (WGM) resonator. Examining the system at microwave frequencies and millikelvin temperatures, spin-photon couplings up to 610 MHz or about 5% of photon energy are observed between the impurity spins and high quality factor (Q >105) WGM. Large tunability and spin-spin interaction allows operation in the strong coupling regime. The system exhibits behavior not predicted by the usual Tavis-Cummings model because of interactions within the two-level spin bath, and the existence of numerous photonic modes.

  12. Enhanced second harmonic generation in coupled semiconductor whispering gallery mode microresonators

    NASA Astrophysics Data System (ADS)

    Dumeige, Yannick

    2009-02-01

    It has been shown that doubly resonant microcavities can be used to obtain miniaturized parametric devices leading for example to efficient second-harmonic generation (SHG). First we will briefly recall the basic properties of SHG in III-V semiconductor whispering gallery mode microdisks or microrings. Then we will show theoretically that by coupling such microresonators and by using the artificial dispersion of a side-coupled integrated spaced sequence of resonators (SCISSOR) it is possible to adapt the Fresnel phase-matching technique to the case of highly confining waveguides or to enhance the second order nonlinear properties of a semiconductor waveguide by slowing fundamental and second-harmonic waves.

  13. Optical apparatus for conversion of whispering-gallery modes into a free space gaussian like beam

    DOEpatents

    Stallard, Barry W.; Makowski, Michael A.; Byers, Jack A.

    1992-01-01

    An optical converter for efficient conversion of millimeter wavelength whispering-gallery gyrotron output into a linearly polarized, free-space Gaussian-like beam. The converter uses a mode-converting taper and three mirror optics. The first mirror has an azimuthal tilt to eliminate the k.sub..phi. component of the propagation vector of the gyrotron output beam. The second mirror has a twist reflector to linearly polarize the beam. The third mirror has a constant phase surface so the converter output is in phase.

  14. Surface Optomechanics: Calculating Optically Excited Acoustical Whispering Gallery Modes in Microspheres

    DTIC Science & Technology

    2011-07-18

    Spillane, and K. J. Vahala, “ Erbium - doped and Raman microlasers on a silicon chip fabricated by the sol-gel process,” Appl. Phys. Lett. 86(9), 091114 (2005...these acoustic whispering gallery modes is widely used in on- chip microdevices [2,3] to allow Raman- [4] and Erbium - [5] lasers , parametric...Ultralow-threshold Raman laser using a spherical dielectric microcavity,” Nature 415(6872), 621–623 (2002). 5. L. Yang, T. Carmon, B. Min, S. M

  15. Whispering-gallery-mode microdisk lasers produced by femtosecond laser direct writing.

    PubMed

    Ku, Jin-Feng; Chen, Qi-Dai; Zhang, Ran; Sun, Hong-Bo

    2011-08-01

    We report in this Letter fabrication of whispering-gallery-mode microdisk lasers by femtosecond laser direct writing of dye-doped resins. Not only is well-defined disk shape upheld on an inverted cone-shaped supporter, but the disk also exhibits significant lasing actions characteristic of an abrupt increase of light output and the significant narrowing of the spectral lines when the threshold is approached. This work shows that the laser micronanofabrication technology is not only applicable to passive micro-optical components, but also it may play an important role in fabrication of active optoelectronic devices and their integrated photonic circuits.

  16. Plasmon-Coupled Whispering Gallery Modes on Nanodisk Arrays for Signal Enhancements.

    PubMed

    Kang, Tae Young; Lee, Wonju; Ahn, Heesang; Shin, Dong-Myeong; Kim, Chang-Seok; Oh, Jin-Woo; Kim, Donghyun; Kim, Kyujung

    2017-09-15

    Metallic nanostructures including single and double nanodisks are successfully used to enhance the localized electric field in vicinity of microcavity in whispering gallery mode (WGM) sensor. We demonstrate numerical calculations of plasmonic coupling of WGMs to single and double nanodisk arrays on a planar substrate. We then experimentally confirmed that the resonance wavelength of WGM sensor was dramatically shifted by adoption of single and double nanodisks on the surface of microcavity in the WGM sensor. Thus, our approach provides the tunable sensitivity of WGM sensor, and has a great potential to be used in numerous areas where the single biomolecule, protein-protein folding and biomolecular interactions are involved.

  17. Whispering-gallery-mode-resonator-based ultranarrow linewidth external-cavity semiconductor laser.

    PubMed

    Liang, W; Ilchenko, V S; Savchenkov, A A; Matsko, A B; Seidel, D; Maleki, L

    2010-08-15

    We demonstrate a miniature self-injection locked distributed-feedback laser using resonant optical feedback from a high-Q crystalline whispering-gallery-mode resonator. The linewidth reduction factor is greater than 10,000, with resultant instantaneous linewidth of less than 200 Hz. The minimal value of the Allan deviation for the laser-frequency stability is 3 x 10(-12) at the integration time of 20 micros. The laser possesses excellent spectral purity and good long-term stability.

  18. Nanoscale welding aerosol sensing based on whispering gallery modes in a cylindrical silica resonator

    PubMed Central

    Lee, Aram; Mills, Thomas; Xu, Yong

    2015-01-01

    We report an experimental technique where one uses a standard silica fiber as a cylindrical whispering gallery mode (WGM) resonator to sense airborne nanoscale aerosols produced by electric arc welding. We find that the accumulation of aerosols on the resonator surface induces a measurable red-shift in resonance frequency, and establish an empirical relation that links the magnitude of resonance shift with the amount of aerosol deposition. The WGM quality factors, by contrast, do not decrease significantly, even for samples with a large percentage of surface area covered by aerosols. Our experimental results are discussed and compared with existing literature on WGM-based nanoparticle sensing. PMID:25837078

  19. Whispering gallery mode photoemission from self-assembled poly-para-phenylenevinylene microspheres

    SciTech Connect

    Kushida, Soh; Yamamoto, Yohei; Braam, Daniel; Lorke, Axel

    2015-12-31

    Poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMOPPV) self-assembles to form well-defined spheres with several micrometers in diameter upon addition of a methanol vapor into a chloroform solution of MDMOPPV. The single sphere of MDMOPPV with 5.7 µm diameter exhibits whispering gallery mode (WGM) photoemission upon excitation with focused laser beam. The periodic emission lines are characterized by transverse electric and magnetic WGMs, and Q-factor reaches ∼345 at the highest.

  20. Infrared light detection using a whispering-gallery-mode optical microcavity

    SciTech Connect

    Zhu, Jiangang E-mail: ozdemir@seas.wustl.edu Ozdemir, Sahin Kaya E-mail: ozdemir@seas.wustl.edu Yang, Lan E-mail: ozdemir@seas.wustl.edu

    2014-04-28

    We demonstrate a thermal infrared (IR) detector based on an ultra-high-quality-factor (Q) whispering-gallery-mode (WGM) microtoroidal silica resonator and investigate its performance to detect IR radiation at 10 μm wavelength. The bandwidth and the sensitivity of the detector are dependent on the power of a probe laser and the detuning between the probe laser and the resonance frequency of the resonator. The microtoroid IR sensor achieved a noise-equivalent-power (NEP) of 7.46 nW, corresponding to an IR intensity of 0.095 mW/cm{sup 2}.

  1. THz Pyro-Optical Detector Based on LiNbO₃ Whispering Gallery Mode Microdisc Resonator.

    PubMed

    Cosci, Alessandro; Cerminara, Matteo; Conti, Gualtiero Nunzi; Soria, Silvia; Righini, Giancarlo C; Pelli, Stefano

    2017-01-28

    This study analyzes the capabilities of a LiNbO₃ whispering gallery mode microdisc resonator as a potential bolometer detector in the THz range. The resonator is theoretically characterized in the stationary regime by its thermo-optic and thermal coefficients. Considering a Q-factor of 10⁷, a minimum detectable power of 20 μW was evaluated, three orders of magnitude above its noise equivalent power. This value opens up the feasibility of exploiting LiNbO₃ disc resonators as sensitive room-temperature detectors in the THz range.

  2. Broadband infrared spectroscopy using optical parametric oscillation in a radially-poled whispering gallery resonator.

    PubMed

    Meisenheimer, Sarah-Katharina; Fürst, Josef Urban; Werner, Christoph; Beckmann, Tobias; Buse, Karsten; Breunig, Ingo

    2015-09-07

    We demonstrate optical parametric oscillation in a millimeter-sized whispering gallery resonator suitable for broadband infrared spectroscopy. This nonlinear-optical process is quasi-phase-matched using a radial domain pattern with 30 µm period length, inscribed by calligraphic poling. The output wavelengths are selected in a controlled way over hundreds of nanometers. We achieve this by increasing the temperature of the resonator in steps such that the azimuthal mode number of the pump wave rises by one. As a proof-of-principle experiment, we measure a characteristic resonance of polystyrene in the spectral range of 2.25 - 2.45 µm.

  3. Second-harmonic generation of light at 245 nm in a lithium tetraborate whispering gallery resonator.

    PubMed

    Fürst, Josef U; Buse, Karsten; Breunig, Ingo; Becker, Petra; Liebertz, Josef; Bohatý, Ladislav

    2015-05-01

    A millimeter-sized, monolithic whispering gallery resonator made of a lithium tetraborate, Li2B4O7, crystal was employed for doubly resonant second-harmonic generation with a continuous-wave laser source at 490 nm. An intrinsic quality factor of 2×10(8) was observed at the pump wavelength. A conversion efficiency of 2.2% was attained with 5.9 mW of mode-matched pump power. In the lithium tetraborate resonator, it is feasible to achieve phase-matching of second-harmonic generation for pump wavelengths between 486 and 506 nm.

  4. Non-Lorentzian pump resonances in whispering gallery optical parametric oscillators

    NASA Astrophysics Data System (ADS)

    Breunig, Ingo; Bückle, Anni; Werner, Christoph S.; Buse, Karsten

    2014-03-01

    Whispering gallery optical parametric oscillators are millimeter-sized monolithic sources for tunable coherent light. Several experiments have revealed that during optical parametric oscillation the pump resonance strongly differs from a Lorentzian shape. We theoretically and experimentally analyze these line-shape distortions. It turns out that the line shape of the pump resonance strongly depends on the coupling strength of the pump light and on the loss ratio between generated light and pump light. The line-widths, i.e. the losses, for the light generated by the parametric process can be deduced without measuring them directly.

  5. CaF2 whispering-gallery-mode-resonator stabilized-narrow-linewidth laser.

    PubMed

    Sprenger, B; Schwefel, H G L; Lu, Z H; Svitlov, S; Wang, L J

    2010-09-01

    A fiber laser is stabilized by introducing a calcium fluoride (CaF(2)) whispering-gallery-mode resonator as a filtering element in a ring cavity. It is set up using a semiconductor optical amplifier as a gain medium. The resonator is critically coupled through prisms, and used as a filtering element to suppress the laser linewidth. A three-cornered-hat method is used and shows a stability of 10(-11) after 10 micros. Using the self-heterodyne beat technique, the linewidth is determined to be 13 kHz. This implies an enhancement factor of 10(3) with respect to the passive cavity linewidth.

  6. Whispering gallery mode stabilization of quantum cascade lasers for infrared sensing and spectroscopy

    NASA Astrophysics Data System (ADS)

    Borri, Simone; Siciliani de Cumis, Mario; Insero, Giacomo; Santambrogio, G.; Savchenkov, Anatoliy; Eliyahu, Danny; Ilchenko, Vladimir; Matsko, Andrey; Maleki, Lute; De Natale, Paolo

    2017-02-01

    Narrow-linewidth lasers are key elements in optical metrology and spectroscopy. From their spectral purity, the measurements accuracy and the overall quality of collected data critically depend. Crystalline micro-resonators have undergone an impressive development in the last decade, opening new ways to photonics from the mm to the μm scale. Their wide transparency range and high Q-factor make them suitable for integration in compact apparatuses for precision spectroscopy from the visible to the mid-IR. Here, we present our recent results on frequency stabilization and linewidth narrowing of quantum cascade lasers using crystalline Whispering Gallery Mode Resonators for mid-IR precision spectroscopy.

  7. Plasmonic enhancement of a whispering-gallery-mode biosensor for single nanoparticle detection

    NASA Astrophysics Data System (ADS)

    Shopova, S. I.; Rajmangal, R.; Holler, S.; Arnold, S.

    2011-06-01

    We describe and demonstrate a physical mechanism that substantially enhances the label-free sensitivity of a whispering-gallery-mode biosensor for the detection of individual nanoparticles in aqueous solution. It involves the interaction of dielectric nanoparticle in an equatorial carousel orbit with a plasmonic nanoparticle bound at the microparticle's equator. As the dielectric particle parks to hot spots on the plasmonic particle we observe frequency shifts that are enhanced by a factor of 4, consistent with a simple reactive model. Once optimized the enhancement by this mechanism should exceed several orders of magnitude, putting individual protein within reach.

  8. Spatiotemporal Lugiato-Lefever formalism for Kerr-comb generation in whispering-gallery-mode resonators

    NASA Astrophysics Data System (ADS)

    Chembo, Yanne K.; Menyuk, Curtis R.

    2013-05-01

    We demonstrate that frequency (Kerr) comb generation in whispering-gallery-mode resonators can be modeled by a variant of the Lugiato-Lefever equation that includes higher-order dispersion and nonlinearity. This spatiotemporal model allows us to explore pulse formation in which a large number of modes interact cooperatively. Pulse formation is shown to play a critical role in comb generation, and we find conditions under which single pulses (dissipative solitons) and multiple pulses (rolls) form. We show that a broadband comb is the spectral signature of a dissipative soliton, and we also show that these solitons can be obtained by using a weak anomalous dispersion and subcritical pumping.

  9. Exploring the Frequency Stability Limits of Whispering Gallery Mode Resonators for Metrological Applications

    NASA Technical Reports Server (NTRS)

    Chembo, Yanne K.; Baumgartel, Lukas; Grudinin, Ivan; Strekalov, Dmitry; Thompson, Robert; Yu, Nan

    2012-01-01

    Whispering gallery mode resonators are attracting increasing interest as promising frequency reference cavities. Unlike commonly used Fabry-Perot cavities, however, they are filled with a bulk medium whose properties have a significant impact on the stability of its resonance frequencies. In this context that has to be reduced to a minimum. On the other hand, a small monolithic resonator provides opportunity for better stability against vibration and acceleration. this feature is essential when the cavity operates in a non-laboratory environment. In this paper, we report a case study for a crystalline resonator, and discuss the a pathway towards the inhibition of vibration-and acceleration-induced frequency fluctuations.

  10. Coupler for coupling gyrotron whispering gallery mode RF into HE11 waveguide

    DOEpatents

    Neilson, Jeffrey M

    2015-02-24

    A cylindrical waveguide with a mode converter transforms a whispering gallery mode from a gyrotron cylindrical waveguide with a helical cut launch edge to a quasi-Gaussian beam suitable for conveyance through a corrugated waveguide. This quasi-Gaussian beam is radiated away from the waveguide using a spiral cut launch edge, which is in close proximity to a first mode converting reflector. The first mode converting reflector is coupled to a second mode converting reflector which provides an output free-space HE11 mode wave suitable for direct coupling into a corrugated waveguide. The radiated beam produced at the output of the second mode converting reflector is substantially circular.

  11. Victorian era esthetic and restorative dentistry: an advertising trade card gallery.

    PubMed

    Croll, Theodore P; Swanson, Ben Z

    2006-01-01

    A chief means of print advertising in the Victorian era was the "trade card." Innumerable products, companies, and services were highlighted on colorful chromolithographic trade cards, and these became desirable collectible objects which were pasted into scrapbooks and enjoyed by many families. Dentistry- and oral health-related subjects were often depicted on Victorian trade cards, and esthetic and restorative dentistry themes were featured. This review describes the history of advertising trade cards and offers a photographic gallery of dentistry-related cards of the era.

  12. Vertically-coupled Whispering Gallery Mode Resonator Optical Waveguide, and Methods

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey B. (Inventor); Savchenkov, Anatolly A. (Inventor); Matleki, Lute (Inventor)

    2007-01-01

    A vertically-coupled whispering gallery mode (WGM) resonator optical waveguide, a method of reducing a group velocity of light, and a method of making a waveguide are provided. The vertically-coupled WGM waveguide comprises a cylindrical rod portion having a round cross-section and an outer surface. First and second ring-shaped resonators are formed on the outer surface of the cylindrical rod portion and are spaced from each other along a longitudinal direction of the cylindrical rod. The first and second ringshaped resonators are capable of being coupled to each other by way an evanescent field formed in an interior of the cylindrical rod portion.

  13. Macrobending Loss Measurements of G.657 Fiber with Suppression of Ripple Effect Induced by Whispering Gallery Modes

    NASA Astrophysics Data System (ADS)

    Li, Chunsheng; Wang, Tao; Li, Linyin; Zhang, Xiaoguang

    2016-02-01

    During the macrobending loss performance tests of ITU-T G.657 fiber under small bending radius, the test results show big differencesin many tests for the same test samples and conditions. Research shows that the main reason for the difference is Whispering gallery modes phenomenon in small bending radius [1]. The inappropriate test conditions can affect the accuracy of macrobending loss test results. In the test of product validation and field application, single wavelength light source and optical power meter were often used. How to judge whether there is effect existing and how to remove the Whispering gallery modes influence in the testing process has become the key to correctly test macrobending loss by light source and optical power meter. This paper introduces the method of eliminating Whispering gallery modes effect during the macrobending test under small bending radius by single wavelength light source and optical power meter.

  14. Telerobotic Haptic Exploration in Art Galleries and Museums for Individuals with Visual Impairments.

    PubMed

    Park, Chung Hyuk; Ryu, Eun-Seok; Howard, Ayanna M

    2015-01-01

    This paper presents a haptic telepresence system that enables visually impaired users to explore locations with rich visual observation such as art galleries and museums by using a telepresence robot, a RGB-D sensor (color and depth camera), and a haptic interface. The recent improvement on RGB-D sensors has enabled real-time access to 3D spatial information in the form of point clouds. However, the real-time representation of this data in the form of tangible haptic experience has not been challenged enough, especially in the case of telepresence for individuals with visual impairments. Thus, the proposed system addresses the real-time haptic exploration of remote 3D information through video encoding and real-time 3D haptic rendering of the remote real-world environment. This paper investigates two scenarios in haptic telepresence, i.e., mobile navigation and object exploration in a remote environment. Participants with and without visual impairments participated in our experiments based on the two scenarios, and the system performance was validated. In conclusion, the proposed framework provides a new methodology of haptic telepresence for individuals with visual impairments by providing an enhanced interactive experience where they can remotely access public places (art galleries and museums) with the aid of haptic modality and robotic telepresence.

  15. Room-temperature near-infrared high-Q perovskite whispering-gallery planar nanolasers.

    PubMed

    Zhang, Qing; Ha, Son Tung; Liu, Xinfeng; Sum, Tze Chien; Xiong, Qihua

    2014-10-08

    Near-infrared (NIR) solid-state micro/nanolasers are important building blocks for true integration of optoelectronic circuitry. Although significant progress has been made in III-V nanowire lasers with achieving NIR lasing at room temperature, challenges remain including low quantum efficiencies and high Auger losses. Importantly, the obstacles toward integrating one-dimensional nanowires on the planar ubiquitous Si platform need to be effectively tackled. Here we demonstrate a new family of planar room-temperature NIR nanolasers based on organic-inorganic perovskite CH3NH3PbI(3-a)X(a) (X = I, Br, Cl) nanoplatelets. Their large exciton binding energies, long diffusion lengths, and naturally formed high-quality planar whispering-gallery mode cavities ensure adequate gain and efficient optical feedback for low-threshold optically pumped in-plane lasing. We show that these remarkable wavelength tunable whispering-gallery nanolasers can be easily integrated onto conductive platforms (Si, Au, indium tin oxide, and so forth). Our findings open up a new class of wavelength tunable planar nanomaterials potentially suitable for on-chip integration.

  16. Shielding design of the linear accelerator at RAON: Accelerator tunnel and utility gallery

    NASA Astrophysics Data System (ADS)

    Kim, Suna; Kang, Bo Sun; Lee, Sangjin; Nam, Shinwoo; Chung, Yeonsei

    2015-10-01

    RAON is the first Korean heavy-ion accelerator for various rare-isotope experiments and will be constructed by the year of 2021. The building for the about 550-m-long superconducting linear accelerator at RAON has three divisions in the vertical layout: accelerator tunnel, intermediate tunnel, and utility gallery. One of the requirements for the building design is that the effective dose rate in the utility gallery should be well below the dose limit for workers. Other parts of the building underground are classified as high-radiation zones where access is strictly controlled. The radiation dose distribution in the building has been calculated by using the Monte Carlo transport code MCNPX including the radiation streaming effects through the intermediate tunnel and penetrating holes. We have applied a point beam loss model in which the continuous beam loss along the beam line is treated as an equivalent point loss with a simple target. We describe the details of the calculation and discuss the results.

  17. Optical method for measuring thermal accommodation coefficients using a whispering-gallery microresonator

    NASA Astrophysics Data System (ADS)

    Ganta, D.; Dale, E. B.; Rezac, J. P.; Rosenberger, A. T.

    2011-08-01

    A novel optical method has been developed for the measurement of thermal accommodation coefficients in the temperature-jump regime. The temperature dependence of the resonant frequency of a fused-silica microresonator's whispering-gallery mode is used to measure the rate at which the microresonator comes into thermal equilibrium with the ambient gas. The thermal relaxation time is related to the thermal conductivity of the gas under some simplifying assumptions and measuring this time as a function of gas pressure determines the thermal accommodation coefficient. Using a low-power tunable diode laser of wavelength around 1570 nm to probe a microsphere's whispering-gallery mode through tapered-fiber coupling, we have measured the accommodation coefficients of air, helium, and nitrogen on fused silica at room temperature. In addition, by applying thin-film coatings to the microsphere's surface, we have demonstrated that accommodation coefficients can be measured for various gases on a wide range of modified surfaces using this method.

  18. Flow cytometer system for single-shot biosensing based on whispering gallery modes of fluorescent microspheres

    NASA Astrophysics Data System (ADS)

    Lessard, Reno; Rousseau-Cyr, Olivier; Charlebois, Maxime; Riviere, Christophe; Mermut, Ozzy; Allen, Claudine Nı.

    2013-02-01

    We report an innovative label-free biosensor based on statistical analysis of several whispering gallery modes spectral shifts in polystyrene fluorescent microspheres using a custom microflow cytometer. Whispering gallery modes analysis enables detection of nanometer-sized analytes showing promising possibilities for virus, bacteria and molecular detection. To demonstrate this, fluorophore-doped microspheres of the appropriate size parameter are mixed in an aqueous solution. Then, a syringe pump pushes the solution through a fiber optic flow cell where a laser beam illuminates the analysis area to excite the microspheres and their fluorescence is collected. This device provides a low-cost and user friendly solution that could enhance spectrum acquisition rates up to 5 spectra per second thanks to the considerable amount of microspheres flowing through the excitation area per unit time. Finally, the fluorescence spectra are statistically investigated using an instantaneous measurement of apparent refractive index algorithm to determine a reliable value for the refractive index of the environment since the exact radius of the microsphere scanned is unknown. This refractive index becomes an effective value for the local perturbation caused by inhomogeneities on the microsphere surface and hence, determines whether or not inhomogeneities, such as bacteria, are adsorbed by comparing to a control sample. Combining a flow cell with our detection algorithm, we reduce the period of a 50 microspheres experiment from 161 minutes to 14 minutes when the flow rate is 2000 µl/h and the microsphere concentration is 5 µsphere/µl.

  19. Pseudo-type-II tuning behavior and mode identification in whispering gallery optical parametric oscillators.

    PubMed

    Meisenheimer, Sarah-Katharina; Fürst, Josef Urban; Schiller, Annelie; Holderied, Florian; Buse, Karsten; Breunig, Ingo

    2016-06-27

    Wavelength tuning of conventional mirror-based optical parametric oscillators (OPOs) exhibits parabolically-shaped tuning curves (type-0 and type-I phase matching) or tuning branches that cross each other with a finite slope (type-II phase matching). We predict and experimentally prove that whispering gallery OPOs based on type-0 phase matching show both tuning behaviors, depending on whether the mode numbers of the generated waves coincide or differ. We investigate the wavelength tuning of optical parametric oscillation in a millimeter-sized radially-poled lithium niobate disk pumped at 1 μm wavelength generating signal and idler waves between 1.7 and 2.6 μm wavelength. Our experimental findings excellently coincide with the theoretical predictions. The investigated whispering gallery optical parametric oscillator combines the employment of the highest nonlinear-optical coefficient of the material with a controlled type-II-like wavelength tuning and with the possibility of self-phase locking.

  20. Interfacing whispering-gallery microresonators and free space light with cavity enhanced Rayleigh scattering

    PubMed Central

    Zhu, Jiangang; Özdemir, Şahin K.; Yilmaz, Huzeyfe; Peng, Bo; Dong, Mark; Tomes, Matthew; Carmon, Tal; Yang, Lan

    2014-01-01

    Whispering gallery mode resonators (WGMRs) take advantage of strong light confinement and long photon lifetime for applications in sensing, optomechanics, microlasers and quantum optics. However, their rotational symmetry and low radiation loss impede energy exchange between WGMs and the surrounding. As a result, free-space coupling of light into and from WGMRs is very challenging. In previous schemes, resonators are intentionally deformed to break circular symmetry to enable free-space coupling of carefully aligned focused light, which comes with bulky size and alignment issues that hinder the realization of compact WGMR applications. Here, we report a new class of nanocouplers based on cavity enhanced Rayleigh scattering from nano-scatterer(s) on resonator surface, and demonstrate whispering gallery microlaser by free-space optical pumping of an Ytterbium doped silica microtoroid via the scatterers. This new scheme will not only expand the range of applications enabled by WGMRs, but also provide a possible route to integrate them into solar powered green photonics. PMID:25227918

  1. Mycelial carton galleries of Azteca brevis (Formicidae) as a multi-species network

    PubMed Central

    Mayer, Veronika E.; Voglmayr, Hermann

    2009-01-01

    Apart from growing fungi for nutrition, as seen in the New World Attini, ants cultivate fungi for reinforcement of the walls of their nests or tunnel-shaped runway galleries. These fungi are grown on organic material such as bark, epiphylls or trichomes, and form stable ‘carton structures’. In this study, the carton of the runway galleries built by Azteca brevis (Formicidae, Dolichoderinae) on branches of Tetrathylacium macrophyllum (Flacourtiaceae) is investigated. For the first time, molecular tools are used to address the biodiversity and phylogenetic affinities of fungi involved in tropical ant carton architecture, a previously neglected ant–fungus mutualism. The A. brevis carton involves a complex association of several fungi. All the isolated fungi were unequivocally placed within the Chaetothyriales by DNA sequence data. Whereas five types of fungal hyphae were morphologically distinguishable, our DNA data showed that more species are involved, applying a phylogenetic species concept based on DNA phylogenies and hyphal morphology. In contrast to the New World Attini with their many-to-one (different ant species—one fungal cultivar) pattern, and temperate Lasius with a one-to-two (one ant species—two mutualists) or many-to-one (different ant species share the same mutualist) system, the A. brevis–fungi association is a one-to-many multi-species network. Vertical fungus transmission has not yet been found, indicating that the A. brevis–fungi interaction is rather generalized. PMID:19556257

  2. Mycelial carton galleries of Azteca brevis (Formicidae) as a multi-species network.

    PubMed

    Mayer, Veronika E; Voglmayr, Hermann

    2009-09-22

    Apart from growing fungi for nutrition, as seen in the New World Attini, ants cultivate fungi for reinforcement of the walls of their nests or tunnel-shaped runway galleries. These fungi are grown on organic material such as bark, epiphylls or trichomes, and form stable 'carton structures'. In this study, the carton of the runway galleries built by Azteca brevis (Formicidae, Dolichoderinae) on branches of Tetrathylacium macrophyllum (Flacourtiaceae) is investigated. For the first time, molecular tools are used to address the biodiversity and phylogenetic affinities of fungi involved in tropical ant carton architecture, a previously neglected ant-fungus mutualism. The A. brevis carton involves a complex association of several fungi. All the isolated fungi were unequivocally placed within the Chaetothyriales by DNA sequence data. Whereas five types of fungal hyphae were morphologically distinguishable, our DNA data showed that more species are involved, applying a phylogenetic species concept based on DNA phylogenies and hyphal morphology. In contrast to the New World Attini with their many-to-one (different ant species-one fungal cultivar) pattern, and temperate Lasius with a one-to-two (one ant species-two mutualists) or many-to-one (different ant species share the same mutualist) system, the A. brevis-fungi association is a one-to-many multi-species network. Vertical fungus transmission has not yet been found, indicating that the A. brevis-fungi interaction is rather generalized.

  3. Image Gallery

    MedlinePlus

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  4. Changing the Rules: Making Space for Interactive Learning in the Galleries of the Detroit Institute of Arts

    ERIC Educational Resources Information Center

    Czajkowski, Jennifer Wild

    2011-01-01

    Three years after the Detroit Institute of Arts opened with all new, "visitor-centered" galleries, the museum's executive director of learning and interpretation shares the processes, successes, and lessons learned at an institution that embraced an array of hands-on learning models. The models are discussed as components of a…

  5. Stories from History, Myth, and the Bible. Snite Museum of Art Gallery Guide. Parts 1-3.

    ERIC Educational Resources Information Center

    Matthias, Diana C. J.; Barrett, Jesse

    This art education resource, designed for use in the Snite Museum of Art, may also be used with slides or reproductions. Black and white reproductions are included for each of the art works represented, along with title, artist, date, and media information. This three part gallery guide presents a brief synopsis of the stories narrated in the…

  6. Social Phenomenological Analysis as a Research Method in Art Education: Developing an Empirical Model for Understanding Gallery Talks

    ERIC Educational Resources Information Center

    Hofmann, Fabian

    2016-01-01

    Social phenomenological analysis is presented as a research method to study gallery talks or guided tours in art museums. The research method is based on the philosophical considerations of Edmund Husserl and sociological/social science concepts put forward by Max Weber and Alfred Schuetz. Its starting point is the everyday lifeworld; the…

  7. A Survey on the Influence of Titles on the Visitor's Interpretation and Learning in Art Galleries: An Iranian Context

    ERIC Educational Resources Information Center

    Samanian, Kouros; Nedaeifar, Hoda; Karimi, Ma'soumeh

    2016-01-01

    As previous studies suggest, titles of works of art have generally proven to be influential elements in reading and interpretation of the artworks. In the exhibition context, titles can be considered as a physical component of the museum or art gallery's space. According to the relatively new approaches, learning, being a subcategory of…

  8. Beyond the Gallery: Interactions between Audiences, Artists, and Their Art through the Kampala Art Tour 2007-2010

    ERIC Educational Resources Information Center

    Nagawa, Margaret

    2012-01-01

    When one walks into an art gallery in Kampala, the capital city of Uganda, one sees a predominantly non-Ugandan audience. Visitors to homes of Ugandans, even those wealthy enough to afford art, find typically bare walls. This begs broader questions: (1) What is it about the education and presentation of contemporary art that excludes local…

  9. Three-wave mixing with whispering-gallery modes for electro-optic modulation and photonic reception

    NASA Technical Reports Server (NTRS)

    Ilchenko, V. S.; Savchenkov, A. A.; Matsko, A. B.; Maleki, L.

    2002-01-01

    We demonstrate an electro-optic microwave modulator with milliWatt control power and a sub-microWatt photonic receiver based on triply-resonant three-wave mixing in high-Q toroidal lithium niobate cavities with whispering-gallery (WG) modes.

  10. Stories from History, Myth, and the Bible. Snite Museum of Art Gallery Guide. Parts 1-3.

    ERIC Educational Resources Information Center

    Matthias, Diana C. J.; Barrett, Jesse

    This art education resource, designed for use in the Snite Museum of Art, may also be used with slides or reproductions. Black and white reproductions are included for each of the art works represented, along with title, artist, date, and media information. This three part gallery guide presents a brief synopsis of the stories narrated in the…

  11. Beyond the Gallery: Interactions between Audiences, Artists, and Their Art through the Kampala Art Tour 2007-2010

    ERIC Educational Resources Information Center

    Nagawa, Margaret

    2012-01-01

    When one walks into an art gallery in Kampala, the capital city of Uganda, one sees a predominantly non-Ugandan audience. Visitors to homes of Ugandans, even those wealthy enough to afford art, find typically bare walls. This begs broader questions: (1) What is it about the education and presentation of contemporary art that excludes local…

  12. Report on the Library Services Study of April 10, 1979 at the City of Brampton Public Library and Art Gallery.

    ERIC Educational Resources Information Center

    Schrader, Alvin M.

    The quality and success of library services to users at the City of Brampton Public Library and Art Gallery, Ontario, Canada, were investigated through a series of questionnaires, statistical data analyses, and comparisons with past use studies of this and other public libraries. The study utilized the operational methodology outlined by Altman in…

  13. Adult Education for Social and Environmental Change in Contemporary Public Art Galleries and Museums in Canada, Scotland and England

    ERIC Educational Resources Information Center

    Clover, Darlene E.

    2015-01-01

    Historically, pubic art galleries and museums have a well-deserved reputation for elitism, colonialism and exclusion and they are, therefore, frequently omitted from the discourse of adult education. However, the escalating social, cultural and ecological problems of this new century have placed pressure on these public institutions to change and…

  14. Changing the Rules: Making Space for Interactive Learning in the Galleries of the Detroit Institute of Arts

    ERIC Educational Resources Information Center

    Czajkowski, Jennifer Wild

    2011-01-01

    Three years after the Detroit Institute of Arts opened with all new, "visitor-centered" galleries, the museum's executive director of learning and interpretation shares the processes, successes, and lessons learned at an institution that embraced an array of hands-on learning models. The models are discussed as components of a…

  15. Adult Education for Social and Environmental Change in Contemporary Public Art Galleries and Museums in Canada, Scotland and England

    ERIC Educational Resources Information Center

    Clover, Darlene E.

    2015-01-01

    Historically, pubic art galleries and museums have a well-deserved reputation for elitism, colonialism and exclusion and they are, therefore, frequently omitted from the discourse of adult education. However, the escalating social, cultural and ecological problems of this new century have placed pressure on these public institutions to change and…

  16. Large-scale parallel surface functionalization of goblet-type whispering gallery mode microcavity arrays for biosensing applications.

    PubMed

    Bog, Uwe; Brinkmann, Falko; Kalt, Heinz; Koos, Christian; Mappes, Timo; Hirtz, Michael; Fuchs, Harald; Köber, Sebastian

    2014-10-15

    A novel surface functionalization technique is presented for large-scale selective molecule deposition onto whispering gallery mode microgoblet cavities. The parallel technique allows damage-free individual functionalization of the cavities, arranged on-chip in densely packaged arrays. As the stamp pad a glass slide is utilized, bearing phospholipids with different functional head groups. Coated microcavities are characterized and demonstrated as biosensors.

  17. The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna

    PubMed Central

    Machado, Tâmara Dias Oliveira; Minuzzi-Souza, Thaís Tâmara Castro; Ferreira, Tauana de Sousa; Freire, Luciana Pereira; Timbó, Renata Velôzo; Vital, Tamires Emanuele; Nitz, Nadjar; Silva, Mariana Neiva; Santos, Alcinei de Souza; Sales, Nathyla Morgana Cunha; Obara, Marcos Takashi; de Andrade, Andrey José; Gurgel-Gonçalves, Rodrigo

    2017-01-01

    BACKGROUND Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. OBJECTIVE To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. METHODS Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. FINDINGS A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. MAIN CONCLUSIONS These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil. PMID

  18. The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna.

    PubMed

    Machado, Tâmara Dias Oliveira; Minuzzi-Souza, Thaís Tâmara Castro; Ferreira, Tauana de Sousa; Freire, Luciana Pereira; Timbó, Renata Velôzo; Vital, Tamires Emanuele; Nitz, Nadjar; Silva, Mariana Neiva; Santos, Alcinei de Souza; Sales, Nathyla Morgana Cunha; Obara, Marcos Takashi; Andrade, Andrey José de; Gurgel-Gonçalves, Rodrigo

    2017-10-01

    Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil.

  19. Quantum electrodynamics in a whispering-gallery microcavity coated with a polymer nanolayer

    SciTech Connect

    Xiao Yunfeng; Xiao Lixin; Li Yan; Gong Qihuang; Zou Changling; Dong Chunhua; Han Zhengfu; Xue Peng

    2010-05-15

    Quasi-transverse-electric and -transverse-magnetic fundamental whispering gallery modes in a polymer-coated silica microtoroid are theoretically investigated and demonstrated to possess very high-quality factors. The existence of a nanometer-thickness layer not only evidently reduces the cavity mode volume but also draws the maximal electric field's position of the mode to the outside of the silica toroid, where single quantum dots or nanocrystals are located. Both effects result in a strongly enhanced coherent interaction between a single dipole (for example, a single defect center in a diamond crystal) and the quantized cavity mode. Since the coated microtoroid is highly feasible and robust in experiments, it may offer an excellent platform to study strong-coupling cavity quantum electrodynamics, quantum information, and quantum computation.

  20. Enhanced Raman scattering of single nanoparticles in a high-Q whispering-gallery microresonator

    NASA Astrophysics Data System (ADS)

    Liu, Rui-Shan; Jin, Wei-Liang; Yu, Xiao-Chong; Liu, Yong-Chun; Xiao, Yun-Feng

    2015-04-01

    We study Raman scattering of single nanoparticles coupled to a high-Q whispering-gallery microresonator. It is found that cavity resonances greatly enhance the Raman signal, and the enhancement factor is as high as 108. Unlike the noncavity case, the signal power exhibits a nonmonotonic dependence on particle size, and it reaches the maximum when the Rayleigh scattering loss and the cavity intrinsic loss are comparable. We further analyze how the Raman signal intensity is influenced by different parameters including cavity quality factors and taper-cavity coupling strength. The detection limit of observing single-nanoparticle Raman signal is discussed finally. As a potential application, this mechanism may provide an alternative way to detect specific biological targets without the need of precovered biorecognitions.

  1. Fiber ring laser for intracavity sensing using a whispering-gallery-mode resonator.

    PubMed

    Nunzi Conti, G; Berneschi, S; Barucci, A; Cosi, F; Soria, S; Trono, C

    2012-07-01

    Whispering-gallery-mode (WGM) microresonators are used as optical transducers for sensing applications. The typical detection scheme is based on tracking the WGM resonance shift, by scanning with a tunable laser, when a change of the refractive index in the region probed by the WGM takes place. We propose a sensing approach based instead on monitoring the position of the laser line of a fiber ring laser having a WGM microsphere in its loop. We have demonstrated that the induced shift is the same for the ring laser line and for the microsphere resonance. The proposed method requires simpler, cheaper equipment and may also improve the sensor resolution because the ring laser line is much narrower than the microsphere WGM resonance.

  2. Continuous-wave whispering-gallery optical parametric oscillator for high-resolution spectroscopy.

    PubMed

    Werner, Christoph S; Buse, Karsten; Breunig, Ingo

    2015-03-01

    We achieve a continuous operation of a whispering gallery optical parametric oscillator by stabilizing the resonator temperature T on the mK level and simultaneously locking the pump frequency to a cavity resonance using the Pound-Drever-Hall technique. The millimeter-sized device converts several mW of a pump wave at 1040 nm wavelength to signal and idler waves around 2000 nm wavelength with more than 50% efficiency. Over 1 h, power and frequency of the signal wave vary by <±1% and by <±25  MHz, respectively. The latter can be tuned over 480 MHz without a mode hop by changing T over 120 mK. In order to prove the suitability for high-resolution spectroscopy, we scan the signal frequency across the resonance of a Fabry-Perot interferometer resolving nicely its 10 MHz linewidth.

  3. Oscillatory vertical coupling between a whispering-gallery resonator and a bus waveguide.

    PubMed

    Ghulinyan, M; Ramiro-Manzano, F; Prtljaga, N; Guider, R; Carusotto, I; Pitanti, A; Pucker, G; Pavesi, L

    2013-04-19

    We report on a theoretical and experimental study of the optical coupling between a whispering-gallery type resonator and a waveguide lying on different planes. In contrast to the usual in-plane geometry, the present vertical one is characterized by an oscillatory behavior of the effective coupling as a function of the vertical gap. This behavior manifests itself as oscillations in both the resonance peak waveguide transmission and the mode quality factor. An analytical description based on coupled-mode theory and a two-port beam-splitter model of the waveguide-resonator vertical coupling is developed for arbitrary phase-matching conditions and is successfully used to interpret the experimental observations.

  4. Optical sum-frequency generation in a whispering-gallery-mode resonator

    NASA Astrophysics Data System (ADS)

    Strekalov, Dmitry V.; Kowligy, Abijith S.; Huang, Yu-Ping; Kumar, Prem

    2014-05-01

    We demonstrate sum-frequency generation between a telecom wavelength and the Rb D2 line, achieved through natural phase matching in a nonlinear whispering gallery mode resonator. Due to the strong optical field confinement and ultra high Q of the cavity, the process saturates already at sub-mW pump peak power, at least two orders of magnitude lower than in existing waveguide-based devices. The experimental data are in agreement with the nonlinear dynamics and phase matching theory based on spherical geometry. Our experimental and theoretical results point toward a new platform for manipulating the color and quantum states of light waves for applications such as atomic memory based quantum networking and logic operations with optical signals.

  5. Bi-material crystalline whispering gallery mode microcavity structure for thermo-opto-mechanical stabilization

    NASA Astrophysics Data System (ADS)

    Itobe, Hiroki; Nakagawa, Yosuke; Mizumoto, Yuta; Kangawa, Hiroi; Kakinuma, Yasuhiro; Tanabe, Takasumi

    2016-05-01

    We fabricated a calcium fluoride (CaF2) whispering gallery mode (WGM) microcavity with a computer controlled ultra-precision cutting process. We observed a thermo-opto-mechanical (TOM) oscillation in the CaF2 WGM microcavity, which may influence the stability of the optical output when the cavity is employed for Kerr comb generation. We studied experimentally and numerically the mechanism of the TOM oscillation and showed that it is strongly dependent on cavity diameter. In addition, our numerical study suggests that a microcavity structure fabricated with a hybrid material (i.e. CaF2 and silicon), which is compatible with an ultra-high Q and high thermal conductivity, will allow us to reduce the TOM oscillation and stabilize the optical output.

  6. The whispering gallery mode biosensor: label-free detection from virus to single protein

    NASA Astrophysics Data System (ADS)

    Holler, S.; Dantham, V. R.; Keng, D.; Kolchenko, V.; Arnold, S.; Mulroe, Brigid; Paspaley-Grbavac, M.

    2014-08-01

    The whispering gallery mode (WGM) biosensor is a micro-optical platform capable of sensitive label-free detection of biological particles. Described by the reactive sensing principle (RSP), this analytic formulation quantifies the response of the system to the adsorption of bioparticles. Guided by the RSP, the WGM biosensor enabling from detection of virus (e.g., Human Papillomavirus, HPV) to the ultimate goal of single protein detection. The latter was derived from insights into the RSP, which resulted in the development of a hybrid plasmonic WGM biosensor, which has recently demonstrated detection of individual protein cancer markers. Enhancements from bound gold nanoparticles provide the sensitivity to detect single protein molecules (66 kDa) with good signal-to-noise (S/N > 10), and project that detection of proteins as small as 5 kDa.

  7. Broadband light management using low-Q whispering gallery modes in spherical nanoshells.

    PubMed

    Yao, Yan; Yao, Jie; Narasimhan, Vijay Kris; Ruan, Zhichao; Xie, Chong; Fan, Shanhui; Cui, Yi

    2012-02-07

    Light trapping across a wide band of frequencies is important for applications such as solar cells and photodetectors. Here, we demonstrate a new approach to light management by forming whispering-gallery resonant modes inside a spherical nanoshell structure. The geometry of the structure gives rise to a low quality-factor, facilitating the coupling of light into the resonant modes and substantial enhancement of the light path in the active material, thus dramatically improving absorption. Using nanocrystalline silicon (nc-Si) as a model system, we observe broadband absorption enhancement across a large range of incident angles. The absorption of a single layer of 50-nm-thick spherical nanoshells is equivalent to a 1-μm-thick planar nc-Si film. This light-trapping structure could enable the manufacturing of high-throughput ultra-thin film absorbers in a variety of material systems that demand shorter deposition time, less material usage and transferability to flexible substrates.

  8. Microsphere whispering gallery mode coupler based on a S-bend waveguide structure

    NASA Astrophysics Data System (ADS)

    Chiang, Hsin-Tung; Lin, Gi-Zen; Tai, Chao-Yi; Liu, Chia-Jong

    2006-09-01

    Resonant cavities are key components in photonic circuits which provide feedback, wavelength selectivity and energy storage. Microspheres [1], in particular, support ultrahigh-Q whispering gallery modes (WGMs) that may lead to large delays and enhanced optical nonlinearity within several tens of microns length scale. Most of the demonstrated devices to date utilize a tapered fiber to excite the WGMs, however this coupling architecture not only lacks of rigid stability but inhibits dense integration to form more sophisticated planar lightwave circuits (PLCs). Here we report an alternative approach based on evanescent coupling between the microsphere and a S-bend waveguide structure. This approach provides better mechanical stability and is capable for on-chip integration.

  9. Origin of optical losses in gallium arsenide disk whispering gallery resonators.

    PubMed

    Parrain, David; Baker, Christophe; Wang, Guillaume; Guha, Biswarup; Santos, Eduardo Gil; Lemaitre, Aristide; Senellart, Pascale; Leo, Giuseppe; Ducci, Sara; Favero, Ivan

    2015-07-27

    Whispering gallery modes in GaAs disk resonators reach half a million of optical quality factor. These high Qs remain still well below the ultimate design limit set by bending losses. Here we investigate the origin of residual optical dissipation in these devices. A Transmission Electron Microscope analysis is combined with an improved Volume Current Method to precisely quantify optical scattering losses by roughness and waviness of the structures, and gauge their importance relative to intrinsic material and radiation losses. The analysis also provides a qualitative description of the surface reconstruction layer, whose optical absorption is then revealed by comparing spectroscopy experiments in air and in different liquids. Other linear and nonlinear optical loss channels in the disks are evaluated likewise. Routes are given to further improve the performances of these miniature GaAs cavities.

  10. Collective behavior of Cr3 + ions in ruby revealed by whispering gallery modes

    NASA Astrophysics Data System (ADS)

    Bourhill, Jeremy; Goryachev, Maxim; Farr, Warrick G.; Tobar, Michael E.

    2015-08-01

    We present evidence for the collective action of Cr3 + ion impurities in a highly concentrated ruby crystal coupled to microwave whispering gallery modes (WGMs). The cylindrical geometry of the crystal allows the creation of superradiant or "spin-mode" doublets, with spatial structures similar to that of WGMs. The formation of these spin patterns allows us to observe directly different selection rules, namely, wave number and azimuthal phase matching. The demonstration is made via an avoided level crossing between spin and photon mode doublets as well as absence of coupling between spin modes of different wave numbers. The effect is observable due to strong spin-photon coupling (67 MHz) exceeding both spin ensemble and cavity losses as well as the photon doublet splitting. We demonstrate that a four harmonic oscillator model not only with coupling between photon resonances (0.43 MHz) but also with a spin doublet (73 MHz) is necessary to accurately describe these results.

  11. Under-Coupling Whispering Gallery Mode Resonator Applied to Resonant Micro-Optic Gyroscope

    PubMed Central

    Qian, Kun; Tang, Jun; Guo, Hao; Liu, Wenyao; Liu, Jun; Xue, Chenyang; Zheng, Yongqiu; Zhang, Chengfei

    2017-01-01

    As an important sensing element, the whispering gallery mode resonator (WGMR) parameters seriously affect the resonant micro-optic gyroscope (RMOG) performance. This work proposes an under-coupling resonator to improve the resonator’s Q value and to optimize the coupling coefficient to maximize the RMOG’s sensitivity. GeO2-doped silica waveguide-type resonators with different coupling coefficients were simulated, designed, fabricated and tested. An under-coupling ring resonator with a quality factor of 10 million is reported. The RMOG system was built based on this resonator and the scale factor was tested on a uniaxial high-precision rotating platform. Experimental results show that this resonator could improve the RMOG sensitivity by five times. PMID:28067824

  12. Under-Coupling Whispering Gallery Mode Resonator Applied to Resonant Micro-Optic Gyroscope.

    PubMed

    Qian, Kun; Tang, Jun; Guo, Hao; Liu, Wenyao; Liu, Jun; Xue, Chenyang; Zheng, Yongqiu; Zhang, Chengfei

    2017-01-06

    As an important sensing element, the whispering gallery mode resonator (WGMR) parameters seriously affect the resonant micro-optic gyroscope (RMOG) performance. This work proposes an under-coupling resonator to improve the resonator's Q value and to optimize the coupling coefficient to maximize the RMOG's sensitivity. GeO₂-doped silica waveguide-type resonators with different coupling coefficients were simulated, designed, fabricated and tested. An under-coupling ring resonator with a quality factor of 10 million is reported. The RMOG system was built based on this resonator and the scale factor was tested on a uniaxial high-precision rotating platform. Experimental results show that this resonator could improve the RMOG sensitivity by five times.

  13. One-dimensional finite-elements method for the analysis of whispering gallery microresonators.

    PubMed

    Bagheri-Korani, Ebrahim; Mohammad-Taheri, Mahmoud; Shahabadi, Mahmoud

    2014-07-01

    By taking advantage of axial symmetry of the planar whispering gallery microresonators, the three-dimensional (3D) problem of the resonator is reduced to a two-dimensional (2D) one; thus, only the cross section of the resonator needs to be analyzed. Then, the proposed formulation, which works based on a combination of the finite-elements method (FEM) and Fourier expansion of the fields, can be applied to the 2D problem. First, the axial field variation is expressed in terms of a Fourier series. Then, a FEM method is applied to the radial field variation. This formulation yields an eigenvalue problem with sparse matrices and can be solved using a well-known numerical technique. This method takes into account both the radiation loss and the dielectric loss; hence, it works efficiently either for high number or low number modes. Efficiency of the method was investigated by comparison of the results with those of commercial software.

  14. Analysis of borehole expansion and gallery tests in anisotropic rock masses

    USGS Publications Warehouse

    Amadei, B.; Savage, W.Z.

    1991-01-01

    Closed-form solutions are used to show how rock anisotropy affects the variation of the modulus of deformation around the walls of a hole in which expansion tests are conducted. These tests include dilatometer and NX-jack tests in boreholes and gallery tests in tunnels. The effects of rock anisotropy on the modulus of deformation are shown for transversely isotropic and regularly jointed rock masses with planes of transverse isotropy or joint planes parallel or normal to the hole longitudinal axis for plane strain or plane stress condition. The closed-form solutions can also be used when determining the elastic properties of anisotropic rock masses (intact or regularly jointed) in situ. ?? 1991.

  15. Computational model and simulation for the whispering gallery modes inside micro-optical cavity

    NASA Astrophysics Data System (ADS)

    Ali, Amir R.; Erian, Abanoub M.; Shokry, Kirelloss

    2017-05-01

    A computational model for the whispering gallery modes inside a microsphere resonator is presented. In the archetypical microsphere resonator sensor, a tunable laser light beam is injected into an optical fiber and coupled with the resonator's cavity. The resonant optical coupling is achieved by bringing the fiber in the vicinity of the cavity's evanescent field. The transmission spectrum is then observed to detect the WGM shifts. In this paper, two-dimensional models of a single laser source put near the equator of a microsphere are simulated using COMSOL Multi-physics 5.1 electromagnetic waves, beam envelopes library. Afterwards, a three-dimensional model of two laser sources put near the horizontal and vertical equators of a microsphere is computed. The transmission spectrum of both simulations was taken and cross correlation was performed on them. Results show a big similarity between both simulations and could bring a breakthrough in the area of optical sensors.

  16. Focused ion beam engineered whispering gallery mode resonators with open cavity structure.

    PubMed

    Aveline, David C; Baumgartel, Lukas; Ahn, Byungmin; Yu, Nan

    2012-07-30

    We report the realization of an open cavity whispering gallery mode optical resonator, in which the circulating light traverses a free space gap. We utilize focused ion beam microfabrication to precisely cut a 10 μm wide notch into the perimeter of a crystalline disc. We have shown that this modified resonator structure supports high quality modes, and demonstrated qualify factor, Q ~/= 10(6), limited by the notch surface roughness due to the ion milling process. Furthermore, we investigated the spatial profile of the modes inside the open cavity with a microfabricated probe mechanism. This new type of resonator structure facilitates interaction of the cavity's optical field with mechanical resonators as well as individual atoms or molecules.

  17. Voice over: Audio-visual congruency and content recall in the gallery setting.

    PubMed

    Fairhurst, Merle T; Scott, Minnie; Deroy, Ophelia

    2017-01-01

    Experimental research has shown that pairs of stimuli which are congruent and assumed to 'go together' are recalled more effectively than an item presented in isolation. Will this multisensory memory benefit occur when stimuli are richer and longer, in an ecological setting? In the present study, we focused on an everyday situation of audio-visual learning and manipulated the relationship between audio guide tracks and viewed portraits in the galleries of the Tate Britain. By varying the gender and narrative style of the voice-over, we examined how the perceived congruency and assumed unity of the audio guide track with painted portraits affected subsequent recall. We show that tracks perceived as best matching the viewed portraits led to greater recall of both sensory and linguistic content. We provide the first evidence that manipulating crossmodal congruence and unity assumptions can effectively impact memory in a multisensory ecological setting, even in the absence of precise temporal alignment between sensory cues.

  18. Broadband wavelength control for optical parametric oscillation in radially-poled whispering gallery resonators

    NASA Astrophysics Data System (ADS)

    Meisenheimer, Sarah-Katharina; Fürst, Josef U.; Schiller, Annelie; Buse, Karsten; Breunig, Ingo

    2016-03-01

    Broadband infrared spectroscopy employing optical parametric oscillation in bow-tie cavities, including a periodically- poled lithium niobate (PPLN) crystal, is well known. We demonstrate, however, that such spectroscopy is also possible using 2-mm-size monolithic whispering gallery resonators (WGRs). This is achieved in a radially-poled WGR by controlling wavelength tuning despite triple resonance of pump, signal, and idler light. Simulated and measured tuning characteristics of the Type-0 OPOs, pumped at about 1 μm wavelength, coincide. Tuning branches, which are crossed or curved at degeneracy, are present over a spectral range of up to 0.9 µm. As a proof-of-principle experiment, we show that all spectroscopic features of ethanol can be resolved using the idler light between 2.2 and 2.55 μm.

  19. Highly sensitive absorption measurements in lithium niobate using whispering gallery resonators

    NASA Astrophysics Data System (ADS)

    Leidinger, Markus; Buse, Karsten; Breunig, Ingo

    2015-02-01

    The absorption coefficient of undoped, congruently grown lithium niobate (LiNbO3) for ordinarily and extraordinarily polarized light is measured in the wavelength range from 390 to 2600 nm using whispering gallery resonators (WGRs). These monolithic cavities guide light by total internal reflection. Their high Q-factor provides several hundred meters of propagation for the coupled light in millimetre size resonators allowing for the measurement of absorption coefficients below 10-2 cm-1, where standard methods such as Fourier-transform or grating spectroscopy meet their limit. In this work the lowest measured value is 10-4 cm-1 at 1700 nm wavelength. Furthermore, the known OH- overtone at 1470 nm wavelength can be resolved clearly.

  20. Thermal-noise-limited crystalline whispering-gallery-mode resonator for laser stabilization

    SciTech Connect

    Alnis, J.; Wang, C. Y.; Hofer, J.; Haensch, T. W.; Schliesser, A.; Kippenberg, T. J.

    2011-07-15

    We have stabilized an external cavity diode laser to a whispering gallery mode resonator formed by a protrusion of a single-crystal magnesium fluoride cylinder. The cylinder's compact dimensions ((less-or-similar sign)1 cm{sup 3}) reduce the sensitivity to vibrations and simplify the stabilization of its temperature in a compact setup. In a comparison to an ultrastable laser used for precision metrology we determine a minimum Allan deviation of 20 Hz at an optical wavelength of 972 nm, corresponding to a relative Allan deviation of 6x10{sup -14}, at an integration time of 100 ms. This level of instability is compatible with the limits imposed by fundamental fluctuations of the material's refractive index at room temperature.

  1. Cascaded Brillouin lasing in monolithic barium fluoride whispering gallery mode resonators

    SciTech Connect

    Lin, Guoping Diallo, Souleymane; Saleh, Khaldoun; Martinenghi, Romain; Beugnot, Jean-Charles; Sylvestre, Thibaut; Chembo, Yanne K.

    2014-12-08

    We report the observation of stimulated Brillouin scattering and lasing at 1550 nm in barium fluoride (BaF{sub 2}) crystal. Brillouin lasing was achieved with ultra-high quality (Q) factor monolithic whispering gallery mode mm-size disk resonators. Overmoded resonators were specifically used to provide cavity resonances for both the pump and all Brillouin Stokes waves. Single and multiple Brillouin Stokes radiations with frequency shift ranging from 8.2 GHz up to 49 GHz have been generated through cascaded Brillouin lasing. BaF{sub 2} resonator-based Brillouin lasing can find potential applications for high-coherence lasers and microwave photonics.

  2. Lesbian identity and the politics of representation in Betty Parsons's gallery.

    PubMed

    Gibson, A

    1994-01-01

    Although Betty Parsons had been unusually open about her love relationships with women in the twenties and thirties, she later became reticent, retiring to the closet. Her increased discretion after World War II, during the Cold War, coincided with her rise as the art dealer most prominently associated with the international emergence of Abstract Expressionism. Parsons incurred the objections of her Abstract Expressionists, however, by showing artists who included both abstraction and naturalism in their work, such as Sonia Sekula, Forrest Bess, and Hedda Sterne. This article examines her definition of abstraction as difference through her friend Theodoros Stamos's notion of camp and helps to explain her admiration of Barnett Newman despite her refusal to devote her gallery exclusively to his narrower version of significant abstraction.

  3. Tunable whispering gallery modes lasing in dye-doped cholesteric liquid crystal microdroplets

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Li, Hanyang; Zhao, Liyuan; Liu, Yongjun; Liu, Shuangqiang; Yang, Jun

    2016-12-01

    This paper reports the observation of optically pumped whispering gallery mode (WGM) lasing emission from dye-doped emulsion microdroplets of cholesteric liquid crystals (CLCs) suspended in an immiscible aqueous environment. The higher index contrast between the immersion liquid and CLC microdroplet contributes to the generation of WGM resonance so that lasing emission can be realized in the CLC microdroplet via total internal reflection. The WGM lasing nature is verified by numerical simulations as well as experiment of size-dependent lasing action. The lasing wavelength depends on the refractive index of the CLC microdroplet and can be tuned by varying the temperature. A tuning range of 9.1 nm within 6 °C temperature interval is realized in a 20-μm-diameter microdroplet. Such a temperature tunable microlaser is promising for applications of flexible photothermic devices.

  4. 3-D density imaging with muon flux measurements from underground galleries

    NASA Astrophysics Data System (ADS)

    Lesparre, N.; Cabrera, J.; Marteau, J.

    2017-03-01

    Atmospheric muon flux measurements provide information on subsurface density distribution. In this study, muon flux was measured underground, in the Tournemire experimental platform (France). The objective was to image the medium between the galleries and the surface and evaluate the feasibility to detect the presence of discontinuities, for example, produced by secondary subvertical faults or by karstic networks. Measurements were performed from three different sites with a partial overlap of muon trajectories, offering the possibility to seek density variations at different depths. The conversion of the measured muon flux to average density values showed global variations further analysed through a 3-D nonlinear inversion procedure. Main results are the presence of a very low density region at the level of the upper aquifer, compatible with the presence of a karstic network hosting local cavities, and the absence of secondary faults. We discuss the validity of the present results and propose different strategies to improve the accuracy of such measurements and analysis.

  5. Barium fluoride whispering-gallery-mode disk-resonator with one billion quality-factor.

    PubMed

    Lin, Guoping; Diallo, Souleymane; Henriet, Rémi; Jacquot, Maxime; Chembo, Yanne K

    2014-10-15

    We demonstrate a monolithic optical whispering-gallery-mode resonator fabricated with barium fluoride (BaF₂) with an ultra-high quality (Q) factor above 10⁹ at 1550 nm, and measured with both the linewidth and cavity-ring-down methods. Vertical scanning optical profilometry shows that the root mean square surface roughness of 2 nm is achieved for our mm-size disk. To the best of our knowledge, we show for the first time that one billion Q-factor is achievable by precision polishing in relatively soft crystals with mohs hardness of 3. We show that complex thermo-optical dynamics can take place in these resonators. Beside usual applications in nonlinear optics and microwave photonics, high-energy particle scintillation detection utilizing monolithic BaF₂ resonators potentially becomes feasible.

  6. Phase noise of whispering gallery photonic hyper-parametric microwave oscillators.

    PubMed

    Savchenkov, Anatoliy A; Rubiola, Enrico; Matsko, Andrey B; Ilchenko, Vladimir S; Maleki, Lute

    2008-03-17

    We report on the experimental study of phase noise properties of a high frequency photonic microwave oscillator based on four wave mixing in calcium fluoride whispering gallery mode resonators. Specifically, the oscillator generates approximately 8.5 GHz signals with -120 dBc/Hz at 100 kHz from the carrier. The floor of the phase noise is limited by the shot noise of the signal received at the photodetector. We argue that the performance of the oscillator can be significantly improved if one uses extremely high finesse resonators, increases the input optical power, supersaturates the oscillator, and suppresses the residual stimulated Raman scattering in the resonator. We also disclose a method of extremely sensitive measurement of the integral dispersion of millimeter scale dielectric resonators.

  7. III-nitride tunable cup-cavities supporting quasi whispering gallery modes from ultraviolet to infrared

    PubMed Central

    Shubina, T. V.; Pozina, G.; Jmerik, V. N.; Davydov, V. Yu.; Hemmingsson, C.; Andrianov, A. V.; Kazanov, D. R.; Ivanov, S. V.

    2015-01-01

    Rapidly developing nanophotonics needs microresonators for different spectral ranges, formed by chip-compatible technologies. In addition, the tunable ones are much in demand. Here, we present site-controlled III-nitride monocrystal cup-cavities grown by molecular beam epitaxy. The cup-cavities can operate from ultraviolet to near-infrared, supporting quasi whispering gallery modes up to room temperature. Besides, their energies are identical in large ’ripened’ crystals. In these cavities, the refractive index variation near an absorption edge causes the remarkable effect of mode switching, which is accompanied by the spatial redistribution of electric field intensity with concentration of light into a subwavelength volume. Our results shed light on the mode behavior in semiconductor cavities and open the way for single-growth-run manufacturing the devices comprising an active region and a cavity with tunable mode frequencies. PMID:26656267

  8. III-nitride tunable cup-cavities supporting quasi whispering gallery modes from ultraviolet to infrared.

    PubMed

    Shubina, T V; Pozina, G; Jmerik, V N; Davydov, V Yu; Hemmingsson, C; Andrianov, A V; Kazanov, D R; Ivanov, S V

    2015-12-11

    Rapidly developing nanophotonics needs microresonators for different spectral ranges, formed by chip-compatible technologies. In addition, the tunable ones are much in demand. Here, we present site-controlled III-nitride monocrystal cup-cavities grown by molecular beam epitaxy. The cup-cavities can operate from ultraviolet to near-infrared, supporting quasi whispering gallery modes up to room temperature. Besides, their energies are identical in large 'ripened' crystals. In these cavities, the refractive index variation near an absorption edge causes the remarkable effect of mode switching, which is accompanied by the spatial redistribution of electric field intensity with concentration of light into a subwavelength volume. Our results shed light on the mode behavior in semiconductor cavities and open the way for single-growth-run manufacturing the devices comprising an active region and a cavity with tunable mode frequencies.

  9. Whispering gallery mode lasing in optically isolated III-nitride nanorings.

    PubMed

    Li, K H; Cheung, Y F; Choi, H W

    2015-06-01

    III-nitride nanorings fabricated from a combination of hybrid-nanosphere-lithography and laser lift-off processes is demonstrated. Being formed on an interfacial metallic layer optically coupling between the optical ring and its substrate is eliminated, maximizing optical confinement of whispering gallery resonant mode within the ring cavity. The tapered cross-sectional profile also promotes coupling of emitted light into resonant modes. Optically pumped lasing with a dominant peak at 421.5 nm is observed at room temperature, with threshold energy density of ∼6.5  mJ/cm2. Etch-induced sidewall roughness causes scattering of light at the interface to diminish confinement, and is also responsible for the mode-splitting effect according to finite-difference time-domain simulations.

  10. III-nitride tunable cup-cavities supporting quasi whispering gallery modes from ultraviolet to infrared

    NASA Astrophysics Data System (ADS)

    Shubina, T. V.; Pozina, G.; Jmerik, V. N.; Davydov, V. Yu.; Hemmingsson, C.; Andrianov, A. V.; Kazanov, D. R.; Ivanov, S. V.

    2015-12-01

    Rapidly developing nanophotonics needs microresonators for different spectral ranges, formed by chip-compatible technologies. In addition, the tunable ones are much in demand. Here, we present site-controlled III-nitride monocrystal cup-cavities grown by molecular beam epitaxy. The cup-cavities can operate from ultraviolet to near-infrared, supporting quasi whispering gallery modes up to room temperature. Besides, their energies are identical in large ’ripened’ crystals. In these cavities, the refractive index variation near an absorption edge causes the remarkable effect of mode switching, which is accompanied by the spatial redistribution of electric field intensity with concentration of light into a subwavelength volume. Our results shed light on the mode behavior in semiconductor cavities and open the way for single-growth-run manufacturing the devices comprising an active region and a cavity with tunable mode frequencies.

  11. Coherent spectroscopy of rare-earth-metal-ion-doped whispering-gallery-mode resonators

    SciTech Connect

    McAuslan, D. L.; Korystov, D.; Longdell, J. J.

    2011-06-15

    We perform an investigation into the properties of Pr{sup 3+}:Y{sub 2}SiO{sub 5} whispering-gallery-mode resonators as a first step toward achieving the strong coupling regime of cavity QED with rare-earth-metal-ion-doped crystals. Direct measurement of cavity QED parameters are made using photon echoes, giving good agreement with theoretical predictions. By comparing the ions at the surface of the resonator to those in the center, it is determined that the physical process of making the resonator does not negatively affect the properties of the ions. Coupling between the ions and resonator is analyzed through the observation of optical bistability and normal-mode splitting.

  12. Surface-Enhanced Raman Scattering Using Silica Whispering-Gallery Mode Resonators

    NASA Technical Reports Server (NTRS)

    Anderson, Mark S.

    2013-01-01

    The motivation of this work was to have robust spectroscopic sensors for sensitive detection and chemical analysis of organic and molecular compounds. The solution is to use silica sphere optical resonators to provide surface-enhanced spectroscopic signal. Whispering-gallery mode (WGM) resonators made from silica microspheres were used for surface-enhanced Raman scattering (SERS) without coupling to a plasmonic mechanism. Large Raman signal enhancement is observed by exclusively using 5.08-micron silica spheres with 785-nm laser excitation. The advantage of this non-plasmonic approach is that the active substrate is chemically inert silica, thermally stable, and relatively simple to fabricate. The Raman signal enhancement is broadly applicable to a wide range of molecular functional groups including aliphatic hydrocarbons, siloxanes, and esters. Applications include trace organic analysis, particularly for in situ planetary instruments that require robust sensors with consistent response.

  13. The BOSS Emission-line Lens Survey. IV. Smooth Lens Models for the BELLS GALLERY Sample

    NASA Astrophysics Data System (ADS)

    Shu, Yiping; Bolton, Adam S.; Mao, Shude; Kochanek, Christopher S.; Pérez-Fournon, Ismael; Oguri, Masamune; Montero-Dorta, Antonio D.; Cornachione, Matthew A.; Marques-Chaves, Rui; Zheng, Zheng; Brownstein, Joel R.; Ménard, Brice

    2016-12-01

    We present Hubble Space Telescope F606W-band imaging observations of 21 galaxy-Lyα emitter lens candidates in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey (BELLS) for the GALaxy-Lyα EmitteR sYstems (BELLS GALLERY) survey. Seventeen systems are confirmed to be definite lenses with unambiguous evidence of multiple imaging. The lenses are primarily massive early-type galaxies (ETGs) at redshifts of approximately 0.55, while the lensed sources are Lyα emitters (LAEs) at redshifts from two to three. Although most of the lens systems are well fit by smooth lens models consisting of singular isothermal ellipsoids in an external shear field, a thorough exploration of dark substructures in the lens galaxies is required. The Einstein radii of the BELLS GALLERY lenses are, on average, 60% larger than those of the BELLS lenses because of the much higher source redshifts. This will allow for a detailed investigation of the radius evolution of the mass profile in ETGs. With the aid of the average ˜13× lensing magnification, the LAEs are frequently resolved into individual star-forming knots with a wide range of properties. They have characteristic sizes from less than 100 pc to several kiloparsecs, rest-frame far-UV apparent AB magnitudes from 29.6 to 24.2, and typical projected separations of 500 pc to 2 kpc. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. These observations are associated with program #14189.

  14. Directional whispering gallery mode emission from Limaçon-shaped electrically pumped quantum dot micropillar lasers

    NASA Astrophysics Data System (ADS)

    Albert, F.; Hopfmann, C.; Eberspächer, A.; Arnold, F.; Emmerling, M.; Schneider, C.; Höfling, S.; Forchel, A.; Kamp, M.; Wiersig, J.; Reitzenstein, S.

    2012-07-01

    We experimentally demonstrate directional far field emission from whispering gallery modes (WGMs) in electrically driven quantum dot micropillar lasers. In-plane directionality of whispering gallery mode emission is obtained by patterning micropillars with Limaçon-shaped cross-section and an upper air-bridge contact for current injection. The micropillar lasers with radii R0 down to 4.5 μm show Q-factors of 40 000 and threshold currents of 40 μA at low temperature. We achieved a far field divergence of about 30° and a directionality of 1.67 ± 0.15 for an optimal Limaçon deformation factor ɛ ≈ 0.5. Parameter dependent studies of the directional emission as a function of ɛ reveal good qualitative agreement with theoretical predictions.

  15. Label-Free Biological and Chemical Sensing Using Whispering Gallery Mode Optical Resonators: Past, Present, and Future

    PubMed Central

    Su, Judith

    2017-01-01

    Sensitive and rapid label-free biological and chemical sensors are needed for a wide variety of applications including early disease diagnosis and prognosis, the monitoring of food and water quality, as well as the detection of bacteria and viruses for public health concerns and chemical threat sensing. Whispering gallery mode optical resonator based sensing is a rapidly developing field due to the high sensitivity and speed of these devices as well as their label-free nature. Here, we describe the history of whispering gallery mode optical resonator sensors, the principles behind detection, the latest developments in the fields of biological and chemical sensing, current challenges toward widespread adoption of these devices, and an outlook for the future. In addition, we evaluate the performance capabilities of these sensors across three key parameters: sensitivity, selectivity, and speed. PMID:28282881

  16. An ultra-narrow-band optical filter based on whispering-gallery-mode hybrid-microsphere-cavity

    NASA Astrophysics Data System (ADS)

    Wan, Hongdan; Zhu, Haohan; Liu, Linqian; Xu, Ji; Wang, Jin

    2016-10-01

    We demonstrate an ultra-narrow-band mode-selection method based on a hybrid-microsphere-cavity which consists of a coated silica microsphere. Optical field distribution and narrow-band transmission spectrum of the whispering gallery modes (WGM) are investigated by finite-difference time-domain method. WGM transmission spectra are measured for microsphere and tapered fibers with different diameters. A high refractive index layer coated on the microsphere-cavity make the Q factor increased, the transmission spectrum bandwidth compressed and the side-mode suppression ratio increased. Parameters of the hybrid-microsphere-cavity, namely, the coated shell thickness and its refractive index are optimized under different excitation light source as to investigate the whispering-gallery-modes' transmission spectrum. The 3dB bandwidth of the proposed filter can be less than MHz which will have great potential for applications in all-optical sensing and communication systems.

  17. Enhancement of a whispering gallery mode microtoroid resonator by plasmonic triangular gold nanoprism for label-free biosensor applications

    NASA Astrophysics Data System (ADS)

    Nadgaran, H.; Afkhami Garaei, M.

    2015-07-01

    Whispering gallery mode microresonators coupled to plasmonic nanoparticles have shown great promise for ultra-sensitive and label-free biological sensing. We analyze a whispering gallery mode microtoroid biosensor with a triangular gold nanoprism bound to its surface. We choose triangular nanoprism because of its capability of considerable enhancement of electromagnetic field at the tips and because its localized surface plasmon resonance band position is readily tunable. The local electric field enhancement at different points of plasmonic triangular gold nanoprism is calculated and the effect of rounded tip is investigated. This field enhancement permits the detection and characterization of some large protein molecules. We have studied the detection of single bovine serum albumin protein using our hybrid microcavity.

  18. Impact of the photorefractive and pyroelectric-electro-optic effect in lithium niobate on whispering-gallery modes.

    PubMed

    Leidinger, Markus; Werner, Christoph S; Yoshiki, Wataru; Buse, Karsten; Breunig, Ingo

    2016-12-01

    Whispering-gallery resonators made of undoped and MgO-doped congruently grown lithium niobate are used to study electro-optic refractive index changes. Hereby, we focus on the volume photovoltaic and the pyroelectric effect, both providing an electric field driving the electro-optic effect. Our findings indicate that the light-induced photorefractive effect, combining the photovoltaic and electro-optic effect, is present only in the non-MgO-doped lithium niobate for exposure with light having wavelengths of up to 850 nm. This leads to strong resonance frequency shifts of the whispering-gallery modes. No photorefractive effect was observed in the MgO-doped material. One has to be aware that surface charges induced by the pyroelectric effect result in a similar phenomenon and are present in both materials.

  19. Magnetic-field sensor based on whispering-gallery modes in a photonic crystal fiber infiltrated with magnetic fluid.

    PubMed

    Mahmood, Aseel; Kavungal, Vishnu; Ahmed, Sudad S; Farrell, Gerald; Semenova, Yuliya

    2015-11-01

    In this work, a magnetic-field sensor was designed to take advantage of the tunability of the resonance wavelengths of a cylindrical whispering-gallery-mode microresonator. The microresonator is based on a 1.3 cm length of photonic crystal fiber infiltrated with a magnetic fluid containing nanoparticles with diameters of either 5 or 10 nm. The Q-factor achieved for the microresonators was 4.24×10(3) or higher. When a magnetic field is applied, the whispering-gallery-mode resonances shift toward longer wavelengths. The experimentally demonstrated sensitivity of the proposed sensor was as high as 110 pm/mT in the magnetic field range from 0 to 38.7 mT.

  20. Beyond the Gallery Forest: Contrasting Habitat and Diet in Lemur catta Troops at Bezà Mahafaly Special Reserve.

    PubMed

    Yamashita, Nayuta; Sauther, Michelle L; Cuozzo, Frank P; Youssouf Jacky, Ibrahim Antho

    2015-01-01

    Ring-tailed lemurs have been studied intensively in the Parcel 1 gallery forest of Bezà Mahafaly Special Reserve. Here, we report on lemur groups in a mixture of deciduous dry forest and spiny forest just 5 km to the west. Compared to Parcel 1, Parcel 2 (P2) has a lower density of Tamarindus indica, a major dietary plant species for gallery forest lemurs. Recent studies in drier habitats have called into question the association of lemur density and tamarind presence. In order to address this question, we measured forest structure and composition of plant plots between parcels and conducted lemur feeding observations. The trees and shrubs within the parcels did not differ in height or diameter at breast height, but the frequencies of plant species that were common between parcels were significantly different. Numbers of feeding observations on foods common to both parcels did not differ, but their relative rankings within parcels did. Frequencies of food plants corresponded to earlier reports of lemur population densities. However, we found that the ring-tailed lemur diet is a mixture of plants that are eaten in abundance regardless of frequency and those that are locally available. In terms of their reliance on Tamarindus, P2 animals appear intermediate between those in gallery forests and nontamarind sites.

  1. Emergence: A Planetarium and Art Gallery Collaboration Between Artist, Astronomer, and Musician

    NASA Astrophysics Data System (ADS)

    Beaver, J.; Waller, J. B.; Turner, M.

    2011-09-01

    We describe an unusual planetarium program and art gallery exhibition that premiered in Menasha, Wisconsin. Emergence combines fine art and improvisational music with astronomy and physics. The authors, Judith Baker Waller, John Beaver, and Matt Turner, are, respectively, artist, astronomer, and musician. All three acted as partners in planning and executing the final production. The overall goal of Emergence is to use art, music, and natural science each as a point of departure to learn about the others, and to explore the interaction between humans and the natural world and the differences and commonalities between art, science, and music. Of particular interest, the planetarium portion includes techniques that are, so far as we know, unique. Each night the show is different, the details chosen randomly, but always according to the same theoretical scheme. Various elements are parameterized, the show varying with time according to subroutines that dictate the overall pacing and look, but with details always chosen randomly according to prearranged probabilities. We believe that some of these techniques could be of interest to others who wish to explore the unique possibilities of the planetarium as educational performance space. We argue that this provides a useful format for collaborations between artist and scientist, as scientific content can be delivered in a way that is consistent with the concerns of the artist. We describe some of the approaches taken toward these ends in Emergence, and some of the lessons learned about the process of collaboration between a scientist, a visual artist and a performing artist.

  2. Biochemical component identification by plasmonic improved whispering gallery mode optical resonance based sensor

    NASA Astrophysics Data System (ADS)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

    2014-05-01

    Experimental data on detection and identification of variety of biochemical agents, such as proteins, microelements, antibiotic of different generation etc. in both single and multi component solutions under varied in wide range concentration analyzed on the light scattering parameters of whispering gallery mode optical resonance based sensor are represented. Multiplexing on parameters and components has been realized using developed fluidic sensor cell with fixed in adhesive layer dielectric microspheres and data processing. Biochemical component identification has been performed by developed network analysis techniques. Developed approach is demonstrated to be applicable both for single agent and for multi component biochemical analysis. Novel technique based on optical resonance on microring structures, plasmon resonance and identification tools has been developed. To improve a sensitivity of microring structures microspheres fixed by adhesive had been treated previously by gold nanoparticle solution. Another technique used thin film gold layers deposited on the substrate below adhesive. Both biomolecule and nanoparticle injections caused considerable changes of optical resonance spectra. Plasmonic gold layers under optimized thickness also improve parameters of optical resonance spectra. Biochemical component identification has been also performed by developed network analysis techniques both for single and for multi component solution. So advantages of plasmon enhancing optical microcavity resonance with multiparameter identification tools is used for development of a new platform for ultra sensitive label-free biomedical sensor.

  3. All-polymer photonic sensing platform based on whispering-gallery mode microgoblet lasers.

    PubMed

    Wienhold, T; Kraemmer, S; Wondimu, S F; Siegle, T; Bog, U; Weinzierl, U; Schmidt, S; Becker, H; Kalt, H; Mappes, T; Koeber, S; Koos, C

    2015-09-21

    We present an all-polymer photonic sensing platform based on whispering-gallery mode microgoblet lasers integrated into a microfluidic chip. The chip is entirely made from polymers, enabling the use of the devices as low-cost disposables. The microgoblet cavities feature quality factors exceeding 10(5) and are fabricated from poly(methyl methacrylate) (PMMA) using spin-coating, mask-based optical lithography, wet chemical etching, and thermal reflow. In contrast to silica-based microtoroid resonators, this approach replaces technically demanding vacuum-based dry etching and serial laser-based reflow techniques by solution-based processing and parallel thermal reflow. This enables scaling to large-area substrates, and hence significantly reduces device costs. Moreover, the resonators can be fabricated on arbitrary substrate materials, e.g., on transparent and flexible polymer foils. Doping the microgoblets with the organic dye pyrromethene 597 transforms the passive resonators into lasers. Devices have lasing thresholds below 0.6 nJ per pulse and can be efficiently pumped via free-space optics using a compact and low-cost green laser diode. We demonstrate that arrays of microgoblet lasers can be readily integrated into a state-of-the-art microfluidic chip replicated via injection moulding. In a proof-of-principle experiment, we show the viability of the lab-on-a-chip via refractometric sensing, demonstrating a bulk refractive index sensitivity (BRIS) of 10.56 nm per refractive index unit.

  4. Split-disk micro-lasers: Tunable whispering gallery mode cavities

    NASA Astrophysics Data System (ADS)

    Siegle, T.; Remmel, M.; Krämmer, S.; Kalt, H.

    2017-09-01

    Optical micro-cavities of various types have emerged as promising photonic structures, for both the investigation of fundamental science in cavity quantum electrodynamics and simultaneously for various applications, e.g., lasers, filters, or modulators. In either branch a demand for adjustable and tunable photonic devices becomes apparent, which has been mainly based on the modification of the refractive index of the micro-resonators so far. In this paper, we report on a novel type of whispering gallery mode resonator where resonance tuning is achieved by modification of the configuration. This is realized by polymeric split-disks consisting of opposing half-disks with an intermediate air gap. Functionality of the split-disk concept and its figures of merit like low-threshold lasing are demonstrated for laser dye-doped split-disks fabricated by electron beam lithography on Si substrates. Reversible resonance tuning is achieved for split-disks structured onto elastomeric substrates by direct laser writing. The gap width and hence the resonance wavelength can be well-controlled by mechanically stretching the elastomer and exploiting the lateral shrinkage of the substrate. We demonstrate a broad spectral tunability of laser modes by more than three times the free spectral range. These cavities have the potential to form a key element of flexible and tunable photonic circuits based on polymers.

  5. High-power solid-state sapphire whispering gallery mode maser.

    PubMed

    Creedon, Daniel L; Benmessaï, Karim; Tobar, Michael E; Hartnett, John G; Bourgeois, Pierre-Yves; Kersale, Yann; Le Floch, Jean-Michel; Giordano, Vincent

    2010-03-01

    We present new results on a cryogenic solid-state maser frequency standard, which relies on the excitation of whispering gallery (WG) modes within a doped monocrystalline sapphire resonator (alpha-Al2O3). Included substitutively within the highest purity HEMEX-grade sapphire crystal lattice are Fe2+ impurities at a concentration of parts per million, an unavoidable result of the manufacturing process. Mass conversion of Fe2+ to Fe3+ ions was achieved by thermally annealing the sapphire in air. Above-threshold maser oscillation was then excited in the resonator at zero applied DC magnetic field by pumping high-Q WG modes coincident in frequency with the electron spin resonance (ESR) energy levels of the Fe3+ spin population. A 2 stage annealing process was undertaken for a sapphire resonator with exceptionally low Fe3+ concentration, resulting in an improvement of 6 orders of magnitude in output power for this particular crystal, and exceeding the previous best implementation of our scheme in another crystal by nearly 20 dB. This represents an output signal 7 orders of magnitude more powerful than a typical commercial hydrogen maser. At this power level, we estimate a limit on the frequency stability of order 1 x 10(-17)/square root(tau) due to the Schawlow-Townes fundamental thermal noise limit.

  6. Integrating Nanostructured Artificial Receptors with Whispering Gallery Mode Optical Microresonators via Inorganic Molecular Imprinting Techniques

    PubMed Central

    Hammond, G. Denise; Vojta, Adam L.; Grant, Sheila A.; Hunt, Heather K.

    2016-01-01

    The creation of label-free biosensors capable of accurately detecting trace contaminants, particularly small organic molecules, is of significant interest for applications in environmental monitoring. This is achieved by pairing a high-sensitivity signal transducer with a biorecognition element that imparts selectivity towards the compound of interest. However, many environmental pollutants do not have corresponding biorecognition elements. Fortunately, biomimetic chemistries, such as molecular imprinting, allow for the design of artificial receptors with very high selectivity for the target. Here, we perform a proof-of-concept study to show how artificial receptors may be created from inorganic silanes using the molecular imprinting technique and paired with high-sensitivity transducers without loss of device performance. Silica microsphere Whispering Gallery Mode optical microresonators are coated with a silica thin film templated by a small fluorescent dye, fluorescein isothiocyanate, which serves as our model target. Oxygen plasma degradation and solvent extraction of the template are compared. Extracted optical devices are interacted with the template molecule to confirm successful sorption of the template. Surface characterization is accomplished via fluorescence and optical microscopy, ellipsometry, optical profilometry, and contact angle measurements. The quality factors of the devices are measured to evaluate the impact of the coating on device sensitivity. The resulting devices show uniform surface coating with no microstructural damage with Q factors above 106. This is the first report demonstrating the integration of these devices with molecular imprinting techniques, and could lead to new routes to biosensor creation for environmental monitoring. PMID:27314397

  7. Drag detection and identification by whispering gallery mode optical resonance based sensor

    NASA Astrophysics Data System (ADS)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

    2013-06-01

    Experimental data on optical resonance spectra of whispering gallery modes of dielectric microspheres in antibiotic solutions under varied in wide range concentration are represented. Optical resonance was demonstrated could be detected at a laser power of less than 1 microwatt. Several antibiotics of different generations: Amoxicillin, Azithromycin, Cephazolin, Chloramphenicol, Levofloxacin, Lincomicin Benzylpenicillin, Riphampicon both in deionized water and physiological solution had been used for measurements. Both spectral shift and the structure of resonance spectra were of specific interest in this investigation. Drag identification has been performed by developed multilayer perceptron network. The network topology was designed included: a number of the hidden layers of multilayered perceptron, a number of neurons in each of layers, a method of training of a neural network, activation functions of layers, type and size of a deviation of the received values from required values. For a network training the method of the back propagation error in various modifications has been used. Input vectors correspond to 6 classes of biological substances under investigation. The result of classification was considered as positive when each of the region, representing a certain substance in a space: relative spectral shift of an optical resonance maxima - relative efficiency of excitation of WGM, was singly connected. It was demonstrated that the approach described in the paper can be a promising platform for the development of sensitive, lab-on-chip type sensors that can be used as an express diagnostic tools for different drugs and instrumentation for proteomics, genomics, drug discovery, and membrane studies.

  8. Using whispering gallery mode micro lasers for biosensing within undiluted serum

    NASA Astrophysics Data System (ADS)

    Reynolds, Tess; François, Alexandre; Riesen, Nicolas; Turvey, Michelle E.; Nicholls, Stephen J.; Hoffmann, Peter; Monro, Tanya M.

    2016-11-01

    Although whispering gallery mode (WGM) biosensors have shown tremendous potential, they are still yet to find practical use as biomedical diagnostic tools. This is primarily due to the nature of the interrogation mechanism itself which relies on indirect measurement of the binding of a specific biomolecule onto the sensor through the associated refractive index change. Since nonspecific binding cannot be differentiated from the specific interaction of interest, this can result in a high rate of false positive readings when the detection is performed in complex biological samples. Here we show that this inherent limitation can be solved using a relatively simple approach. This approach involves the development of a self-referenced biosensor consisting of two almost identically sized dye-doped polystyrene microspheres placed on adjacent holes at the tip of a suspended core optical fiber. Here self-referenced biosensing is demonstrated with the detection of Neutravidin in undiluted human serum samples. The fiber allows remote excitation and collection of the WGMs of the microspheres in a dip sensing setting. By taking advantage of surface functionalization techniques, one microsphere acts as a dynamic reference, compensating for nonspecific binding events, while the other microsphere is functionalized to detect the specific interaction. The almost identical size allows the two spheres to have virtually identical refractive index sensitivity and surface area. This ensures their responses to nonspecific binding and environmental changes are almost identical, whereby any specific changes such as binding events, can be monitored via the relative movement between the two sets of WGM peaks.

  9. Optimally Coherent Kerr Combs Generated with Crystalline Whispering Gallery Mode Resonators for Ultrahigh Capacity Fiber Communications

    NASA Astrophysics Data System (ADS)

    Pfeifle, Joerg; Coillet, Aurélien; Henriet, Rémi; Saleh, Khaldoun; Schindler, Philipp; Weimann, Claudius; Freude, Wolfgang; Balakireva, Irina V.; Larger, Laurent; Koos, Christian; Chembo, Yanne K.

    2015-03-01

    Optical Kerr frequency combs are known to be effective coherent multiwavelength sources for ultrahigh capacity fiber communications. These combs are the frequency-domain counterparts of a wide variety of spatiotemporal dissipative structures, such as cavity solitons, chaos, or Turing patterns (rolls). In this Letter, we demonstrate that Turing patterns, which correspond to the so-called primary combs in the spectral domain, are optimally coherent in the sense that for the same pump power they provide the most robust carriers for coherent data transmission in fiber communications using advanced modulation formats. Our model is based on a stochastic Lugiato-Lefever equation which accounts for laser pump frequency jitter and amplified spontaneous emission noise induced by the erbium-doped fiber amplifier. Using crystalline whispering-gallery-mode resonators with quality factor Q ˜109 for the comb generation, we show that when the noise is accounted for, the coherence of a primary comb is significantly higher than the coherence of their solitonic or chaotic counterparts for the same pump power. In order to confirm this theoretical finding, we perform an optical fiber transmission experiment using advanced modulation formats, and we show that the coherence of the primary comb is high enough to enable data transmission of up to 144 Gbit /s per comb line, the highest value achieved with a Kerr comb so far. This performance evidences that compact crystalline photonic systems have the potential to play a key role in a new generation of coherent fiber communication networks, alongside fully integrated systems.

  10. Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets

    PubMed Central

    Wildgen, Sarah M.; Dunn, Robert C.

    2015-01-01

    Rapid biosensing requires fast mass transport of the analyte to the surface of the sensing element. To optimize analysis times, both mass transport in solution and the geometry and size of the sensing element need to be considered. Small dielectric spheres, tens of microns in diameter, can act as label-free biosensors using whispering gallery mode (WGM) resonances. WGM resonances are sensitive to the effective refractive index, which changes upon analyte binding to recognition sites on functionalized resonators. The spherical geometry and tens of microns diameter of these resonators provides an efficient target for sensing while their compact size enables detection in limited volumes. Here, we explore conditions leading to rapid analyte detection using WGM resonators as label-free sensors in 10 μL sample droplets. Droplet evaporation leads to potentially useful convective mixing, but also limits the time over which analysis can be completed. We show that active droplet mixing combined with initial binding rate measurements is required for accurate nanomolar protein quantification within the first minute following injection. PMID:25806835

  11. A Guide to Quantitative Biomarker Assay Development using Whispering Gallery Mode Biosensors.

    PubMed

    Robison, Heather M; Bailey, Ryan C

    2017-09-14

    Whispering gallery mode (WGM) sensors are a class of powerful analytical techniques defined by the measurement of changes in the local refractive index at or near the sensor surface. When functionalized with target-specific capture agents, analyte binding can be measured with very low limits of detection. There are many geometric manifestations of WGM sensors, with chip-integrated silicon photonic devices first commercialized because of the robust, wafer-scale device fabrication, facile optical interrogation, and amenability to the creation of multiplexed sensor arrays. Using these arrays, a number of biomolecular targets have been detected in both label-free and label-enhanced assay formats. For example, sub-picomolar detection limits for multiple cytokines were achieved using an enzymatically enhanced sandwich immunoassay that showed high analyte specificity suitable for detection in complex, clinical matrices. This protocol describes a generalizable approach for the development of quantitative, multiplexed immunoassays using silicon photonic microrings as an example WGM platform. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley and Sons, Inc.

  12. Superpersistent currents and whispering gallery modes in relativistic quantum chaotic systems

    PubMed Central

    Xu, Hongya; Huang, Liang; Lai, Ying-Cheng; Grebogi, Celso

    2015-01-01

    Persistent currents (PCs), one of the most intriguing manifestations of the Aharonov-Bohm (AB) effect, are known to vanish for Schrödinger particles in the presence of random scatterings, e.g., due to classical chaos. But would this still be the case for Dirac fermions? Addressing this question is of significant value due to the tremendous recent interest in two-dimensional Dirac materials. We investigate relativistic quantum AB rings threaded by a magnetic flux and find that PCs are extremely robust. Even for highly asymmetric rings that host fully developed classical chaos, the amplitudes of PCs are of the same order of magnitude as those for integrable rings, henceforth the term superpersistent currents (SPCs). A striking finding is that the SPCs can be attributed to a robust type of relativistic quantum states, i.e., Dirac whispering gallery modes (WGMs) that carry large angular momenta and travel along the boundaries. We propose an experimental scheme using topological insulators to observe and characterize Dirac WGMs and SPCs, and speculate that these features can potentially be the base for a new class of relativistic qubit systems. Our discovery of WGMs in relativistic quantum systems is remarkable because, although WGMs are common in photonic systems, they are relatively rare in electronic systems. PMID:25758591

  13. Integrating Nanostructured Artificial Receptors with Whispering Gallery Mode Optical Microresonators via Inorganic Molecular Imprinting Techniques.

    PubMed

    Hammond, G Denise; Vojta, Adam L; Grant, Sheila A; Hunt, Heather K

    2016-06-15

    The creation of label-free biosensors capable of accurately detecting trace contaminants, particularly small organic molecules, is of significant interest for applications in environmental monitoring. This is achieved by pairing a high-sensitivity signal transducer with a biorecognition element that imparts selectivity towards the compound of interest. However, many environmental pollutants do not have corresponding biorecognition elements. Fortunately, biomimetic chemistries, such as molecular imprinting, allow for the design of artificial receptors with very high selectivity for the target. Here, we perform a proof-of-concept study to show how artificial receptors may be created from inorganic silanes using the molecular imprinting technique and paired with high-sensitivity transducers without loss of device performance. Silica microsphere Whispering Gallery Mode optical microresonators are coated with a silica thin film templated by a small fluorescent dye, fluorescein isothiocyanate, which serves as our model target. Oxygen plasma degradation and solvent extraction of the template are compared. Extracted optical devices are interacted with the template molecule to confirm successful sorption of the template. Surface characterization is accomplished via fluorescence and optical microscopy, ellipsometry, optical profilometry, and contact angle measurements. The quality factors of the devices are measured to evaluate the impact of the coating on device sensitivity. The resulting devices show uniform surface coating with no microstructural damage with Q factors above 10⁶. This is the first report demonstrating the integration of these devices with molecular imprinting techniques, and could lead to new routes to biosensor creation for environmental monitoring.

  14. Polarization characteristics of Whispering-Gallery-Mode fiber lasers based on evanescent-wave-coupled gain.

    PubMed

    Zhang, Yuan-Xian; Pu, Xiao-Yun; Feng, Li; Han, De-Yu; Ren, Yi-Tao

    2013-05-20

    The polarization characteristics of Whispering-Gallery-Mode (WGM) fiber lasers based on evanescent-wave-coupled gain are investigated. For the laser gain is excited by side-pumping scheme, it is found that the polarization property of lasing emission is simply dependent on the polarized states of the pump beams. The polarization property of lasing emission depends on the propagating situation of the pump beams in an optical fiber if the laser gain is excited by evanescent-wave pumping scheme, that is, if the pump beams within the fiber are meridional beams, the lasing emission is a transverse electric (TE) wave that forms a special radial polarization emission. However, if the pump beams within the fiber are skew beams, both transverse magnetic (TM) and TE waves exist simultaneously in lasing emission that forms a special axially and radially mixed polarization emission. Pumped by skew beams, the wave-number differences between TE and TM waves are also investigated quantitatively, the results demonstrate that the wave-number difference decreases with the increase of the fiber diameter and the refractive index (RI) of the cladding solution. The observed polarization characteristics have been well explained based on lasing radiation mechanism of WGM fiber laser of gain coupled by evanescent wave.

  15. Dielectric tuning and coupling of whispering gallery modes using an anisotropic prism

    NASA Astrophysics Data System (ADS)

    Foreman, Matthew R.; Sedlmeir, Florian; Schwefel, Harald G. L.; Leuchs, Gerd

    2016-11-01

    Optical whispering gallery mode (WGM) resonators are a powerful and versatile tool used in many branches of science. Fine tuning of the central frequency and line width of individual resonances is however desirable in a number of applications including frequency conversion, optical communications and efficient light-matter coupling. To this end we present a detailed theoretical analysis of dielectric tuning of WGMs supported in axisymmetric resonators. Using the Bethe-Schwinger equation and adopting an angular spectrum field representation we study the resonance shift and mode broadening of high $Q$ WGMs when a planar dielectric substrate is brought close to the resonator. Particular focus is given to use of a uniaxial substrate with an arbitrarily aligned optic axis. Competing red and blue resonance shifts ($\\sim 30$ MHz), deriving from generation of a near field material polarisation and back action from the radiation continuum respectively, are found. Anomalous resonance shifts can hence be observed depending on the substrate material, whereas mode broadening on the order of $\\sim 50$ MHz can also be simply realised. Furthermore, polarisation selective coupling with extinction ratios of $> 10^4$ can be achieved when the resonator and substrate are of the same composition and their optic axes are chosen correctly. Double refraction and properties of out-coupled beams are also discussed.

  16. Optical signal processing and tracking of whispering gallery modes in real-time for sensing applications

    NASA Astrophysics Data System (ADS)

    Ali, Amir R.; Afifi, Amr N.; Taha, Hazem

    2017-05-01

    A novel approach for tracking of whispering gallery modes (WGM) in real-time for dielectric cavities used in sensing application is presented in this paper. Real-time tracking for the shifts of the WGM can be used to measure the physical quantity of interest precisely, under high repetition rates. The tracking algorithm is based on cross-correlation signal processing technique which has been proved to be accurate in WGM shifts detection. In order to achieve portability, the aforementioned real-time algorithm is implemented using a single-board re-configurable input-output hardware. The hardware platform used combines a real-time processor and a field programmable gate array (FPGA), it also allows for data exchange between them. The tracking algorithm's accuracy and real-time behavior is verified by preforming simulations based on experiments conducted on the dielectric cavity, where the cavity is used as a force sensor measuring mechanical compression. The light from a laser diode is tuned with rates up to 10 kHz and then tangentially coupled into the cavity to excite the WGM. Results show that shifts of the WGM are tracked by the algorithm providing real-time force readings.

  17. Polarization-Selective Out-Coupling of Whispering-Gallery Modes

    NASA Astrophysics Data System (ADS)

    Sedlmeir, Florian; Foreman, Matthew R.; Vogl, Ulrich; Zeltner, Richard; Schunk, Gerhard; Strekalov, Dmitry V.; Marquardt, Christoph; Leuchs, Gerd; Schwefel, Harald G. L.

    2017-02-01

    Whispering-gallery mode (WGM) resonators are an important platform for linear, nonlinear, and quantum optical experiments. In such experiments, independent control of in-coupling and out-coupling rates to different modes can lead to higher conversion efficiencies and greater flexibility in the generation of nonclassical states based on parametric down-conversion. In this work, we introduce a scheme that enables selective out-coupling of WGMs belonging to a specific polarization family, while the orthogonally polarized modes remain largely unperturbed. Our technique utilizes material birefringence in both the resonator and the coupler such that a negative (positive) birefringence allows for polarization-selective coupling to TE (TM) WGMs. We formulate a refined coupling condition suitable for describing the case where the refractive indices of the resonator and the coupler are almost the same, from which we derive a criterion for polarization-selective coupling. Finally, we experimentally demonstrate our proposed method using a lithium niobate disk resonator coupled to a lithium niobate prism, where we show a 22-dB suppression of coupling to TM modes relative to TE modes.

  18. Watermarking for IPR protection of the Tuscany and Gifu Art Virtual Gallery

    NASA Astrophysics Data System (ADS)

    Bartolini, Franco; Caldelli, Roberto; Cappellini, Vito; De Rosa, Alessia; Wada, Manami; Nozzoli, Alessandro; Piva, Alessandro

    1999-12-01

    Digital watermarking has been indicated as a technique in the position to cope with the problem of Intellectual Property Rights (IPR) protection of images; this result should be achieved by embedding into the data an unperceivable digital code, namely the watermark, carrying information about the copyright status of the work to be protected. In this paper, the practical feasibility of IPR protection through digital watermarking is investigated. The most common requirements application scenarios impose to the watermarking technology to satisfy are discussed. Watermarking schemes are first classified according to the approach used to extract the embedded code and then the impact, such a classification has on watermark usability, is investigated form an application point of view. As it will be shown, the effectiveness of watermarking as an IPR protection tool turns out to be heavily affected by the detection strategy, which as to be carefully matched to the application at hand. Finally, the practical case of the Tuscany and Gifu Art Virtual Gallery has been considered in detail, to further explain in which manner a watermarking technique can be actually used.

  19. New spherical optical cavities with non-degenerated whispering gallery modes

    NASA Astrophysics Data System (ADS)

    Kumagai, Tsutaru; Palma, Giuseppe; Prudenzano, Francesco; Kishi, Tetsuo; Yano, Tetsuji

    2017-02-01

    New spherical resonators with internal defects are introduced to show anomalous whispering gallery modes (WGMs). The defect induces a symmetry breaking spherical cavity and splits the WGMs. A couple of defects, a hollow sphere (bubble), and a hollow ring, have been studied. The hollow sphere was fabricated and the splitting of WGM was observed. In this paper, this "non-degenerated WGMs (non-DWGMs) resonance" in a microsphere with hollow defect structure is reviewed based on our research. The resonance of WGMs in a sphere is identified by three integer parameters: the angular mode number, l, azimuthal mode number m, and radial mode number, n. The placement of the defect such as a hollow ring or single bubble is shown to break symmetry and resolve the degeneracy concerning m. This induces a variety of resonant wavelengths of the spherical cavity. A couple of simulations using the eigenmode and transient analyses propose how the placed defects affect the WGM resonance in the spherical cavity. For the sphere with a single bubble defect, the experimentally observed resonances in Nd-doped tellurite glass microsphere with a single bubble are clarified to be due to the splitting of resonance modes, i.e., the existence of "non-DWGMs" in the sphere. The defect bubble plays a role of opening the optically wide gate to introduce excitation light for Nd3+ pumping using non-DWGMs in the sphere efficiently.

  20. Whispering gallery mode resonators for rapid label-free biosensing in small volume droplets.

    PubMed

    Wildgen, Sarah M; Dunn, Robert C

    2015-03-23

    Rapid biosensing requires fast mass transport of the analyte to the surface of the sensing element. To optimize analysis times, both mass transport in solution and the geometry and size of the sensing element need to be considered. Small dielectric spheres, tens of microns in diameter, can act as label-free biosensors using whispering gallery mode (WGM) resonances. WGM resonances are sensitive to the effective refractive index, which changes upon analyte binding to recognition sites on functionalized resonators. The spherical geometry and tens of microns diameter of these resonators provides an efficient target for sensing while their compact size enables detection in limited volumes. Here, we explore conditions leading to rapid analyte detection using WGM resonators as label-free sensors in 10 μL sample droplets. Droplet evaporation leads to potentially useful convective mixing, but also limits the time over which analysis can be completed. We show that active droplet mixing combined with initial binding rate measurements is required for accurate nanomolar protein quantification within the first minute following injection.

  1. Robust Whispering-Gallery-Mode Microbubble Lasers from Colloidal Quantum Dots.

    PubMed

    Wang, Yue; Ta, Van Duong; Leck, Kheng Swee; Tan, Beng Hau Ian; Wang, Zeng; He, Tingchao; Ohl, Claus-Dieter; Demir, Hilmi Volkan; Sun, Handong

    2017-03-21

    Microlasers hold great promise for the development of photonics and optoelectronics. Among the discovered optical gain materials, colloidal quantum dots (CQDs) have been recognized as the most appealing candidate due to the facile emission tunability and solution processability. However, to date, it is still challenging to develop CQD-based microlasers with low cost yet high performance. Moreover, the poor long-term stability of CQDs remains to be the most critical issue, which may block their laser aspirations. Herein, we developed a unique but generic approach to forming a novel type of a whispering-gallery-mode (WGM) microbubble laser from the hybrid CQD/poly(methyl methacrylate) (PMMA) nanocomposites. The formation mechanism of the microbubbles was unraveled by recording the drying process of the nanocomposite droplets. Interestingly, these microbubbles naturally serve as the high-quality WGM laser resonators. By simply changing the CQDs, the lasing emission can be tuned across the whole visible spectral range. Importantly, these microbubble lasers exhibit unprecedented long-term stability (over one year), sufficient for practical applications. As a proof-of-concept, the potential of water vapor sensing was demonstrated. Our results represent a significant advance in microlasers based on the advantageous CQDs and may offer new possibilities for photonics and optoelectronics.

  2. Ultrahigh Q whispering gallery mode electro-optic resonators on a silicon photonic chip.

    PubMed

    Soltani, Mohammad; Ilchenko, Vladimir; Matsko, Andrey; Savchenkov, Anatoliy; Schlafer, John; Ryan, Colm; Maleki, Lute

    2016-09-15

    Crystalline whispering gallery mode (WGM) electro-optic resonators made of LiNbO3 and LiTaO3 are critical for a wide range of applications in nonlinear and quantum optics, as well as RF photonics, due to their remarkably ultrahigh Q(>108) and large electro-optic coefficient. Achieving efficient coupling of these resonators to planar on-chip optical waveguides is essential for any high-yield and robust practical applications. However, it has been very challenging to demonstrate such coupling while preserving the ultrahigh Q properties of the resonators. Here, we show how the silicon photonic platform can overcome this long-standing challenge. Silicon waveguides with appropriate designs enable efficient and strong coupling to these WGM electro-optic resonators. We discuss various integration architectures of these resonators onto a silicon chip and experimentally demonstrate critical coupling of a planar Si waveguide and an ultrahigh QLiTaO3 resonator (Q∼108). Our results show a promising path for widespread and practical applications of these resonators on a silicon photonic platform.

  3. Biochemical component identification by light scattering techniques in whispering gallery mode optical resonance based sensor

    NASA Astrophysics Data System (ADS)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

    2014-03-01

    Experimental data on detection and identification of variety of biochemical agents, such as proteins (albumin, interferon, C reactive protein), microelements (Na+, Ca+), antibiotic of different generations, in both single and multi component solutions under varied in wide range concentration are represented. Analysis has been performed on the light scattering parameters of whispering gallery mode (WGM) optical resonance based sensor with dielectric microspheres from glass and PMMA as sensitive elements fixed by spin - coating techniques in adhesive layer on the surface of substrate or directly on the coupling element. Sensitive layer was integrated into developed fluidic cell with a digital syringe. Light from tuneable laser strict focusing on and scattered by the single microsphere was detected by a CMOS camera. The image was filtered for noise reduction and integrated on two coordinates for evaluation of integrated energy of a measured signal. As the entrance data following signal parameters were used: relative (to a free spectral range) spectral shift of frequency of WGM optical resonance in microsphere and relative efficiency of WGM excitation obtained within a free spectral range which depended on both type and concentration of investigated agents. Multiplexing on parameters and components has been realized using spatial and spectral parameters of scattered by microsphere light with developed data processing. Biochemical component classification and identification of agents under investigation has been performed by network analysis techniques based on probabilistic network and multilayer perceptron. Developed approach is demonstrated to be applicable both for single agent and for multi component biochemical analysis.

  4. What is and what is not electromagnetically induced transparency in whispering-gallery microcavities.

    PubMed

    Peng, Bo; Özdemir, Sahin Kaya; Chen, Weijian; Nori, Franco; Yang, Lan

    2014-10-24

    There has been an increasing interest in all-optical analogues of electromagnetically induced transparency and Autler-Townes splitting. Despite the differences in their underlying physics, both electromagnetically induced transparency and Autler-Townes splitting are quantified by a transparency window in the absorption or transmission spectrum, which often leads to a confusion about its origin. While the transparency window in electromagnetically induced transparency is a result of Fano interference among different transition pathways, in Autler-Townes splitting it is the result of strong field-driven interactions leading to the splitting of energy levels. Being able to tell objectively whether an observed transparency window is because of electromagnetically induced transparency or Autler-Townes splitting is crucial for applications and for clarifying the physics involved. Here we demonstrate the pathways leading to electromagnetically induced transparency, Fano resonances and Autler-Townes splitting in coupled whispering-gallery-mode resonators. Moreover, we report the application of the Akaike Information Criterion discerning between all-optical analogues of electromagnetically induced transparency and Autler-Townes splitting and clarifying the transition between them.

  5. Graphene induced high-Q hybridized plasmonic whispering gallery mode microcavities.

    PubMed

    Jiang, Mingming; Li, Jitao; Xu, Chunxiang; Wang, Shuangpeng; Shan, Chongxin; Xuan, Bin; Ning, Yongqiang; Shen, Dezhen

    2014-10-06

    A novel hybridized plasmonic whispering gallery mode (WGM) microcavities composed of graphene monolayer coated ZnO microrod with hexagonal cross section were proposed that operates in the ultraviolet region. π and π + σ surface plasmon modes in graphene monolayer at 4.7 eV and 14.6 eV can be used to achieve the near field coupling interaction between surface plasmonic modes and the conventional WGM microcavity modes in the ultraviolet band. Significantly, the coupling, happened in the evanescent wave field excited along the interface between ZnO and graphene, can lead to distinct optical field confinement and lasing enhancement experimentally, so as well as WGM lasing characteristics, such as the higher cavity quality factor (Q), narrower linewidth, lasing intensities enhancement. The results could provide a platform to study hybridized plasmonic cavity dynamics, and also provides the building blocks to construct graphene based novel microcavity for high performance ultraviolet laser devices with potential application to optical signal processing, biological monitoring, and so on.

  6. Interfacing whispering gallery mode optical microresonator biosensors with the plant defense elicitor chitin.

    PubMed

    Dahmen, Jeremy L; Yang, Yongqiang; Greenlief, C Michael; Stacey, Gary; Hunt, Heather K

    2014-10-01

    The biomaterial class of chitooligosaccharides (chitin), commonly found in insects and fungi, is one of the most abundant on earth. Substantial evidence implicates chitin in mediating a diverse array of plant cellular signaling events, including the induction of plant defense mechanisms against invading pests. However, these recognition and mediation mechanisms, including the binding kinetics between chitin and their plant recognition receptors, are not fully understood. Therefore, the creation of a platform capable of both interfacing with chitin and plant cell receptors, and monitoring their interactions, would significantly advance our understanding of this plant defense elicitor. Recently, a label-free, highly sensitive biosensor platform, based on Whispering Gallery Mode optical microresonators, has been developed to study such biomolecular interactions. Here, we demonstrate how this unique platform can be interfaced with chitin using simple carbohydrate chemistry. The surface chemistry is demonstrated using X-ray photoelectron spectroscopy, fluorescence microscopy, optical profilometry, ellipsometry, and contact angle measurements. The resulting surface is uniform, with an average surface roughness of 1.25nm, and is active toward chitin recognition elements. Optical loss measurements using standard quantitative cavity analysis techniques demonstrate that the bioconjugated platforms maintain the high performance (Q>10(6)) required to track binding interactions in this system. The platform is able to detect lectin, which binds COs, at 10μg/mL concentration. This biosensor platform's unique capabilities for label-free, high sensitivity biodetection, when properly interfaced with the biomaterials of interest, could provide the basis for a robust analytical technique to probe the binding dynamics of chitin-plant cell receptors.

  7. Whispering gallery modes microcavities with J-aggregates and plasmonic hot spots

    NASA Astrophysics Data System (ADS)

    Rakovich, Yury P.; Melnikau, Dzmitry; Savateeva, Diana; Chuvilin, Andrey; Hillenbrand, Rainer

    2012-06-01

    We have studied the optical properties of a hybrid system consisting of cyanine dye J-aggregates (both PIC and TDBC) attached to a spherical microcavity. Instead of the commonly accepted chemical bonding of dye molecules to the surface of microspheres or deposition of dye-doped sol-gel film, in our experiments microspheres were coated with J-aggregate shell utilizing the layer-by-layer assembly of the ultrathin films. In this approach we aimed to take advantage of light confinement in the Whispering Gallery Modes (WGMs) microcavity by placing the emitter (shell of J-aggregates) just at the rim of the microsphere, where the resonant electromagnetic field reaches its maximum. A periodic structure of narrow peaks was observed in the photoluminescence spectrum of the J-aggregates, arising from the coupling between the emission of J-aggregates and the WGMs of the microcavity. The most striking result of our study is the observation of polarization sensitive mode damping caused by re-absorption of J-aggregate emission. This effect manifests itself in dominating emission from the transverse magnetic modes in the spectral region of J-aggregates absorption band where the transverse electric (TE) modes are strongly suppressed. Strong suppression of TE modes reflects preferential tangential orientation of transition dipole moment of J-aggregates in deposited microcavity shell. Observed polarization sensitive mode damping observed in the spectral region of high J-aggregate absorption can be used for suppression of unwanted modes in high Q optical resonators. We also demonstrate that the emission intensity can be further enhanced by depositing a hybrid layer of J-aggregates and Ag nanoparticles onto the spherical microcavity. Owing to the concerted action of WGMs and plasmonic hot spots in the Ag aggregates, we observe strongly enhanced Raman signal from the Jaggregates. Microcavities covered by J-aggregates and plasmonic nanoparticles could be thus useful for a variety of

  8. Bio-optical sensor for brain activity measurement based on whispering gallery modes

    NASA Astrophysics Data System (ADS)

    Ali, Amir R.; Massoud, Yasmin M.

    2017-05-01

    In this paper, a high-resolution bio-optical sensor is developed for brain activity measurement. The aim is to develop an optical sensor with enough sensitivity to detect small electric field perturbations caused by neuronal action potential. The sensing element is a polymeric dielectric micro-resonator fabricated in a spherical shape with a few hundred microns in diameter. They are made of optical quality polymers that are soft which make them mechanically compatible with tissue. The sensors are attached to or embedded in optical fibers which serve as input/output conduits for the sensors. Hundreds or even thousands of spheres can be attached to a single fiber to detect and transmit signals at different locations. The high quality factor for the optical resonator makes it significantly used in such bio-medical applications. The sensing phenomenon is based on whispering gallery modes (WGM) shifts of the optical sensor. To mimic the brain signals, the spherical resonator is immersed in a homogeneous electrical field that is created by applying potential difference across two metallic plates. One of the plates has a variable voltage while the volt on the other plate kept fixed. Any small perturbations of the potential difference (voltage) lead to change in the electric field intensity. In turn the sensor morphology will be affected due to the change in the electrostriction force acting on it causing change in its WGM. By tracking these WGM shift on the transmission spectrum, the induced potential difference (voltage change) could be measured. Results of a mathematical model simulation agree well with the preliminary experiments. Also, the results show that the brain activity could be measured using this principle.

  9. Optimally coherent Kerr combs generated with crystalline whispering gallery mode resonators for ultrahigh capacity fiber communications.

    PubMed

    Pfeifle, Joerg; Coillet, Aurélien; Henriet, Rémi; Saleh, Khaldoun; Schindler, Philipp; Weimann, Claudius; Freude, Wolfgang; Balakireva, Irina V; Larger, Laurent; Koos, Christian; Chembo, Yanne K

    2015-03-06

    Optical Kerr frequency combs are known to be effective coherent multiwavelength sources for ultrahigh capacity fiber communications. These combs are the frequency-domain counterparts of a wide variety of spatiotemporal dissipative structures, such as cavity solitons, chaos, or Turing patterns (rolls). In this Letter, we demonstrate that Turing patterns, which correspond to the so-called primary combs in the spectral domain, are optimally coherent in the sense that for the same pump power they provide the most robust carriers for coherent data transmission in fiber communications using advanced modulation formats. Our model is based on a stochastic Lugiato-Lefever equation which accounts for laser pump frequency jitter and amplified spontaneous emission noise induced by the erbium-doped fiber amplifier. Using crystalline whispering-gallery-mode resonators with quality factor Q∼10^{9} for the comb generation, we show that when the noise is accounted for, the coherence of a primary comb is significantly higher than the coherence of their solitonic or chaotic counterparts for the same pump power. In order to confirm this theoretical finding, we perform an optical fiber transmission experiment using advanced modulation formats, and we show that the coherence of the primary comb is high enough to enable data transmission of up to 144  Gbit/s per comb line, the highest value achieved with a Kerr comb so far. This performance evidences that compact crystalline photonic systems have the potential to play a key role in a new generation of coherent fiber communication networks, alongside fully integrated systems.

  10. Combining whispering gallery mode lasers and microstructured optical fibers for in-vivo biosensing applications

    NASA Astrophysics Data System (ADS)

    François, A.; Rowland, K. J.; Reynolds, T.; Nicholls, S. J.; Monro, T. M.

    2013-10-01

    Whispering Gallery Modes (WGMs) have been widely studied for the past 20 years for various applications, including biological sensing. While the different WGM-based sensing approaches reported in the literature enable useful sensor characteristics, at present this technology is not yet mature, mainly for practical reasons. Our work has been focused on developing a simple, yet efficient, WGM-based sensing platform capable of being used as a dip sensor for in-vivo biosensing applications. We recently demonstrated that a dye-doped polymer microresonator, supporting WGMs, positioned onto the tip of a suspended core Microstructured Optical Fiber can be used as a dip sensor. In this architecture, the resonator is located on an air hole next to the fiber core at the fiber's tip, enabling a significant portion of the sphere to overlap with the guided light emerging from the fiber tip. This architecture offers significant benefits that have never been reported in the literature in terms of radiation efficiency, compared to the standard freestanding resonators, which arise from breaking the symmetry of the resonator. In addition to providing the remote excitation and collection of the WGMs' signal, the fiber also allows easy manipulation of the microresonator and the use this sensor in a dip sensing architecture, alleviating the need for a complex microfluidic interface. Here, we present our recent results on the microstructured fiber tip WGM-based sensor, including its lasing behavior and enhancement of the radiation efficiency as a function of the position of the resonator on the fiber tip. We also show that this platform can be used for clinical diagnostics and applying this technology to the detection of Troponin T, an acute myocardial infarction biomarker, down to a concentration of 7.4 pg/mL.

  11. Tailoring the protein adsorption properties of whispering gallery mode optical biosensors.

    PubMed

    Soteropulos, Carol E; Zurick, Kevin M; Bernards, Matthew T; Hunt, Heather K

    2012-11-06

    Label-free biosensor technologies have the potential to revolutionize environmental monitoring, medical diagnostics, and food safety evaluation processes due to their unique combinations of high-sensitivity signal transducers and high-specificity recognition elements. This enables their ability to perform real-time detection of deleterious compounds at extremely low concentrations. However, to further improve the biosensors' performance in complex environments, such as wastewater, blood, and urine, it is necessary to minimize nonspecific binding, which in turn will increase their specificity, and decrease the rate of false positives. In the present work, we illustrate the potential of combining emerging high-sensitivity optical signal transducers, such as whispering gallery mode (WGM) microcavities, with covalently bound poly(ethylene glycol) (PEG) coatings of varying thickness, as an effective treatment for the prevention of nonspecific protein adsorption onto the biosensor surface. We monitor the sensitivity of the coated biosensor, and investigate the effect of PEG chain length on minimizing nonspecific adsorption via protein adsorption studies. Experimental results confirm not only that PEG-functionalization reduces nonspecific protein adsorption to the surface of the sensor by as much as a factor of 4 compared to an initialized control surface, but also that chain length significantly impacts the nonfouling character of the microcavity surface. Surprisingly, it is the short chain PEG surfaces that experience the best improvement in specificity, unlike many other systems where longer PEG chains are preferred. The combination of WGM microcavities with PEG coatings tuned specifically to the device will significantly improve the overall performance of biosensor platforms, and enable their wider application in complex, real-world monitoring scenarios.

  12. The Role of Transport Phenomena in Whispering Gallery Mode Optical Biosensor Performance

    NASA Astrophysics Data System (ADS)

    Gamba, Jason

    Whispering gallery mode (WGM) optical resonator sensors have emerged as promising tools for label-free detection of biomolecules in solution. These devices have even demonstrated single-molecule limits of detection in complex biological uids. This extraordinary sensitivity makes them ideal for low-concentration analytical and diagnostic measurements, but a great deal of work must be done toward understanding and optimizing their performance before they are capable of reliable quantitative measurents. The present work explores the physical processes behind this extreme sensitivity and how to best take advantage of them for practical applications of this technology. I begin by examining the nature of the interaction between the intense electromagnetic elds that build up in the optical biosensor and the biomolecules that bind to its surface. This work addresses the need for a coherent and thorough physical model that can be used to predict sensor behavior for a range of experimental parameters. While this knowledge will prove critical for the development of this technology, it has also shone a light on nonlinear thermo-optical and optical phenomena that these devices are uniquely suited to probing. The surprisingly rapid transient response of toroidal WGM biosensors despite sub-femtomolar analyte concentrations is also addressed. The development of asymmetric boundary layers around these devices under ow is revealed to enhance the capture rate of proteins from solution compared to the spherical sensors used previously. These lessons will guide the design of ow systems to minimize measurement time and consumption of precious sample, a key factor in any medically relevant assay. Finally, experimental results suggesting that WGM biosensors could be used to improve the quantitative detection of small-molecule biomarkers in exhaled breath condensate demonstrate how their exceptional sensitivity and transient response can enable the use of this noninvasive method to probe

  13. Contributions by Host Trees and Insect Activity to Bacterial Communities in Dendroctonus valens (Coleoptera: Curculionidae) Galleries, and Their High Overlap With Other Microbial Assemblages of Bark Beetles.

    PubMed

    Mason, Charles J; Hanshew, Alissa S; Raffa, Kenneth F

    2016-04-01

    Bark beetles are associated with a diversity of symbiotic microbiota that can mediate interactions with their host plants. Dendroctonus valens LeConte is a widely distributed bark beetle in North and Central America, and initiates solitary attacks on several species of Pinus in the Great Lakes region. In this study, we aimed to further characterize the bacterial community associated with D. valens feeding galleries using next-generation sequencing, and the possible contributions of both tree-resident and insect-associated bacteria to these consortia. We found that D. valens galleries harbor a diversity of microbial associates. Many of these associates were classified into a few taxonomic groups, of which Gammaproteobacteria were the most abundant class. Of the Gammaproteobacteria detected, many formed clades with 16S-rRNA sequences of bacteria previously associated with D. valens Many of the bacteria sequences detected in the galleries were similar to bacteria that function in detoxification, kairomone metabolism, and nitrogen fixation and cycling. The abundance of bacteria in galleries were 7× and 44× higher than in the surrounding uninfested tissues, and that were not attacked by D. valens, respectively. This suggests that the bacteria present in beetle galleries are largely introduced by D. valens and proliferate in this environment.

  14. Classification of antibiotics by neural network analysis of optical resonance data of whispering gallery modes in dielectric microspheres

    NASA Astrophysics Data System (ADS)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Schweiger, Gustav; Ostendorf, Andreas

    2012-04-01

    A novel emerging technique for the label-free analysis of nanoparticles and biomolecules in liquid fluids using optical micro cavity resonance of whispering-gallery-type modes is being developed.A scheme based on polymer microspheres fixed by adhesive on the evanescence wave coupling element has been used. We demonstrated that the only spectral shift can't be used for identification of biological agents by developed approach. So neural network classifier for biological agents and micro/nano particles classification has been developed. The developed technique is the following. While tuning the laser wavelength images were recorded as avi-file. All sequences were broken into single frames and the location of the resonance was allocated in each frame. The image was filtered for noise reduction and integrated over two coordinates for evaluation of integrated energy of a measured signal. As input data normalized resonance shift of whispering-gallery modes and the relative efficiency of whispering-gallery modes excitation were used. Other parameters such as polarization of excited light, "center of gravity" of a resonance spectra etc. are also tested as input data for probabilistic neural network. After network designing and training we estimated the accuracy of classification. The classification of antibiotics such as penicillin and cephasolin have been performed with the accuracy of not less 97 %. Developed techniques can be used for lab-on-chip sensor based diagnostic tools as for identification of different biological molecules, e.g. proteins, oligonucleotides, oligosaccharides, lipids, small molecules, viral particles, cells and for dynamics of a delivery of medicines to bodies.

  15. Crafting glass vessels: current research on the ancient glass collections in the Freer Gallery of Art, Washington, D.C.

    NASA Astrophysics Data System (ADS)

    Nagel, Alexander; McCarthy, Blythe; Bowe, Stacy

    Our knowledge of glass production in ancient Egypt has been well augmented by the publication of recently excavated materials and glass workshops, but also by more recent materials analysis, and experiments of modern glass-makers attempting to reconstruct the production process of thin-walled coreformed glass vessels. From the mounting of a prefabricated core to the final glass product our understanding of this profession has much improved. The small but well preserved glass collection of the Freer Gallery of Art in Washington, D.C. is a valid tool for examining and studying the technology and production of ancient Egyptian core formed glass vessels. Charles Lang Freer (1854-1919) acquired most of the material from Giovanni Dattari in Cairo in 1909. Previously the glass had received only limited discussion, suggesting that most of these vessels were produced in the 18th Dynasty in the 15th and 14th centuries BCE, while others date from the Hellenistic period and later. In an ongoing project we conducted computed radiography in conjunction with qualitative x-ray fluorescence analysis on a selected group of vessels to understand further aspects of the ancient production process. This paper will provide an overview of our recent research and present our data-gathering process and preliminary results. How can the examinations of core formed glass vessels in the Freer Gallery contribute to our understanding of ancient glass production and technology? By focusing on new ways of looking at old assumptions using the Freer Gallery glass collections, we hope to increase understanding of the challenges of the production process of core-vessel technology as represented by these vessels.

  16. Sub-kHz lasing of a CaF₂ whispering gallery mode resonator stabilized fiber ring laser.

    PubMed

    Collodo, M C; Sedlmeir, F; Sprenger, B; Svitlov, S; Wang, L J; Schwefel, H G L

    2014-08-11

    We utilize a high quality calcium fluoride whispering-gallery-mode resonator to passively stabilize a simple erbium doped fiber ring laser with an emission frequency of 196THz (wavelength 1530nm) to an instantaneous linewidth below 650Hz. This corresponds to a relative stability of 3.3 × 10(-12) over 16μs. In order to characterize the linewidth we use two identical self-built lasers and a commercial laser to determine the individual lasing linewidth via the three-cornered-hat method. We further show that the lasers are finely tunable throughout the erbium gain region.

  17. Two-photon excited whispering-gallery mode ultraviolet laser from an individual ZnO microneedle

    NASA Astrophysics Data System (ADS)

    Zhu, G. P.; Xu, C. X.; Zhu, J.; Lv, C. G.; Cui, Y. P.

    2009-02-01

    Wurtzite structural ZnO microneedles with hexagonal cross section were fabricated by vapor-phase transport method and an individual microneedle was employed as a lasing microcavity. Under excitation of a femtosecond pulse laser with 800 nm wavelength, the ultraviolet (UV) laser emission was obtained, which presented narrow linewidth and high Q value. The UV emission, resonant mechanism, and laser mode characteristics were discussed in detail. The results demonstrated that the UV laser originated from the whispering-gallery mode induced by two-photon absorption assisted by Rabi oscillation.

  18. Measurements of the Complex Permittivity of Liquid Helium-4 in the Millimeter Wave Range by a Whispering Gallery Mode Resonator

    NASA Astrophysics Data System (ADS)

    Smorodin, A. V.; Rybalko, A. S.; Konstantinov, D.

    2017-02-01

    We report an experimental study of the electrical properties of liquid helium-4 in the temperature range 1.2-3 K. The experiment is carried out in the millimeter wave range using a whispering gallery mode dielectric resonator, and the complex permittivity of liquid helium is extracted from the data using the resonant perturbation method. The results for the temperature dependence of the dielectric constant are consistent with the previous studies. In addition, we find strong enhancement of the loss tangent around the superfluid transition temperature.

  19. Measurements of the Complex Permittivity of Liquid Helium-4 in the Millimeter Wave Range by a Whispering Gallery Mode Resonator

    NASA Astrophysics Data System (ADS)

    Smorodin, A. V.; Rybalko, A. S.; Konstantinov, D.

    2017-06-01

    We report an experimental study of the electrical properties of liquid helium-4 in the temperature range 1.2-3 K. The experiment is carried out in the millimeter wave range using a whispering gallery mode dielectric resonator, and the complex permittivity of liquid helium is extracted from the data using the resonant perturbation method. The results for the temperature dependence of the dielectric constant are consistent with the previous studies. In addition, we find strong enhancement of the loss tangent around the superfluid transition temperature.

  20. The structure of gallery networks in the nests of termite Cubitermes spp. revealed by X-ray tomography

    NASA Astrophysics Data System (ADS)

    Perna, Andrea; Jost, Christian; Couturier, Etienne; Valverde, Sergi; Douady, Stéphane; Theraulaz, Guy

    2008-09-01

    Recent studies have introduced computer tomography (CT) as a tool for the visualisation and characterisation of insect architectures. Here, we use CT to map the three-dimensional networks of galleries inside Cubitermes nests in order to analyse them with tools from graph theory. The structure of these networks indicates that connections inside the nest are rearranged during the whole nest life. The functional analysis reveals that the final network topology represents an excellent compromise between efficient connectivity inside the nest and defence against attacking predators. We further discuss and illustrate the usefulness of CT to disentangle environmental and specific influences on nest architecture.

  1. Multiple-Rayleigh-scatterer-induced mode splitting in a high-Q whispering-gallery-mode microresonator

    SciTech Connect

    Yi Xu; Xiao Yunfeng; Liu Yongchun; Li Beibei; Chen Youling; Li Yan; Gong Qihuang

    2011-02-15

    We theoretically investigate the mode-splitting phenomenon in a high-Q whispering-gallery-mode (WGM) microresonator coupled to multiple subwavelength Rayleigh scatterers. It is shown that the phase factors of the WGMs play the central role in such a system. Unlike the single-scatterer case, these phase factors in a multiscatterer system significantly influence both the modal coupling strength and the scattering-induced loss of a pair of counterpropagating WGMs. We scrutinize the condition for observing the splitting of transmission spectra. The mechanism can be used for highly sensitive biosensing, and the size of nanoparticles that can be detected is extended down to tens of nanometers.

  2. Fine-tuning of whispering gallery modes in on-chip silica microdisk resonators within a full spectral range

    NASA Astrophysics Data System (ADS)

    Henze, Rico; Pyrlik, Christoph; Thies, Andreas; Ward, Jonathan M.; Wicht, Andreas; Benson, Oliver

    2013-01-01

    We investigate an efficient method for fine-tuning whispering gallery mode resonances in disk-type silica microresonators to reach an arbitrary frequency within the free spectral range of the system. This method is based on a post-production hydrofluoric acid etching process to precisely resize the radius of such microresonators. We show the effectiveness of this approach by tuning their resonance frequency within 10 GHz of specific hydrogen cyanide reference lines (P16, P18). This technique allows for simple and exact matching of narrow-linewidth lasers or spectroscopic lines with the high-Q resonances of on-chip silica microresonators.

  3. THz Pyro-Optical Detector Based on LiNbO3 Whispering Gallery Mode Microdisc Resonator

    PubMed Central

    Cosci, Alessandro; Cerminara, Matteo; Nunzi Conti, Gualtiero; Soria, Silvia; Righini, Giancarlo C.; Pelli, Stefano

    2017-01-01

    This study analyzes the capabilities of a LiNbO3 whispering gallery mode microdisc resonator as a potential bolometer detector in the THz range. The resonator is theoretically characterized in the stationary regime by its thermo-optic and thermal coefficients. Considering a Q-factor of 107, a minimum detectable power of 20 μW was evaluated, three orders of magnitude above its noise equivalent power. This value opens up the feasibility of exploiting LiNbO3 disc resonators as sensitive room-temperature detectors in the THz range. PMID:28134857

  4. Whispering gallery modes at the rim of an axisymmetric optical resonator: analytical versus numerical description and comparison with experiment.

    PubMed

    Breunig, I; Sturman, B; Sedlmeir, F; Schwefel, H G L; Buse, K

    2013-12-16

    Optical whispering gallery modes (WGMs) of mm-sized axisymmetric resonators are well localized at the equator. Employing this distinctive feature, we obtain simple analytical relations for the frequencies and eigenfunctions of WGMs which include the major radius of the resonator and the curvature radius of the rim. Being compared with results of finite-element simulations, these relations show a high accuracy and practicability. High-precision free-spectral-range measurements with a millimeter-sized disc resonator made of MgF(2) allow us to identify the WGMs and confirm the applicability of our analytical description.

  5. Strong forward-backward asymmetry of stimulated Raman scattering in lithium-niobate-based whispering gallery resonators.

    PubMed

    Leidinger, M; Sturman, B; Buse, K; Breunig, I

    2016-06-15

    We show experimentally and prove theoretically that the pump-power thresholds of stimulated Raman scattering (SRS) in lithium-niobate-based whispering gallery resonators (WGRs) are strongly different for the signal waves propagating in the backward and forward directions with respect to the pump wave. This feature is due to a strong polaritonic effect. It leads to a cascade of alternating forward-backward Raman lines with increasing pump power. The measured polarization and spectral properties of SRS are in good agreement with theory. Similar properties have to be inherent in other WGRs made of polar crystals.

  6. Subwavelength silicon disk whispering-gallery-mode microcavities for size-dependent nanoparticles detection in the mid-infrared

    NASA Astrophysics Data System (ADS)

    Dionne, Jeffrey; Ashwath, Harshitha; Kuznetsova, Lyuba

    2017-05-01

    Three-dimensional finite-element-method numerical simulations are used to investigate a size-dependent sensing technique by observing the effects that a spherical nanoparticle had on the frequency resonances of whispering-gallery modes of a subwavelength silicon microdisk. Results show that the observed spectral shift varies significantly (˜2 to 8 nm) for the TM optical mode with an attached nanoparticle with radii between 150 and 400 nm. This frequency shift size-dependence makes it possible to identify viruses of different sizes by the resonant frequency change in the transmission spectrum in the mid-infrared.

  7. Lamping process and application of ultra small U-shaped, whispery gallery mode (WGM) based optic fiber sensors

    NASA Astrophysics Data System (ADS)

    Chang, Yuan Cheng; Chiang, Chia Chin

    2015-07-01

    This study success to smaller and control the diameter of single mode optical fiber whispery gallery mode (WGM) to diameter 0.8 mm nonetching and nontaping treated. The sensitivity of this type ultra-small U-shape WGM strengthens neither etching nor taping fibre. The sensitivity we apply to thermo test depends on wavelength shift from 40 ~ 96°C (R2 = 0.99 ). The specially characteristics of the optical fiber could be tested for temperature, refraction, vibration, concussion, and CO2 detection.

  8. High-Q enhancement of attractive and repulsive optical forces between coupled whispering-gallery- mode resonators.

    PubMed

    Povinelli, Michelle; Johnson, Steven; Lonèar, Marko; Ibanescu, Mihai; Smythe, Elizabeth; Capasso, Federico; Joannopoulos, J

    2005-10-03

    We have calculated the optically-induced force between coupled high-Q whispering gallery modes of microsphere resonators. Attractive and repulsive forces are found, depending whether the bi-sphere mode is symmetric or antisymmetric. The magnitude of the force is linearly proportional to the total power in the spheres and consequently linearly enhanced by Q. Forces on the order of 100 nN are found for Q=108, large enough to cause displacements in the range of 1mum when the sphere is attached to a fiber stem with spring constant 0.004 N/m.

  9. Optical whispering-gallery mode resonators for applications in optical communication and frequency control

    NASA Astrophysics Data System (ADS)

    Grutter, Karen Esther

    High quality factor (Q) optical whispering gallery mode resonators are a key component in many on-chip optical systems, such as delay lines, modulators, and add-drop filters. They are also a convenient, compact structure for studying optomechanical interactions on-chip. In all these applications, optical Q is an important factor for high performance. For optomechanical reference oscillators in particular, high mechanical Q is also necessary. Previously, optical microresonators have been made in a wide variety of materials, but it has proven challenging to demonstrate high optical Q and high mechanical Q in a single, integrated device. This work demonstrates a new technique for achieving high optical Q on chip, a fully-integrated tunable filter with ultra-narrow minimum bandwidth, and the effect of material choice and device design on optical Q, mechanical Q and phase noise in microring optomechanical oscillators. To achieve a high optical Q, phosphosilicate glass (PSG) is studied as a resonator material. The low melting point of PSG enables wafer-scale reflow, which reduces sidewall roughness without significantly changing lithographically-defined dimensions. With this process, optical Qs up to 1.5 x 10. 7 are achieved, overten times higher than typical silicon optical resonators. These high-Q PSG resonators are then integrated with MEMS-actuated waveguides in a tunable-bandwidth filter. Due to the high Q of the PSG resonator, this device has a best-to-date minimum bandwidth of 0.8 GHz, with a tuning range of 0.8 to 8.5GHz. Finally, microring optomechanical oscillators (OMOs) in PSG, stoichiometric silicon nitride, and silicon are fabricated, and their performance is compared after characterization via a tapered optical fiber in vacuum. The silicon nitride device has the best performance, with a mechanical Q of more than 1 x 10. 4and record-breaking OMO phase noise of -102 dBc/Hz at a 1 kHz offset from a 72 MHz carrier.

  10. Seismic tomography of the Excavation Damaged Zone of the Gallery 04 in the Mont Terri Rock Laboratory

    NASA Astrophysics Data System (ADS)

    Nicollin, F.; Gibert, D.; Bossart, P.; Nussbaum, Ch.; Guervilly, C.

    2008-01-01

    An endoscopic antenna is used to perform a seismic cross-hole tomography in the Excavation Damaged Zone (EDZ) of the new G04 gallery of the Mont Terri Underground Rock Laboratory (Switzerland) excavated in Opalinus clay. More than 800 seismic traces were recorded between two vertical boreholes by combining 22 source and 48 receiver locations. A vertical area of 1.2 × 3.4 m under the floor of the gallery is investigated with a high-resolution tomography. Data with a very good quality allow to determine the traveltimes and the amplitudes of a 40kHz source wavelet propagating between the two boreholes. The analysis of the traveltimes shows that the wave velocity is homogeneous but anisotropic with a minimum value of 2490 +/- 45ms-1 in the direction normal to the bedding and a maximum of 3330 +/- 90ms-1 parallel to the bedding. The amplitude of the first arrivals strongly varies depending on the source-receiver locations, and suggesting an heterogeneous distribution of the attenuation coefficient of the seismic waves. A Bayesian inversion provides likely models of attenuation that are compared with geological observations. The areas where fractures or cracks exist in the Opalinus clay appear as highly absorbing the seismic waves.

  11. Observation of defect-assisted enhanced visible whispering gallery modes in ytterbium-doped ZnO microsphere

    NASA Astrophysics Data System (ADS)

    Khanum, Rizwana; Moirangthem, Rakesh S.; Das, Nayan Mani

    2017-06-01

    Smooth surfaced and crystalline undoped and ytterbium doped zinc oxide (ZnO) microspheres having an approximate size of 3-5 μm were synthesized by hydrothermal process. Out of these microspheres, a single microparticle was chosen and engaged as a whispering gallery wave microresonator. The defect induced luminescence from an individual ZnO microsphere was investigated with micro-photoluminescence measurement in the spectral range of 565 to 740 nm under the excitation of a green laser having a centered wavelength at 532 nm. The defects-related emissions from a single ZnO microsphere show optical resonance peaks so-called "whispering gallery modes" (WGMs) which are confirmed with the theoretical calculation. Further, ZnO microspheres were chemically doped with the different molar percentages of Ytterbium (Yb), and enhancement in their emission properties was investigated. Our experimental results show that ZnO microspheres with 0.5 mol. % doping of Yb gives the strongest optical emission and has highest Q-factor which can be employed in the development of WGM based optical biosensor or laser.

  12. What is the password? Female bark beetles (Scolytinae) grant males access to their galleries based on courtship song.

    PubMed

    Lindeman, Amanda A; Yack, Jayne E

    2015-06-01

    Acoustic signals are commonly used by insects in the context of mating, and signals can vary depending on the stage of interaction between a male and female. While calling songs have been studied extensively, particularly in the Orthoptera, much less is known about courtship songs. One outstanding question is how potential mates are differentiated by their courtship signal characteristics. We examined acoustic courtship signals in a new system, bark beetles (Scolytinae). In the red turpentine beetle (Dendroctonus valens) males produce chirp trains upon approaching the entrance of a female's gallery. We tested the hypotheses that acoustic signals are honest indicators of male condition and that females choose males based on signal characteristics. Males generated two distinct chirp types (simple and interrupted), and variability in their prevalence correlated with an indicator of male quality, body size, with larger males producing significantly more interrupted chirps. Females showed a significant preference for males who produced interrupted chirps, suggesting that females distinguish between males on the basis of their chirp performances. We suggest that interrupted chirps during courtship advertise a male's size and/or motor skills, and function as the proverbial 'passwords' that allow him entry to a female's gallery.

  13. Microsensors based on a whispering gallery mode in AlGaN microdisks undercut by hydrogen-environment thermal etching.

    PubMed

    Kouno, Tetsuya; Sakai, Masaru; Takeshima, Hoshi; Suzuki, Sho; Kikuchi, Akihiko; Kishino, Katsumi; Hara, Kazuhiko

    2017-04-20

    AlGaN microdisks were fabricated via a top-down process using electron-beam lithography, inductively coupled plasma reactive-ion etching, and hydrogen-environment thermal etching from commercial epitaxial wafers with a 100-300 nm thick AlGaN layer grown on a c-plane GaN layer by metal-organic chemical vapor deposition. The hydrogen-environment thermal etching performed well in undercutting the AlGaN microdisks owing to the selective etching for the GaN layer. The AlGaN microdisks acted as the whispering gallery mode (WGM) optical microresonators, exhibiting sharp resonant peaks in room temperature photoluminescence spectra. The evanescent component of the whispering gallery mode (WGM) is influenced by the ambient condition of the microdisk, resulting in the shift of the resonant peaks. The phenomenon is considered to be used for microsensors. Using the WGM in the AlGaN microdisks, we demonstrated microsensors and a microsensor system, which can potentially be used to evaluate biological and chemical actions in a microscale area in real time.

  14. A gallery of oil components, their metals and Re-Os signatures

    NASA Astrophysics Data System (ADS)

    Stein, Holly J.; Hannah, Judith L.

    2016-04-01

    Most sediment-hosted metallic ore deposits are one degree of freedom from hydrocarbon. That is, sulfide fluid inclusions may contain vestiges of travel in tandem with hydrocarbon-bearing fluids. For metallic ore deposits of stated metamorphic and magmatic origin, the degrees of freedom are several times more or, in some cases, no relationship exists. Still, the fetish for stereotyping and classifying ore types into hardline ore deposit models (or hybrid models when the data are wildly uncooperative) impedes our ability to move toward a better understanding of source rock. Fluids in the deeper earth, fluids in the crust, and the extraterrestrial rain of metals provide the Re-Os template for oil. So, too, this combination ultimately drives the composition of many metallic ore deposits. The world of crude oil and its complex history of maturation, migration, mixing, metal-rich asphaltene precipitation, and subsequent mobility of lighter and metal-poor components, is an untapped resource for students of ore geology. In the same way that Mississippi Valley-type lead and zinc deposits are described as the outcome of two converging and mixing fluids (metal-bearing and sulfur-bearing fluids), asphaltene precipitation can be an outcome of a lighter oil meeting and mixing with a heavier one. In the petroleum industry, this can spell economic disaster if the pore-space becomes clogged with a non-producible heavy oil or solid bitumen. In ore geology, sulfide precipitation on loss of permeability may create a Pb-Zn deposit. Petroleum systems provide a gallery of successive time-integrated Re-Os results. Heavy or biodegraded oils, if intersected by lighter oil or gas, can generate asphaltite or tar mats, and release a reservoir of still lighter oil (or gas). During this process there are opportunities for separation of metal-enriched aqueous fluids that may retain an imprint of their earlier hydrocarbon history, ultimately trapped in fluid inclusions. Salinity, temperature and p

  15. Passion Trumps Pay: A Study of the Future Skills Requirements of Information Professionals in Galleries, Libraries, Archives and Museums in Australia

    ERIC Educational Resources Information Center

    Howard, Katherine; Partridge, Helen; Hughes, Hilary; Oliver, Gillian

    2016-01-01

    Introduction: This paper explores the current and future skills and knowledge requirements of contemporary information professionals in a converged gallery, library, archive and museum sector (also referred to as the GLAM sector) in Australia. This research forms part of a larger study that investigated the education needs of information…

  16. How to use The National Gallery as a cross curricular approach to weather and climate studies at primary level.

    NASA Astrophysics Data System (ADS)

    Hansen, P. J. K.

    2009-09-01

    How to use The National Gallery as a cross curricular approach to weather and climate studies at primary level. Pål J. Kirkeby Hansen Faculty of Education and International Studies, Oslo University College (PalKirkeby.Hansen@lui.hio.no) Weather and climate are topics in natural science and geography in primary and secondary education in most countries. The pupils are often doing own weather observations and measurements and are presenting the results oral, by posters or with digital aids. They also use the Internet with all its relevant resources in their studies to develop vocabulary, practical and conceptual knowledge. Knowledge about weather and climate is parts of liberal education and could be projected to other topics in science and to topics in other subjects, for instance: history, social geography, literature and arts. This article reports from a case study in grade 3 classes (age 9 year) during their Weather Week. Their science teacher was, quite untypical, also educated in art history. She arranged a visited to The National Gallery with the double agenda: 1. To introduce the pupils to Norwegian canon paintings from the national romantic period, our so-called "golden age”. 2. To look for and discuss weather elements in this paintings. For one hour the museum curator guided the pupils around the water cycle by using the paintings. While the pupils' own observations of weather, clouds and wind and measurements of temperature and precipitation during the Weather Week only are point checks, the guided tour in The National Gallery gave literally "the whole picture” of the Norwegian weather and climate and of the water cycle. During the tour, the curator constantly invited the pupils to tell about and discuss what weather and water elements they were looking at when standing in front of a painting. The pupils were responsive and interested all the time. Back at school, they demonstrated that they had learned much about both weather elements, the water

  17. The potential of Lemna gibba L. and Lemna minor L. to remove Cu, Pb, Zn, and As in gallery water in a mining area in Keban, Turkey.

    PubMed

    Sasmaz, Merve; Arslan Topal, Emine Işıl; Obek, Erdal; Sasmaz, Ahmet

    2015-11-01

    This study was designed to investigate removal efficiencies of Cu, Pb, Zn, and As in gallery water in a mining area in Keban, Turkey by Lemna gibba L. and Lemna minor L. These plants were placed in the gallery water of Keban Pb-Zn ore deposits and adapted individually fed to the reactors. During the study period (8 days), the plant and water samples were collected daily and the temperature, pH, and electric conductivity of the gallery water were measured daily. The plants were washed, dried, and burned at 300 °C for 24 h in a drying oven. These ash and water samples were analyzed by ICP-MS to determine the amounts of Cu, Pb, Zn, and As. The Cu, Pb, Zn and As concentrations in the gallery water of the study area detected 67, 7.5, 7230, and 96 μg L(-1), respectively. According to the results, the obtained efficiencies in L. minor L. and L. gibba L. are: 87% at day 2 and 36% at day 3 for Cu; 1259% at day 2 and 1015% at day 2 for Pb; 628% at day 3 and 382% at day 3 for Zn; and 7070% at day 3 and 19,709% at day 2 for As, respectively. The present study revealed that both L. minor L. and L. gibba L. had very high potential to remove Cu, Pb, Zn, and As in gallery water contaminated by different ores.

  18. Coupling of a single diamond nanocrystal to a whispering-gallery microcavity: Photon transport benefitting from Rayleigh scattering

    SciTech Connect

    Liu Yongchun; Xiao Yunfeng; Li Beibei; Jiang Xuefeng; Li Yan; Gong Qihuang

    2011-07-15

    We study the Rayleigh scattering induced by a diamond nanocrystal in a whispering-gallery-microcavity-waveguide coupling system and find that it plays a significant role in the photon transportation. On the one hand, this study provides insight into future solid-state cavity quantum electrodynamics aimed at understanding strong-coupling physics. On the other hand, benefitting from this Rayleigh scattering, effects such as dipole-induced transparency and strong photon antibunching can occur simultaneously. As a potential application, this system can function as a high-efficiency photon turnstile. In contrast to B. Dayan et al. [Science 319, 1062 (2008)], the photon turnstiles proposed here are almost immune to the nanocrystal's azimuthal position.

  19. Coupling of a single diamond nanocrystal to a whispering-gallery microcavity: Photon transport benefitting from Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Liu, Yong-Chun; Xiao, Yun-Feng; Li, Bei-Bei; Jiang, Xue-Feng; Li, Yan; Gong, Qihuang

    2011-07-01

    We study the Rayleigh scattering induced by a diamond nanocrystal in a whispering-gallery-microcavity-waveguide coupling system and find that it plays a significant role in the photon transportation. On the one hand, this study provides insight into future solid-state cavity quantum electrodynamics aimed at understanding strong-coupling physics. On the other hand, benefitting from this Rayleigh scattering, effects such as dipole-induced transparency and strong photon antibunching can occur simultaneously. As a potential application, this system can function as a high-efficiency photon turnstile. In contrast to B. Dayan [ScienceSCIEAS0036-807510.1126/science.1152261 319, 1062 (2008)], the photon turnstiles proposed here are almost immune to the nanocrystal’s azimuthal position.

  20. Integrating a DNA Strand Displacement Reaction with a Whispering Gallery Mode Sensor for Label-Free Mercury (II) Ion Detection.

    PubMed

    Wu, Fengchi; Wu, Yuqiang; Niu, Zhongwei; Vollmer, Frank

    2016-07-29

    Mercury is an extremely toxic chemical pollutant of our environment. It has attracted the world's attention due to its high mobility and the ease with which it accumulates in organisms. Sensitive devices and methods specific for detecting mercury ions are, hence, in great need. Here, we have integrated a DNA strand displacement reaction with a whispering gallery mode (WGM) sensor for demonstrating the detection of Hg(2+) ions. Our approach relies on the displacement of a DNA hairpin structure, which forms after the binding of mercury ions to an aptamer DNA sequence. The strand displacement reaction of the DNA aptamer provides highly specific and quantitative means for determining the mercury ion concentration on a label-free WGM sensor platform. Our approach also shows the possibility for manipulating the kinetics of a strand displacement reaction with specific ionic species.

  1. Single-crystal sapphire resonator at millikelvin temperatures: Observation of thermal bistability in high- Q factor whispering gallery modes

    NASA Astrophysics Data System (ADS)

    Creedon, Daniel L.; Tobar, Michael E.; Le Floch, Jean-Michel; Reshitnyk, Yarema; Duty, Timothy

    2010-09-01

    Resonance modes in single crystal sapphire (α-Al2O3) exhibit extremely high electrical and mechanical Q factors ( ≈109 at 4 K), which are important characteristics for electromechanical experiments at the quantum limit. We report the cool down of a bulk sapphire sample below superfluid liquid-helium temperature (1.6 K) to as low as 25 mK. The electromagnetic properties were characterized at microwave frequencies, and we report the observation of electromagnetically induced thermal bistability in whispering gallery modes due to the material T3 dependence on thermal conductivity and the ultralow dielectric loss tangent. We identify “magic temperatures” between 80 and 2100 mK, the lowest ever measured, at which the onset of bistability is suppressed and the frequency-temperature dependence is annulled. These phenomena at low temperatures make sapphire suitable for quantum metrology and ultrastable clock applications, including the possible realization of the quantum-limited sapphire clock.

  2. Integrating a DNA Strand Displacement Reaction with a Whispering Gallery Mode Sensor for Label-Free Mercury (II) Ion Detection

    PubMed Central

    Wu, Fengchi; Wu, Yuqiang; Niu, Zhongwei; Vollmer, Frank

    2016-01-01

    Mercury is an extremely toxic chemical pollutant of our environment. It has attracted the world’s attention due to its high mobility and the ease with which it accumulates in organisms. Sensitive devices and methods specific for detecting mercury ions are, hence, in great need. Here, we have integrated a DNA strand displacement reaction with a whispering gallery mode (WGM) sensor for demonstrating the detection of Hg2+ ions. Our approach relies on the displacement of a DNA hairpin structure, which forms after the binding of mercury ions to an aptamer DNA sequence. The strand displacement reaction of the DNA aptamer provides highly specific and quantitative means for determining the mercury ion concentration on a label-free WGM sensor platform. Our approach also shows the possibility for manipulating the kinetics of a strand displacement reaction with specific ionic species. PMID:27483277

  3. Apparatus for studying wave motion and sound at the University of Nebraska-Lincoln's ``Historical Scientific Instrument Gallery.''

    NASA Astrophysics Data System (ADS)

    Wang, Lily M.; Rudd, M. Eugene

    2004-05-01

    The University of Nebraska-Lincoln's ``Historical Scientific Instrument Gallery,'' compiled by the second author in 1998, contains approximately 700 inventoried items and may be visited on-line at http://physics.unl.edu/outreach/histinstr/. Amidst the collection are several acoustical instruments that were used in the early 1900s. These include equipment that demonstrate wave motion (traveling wave machine, mercury ripple dish, vibration microscope), wave interference (interference machine), resonance conditions (Helmholtz resonators, vibrating rods, singing flames, sonometer), and sound generation (Galton's whistles, high-frequency tuning forks, large tuning forks, organ pipes, siren saw). A review of the equipment and the history of their use at the University of Nebraska are discussed. Much of the equipment was superbly manufactured by the Max Kohl/Chemnitz Company in Germany and Rudolph Koenig in France. Pages from the Max Kohl/Chemnitz equipment catalogs of 1910 and 1925 helped to characterize several of the pieces and are shown in this presentation.

  4. Whispering gallery and Fabry-Pérot modes enhanced luminescence from individual ZnO micro mushroom

    NASA Astrophysics Data System (ADS)

    Wang, B.; Jin, X.; Wu, H. Y.; Zheng, Z. Q.

    2013-01-01

    One kind of micro structures, ZnO mushrooms, have been synthesized by self-assembled method on single silicon substrates with Au catalyst assisted thermal evaporation of ZnO and active carbon powders. Cathodoluminescence for individual ZnO micro mushroom has been invested. The luminescence from the center region is attributed to the Fabry-Pérot mode enhanced emission, and the one from the hexagonal profiles is attributed to the whispering gallery mode enhanced emission when the individual ZnO micro mushroom is regarded as an optical resonator. The field-emission property of these ZnO micro mushrooms has been measured and the turn-on electric field is 5.9 V/μm.

  5. Selective excitation of Fabry-Perot or whispering-gallery mode-type lasing in GaN microrods

    SciTech Connect

    Baek, Hyeonjun; Hyun, Jerome K.; Chung, Kunook; Oh, Hongseok; Yi, Gyu-Chul

    2014-11-17

    Lasing from long semiconductor nanorods is dictated by Fabry-Perot (FP) resonances whereas that from large-diameter microrods is determined by whispering gallery modes (WGMs). Lengths and diameters intermediate between the two systems represent an important size regime for photonics and electronics, but have not been studied in detail. Here, we report on the detection of FP and WGM lasing emissions from a single GaN microrod, and demonstrate the ability to switch between the two lasing mechanisms by translating the excitation beam along the microrod. The competition between FP and WGM-type lasing was studied by finite-difference time-domain simulation and statistical analysis by measuring microrods of various diameters. Finally, control over the relative lasing intensities originating from either FPs or WGMs was demonstrated by tuning the polarization of the emission.

  6. Controlled self-assembly of organic composite microdisks for efficient output coupling of whispering-gallery-mode lasers.

    PubMed

    Wei, Cong; Liu, Si-Yun; Zou, Chang-Ling; Liu, Yingying; Yao, Jiannian; Zhao, Yong Sheng

    2015-01-14

    Flexible microdisk whispering-gallery-mode (WGM) resonators with high quality factors were achieved through the controlled assembly of organic materials with an emulsion-solvent-evaporation method. The high material compatibility of the assembled microdisks enabled us to realize low-threshold WGM lasers by doping with organic dyes as gain media. Furthermore, the emulsion-assisted self-assembly provided a strategy for the one-step fabrication of microwire-waveguide-connected microdisk heterostructures, which can be utilized for the efficient output of the isotropic WGM lasers from the coupled waveguides. We hope that these results will pave an avenue for the construction of new types of flexible WGM-based components for photonic integration.

  7. Thermo-optic tuning of whispering gallery mode lasing from a dye-doped hollow polymer optical fiber.

    PubMed

    Anand, V R; Mathew, S; Samuel, Boni; Radhakrishnan, P; Kailasnath, M

    2017-08-01

    We report temperature-induced tuning of whispering gallery mode (WGM) laser emission from a Rhodamine-B-doped polymethylmethacrylate hollow optical fiber. Lasing studies on dye-doped hollow fibers with different radii were carried out with optical pumping using a Q-switched Nd:YAG laser. The observed lasing modes were confirmed as WGM emission with a high quality factor of 7.58×10(3). The diameter-dependent variation in lasing spectra of these hollow fibers was investigated. A tuning range of 0.44 nm with a sensitivity of 0.011  nm/°C was obtained for the lasing modes by varying the temperature from 25°C to 60°C from a dye-doped polymethylmethacrylate hollow fiber of diameter 305 μm.

  8. Tunable waveguide and cavity in a phononic crystal plate by controlling whispering-gallery modes in hollow pillars

    NASA Astrophysics Data System (ADS)

    Jin, Yabin; Fernez, Nicolas; Pennec, Yan; Bonello, Bernard; Moiseyenko, Rayisa P.; Hémon, Stéphanie; Pan, Yongdong; Djafari-Rouhani, Bahram

    2016-02-01

    We investigate the properties of a phononic crystal plate with hollow pillars and introduce the existence of whispering-gallery modes (WGMs). We show that by tuning the inner radius of the hollow pillar, these modes can merge inside both Bragg and low frequency band gaps, deserving phononic crystal and acoustic metamaterial applications. These modes can be used as narrow pass bands for which the quality factor can be greatly enhanced by the introduction of an additional cylinder between the hollow cylinder and the plate. We discuss some functionalities of these confined WGM in both Bragg and low frequency gaps for wavelength division in multiplexer devices using heteroradii pillars introduced into waveguide and cavity structures.

  9. Relationship between height and width of resonance peaks in a whispering gallery mode resonator immersed in water and sucrose solutions

    NASA Astrophysics Data System (ADS)

    Teraoka, Iwao; Yao, Haibei; Huiyi Luo, Natalie

    2017-06-01

    We employed a recently developed whispering gallery mode (WGM) dip sensor made of silica to obtain spectra for many resonance peaks in water and solutions of sucrose at different concentrations and thus having different refractive indices (RI). The apparent Q factor was estimated by fitting each peak profile in the busy resonance spectrum by a Lorentzian or a sum of Lorentzians. A plot of the Q factor as a function the peak height for all the peaks analyzed indicates a straight line with a negative slope as the upper limit, for each of water and the solutions. A coupling model for a resonator and a pair of fiber tapers to feed and pick up light, developed here, supports the presence of the upper limit. We also found that the round-trip attenuation of WGM was greater than the one estimated from light absorption by water, and the difference increased with the concentration of sucrose.

  10. Surface-plasmon-polariton whispering-gallery mode analysis of the graphene monolayer coated InGaAs nanowire cavity.

    PubMed

    Zhao, Jing; Liu, Xianhe; Qiu, Weibin; Ma, Yuhui; Huang, Yixin; Wang, Jia-Xian; Qiang, Kan; Pan, Jiao-Qing

    2014-03-10

    In this article, we proposed and numerically studied the surface plasmon polariton whispering gallery mode properties of the graphene coated InGaAs nanowire cavity. The quality factor and the mode area were investigated as a function of the chemical potential, the cavity radius and the wavelength. A high cavity quality factor of 235 is predicted for a 5 nm radius cavity, accompanied by a mode area as small as3.75×10(-5)(λ(0))(2), when the chemical potential is 1.2 eV. The proposed structure offers a potential solution to high density integration of the nanophotonic devices with an ultra-compact footprint.

  11. Whispering Gallery mode ESR spectroscopy and parameters measurement in single crystal SrLaAlO4 at millikelvin temperature

    NASA Astrophysics Data System (ADS)

    Hosain, M. A.; Le Floch, J.-M.; Krupka, J.; Tobar, M. E.

    2017-08-01

    A cylindrical single crystal SrLaAlO4 Whispering Gallery mode dielectric resonator was cooled to millikelvin temperature using a dilution refrigerator. By controlling a DC-magnetic field, impurity ions' spins were coupled to a variety of modes allowing the measurement of hybrid spin-photon systems. This Electron Spin Resonance mapping technique allowed us to detect Cu2+,Fe3+ and Mn4+ impurity ions (at the level of parts per million (ppm) to parts per billion (ppb)), verified by the measurement of the spin parameters along with their site symmetry. Whispering Gallery modes exhibited Q-factors ⩾105 at a temperature less than 20mK , allowing sensitive spectroscopy with high precision. Measured hyperfine line constants of the Cu2+ ion shows different parallel g-factors, g‖Cu , of 2.526, 2.375, 2.246 and 2.142 . The spin-orbit coupling constant of the Cu2+ ion was determined to be λ ≃ - 635cm-1 . The low-spin state Fe3+ ion's measured parallel g-factor, g‖Fe , of 2.028 reveals tetragonal anisotropy. The Mn4+ ion is identified in the lattice, producing hyperfine structure with high-valued g-factors,g‖Mn , of 7.789, 7.745, 7.688, 7.613, 7.5304 and 7.446 . The hyperfine structures of the Cu2+ and Mn4+ ions show broadening of about 79G between 9.072GHz and 10.631GHz , and 24.5G broadening between 9.072GHz and 14.871GHz , respectively.

  12. Seabed gallery intakes: Investigation of the water pretreatment effectiveness of the active layer using a long-term column experiment.

    PubMed

    Dehwah, Abdullah H A; Missimer, Thomas M

    2017-09-15

    Seabed gallery intake systems used for seawater reverse osmosis facilities employ the same principle of water treatment as slow sand filtration in freshwater systems. An investigation concerning the effectiveness of the active layer (top layer) in improving raw water quality was conducted by using a long-term bench-scale columns experiment. Two different media types, silica and carbonate sand, were tested in 1 m columns to evaluate the effectiveness of media type in terms of algae, bacteria, Natural Organic Matter (NOM) and Transparent Exopolymer Particles (TEP) removal over a period of 620 days. Nearly all algae in the silica sand column, 87% (σ = 0.04) of the bacteria, 59% (σ = 0.11) of the biopolymer fraction of NOM, 59% (σ = 0.16) of particulate and 32% (σ = 0.25) of colloidal TEP were removed during the last 330 days of the experiment. Total removal was observed in the carbonate sand column for algal concentration, while the bacterial removal was lower at 74% (σ = 0.08). Removal of biopolymers, particulate and colloidal TEP were higher in the carbonate column during the last 330 days with 72% (σ = 0.15), 66% (σ = 0.08) and 36% (σ = 0.12) removed for these organics respectively. Removal of these key organics through the 1 m thick column, representing the active layer, will likely reduce the rate of biofouling, reduce chemical usage and minimize operating cost in SWRO systems. The data show that the media will require several months at the beginning of operation to reach equilibrium so that high organic removal rates can be achieved. No development of a "schmutzdecke" layer occurred. The experimental results suggest that unlike freshwater slow sand filtration wherein most water treatment occurs in the upper 10 cm, in seawater systems treatment occurs throughout the full active layer depth of 1 m. The results of this study will help in designing and operating seabed gallery intake systems in varied geological conditions. Copyright

  13. Sex ratio and female sexual status of the coconut pest, Oryctes monoceros (Coleoptera: Dynastidae), differ in feeding galleries and pheromone-baited traps.

    PubMed

    Allou, K; Morin, J-P; Kouassi, P; Hala N'klo, F; Rochat, D

    2008-12-01

    Oryctes monoceros is a serious coconut pest, causing up to 40% damage in tropical Africa. Synthetic aggregation pheromone, ethyl 4-methyloctanoate, has been used to lure adults to traps. Traps with pheromone plus decaying palm material captured a high proportion of males. This raises the question whether individuals, which damage palms are receptive to the pheromone. We studied the sex ratio of the insects feeding on coconuts and those attracted to pheromone traps. Sixty two percent of adults from feeding galleries on living coconut palms were females. Pheromone with rotting palm material lured 43% females. To investigate the reasons for this difference, we compared the reproductive system of females lured to the odour traps or feeding in coconut galleries, or present in old rotting stems. Ninety six percent of the females trapped by pheromone had mated, and were sexually mature. In the galleries on living palms, 46% of females were immature, and 24% had not mated. In old rotting stems where eggs are laid and larvae develop, a mixture of 52% mated and 48% virgin females was found. Therefore, the pheromone together with the odour of rotting coconut stems signals a reproduction site to beetles, particularly mature females. In practice, the pheromone-baited traps will help in reducing the dissemination of gravid females, but will not affect directly the numbers of immature ones attacking palms. Our results show that when using pheromones for monitoring or controlling insects, the physiological status of the insects may have unexpected effects on the outcome.

  14. Tuning of whispering gallery modes in a magnetic-fluid-infiltrated silica capillary based on lateral pumping scheme

    NASA Astrophysics Data System (ADS)

    Li, Yuetao; Zhang, Hao; Liu, Bo; Wu, Jixuan; Song, Binbin; Yan, Donglin; Yang, Chengkun

    2017-01-01

    An all-optical tuning method of whispering gallery modes (WGMs) in a silica capillary based on lateral pumping scheme has been proposed and experimentally demonstrated by exploiting the photo-thermal effect of magnetic fluids (MFs) infiltrated into a micro-capillary. The WGMs are coupled from a tapered fiber perpendicular to the silica capillary. Experimental results indicate that the microresonator integrated with MFs shows a Q-factor of 1.2867 × 104 and its optical tunability reaches 0.0382 nm/(mW · mm-2) under 532 nm laser illumination. Compared with the one infiltrated with pure water, our proposed capillary shows an optical tuning sensitivity increase of about 4270 times. The experimental results on the WGM resonance wavelength sensitivity for the capillaries with different diameters are in accordance with our simulation outcome using radially dependent heat conducting equation. Further experimental studies indicate that the proposed microresonator possesses a good spectral reversibility. Moreover, the dynamic response experiment shows that the rise and fall time of this microresonator is about 231 ms and 255 ms, respectively. The above intriguing features make the proposed WGM resonator a promising candidate for potential applications in optical filtering, microfluidic sensing, and signal processing as well as reconfigurable devices for future all-optical networks.

  15. Whispering Gallery Mode Biosensor Quantification of Fibronectin Adsorption Kinetics onto Alkylsilane Monolayers and Interpretation of Resultant Cellular Response

    PubMed Central

    Wilson, Kerry A.; Finch, Craig A.; Anderson, Phillip; Vollmer, Frank; Hickman, James J.

    2011-01-01

    A Whispering Gallery Mode (WGM) biosensor was constructed to measure the adsorption of protein onto alkysilane self-assembled monolayers (SAMs) at solution concentrations unattainable with other techniques. The high sensitivity was provided by a WGM resonance excited in a silica microsphere that was functionalized with alkylsilane SAMs and integrated in a microfluidic flow cell under laminar flow conditions. It was found that FN adsorbed at biologically relevant surface densities, however, the adsorption kinetics and concentration dependent saturation values varied significantly from work published utilizing alkanethiol SAMs. Mathematical models were applied to the experimental results to interpret the observed kinetics of FN adsorption. Embryonic hippocampal neurons and skeletal myoblasts were cultured on the modified surfaces, and a live-dead assay was used to determine the viability of the FN surfaces for cell culture, and major differences were noted in the biological response to the different SAMs. The high sensitivity and simplicity of the WGM biosensor, combined with its ability to quantify the adsorption of any dilute protein in a label-free assay, establishes the importance of this technology for the study of surface accretion and its effect on cellular function, which can affect biomaterials for both in vivo and in vitro applications. PMID:21983134

  16. Protein-Based Three-Dimensional Whispering-Gallery-Mode Micro-Lasers with Stimulus-Responsiveness

    PubMed Central

    Sun, Yun-Lu; Hou, Zhi-Shan; Sun, Si-Ming; Zheng, Bo-Yuan; Ku, Jin-Feng; Dong, Wen-Fei; Chen, Qi-Dai; Sun, Hong-Bo

    2015-01-01

    For the first time, proteins, a promising biocompatible and functionality-designable biomacromolecule material, acted as the host material to construct three-dimensional (3D) whispering-gallery-mode (WGM) microlasers by multiphoton femtosecond laser direct writing (FsLDW). Protein/Rhodamine B (RhB) composite biopolymer was used as optical gain medium innovatively. By adopting high-viscosity aqueous protein ink and optimized scanning mode, protein-based WGM microlasers were customized with exquisite true 3D geometry and smooth morphology. Comparable to previously reported artificial polymers, protein-based WGM microlasers here were endowed with valuable performances including steady operation in air and even in aqueous environments, and a higher quality value (Q) of several thousands (without annealing). Due to the “smart” feature of protein hydrogel, lasing spectrum was responsively adjusted by step of ~0.4 nm blueshift per 0.83-mmol/L Na2SO4 concentration change (0 ~ 5-mmol/L in total leading to ~2.59-nm blueshift). Importantly, other performances including Q, FWHM, FSR, peak intensities, exhibited good stability during adjustments. So, these protein-based 3D WGM microlasers might have potential in applications like optical biosensing and tunable “smart” biolasers, useful in novel photonic biosystems and bioengineering. PMID:26238255

  17. Lasing mode regulation and single-mode realization in ZnO whispering gallery microcavities by the Vernier effect.

    PubMed

    Wang, Y Y; Xu, C X; Jiang, M M; Li, J T; Dai, J; Lu, J F; Li, P L

    2016-10-07

    The wide direct bandgap and strong exciton binding energy of ZnO have inspired examinations of ultraviolet lasing over the previous decades. However, regulation of the lasing mode, especially the realization of single mode lasing, is still a challenge. In this study, a ZnO comb-like structure with an array of microrods was selected to design coupled whispering-gallery-mode cavities, wherein the naturally varied air-gap between the adjacent microrods created a flexible condition for optical field coupling without any complicated micromanipulation. Spectral behaviour of lasing and coupling interaction between coupled ZnO microrods were systematically investigated. By regulating the nano-scale inter-space of dual coupled microrods, stable single-mode lasing with a higher Q factor and lower threshold was obtained successfully based on the Vernier effect. The formation conditions and the mechanism of single-mode lasing derived from the coupled ZnO microrods were discussed in detail. It also demonstrated an approach to construct high quality single-mode lasing by tuning the diameters of the coupled ZnO microrods.

  18. [Concordance among analysts from Latin-American laboratories for rice grain appearance determination using a gallery of digital images].

    PubMed

    Avila, Manuel; Graterol, Eduardo; Alezones, Jesús; Criollo, Beisy; Castillo, Dámaso; Kuri, Victoria; Oviedo, Norman; Moquete, Cesar; Romero, Marbella; Hanley, Zaida; Taylor, Margie

    2012-06-01

    The appearance of rice grain is a key aspect in quality determination. Mainly, this analysis is performed by expert analysts through visual observation; however, due to the subjective nature of the analysis, the results may vary among analysts. In order to evaluate the concordance between analysts from Latin-American rice quality laboratories for rice grain appearance through digital images, an inter-laboratory test was performed with ten analysts and images of 90 grains captured with a high resolution scanner. Rice grains were classified in four categories including translucent, chalky, white belly, and damaged grain. Data was categorized using statistic parameters like mode and its frequency, the relative concordance, and the reproducibility parameter kappa. Additionally, a referential image gallery of typical grain for each category was constructed based on mode frequency. Results showed a Kappa value of 0.49, corresponding to a moderate reproducibility, attributable to subjectivity in the visual analysis of grain images. These results reveal the need for standardize the evaluation criteria among analysts to improve the confidence of the determination of rice grain appearance.

  19. Micro-CTvlab: A web based virtual gallery of biological specimens using X-ray microtomography (micro-CT)

    PubMed Central

    Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos

    2016-01-01

    Abstract Background During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CTvlab) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. New information The Micro-CTvlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CTvlab can be accessed either on a normal computer or through a dedicated version for mobile devices. PMID:27956848

  20. Whispering Gallery Modes Used to Determine the Changing Size of Levitated Aerosol Droplets in a Fluctuating Optical Trap

    NASA Astrophysics Data System (ADS)

    Ludvigsen, Angela; McCann, Lowell

    A laser can be used as an optical trap to catch and hold small, transparent objects. Observations of optically trapped aqueous aerosol droplets have demonstrated that the droplet moves between two or more stable positions dependent upon the power of the trapping laser. It is hypothesized that this movement coincides with a resonance between the trapping light and the droplet's surface, called a Whispering Gallery Mode. When this resonance occurs, forces acting on the droplet cause it to move. To investigate this behavior, Raman scattered light from the droplet as well as the droplet's position are measured. The Raman spectrum exhibits a series of peaks resulting from the droplet's spherical shape, referred to as Cavity Enhanced Raman Spectroscopy. The location and spacing of these peaks are known to be related to the diameter and the optical properties of the droplet. From this spectrum, the magnitude of the electric and magnetic fields of the scattered light are calculated. This allows for a precise measurement of the droplet's radius at the moment that the droplet moves between stable positions. After determining the droplet's radius from the spectrum, the effect of varying the intensity of the trapping laser beam on the droplet radius can be investigated.

  1. Toward Automatic Label-Free Whispering Gallery Modes Biodetection with a Quantum Dot-Coated Microsphere Population

    NASA Astrophysics Data System (ADS)

    Charlebois, M.; Paquet, A.; Verret, L. S.; Boissinot, K.; Boissinot, M.; Bergeron, M. G.; Allen, C. Nì.

    2010-03-01

    We explore a new calibration-free approach to biodetection based on whispering gallery modes (WGMs) without a reference measure and relative shifts. Thus, the requirement to keep track of the sensor position is removed, and a freely moving population of fluorophore-doped polystyrene microspheres can now fulfill this role of sensing resonator. Breaking free from fixed surface-based biosensing promotes adhesion between the microsphere sensors and the analytes since both can now be thoroughly mixed. The 70-nm-wide spectrum of green fluorescent microbeads allows us to monitor over 20 WGMs simultaneously without needing evanescent light coupling into the microspheres, hence enabling remote sensing. Since the exact radius of each microsphere is unknown a priori, it requires algorithmic analyses to obtain a reliable result for the refractive index of a solution. We first test our approach with different solutions of alcohol in water obtaining 3 × 10-4 precision on the refractive index at lower concentrations. Then, the solutions of bacterial spores in water yield clear evidence of biodetection in the statistical analysis of WGMs from 50 microspheres. To extend the fluorescence spectral range of our WGM sensors, we present preliminary results on coating microspheres with CdSe/ZnS quantum dots.

  2. Raman gain induced mode evolution and on-demand coupling control in whispering-gallery-mode microcavities.

    PubMed

    Yang, Xu; Özdemir, Şahin Kaya; Peng, Bo; Yilmaz, Huzeyfe; Lei, Fu-Chuan; Long, Gui-Lu; Yang, Lan

    2015-11-16

    Waveguide-coupled optical resonators have played an important role in a wide range of applications including optical communication, sensing, nonlinear optics, slow/fast light, and cavity QED. In such a system, the coupling regimes strongly affect the resonance feature in the light transmission spectra, and hence the performance and outcomes of the applications. Therefore it is crucial to control the coupling between the waveguide and the microresonator. In this work, we investigated a fiber-taper coupled whispering-gallery-mode microresonator system, in which the coupling regime is traditionally controlled by adjusting the distance between the resonator and the fiber-taper mechanically. We propose and experimentally demonstrate that by utilizing Raman gain one can achieve on-demand control of the coupling regime without any mechanical movement in the resonator system. Particularly, the application of Raman gain is accompanied by Q enhancement. We also show that with the help of Raman gain control, the transitions between various coupling regimes can affect the light transmission spectra so as to provide better resolvability and signal amplification. This all-optical approach is also suitable for monolithically integrated and packaged waveguide-resonator systems, whose coupling regime is fixed at the time of manufacturing. It provides an effective route to control the light transmission in a waveguide-couple resonator system without mechanically moving individual optical components.

  3. Enhanced second-harmonic generation from metal-integrated semiconductor nanowires via highly confined whispering gallery modes.

    PubMed

    Ren, Ming-Liang; Liu, Wenjing; Aspetti, Carlos O; Sun, Liaoxin; Agarwal, Ritesh

    2014-11-12

    Coherent and tunable nanoscale light sources utilizing optical nonlinearities are required for applications ranging from imaging and bio-sensing to on-chip all-optical signal processing. However, owing to their small sizes, the efficiency of nanostructures even with high nonlinear coefficients is poor, therefore requiring very high excitation energies. Although surface-plasmon resonances of metal nanostructures can enhance surface nonlinear processes such as second-harmonic generation, they still suffer from low conversion efficiencies owing to their intrinsically low nonlinear coefficients. Here we show highly enhanced and directional second-harmonic generation from individual CdS nanowires integrated with silver nanocavities (>1,000 times higher external efficiency compared with bare CdS), in which the lowest-order whispering gallery mode is engineered to concentrate light in the nonlinear material while minimizing Ohmic losses. The directional nonlinear signal is redirected into another waveguide, which is then utilized to configure an optical router that can potentially serve as a tunable coherent light source to enable on-chip signal processing for integrated nanophotonic systems.

  4. Micro-CTvlab: A web based virtual gallery of biological specimens using X-ray microtomography (micro-CT).

    PubMed

    Keklikoglou, Kleoniki; Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos

    2016-01-01

    During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CTvlab) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. The Micro-CTvlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CTvlab can be accessed either on a normal computer or through a dedicated version for mobile devices.

  5. Laser-tuned whispering gallery modes in a solid-core microstructured optical fibre integrated with magnetic fluids

    PubMed Central

    Lin, Wei; Zhang, Hao; Liu, Bo; Song, Binbin; Li, Yuetao; Yang, Chengkun; Liu, Yange

    2015-01-01

    A laser-assisted tuning method of whispering gallery modes (WGMs) in a cylindrical microresonator based on magnetic-fluids-infiltrated microstructured optical fibres (MFIMOFs, where MF and MOF respectively refer to magnetic fluid and microstructured optical fibre) is proposed, experimentally demonstrated and theoretically analysed in detail. The MFIMOF is prepared by infiltrating the air-hole array of the MOF using capillary action effect. A fibre-coupling system is set up for the proposed MFIMOF-based microresonator to acquire an extinction ratio up to 25 dB and a Q-factor as large as 4.0 × 104. For the MF-infiltrated MOF, the light propagating in the fibre core region would rapidly spread out and would be absorbed by the MF-rod array cladding to induce significant thermal effect. This has been exploited to achieve a WGM resonance wavelength sensitivity of 0.034 nm/mW, which is ~20 times higher than it counterpart without MF infiltration. The wavelength response of the resonance dips exhibit linear power dependence, and owing to such desirable merits as ease of fabrication, high sensitivity and laser-assisted tunability, the proposed optical tuning approach of WGMs in the MFIMOF would find promising applications in the areas of optical filtering, sensing, and signal processing, as well as future all-optical networking systems. PMID:26632445

  6. Optical multistability and Fano line-shape control via mode coupling in whispering-gallery-mode microresonator optomechanics

    PubMed Central

    Zhang, Suzhen; Li, Jiahua; Yu, Rong; Wang, Wei; Wu, Ying

    2017-01-01

    We study a three-mode (i.e., a clockwise mode, a counterclockwise mode, and a mechanical mode) coherent coupling regime of the optical whispering-gallery-mode (WGM) microresonator optomechanical system by considering a pair of counterpropagating modes in a general case. The WGM microresonator is coherently driven by a strong control laser field and a relatively weak probe laser field via a tapered fiber. The system parameters utilized to explore this process correspond to experimentally demonstrated values in the WGM microresonator optomechanical systems. By properly adjusting the coupling rate of these two counterpropagating modes in the WGM microresonator, the steady-state displacement behaviors of the mechanical oscillation and the normalized power transmission and reflection spectra of the output fields are analyzed in detail. It is found that the mode coupling plays a crucial role in rich line-shape structures. Some interesting phenomena of the system, including optical multistability and sharp asymmetric Fano-shape optomechanically induced transparency (OMIT), can be generated with a large degree of control and tunability. Our obtained results in this study can be used for designing efficient all-optical switching and high-sensitivity sensor. PMID:28045120

  7. Light coupling into the Whispering Gallery Modes of a fiber array thin film solar cell for fixed partial Sun tracking

    PubMed Central

    Mariano, Marina; Rodríguez, Francisco J.; Romero-Gomez, Pablo; Kozyreff, Gregory; Martorell, Jordi

    2014-01-01

    We propose the use of whispering gallery mode coupling in a novel configuration based on implementing a thin film cell on the backside of an array of parallel fibers. We performed numerical calculations using the parameters of a thin film organic cell which demonstrate that light coupling becomes more effective as the angle for the incident light relative to the fiber array normal increases up to an optimal angle close to 55 deg. At this angle the power conversion efficiency of the fiber array solar cell we propose becomes 30% times larger than the one from an equivalent planar cell configuration. We demonstrate that the micro fiber array solar cell we propose may perform an effective partial tracking of the sun movement for over 100 degrees without any mechanical help. In addition, in the event that such fiber array cell would be installed with the adequate orientation on a vertical façade, an optimal photon-to-charge conversion would be reached for sunlight incident at 55 deg with respect to the horizon line, very close to the yearly average position for the sun at Latitude of 40 deg.

  8. Frequency tuning of single photons from a whispering-gallery mode resonator to MHz-wide transitions

    NASA Astrophysics Data System (ADS)

    Schunk, G.; Vogl, U.; Sedlmeir, F.; Strekalov, D. V.; Otterpohl, A.; Averchenko, V.; Schwefel, H. G. L.; Leuchs, G.; Marquardt, Ch.

    2016-11-01

    Quantum repeaters rely on interfacing flying qubits with quantum memories. The most common implementations include a narrowband single photon matched in bandwidth and central frequency to an atomic system. Previously, we demonstrated the compatibility of our versatile source of heralded single photons, which is based on parametric down-conversion in a triply resonant whispering-gallery mode resonator, with alkaline transitions [Schunk et al., Optica 2015, 2, 773]. In this paper, we analyse our source in terms of phase matching, available wavelength-tuning mechanisms and applications to narrowband atomic systems. We resonantly address the D1 transitions of caesium and rubidium with this optical parametric oscillator pumped above its oscillation threshold. Below threshold, the efficient coupling of single photons to atomic transitions heralded by single telecom-band photons is demonstrated. Finally, we present an accurate analytical description of our observations. Providing the demonstrated flexibility in connecting various atomic transitions with telecom wavelengths, we show a promising approach to realize an essential building block for quantum repeaters.

  9. Optical multistability and Fano line-shape control via mode coupling in whispering-gallery-mode microresonator optomechanics

    NASA Astrophysics Data System (ADS)

    Zhang, Suzhen; Li, Jiahua; Yu, Rong; Wang, Wei; Wu, Ying

    2017-01-01

    We study a three-mode (i.e., a clockwise mode, a counterclockwise mode, and a mechanical mode) coherent coupling regime of the optical whispering-gallery-mode (WGM) microresonator optomechanical system by considering a pair of counterpropagating modes in a general case. The WGM microresonator is coherently driven by a strong control laser field and a relatively weak probe laser field via a tapered fiber. The system parameters utilized to explore this process correspond to experimentally demonstrated values in the WGM microresonator optomechanical systems. By properly adjusting the coupling rate of these two counterpropagating modes in the WGM microresonator, the steady-state displacement behaviors of the mechanical oscillation and the normalized power transmission and reflection spectra of the output fields are analyzed in detail. It is found that the mode coupling plays a crucial role in rich line-shape structures. Some interesting phenomena of the system, including optical multistability and sharp asymmetric Fano-shape optomechanically induced transparency (OMIT), can be generated with a large degree of control and tunability. Our obtained results in this study can be used for designing efficient all-optical switching and high-sensitivity sensor.

  10. Protein-Based Three-Dimensional Whispering-Gallery-Mode Micro-Lasers with Stimulus-Responsiveness

    NASA Astrophysics Data System (ADS)

    Sun, Yun-Lu; Hou, Zhi-Shan; Sun, Si-Ming; Zheng, Bo-Yuan; Ku, Jin-Feng; Dong, Wen-Fei; Chen, Qi-Dai; Sun, Hong-Bo

    2015-08-01

    For the first time, proteins, a promising biocompatible and functionality-designable biomacromolecule material, acted as the host material to construct three-dimensional (3D) whispering-gallery-mode (WGM) microlasers by multiphoton femtosecond laser direct writing (FsLDW). Protein/Rhodamine B (RhB) composite biopolymer was used as optical gain medium innovatively. By adopting high-viscosity aqueous protein ink and optimized scanning mode, protein-based WGM microlasers were customized with exquisite true 3D geometry and smooth morphology. Comparable to previously reported artificial polymers, protein-based WGM microlasers here were endowed with valuable performances including steady operation in air and even in aqueous environments, and a higher quality value (Q) of several thousands (without annealing). Due to the “smart” feature of protein hydrogel, lasing spectrum was responsively adjusted by step of ~0.4 nm blueshift per 0.83-mmol/L Na2SO4 concentration change (0 ~ 5-mmol/L in total leading to ~2.59-nm blueshift). Importantly, other performances including Q, FWHM, FSR, peak intensities, exhibited good stability during adjustments. So, these protein-based 3D WGM microlasers might have potential in applications like optical biosensing and tunable “smart” biolasers, useful in novel photonic biosystems and bioengineering.

  11. Highly sensitive detection of nanoparticles with a self-referenced and self-heterodyned whispering-gallery Raman microlaser

    PubMed Central

    Özdemir, Şahin Kaya; Zhu, Jiangang; Yang, Xu; Peng, Bo; Yilmaz, Huzeyfe; He, Lina; Monifi, Faraz; Huang, Steven He; Long, Gui Lu; Yang, Lan

    2014-01-01

    Optical whispering-gallery-mode resonators (WGMRs) have emerged as promising platforms for label-free detection of nano-objects. The ultimate sensitivity of WGMRs is determined by the strength of the light–matter interaction quantified by quality factor/mode volume, Q/V, and the resolution is determined by Q. To date, to improve sensitivity and precision of detection either WGMRs have been doped with rare-earth ions to compensate losses and increase Q or plasmonic resonances have been exploited for their superior field confinement and lower V. Here, we demonstrate, for the first time to our knowledge, enhanced detection of single-nanoparticle-induced mode splitting in a silica WGMR via Raman gain-assisted loss compensation and WGM Raman microlaser. In particular, the use of the Raman microlaser provides a dopant-free, self-referenced, and self-heterodyned scheme with a detection limit ultimately determined by the thermorefractive noise. Notably, we detected and counted individual nanoparticles with polarizabilities down to 3.82 × 10−6 μm3 by monitoring a heterodyne beatnote signal. This level of sensitivity is achieved without exploiting plasmonic effects, external references, or active stabilization and frequency locking. Single nanoparticles are detected one at a time; however, their characterization by size or polarizability requires ensemble measurements and statistical averaging. This dopant-free scheme retains the inherited biocompatibility of silica and could find widespread use for sensing in biological media. The Raman laser and operation band of the sensor can be tailored for the specific sensing environment and the properties of the targeted materials by changing the pump laser wavelength. This scheme also opens the possibility of using intrinsic Raman or parametric gain for loss compensation in other systems where dissipation hinders progress and limits applications. PMID:25197086

  12. Electro-optic modulation of high-Q lithium niobate whispering gallery resonator with integrated ground plane (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Douglas, Kenneth; Moore, Jeremy; Friedman, Thomas; Eichenfield, Matthew

    2017-02-01

    We experimentally demonstrate electro-optic modulation in thin film lithium niobate microdisk resonators with an integrated bottom electrode fabricated from a z-cut Lithium Niobate on Insulator wafer. The structure consisted of a 400nm thick crystalline z-cut lithium niobate/2um SiO2/20nm Cr/100nm Au/10nm Cr film stack on top of a z-cut lithium niobate handle wafer. The integrated bottom electrode is located 2um beneath the resonator. This proximity, coupled with positioning an electrical probe close to the top of the resonator, allows large optical frequency shifts with low voltages. We observed a 0.111pm/V resonance shift of vertically polarized (TM) optical whispering gallery modes, with the voltage applied perpendicular to the wafer surface. This corresponds to a shift of one optical linewidth at an applied voltage of 180V, using the r33 component of the eletro-optic tensor. We observed a smaller shift of 0.066pm/V for the radially polarized (TE) modes, using the r13 component of the electro-optic tensor. The experiment was performed using a 1550nm tunable laser that was coupled to the optical resonator modes using a tapered optical fiber. To measure the electro-optic shift of the resonance, a voltage was applied across the device via DC probe tips and the peak shift was calibrated with a Toptica WS6 IR wavemeter with 200 MHz absolute accuracy. We also present a finite element model that accurately predicts the resonance shift as a function of applied voltage for both polarizations.

  13. Inventory using laser scanning of the control gallery and overflow sectionof Klimkówka earthfill dam - experiences and conclusions. (Polish Title: Inwentaryzacja galerii kontrolnej i przelewu zapory ziemnej Klimkówka metodą skanowania laserowego)

    NASA Astrophysics Data System (ADS)

    Zaczek-Peplinska, J.; Adamek, Artur; Osińska-Skotak, K.; Adamek, Anna

    2013-12-01

    The paper discusses experiences resulting from the surveying inventory of Klimkówka earthdam's control gallery. Current status of the law, which impose obligation of adequate technical control onthe unit administering and operating hydraulic structures is presented. Laser scanning due to the lack of suitable developed measurements methodology for this type of objects is rarely used for its inventory and control. In August 2012, the measurement of displacements of control gallery of this object using precise levelling was conducted by the staff and the students from the Department of Engineering and Detailed Surveying (WUT, Faculty of Geodesy and Cartography). Simultaneously, an inventory of control gallery using terrestrial laser scanning was made. In addition, during the processing the data an attempt to analyse the I values (Intensity) was made which were recorded during the measure of concrete overflow using automated image analysis in order to carry out the characteristic classification of the concrete -this analysis is to be used as a starting material for the analysis of changes in the surface of the concrete in the following years. The results of an inventory of geometry of the control gallery and a preliminary analysis of the surface of the concrete overflow using unsupervised classification method have been presented. The process of gallery model creation, as well as selected possible analyses and measurements based on the data from terrestrial laser scanning have been also described.

  14. Monitoring the Excavation Damaged Zone in Opalinus clay by three dimensional reconstruction of the electrical resistivity in the Mont Terri gallery G-04

    NASA Astrophysics Data System (ADS)

    Lesparre, N.; Adler, A.; Nicollin, F.; Gibert, D.; Nussbaum, C.

    2012-04-01

    The characteristics of opalinus clay have been studied in the last years for its capacity to retain radionuclide transport as a low permeable rock. This formation presents thereby suitable properties for hosting repository sites of radioactive waste. The Mont Terri underground rock laboratory (Switzerland) has been excavated in opalinus clay layer in order to develop experiences improving the knowledge on the physico-chemical properties of the rock. The study of electrical properties furnishes information on the rock structure, its anisotropy and the changes of these properties with time (Nicollin et al., 2010 ; Thovert et al., 2011). Here the three dimensional reconstruction of the electrical resistivity aims at monitoring the temporal evolution of the excavation damaged zone. Three rings of electrodes have been set-up around the gallery and voltage is measured between two electrodes while a current is injected between two others (Gibert et al., 2006). Measurements have been achieved from July 2004 until April 2008 before, during and after the excavation of the gallery 04. In this study we develop a computational approach to reconstruct three dimensional images of the resistivity in the vicinity of the electrodes. A finite element model is used to represent the complex geometry of the gallery. The measurements inferred from a given resistivity distribution are estimated using the software EIDORS (Adler and Lionheart, 2006), this constitutes the forward problem. The reconstruction of the media resistivity is then implemented by fitting the estimated to the measured data, via the resolution of an inverse problem. The parameters of this inverse problem are defined by mapping the forward problem elements into a coarser mesh. This allows to reduce drastically the number of unknowns and so increases the robustness of the inversion. The inversion is executed with the conjugate gradient method regularised by an analysis of the Jacobian singular values. The results show an

  15. Formation of optical fields of stimulated Raman scattering with a resolution beyond the Abbe diffraction limit by spherical microlens cavities with whispering gallery modes: Near-field approximation

    NASA Astrophysics Data System (ADS)

    Jouravlev, M. V.

    2012-04-01

    We consider a significant lowering of the threshold of stimulated Raman scattering in solid fused silica spherical microlenses cavities that is caused by an increase in the integral overlap factor of whispering gallery modes. The structure of focal regions of a microlens is shown to have the shape of honeycombs, forming a photonic crystal or a photonic nanojet. We show that, at comparatively small numerical apertures NA = 0.7-0.8, which correspond to hemispherical microlenses, a spherical microlens cavity exhibits the possibility of focusing laser radiation beyond the Abbe diffraction limit. This enables the possibility of wide practical applications of microspheres as a focusing element the resolving power of which exceeds the Abbe diffraction limit in the near field. The whispering-gallery-mode spherical microlens cavity makes it possible to perform laser generation with a duration of a coherent pulse in the subfemtosecond range and to form a subwavelength focal region of the near field. This ensures the possibility of detecting single molecules of a substance in the subwavelength range in the near field and can be used to increase the sensitivity of intracavity spectroscopy methods and as microlasers for excitation of molecules in metal molecular nanoswitches and semiconductor heterostructures. From an array of microlens cavities, metamaterials with a negative refractive index can be formed.

  16. HUBBLE'S INFRARED GALAXY GALLERY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronomers have used the NASA Hubble Space Telescope to produce an infrared 'photo essay' of spiral galaxies. By penetrating the dust clouds swirling around the centers of these galaxies, the telescope's infrared vision is offering fresh views of star birth. These six images, taken with the Near Infrared Camera and Multi-Object Spectrometer, showcase different views of spiral galaxies, from a face-on image of an entire galaxy to a close-up of a core. The top row shows spirals at diverse angles, from face-on, (left); to slightly tilted, (center); to edge-on, (right). The bottom row shows close-ups of the hubs of three galaxies. In these images, red corresponds to glowing hydrogen, the raw material for star birth. The red knots outlining the curving spiral arms in NGC 5653 and NGC 3593, for example, pinpoint rich star-forming regions where the surrounding hydrogen gas is heated by intense ultraviolet radiation from young, massive stars. In visible light, many of these regions can be hidden from view by the clouds of gas and dust in which they were born. The glowing hydrogen found inside the cores of these galaxies, as in NGC 6946, may be due to star birth; radiation from active galactic nuclei (AGN), which are powered by massive black holes; or a combination of both. White is light from middle-age stars. Clusters of stars appear as white dots, as in NGC 2903. The galaxy cores are mostly white because of their dense concentration of stars. The dark material seen in these images is dust. These galaxies are part of a Hubble census of about 100 spiral galaxies. Astronomers at Space Telescope Science Institute took these images to fill gaps in the scheduling of a campaign using the NICMOS-3 camera. The data were non-proprietary, and were made available to the entire astronomical community. Filters: Three filters were used: red, blue, and green. Red represents emission at the Paschen Alpha line (light from glowing hydrogen) at a wavelength of 1.87 microns. Blue shows the galaxies in near-infrared light, measured between 1.4 and 1.8 microns (H-band emission). Green is a mixture of the two. Distance of galaxies from Earth: NGC 5653 - 161 million light-years; NGC 3593 - 28 million light-years; NGC 891 - 24 million light-years; NGC 4826 - 19 million light-years; NGC 2903 - 25 million light-years; and NGC 6946 - 20 million light-years. Credits: Torsten Boeker, Space Telescope Science Institute, and NASA NOTE TO EDITORS: Image files and photo caption are available on the Internet at: http://oposite.stsci.edu/pubinfo/pr/1999/10 or via links in http://oposite.stsci.edu/pubinfo/latest.html and http://oposite.stsci.edu/pubinfo/pictures.html Higher resolution digital versions of (300 dpi JPEG and TIFF) of the release photo are available at: http://oposite.stsci.edu/pubinfo/pr/1999/10/extra-photos.html STScI press releases and other information are available automatically by sending an Internet electronic mail message to pio-request@stsci.edu. In the body of the message (not the subject line) users should type the word 'subscribe' (don't use quotes). The system will respond with a confirmation of the subscription, and users will receive new press releases as they are issued. To unsubscribe, send mail to pio-request@stsci.edu. Leave the subject line blank, and type 'unsubscribe' (don't use quotes) in the body of the message.

  17. Walking, Talking Art Gallery.

    ERIC Educational Resources Information Center

    Piazza, Sheila

    2002-01-01

    Discusses a project that aimed at educating the public about art by bringing art to the people. Explains that students selected their favorite artwork and made a t-shirt displaying their artwork. States that the students went into their community and also created a mural. (CMK)

  18. HUBBLE'S PLANETARY NEBULA GALLERY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [Top left] - IC 3568 lies in the constellation Camelopardalis at a distance of about 9,000 light-years, and has a diameter of about 0.4 light-years (or about 800 times the diameter of our solar system). It is an example of a round planetary nebula. Note the bright inner shell and fainter, smooth, circular outer envelope. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Top center] - NGC 6826's eye-like appearance is marred by two sets of blood-red 'fliers' that lie horizontally across the image. The surrounding faint green 'white' of the eye is believed to be gas that made up almost half of the star's mass for most of its life. The hot remnant star (in the center of the green oval) drives a fast wind into older material, forming a hot interior bubble which pushes the older gas ahead of it to form a bright rim. (The star is one of the brightest stars in any planetary.) NGC 6826 is 2,200 light- years away in the constellation Cygnus. The Hubble telescope observation was taken Jan. 27, 1996 with the Wide Field and Planetary Camera 2. Credits: Bruce Balick (University of Washington), Jason Alexander (University of Washington), Arsen Hajian (U.S. Naval Observatory), Yervant Terzian (Cornell University), Mario Perinotto (University of Florence, Italy), Patrizio Patriarchi (Arcetri Observatory, Italy) and NASA [Top right ] - NGC 3918 is in the constellation Centaurus and is about 3,000 light-years from us. Its diameter is about 0.3 light-year. It shows a roughly spherical outer envelope but an elongated inner balloon inflated by a fast wind from the hot central star, which is starting to break out of the spherical envelope at the top and bottom of the image. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Bottom left] - Hubble 5 is a striking example of a 'butterfly' or bipolar (two-lobed) nebula. The heat generated by fast winds causes each of the lobes to expand, much like a pair of balloons with internal heaters. This observation was taken Sept. 9, 1997 by the Hubble telescope's Wide Field and Planetary Camera 2. Hubble 5 is 2,200 light-years away in the constellation Sagittarius. Credits: Bruce Balick (University of Washington), Vincent Icke (Leiden University, The Netherlands), Garrelt Mellema (Stockholm University), and NASA [Bottom center ] - Like NGC 6826, NGC 7009 has a bright central star at the center of a dark cavity bounded by a football-shaped rim of dense, blue and red gas. The cavity and its rim are trapped inside smoothly-distributed greenish material in the shape of a barrel and comprised of the star's former outer layers. At larger distances, and lying along the long axis of the nebula, a pair of red 'ansae', or 'handles' appears. Each ansa is joined to the tips of the cavity by a long greenish jet of material. The handles are clouds of low-density gas. NGC 7009 is 1,400 light-years away in the constellation Aquarius. The Hubble telescope observation was taken April 28, 1996 by the Wide Field and Planetary Camera 2. Credits: Bruce Balick (University of Washington), Jason Alexander (University of Washington), Arsen Hajian (U.S. Naval Observatory), Yervant Terzian (Cornell University), Mario Perinotto (University of Florence, Italy), Patrizio Patriarchi (Arcetri Observatory, Italy), NASA [Bottom right ] - NGC 5307 also lies in Centaurus but is about 10,000 light-years away and has a diameter of approximately 0.6 light-year. It is an example of a planetary nebula with a pinwheel or spiral structure; each blob of gas ejected from the central star has a counterpart on the opposite side of the star. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA

  19. Making the Gallery Scene

    ERIC Educational Resources Information Center

    Wasserman, Burton

    1975-01-01

    Author examined the art of Alberto Giacommetti and Max Ernst, recently shown at The Art Institute of Chicago, while presenting to us his interpretation of what occurs during the observation of art work. (RK)

  20. NIMROD Visualizations Plot Gallery

    DOE Data Explorer

    Sovinec, C. R. [Nimrod Team

    NIMROD solves the extended magnetohydrodynamic equations using: 1) Spectral finite element discretization in two dimensions, 2) Finite Fourier series in the third dimension, 3) Semi-implicit and implicit temporal discretization for the range of temporal scales found in fusion experiments, 4) Simulation particles for kinetic effects from a minority species of energetic ions, and 5) Integro-differential methods for kinetic effects from free-streaming. [copied from the NIMROD home page

  1. HUBBLE'S PLANETARY NEBULA GALLERY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [Top left] - IC 3568 lies in the constellation Camelopardalis at a distance of about 9,000 light-years, and has a diameter of about 0.4 light-years (or about 800 times the diameter of our solar system). It is an example of a round planetary nebula. Note the bright inner shell and fainter, smooth, circular outer envelope. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Top center] - NGC 6826's eye-like appearance is marred by two sets of blood-red 'fliers' that lie horizontally across the image. The surrounding faint green 'white' of the eye is believed to be gas that made up almost half of the star's mass for most of its life. The hot remnant star (in the center of the green oval) drives a fast wind into older material, forming a hot interior bubble which pushes the older gas ahead of it to form a bright rim. (The star is one of the brightest stars in any planetary.) NGC 6826 is 2,200 light- years away in the constellation Cygnus. The Hubble telescope observation was taken Jan. 27, 1996 with the Wide Field and Planetary Camera 2. Credits: Bruce Balick (University of Washington), Jason Alexander (University of Washington), Arsen Hajian (U.S. Naval Observatory), Yervant Terzian (Cornell University), Mario Perinotto (University of Florence, Italy), Patrizio Patriarchi (Arcetri Observatory, Italy) and NASA [Top right ] - NGC 3918 is in the constellation Centaurus and is about 3,000 light-years from us. Its diameter is about 0.3 light-year. It shows a roughly spherical outer envelope but an elongated inner balloon inflated by a fast wind from the hot central star, which is starting to break out of the spherical envelope at the top and bottom of the image. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Bottom left] - Hubble 5 is a striking example of a 'butterfly' or bipolar (two-lobed) nebula. The heat generated by fast winds causes each of the lobes to expand, much like a pair of balloons with internal heaters. This observation was taken Sept. 9, 1997 by the Hubble telescope's Wide Field and Planetary Camera 2. Hubble 5 is 2,200 light-years away in the constellation Sagittarius. Credits: Bruce Balick (University of Washington), Vincent Icke (Leiden University, The Netherlands), Garrelt Mellema (Stockholm University), and NASA [Bottom center ] - Like NGC 6826, NGC 7009 has a bright central star at the center of a dark cavity bounded by a football-shaped rim of dense, blue and red gas. The cavity and its rim are trapped inside smoothly-distributed greenish material in the shape of a barrel and comprised of the star's former outer layers. At larger distances, and lying along the long axis of the nebula, a pair of red 'ansae', or 'handles' appears. Each ansa is joined to the tips of the cavity by a long greenish jet of material. The handles are clouds of low-density gas. NGC 7009 is 1,400 light-years away in the constellation Aquarius. The Hubble telescope observation was taken April 28, 1996 by the Wide Field and Planetary Camera 2. Credits: Bruce Balick (University of Washington), Jason Alexander (University of Washington), Arsen Hajian (U.S. Naval Observatory), Yervant Terzian (Cornell University), Mario Perinotto (University of Florence, Italy), Patrizio Patriarchi (Arcetri Observatory, Italy), NASA [Bottom right ] - NGC 5307 also lies in Centaurus but is about 10,000 light-years away and has a diameter of approximately 0.6 light-year. It is an example of a planetary nebula with a pinwheel or spiral structure; each blob of gas ejected from the central star has a counterpart on the opposite side of the star. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA

  2. HUBBLE'S INFRARED GALAXY GALLERY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronomers have used the NASA Hubble Space Telescope to produce an infrared 'photo essay' of spiral galaxies. By penetrating the dust clouds swirling around the centers of these galaxies, the telescope's infrared vision is offering fresh views of star birth. These six images, taken with the Near Infrared Camera and Multi-Object Spectrometer, showcase different views of spiral galaxies, from a face-on image of an entire galaxy to a close-up of a core. The top row shows spirals at diverse angles, from face-on, (left); to slightly tilted, (center); to edge-on, (right). The bottom row shows close-ups of the hubs of three galaxies. In these images, red corresponds to glowing hydrogen, the raw material for star birth. The red knots outlining the curving spiral arms in NGC 5653 and NGC 3593, for example, pinpoint rich star-forming regions where the surrounding hydrogen gas is heated by intense ultraviolet radiation from young, massive stars. In visible light, many of these regions can be hidden from view by the clouds of gas and dust in which they were born. The glowing hydrogen found inside the cores of these galaxies, as in NGC 6946, may be due to star birth; radiation from active galactic nuclei (AGN), which are powered by massive black holes; or a combination of both. White is light from middle-age stars. Clusters of stars appear as white dots, as in NGC 2903. The galaxy cores are mostly white because of their dense concentration of stars. The dark material seen in these images is dust. These galaxies are part of a Hubble census of about 100 spiral galaxies. Astronomers at Space Telescope Science Institute took these images to fill gaps in the scheduling of a campaign using the NICMOS-3 camera. The data were non-proprietary, and were made available to the entire astronomical community. Filters: Three filters were used: red, blue, and green. Red represents emission at the Paschen Alpha line (light from glowing hydrogen) at a wavelength of 1.87 microns. Blue shows the galaxies in near-infrared light, measured between 1.4 and 1.8 microns (H-band emission). Green is a mixture of the two. Distance of galaxies from Earth: NGC 5653 - 161 million light-years; NGC 3593 - 28 million light-years; NGC 891 - 24 million light-years; NGC 4826 - 19 million light-years; NGC 2903 - 25 million light-years; and NGC 6946 - 20 million light-years. Credits: Torsten Boeker, Space Telescope Science Institute, and NASA NOTE TO EDITORS: Image files and photo caption are available on the Internet at: http://oposite.stsci.edu/pubinfo/pr/1999/10 or via links in http://oposite.stsci.edu/pubinfo/latest.html and http://oposite.stsci.edu/pubinfo/pictures.html Higher resolution digital versions of (300 dpi JPEG and TIFF) of the release photo are available at: http://oposite.stsci.edu/pubinfo/pr/1999/10/extra-photos.html STScI press releases and other information are available automatically by sending an Internet electronic mail message to pio-request@stsci.edu. In the body of the message (not the subject line) users should type the word 'subscribe' (don't use quotes). The system will respond with a confirmation of the subscription, and users will receive new press releases as they are issued. To unsubscribe, send mail to pio-request@stsci.edu. Leave the subject line blank, and type 'unsubscribe' (don't use quotes) in the body of the message.

  3. Physical Investigations of Small Particles: (I) Aerosol Particle Charging and Flux Enhancement and (II) Whispering Gallery Mode Sensing

    NASA Astrophysics Data System (ADS)

    Lopez-Yglesias, Xerxes

    of the molecule and the electromagnetic interaction between the molecule and particle, especially for the neutral particle case, are completely ignored, or, as is often the case for a permanent dipole vapor species, strongly underestimated. Comparing our model to these classical models we determine an "enhancement factor" to characterize how important the addition of these physical parameters and processes is to the understanding of particle nucleation and growth. Part II: Whispering gallery mode (WGM) optical biosensors are capable of extraordinarily sensitive specific and non-specific detection of species suspended in a gas or fluid. Recent experimental results suggest that these devices may attain single-molecule sensitivity to protein solutions in the form of stepwise shifts in their resonance wavelength, lambdaR, but present sensor models predict much smaller steps than were reported. This study examines the physical interaction between a WGM sensor and a molecule adsorbed to its surface, exploring assumptions made in previous efforts to model WGM sensor behavior, and describing computational schemes that model the experiments for which single protein sensitivity was reported. The resulting model is used to simulate sensor performance, within constraints imposed by the limited material property data. On this basis, we conclude that nonlinear optical effects would be needed to attain the reported sensitivity, and that, in the experiments for which extreme sensitivity was reported, a bound protein experiences optical energy fluxes too high for such effects to be ignored.

  4. Parallel inversion of a massive ERT data set to characterize deep vadose zone contamination beneath former nuclear waste infiltration galleries at the Hanford Site B-Complex (Invited)

    NASA Astrophysics Data System (ADS)

    Johnson, T.; Rucker, D. F.; Wellman, D.

    2013-12-01

    The Hanford Site, located in south-central Washington, USA, originated in the early 1940's as part of the Manhattan Project and produced plutonium used to build the United States nuclear weapons stockpile. In accordance with accepted industrial practice of that time, a substantial portion of relatively low-activity liquid radioactive waste was disposed of by direct discharge to either surface soil or into near-surface infiltration galleries such as cribs and trenches. This practice was supported by early investigations beginning in the 1940s, including studies by Geological Survey (USGS) experts, whose investigations found vadose zone soils at the site suitable for retaining radionuclides to the extent necessary to protect workers and members of the general public based on the standards of that time. That general disposal practice has long since been discontinued, and the US Department of Energy (USDOE) is now investigating residual contamination at former infiltration galleries as part of its overall environmental management and remediation program. Most of the liquid wastes released into the subsurface were highly ionic and electrically conductive, and therefore present an excellent target for imaging by Electrical Resistivity Tomography (ERT) within the low-conductivity sands and gravels comprising Hanford's vadose zone. In 2006, USDOE commissioned a large scale surface ERT survey to characterize vadose zone contamination beneath the Hanford Site B-Complex, which contained 8 infiltration trenches, 12 cribs, and one tile field. The ERT data were collected in a pole-pole configuration with 18 north-south trending lines, and 18 east-west trending lines ranging from 417m to 816m in length. The final data set consisted of 208,411 measurements collected on 4859 electrodes, covering an area of 600m x 600m. Given the computational demands of inverting this massive data set as a whole, the data were initially inverted in parts with a shared memory inversion code, which

  5. Under the Skin of a Lion: Unique Evidence of Upper Paleolithic Exploitation and Use of Cave Lion (Panthera spelaea) from the Lower Gallery of La Garma (Spain)

    PubMed Central

    Camarós, Edgard; Castaños, Pedro; Ontañón, Roberto; Arias, Pablo

    2016-01-01

    Pleistocene skinning and exploitation of carnivore furs have been previously inferred from archaeological evidence. Nevertheless, the evidence of skinning and fur processing tends to be weak and the interpretations are not strongly sustained by the archaeological record. In the present paper, we analyze unique evidence of patterned anthropic modification and skeletal representation of fossil remains of cave lion (Panthera spelaea) from the Lower Gallery of La Garma (Cantabria, Spain). This site is one of the few that provides Pleistocene examples of lion exploitation by humans. Our archaeozoological study suggests that lion-specialized pelt exploitation and use might have been related to ritual activities during the Middle Magdalenian period (ca. 14800 cal BC). Moreover, the specimens also represent the southernmost European and the latest evidence of cave lion exploitation in Iberia. Therefore, the study seeks to provide alternative explanations for lion extinction in Eurasia and argues for a role of hunting as a factor to take into account. PMID:27783697

  6. Under the Skin of a Lion: Unique Evidence of Upper Paleolithic Exploitation and Use of Cave Lion (Panthera spelaea) from the Lower Gallery of La Garma (Spain).

    PubMed

    Cueto, Marián; Camarós, Edgard; Castaños, Pedro; Ontañón, Roberto; Arias, Pablo

    2016-01-01

    Pleistocene skinning and exploitation of carnivore furs have been previously inferred from archaeological evidence. Nevertheless, the evidence of skinning and fur processing tends to be weak and the interpretations are not strongly sustained by the archaeological record. In the present paper, we analyze unique evidence of patterned anthropic modification and skeletal representation of fossil remains of cave lion (Panthera spelaea) from the Lower Gallery of La Garma (Cantabria, Spain). This site is one of the few that provides Pleistocene examples of lion exploitation by humans. Our archaeozoological study suggests that lion-specialized pelt exploitation and use might have been related to ritual activities during the Middle Magdalenian period (ca. 14800 cal BC). Moreover, the specimens also represent the southernmost European and the latest evidence of cave lion exploitation in Iberia. Therefore, the study seeks to provide alternative explanations for lion extinction in Eurasia and argues for a role of hunting as a factor to take into account.

  7. Low-threshold whispering-gallery-mode microlasers fabricated in a Nd:glass substrate by three-dimensional femtosecond laser micromachining.

    PubMed

    Lin, Jintian; Xu, Yingxin; Song, Jiangxin; Zeng, Bin; He, Fei; Xu, Huailiang; Sugioka, Koji; Fang, Wei; Cheng, Ya

    2013-05-01

    We report on fabrication of whispering-gallery-mode microlasers in a Nd:glass chip by femtosecond laser three-dimensional micromachining. The main fabrication procedures include the fabrication of freestanding microdisks supported by thin pillars by femtosecond laser ablation of the glass substrate immersed in water, followed by CO2 laser annealing for surface smoothing. The quality (Q) factor of the fabricated microcavity is measured to be 1.065×10(6). Lasing is observed at a pump threshold as low as ~69 μW at room temperature with a continuous-wave laser diode operating at 780 nm. This technique allows for fabrication of microcavities of high Q factors in various dielectric materials, such as glasses and crystals.

  8. Controlling slow and fast light and dynamic pulse-splitting with tunable optical gain in a whispering-gallery-mode microcavity

    NASA Astrophysics Data System (ADS)

    Asano, M.; Özdemir, Ş. K.; Chen, W.; Ikuta, R.; Yang, L.; Imoto, N.; Yamamoto, T.

    2016-05-01

    We report controllable manipulation of slow and fast light in a whispering-gallery-mode microtoroid resonator fabricated from Erbium (Er3+) doped silica. We observe continuous transition of the coupling between the fiber-taper waveguide and the microresonator from undercoupling to critical coupling and then to overcoupling regimes by increasing the pump power even though the spatial distance between the resonator and the waveguide was kept fixed. This, in turn, enables switching from fast to slow light and vice versa just by increasing the optical gain. An enhancement of delay of two-fold over the passive silica resonator (no optical gain) was observed in the slow light regime. Moreover, we show dynamic pulse splitting and its control in slow/fast light systems using optical gain.

  9. Test of the FDTD accuracy in the analysis of the scattering resonances associated with high-Q whispering-gallery modes of a circular cylinder.

    PubMed

    Boriskin, Artem V; Boriskina, Svetlana V; Rolland, Anthony; Sauleau, Ronan; Nosich, Alexander I

    2008-05-01

    Our objective is the assessment of the accuracy of a conventional finite-difference time-domain (FDTD) code in the computation of the near- and far-field scattering characteristics of a circular dielectric cylinder. We excite the cylinder with an electric or magnetic line current and demonstrate the failure of the two-dimensional FDTD algorithm to accurately characterize the emission rate and the field patterns near high-Q whispering-gallery-mode resonances. This is proven by comparison with the exact series solutions. The computational errors in the emission rate are then studied at the resonances still detectable with FDTD, i.e., having Q-factors up to 10(3).

  10. Controlling slow and fast light and dynamic pulse-splitting with tunable optical gain in a whispering-gallery-mode microcavity

    SciTech Connect

    Asano, M.; Ikuta, R.; Imoto, N.; Yamamoto, T. E-mail: yamamoto@mp.es.osaka-u.ac.jp; Özdemir, Ş. K. E-mail: yamamoto@mp.es.osaka-u.ac.jp; Chen, W.; Yang, L.

    2016-05-02

    We report controllable manipulation of slow and fast light in a whispering-gallery-mode microtoroid resonator fabricated from Erbium (Er{sup 3+}) doped silica. We observe continuous transition of the coupling between the fiber-taper waveguide and the microresonator from undercoupling to critical coupling and then to overcoupling regimes by increasing the pump power even though the spatial distance between the resonator and the waveguide was kept fixed. This, in turn, enables switching from fast to slow light and vice versa just by increasing the optical gain. An enhancement of delay of two-fold over the passive silica resonator (no optical gain) was observed in the slow light regime. Moreover, we show dynamic pulse splitting and its control in slow/fast light systems using optical gain.

  11. Ogataea paradorogensis sp. nov., a novel methylotrophic ascomycetous yeast species isolated from galleries of ambrosia beetles in Japan, with a close relation to Pichia dorogensis.

    PubMed

    Nakase, Takashi; Ninomiya, Shinya; Imanishi, Yumi; Nakagiri, Akira; Kawasaki, Hiroko; Limtong, Savitree

    2008-12-01

    Two yeast strains isolated from galleries of ambrosia beetles in Japan and maintained in NITE Biological Resource Center (NBRC) as Pichia pini were found to represent a hitherto undescribed species. This species shows close relationship to Pichia dorogensis by the sequence analysis of the D1/D2 domain of 26S rDNA but is clearly differentiated from it by a DNA-DNA reassociation experiment. It is described as Ogataea paradorogensis sp. nov. The vegetative cells and asci of this species are surrounded with distinct capsules like P. dorogensis. One to four hat-shaped ascospores, which tend to be liberated from the asci at maturation, are formed in the ascus.

  12. Classification of the micro and nanoparticles and biological agents by neural network analysis of the parameters of optical resonance of whispering gallery mode in dielectric microspheres

    NASA Astrophysics Data System (ADS)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Schweiger, Gustav; Ostendorf, Andreas

    2011-07-01

    A novel technique for the label-free analysis of micro and nanoparticles including biomolecules using optical micro cavity resonance of whispering-gallery-type modes is being developed. Various schemes of the method using both standard and specially produced microspheres have been investigated to make further development for microbial application. It was demonstrated that optical resonance under optimal geometry could be detected under the laser power of less 1 microwatt. The sensitivity of developed schemes has been tested by monitoring the spectral shift of the whispering gallery modes. Water solutions of ethanol, ascorbic acid, blood phantoms including albumin and HCl, glucose, biotin, biomarker like C reactive protein so as bacteria and virus phantoms (gels of silica micro and nanoparticles) have been used. Structure of resonance spectra of the solutions was a specific subject of investigation. Probabilistic neural network classifier for biological agents and micro/nano particles classification has been developed. Several parameters of resonance spectra as spectral shift, broadening, diffuseness and others have been used as input parameters to develop a network classifier for micro and nanoparticles and biological agents in solution. Classification probability of approximately 98% for probes under investigation have been achieved. Developed approach have been demonstrated to be a promising technology platform for sensitive, lab-on-chip type sensor which can be used for development of diagnostic tools for different biological molecules, e.g. proteins, oligonucleotides, oligosaccharides, lipids, small molecules, viral particles, cells as well as in different experimental contexts e.g. proteomics, genomics, drug discovery, and membrane studies.

  13. Analytical and simulation results of a triple micro whispering gallery mode probe system for a 3D blood flow rate sensor.

    PubMed

    Phatharacorn, Prateep; Chiangga, Surasak; Yupapin, Preecha

    2016-11-20

    The whispering gallery mode (WGM) is generated by light propagating within a nonlinear micro-ring resonator, which is modeled and made by an InGaAsP/InP material, and called a Panda ring resonator. An imaging probe can also be formed by the micro-conjugate mirror function for the appropriate Panda ring parameter control. The 3D WGM probe can be generated and used for a 3D sensor head and imaging probe. The analytical details and simulation results are given, in which the simulation results are obtained by using the MATLAB and Optiwave programs. From the obtained results, such a design system can be configured to be a thin-film sensor system that can contact the sample surface for the required measurements The outputs of the system are in the form of a WGM beam, in which the 3D WGM probe is also available with the micro-conjugate mirror function. Such a 3D probe can penetrate into the blood vessel and content, from which the time delay among those probes can be detected and measured, and where finally the blood flow rate can be calculated and the blood content 3D image can also be seen and used for medical diagnosis. The tested results have shown that the blood flow rate of 0.72-1.11  μs-1, with the blood density of 1060  kgm-3, can be obtained.

  14. Discovery of iron group impurity ion spin states in single crystal Y{sub 2}SiO{sub 5} with strong coupling to whispering gallery photons

    SciTech Connect

    Goryachev, Maxim; Farr, Warrick G.; Carmo Carvalho, Natalia do; Creedon, Daniel L.; Le Floch, Jean-Michel; Probst, Sebastian; Bushev, Pavel; Tobar, Michael E.

    2015-06-08

    Interaction of Whispering Gallery Modes (WGMs) with dilute spin ensembles in solids is an interesting paradigm of Hybrid Quantum Systems potentially beneficial for Quantum Signal Processing applications. Unexpected ion transitions are measured in single crystal Y{sub 2}SiO{sub 5} using WGM spectroscopy with large Zero Field Splittings at 14.7 GHz, 18.4 GHz, and 25.4 GHz, which also feature considerable anisotropy of the g-tensors as well as two inequivalent lattice sites, indicating spins from Iron Group Ion (IGI) impurities. The comparison of undoped and Rare-Earth doped crystals reveal that the IGIs are introduced during co-doping of Eu{sup 3+} or Er{sup 3+} with concentration at much lower levels of order 100 ppb. The strong coupling regime between an ensemble of IGI spins and WGM photons have been demonstrated at 18.4 GHz and near zero field. This approach together with useful optical properties of these ions opens avenues for “spins-in-solids” Quantum Electrodynamics.

  15. Low threshold lasing of bubble-containing glass microspheres by non-whispering gallery mode excitation over a wide wavelength range

    SciTech Connect

    Kumagai, Tsutaru Kishi, Tetsuo; Yano, Tetsuji

    2015-03-21

    Bubble-containing Nd{sup 3+}-doped tellurite glass microspheres were fabricated by localized laser heating technique to investigate their optical properties for use as microresonators. Fluorescence and excitation spectra measurements were performed by pumping with a tunable CW-Ti:Sapphire laser. The excitation spectra manifested several sharp peaks due to the conventional whispering gallery mode (WGM) when the pumping laser was irradiated to the edge part of the microsphere. However, when the excitation light was irradiated on the bubble position inside the microsphere, “non-WGM excitation” was induced, giving rise to numerous peaks at a broad wavelength range in the excitation spectra. Thus, efficient excitation was achieved over a wide wavelength range. Lasing threshold excited at the bubble position was much lower than that for the excitation at the edges of the microsphere. The lowest value of the laser threshold was 34 μW for a 4 μm sphere containing a 0.5 μm bubble. Efficiency of the excitation at the bubble position with broadband light was calculated to be 5 times higher than that for the edge of the microsphere. The bubble-containing microsphere enables efficient utilization of broadband light excitation from light-emitting diodes and solar light.

  16. On the dispersion management of fluorite whispering-gallery mode resonators for Kerr optical frequency comb generation in the telecom and mid-infrared range.

    PubMed

    Lin, Guoping; Chembo, Yanne K

    2015-01-26

    Optical whispering gallery mode (WGM) resonators have been very attracting platforms for versatile Kerr frequency comb generations. We report a systematic study on the material dispersion of various optical materials that are capable of supporting quality factors above 109. Using an analytical approximation of WGM resonant frequencies in disk resonators, we investigate the effect of the geometry and transverse mode order on the total group-velocity dispersion (GVD). We demonstrate that the major radii and the radial mode indices play an important role in tailoring the GVD of WGM resonators. In particular, our study shows that in WGM disk-resonators, the polar families of modes have very similar GVD, while the radial families of modes feature dispersion values that can differ by up to several orders of magnitude. The effect of these giant dispersion shifts are experimentally evidenced in Kerr comb generation with magnesium fluoride. From a more general perspective, this critical feature enables to push the zero-dispersion wavelength of fluorite crystals towards the mid-infrared (mid-IR) range, thereby allowing for efficient Kerr comb generation in that spectral range. We show that barium fluoride is the most interesting crystal in this regard, due to its zero dispersion wavelength (ZDW) at 1.93 μm and an optimal dispersion profile in the mid-IR regime. We expect our results to facilitate the design of different platforms for Kerr frequency comb generations in both telecommunication and mid-IR spectral ranges.

  17. Q-factor enhancement of integrated lithium-niobate-on-insulator ridge waveguide whispering-gallery-mode resonators by surface polishing

    NASA Astrophysics Data System (ADS)

    Wolf, Richard; Breunig, Ingo; Zappe, Hans; Buse, Karsten

    2017-02-01

    Whispering-gallery resonators (WGRs) are most promising for nonlinear-optical frequency-conversion due to their intensity enhancement by small mode volumes and high Q-factors. This has been shown frequently by millimeter-sized diamond-blade cut and polished bulk WGRs. For reproducible batch fabrication, however, the integration of WGRs into lithium-niobate-on-insulator (LNOI) substrates became of great interest. Here we report on integrated WGRs made by batch processes like lithography and reactive-ion etching. Since the Q-factor of integrated WGRs is limited by scattering losses, we focused on developing a polishing process for the waveguide sidewalls that allowed us to enhance the unloaded Q-factors already to more than 106 with room for further improvements. Furthermore we employ a coupling scheme with two waveguide chips, one comprising a linear coupling waveguide and one with the integrated WGR. By adjusting the distance between the coupling waveguide and the WGR, we can reproducibly and stably tune the coupling-efficiency between 0 and 95 %.

  18. Implementation of single-photon quantum routing and decoupling using a nitrogen-vacancy center and a whispering-gallery-mode resonator-waveguide system.

    PubMed

    Cao, Cong; Duan, Yu-Wen; Chen, Xi; Zhang, Ru; Wang, Tie-Jun; Wang, Chuan

    2017-07-24

    Quantum router is a key element needed for the construction of future complex quantum networks. However, quantum routing with photons, and its inverse, quantum decoupling, are difficult to implement as photons do not interact, or interact very weakly in nonlinear media. In this paper, we investigate the possibility of implementing photonic quantum routing based on effects in cavity quantum electrodynamics, and present a scheme for single-photon quantum routing controlled by the other photon using a hybrid system consisting of a single nitrogen-vacancy (NV) center coupled with a whispering-gallery-mode resonator-waveguide structure. Different from the cases in which classical information is used to control the path of quantum signals, both the control and signal photons are quantum in our implementation. Compared with the probabilistic quantum routing protocols based on linear optics, our scheme is deterministic and also scalable to multiple photons. We also present a scheme for single-photon quantum decoupling from an initial state with polarization and spatial-mode encoding, which can implement an inverse operation to the quantum routing. We discuss the feasibility of our schemes by considering current or near-future techniques, and show that both the schemes can operate effectively in the bad-cavity regime. We believe that the schemes could be key building blocks for future complex quantum networks and large-scale quantum information processing.

  19. PEG Functionalization of Whispering Gallery Mode Optical Microresonator Biosensors to Minimize Non-Specific Adsorption during Targeted, Label-Free Sensing.

    PubMed

    Wang, Fanyongjing; Anderson, Mark; Bernards, Matthew T; Hunt, Heather K

    2015-07-24

    Whispering Gallery Mode (WGM) optical microresonator biosensors are a powerful tool for targeted detection of analytes at extremely low concentrations. However, in complex environments, non-specific adsorption can significantly reduce their signal to noise ratio, limiting their accuracy. To overcome this, poly(ethylene glycol) (PEG) can be employed in conjunction with appropriate recognition elements to create a nonfouling surface capable of detecting targeted analytes. This paper investigates a general route for the addition of nonfouling elements to WGM optical biosensors to reduce non-specific adsorption, while also retaining high sensitivity. We use the avidin-biotin analyte-recognition element system, in conjunction with PEG nonfouling elements, as a proof-of-concept, and explore the extent of non-specific adsorption of lysozyme and fibrinogen at multiple concentrations, as well as the ability to detect avidin in a concentration-dependent fashion. Ellipsometry, contact angle measurement, fluorescence microscopy, and optical resonator characterization methods were used to study non-specific adsorption, the quality of the functionalized surface, and the biosensor's performance. Using a recognition element ratio to nonfouling element ratio of 1:1, we showed that non-specific adsorption could be significantly reduced over the controls, and that high sensitivity could be maintained. Due to the frequent use of biotin-avidin-biotin sandwich complexes in functionalizing sensor surfaces with biotin-labeled recognition elements, this chemistry could provide a common basis for creating a non-fouling surface capable of targeted detection. This should improve the ability of WGM optical biosensors to operate in complex environments, extending their application towards real-world detection.

  20. Drilling effect on subsurface microbial community structure in groundwater from the -250 m gallery at the Horonobe Underground Research Laboratory, Japan

    NASA Astrophysics Data System (ADS)

    Ise, K.; Amano, Y.; Sasaki, Y.; Yoshikawa, H.

    2014-12-01

    The deep geological disposal system is regarded as the most secure and practical disposal method of high-level radioactive waste in the world. In this disposal system, preservation of reducing condition is one of the key requirements, because most of radionuclides have low solubilities in such condition. However, the host rocks near the shafts and galleries would be affected by oxidization during the construction and operation period of a repository (for about 50 years). Therefore, the recovery of reducing condition after closing the repository should be verified. During the recovery processes, it is considered that microbial activities play important roles, but the mechanisms are poorly understood. In this study, we monitored the changes in microbial communities by molecular method to evaluate microbial response toward the oxygen stress. The groundwater samples were collected from a borehole of 250 m depth at the Horonobe Underground Research Laboratory, for two years immediately after drilling of a borehole without any contamination as much as possible. Immediately after drilling of the borehole, the phylotype related to Arcobacter spp. was dominated about 65 % of the total clone library. Arcobacter spp. is known as sulfide oxidizer and which can growth chemoautotrophically. Half a year later, the phylotype related to Azoarcus spp. and Pseudomonas spp. known as nitrate reducing bacteria increased, instead of the phylotype related to Arcobacter spp. One year later, in addition to nitrate reducing bacteria, phylotype related to Dethiobacterspp. known as thiosulfate reducing bacteria was dominantly detected. Two years later, most of detected clones were related to uncultured species such as candidate division WS6 and JS1 which are detected frequently in deep-sea sediments. Our results indicate that these redox sequential reactions could contribute to the recovery and maintenance of reducing conditions and provide a conceptual model for evaluating the capacity to

  1. PEG Functionalization of Whispering Gallery Mode Optical Microresonator Biosensors to Minimize Non-Specific Adsorption during Targeted, Label-Free Sensing

    PubMed Central

    Wang, Fanyongjing; Anderson, Mark; Bernards, Matthew T.; Hunt, Heather K.

    2015-01-01

    Whispering Gallery Mode (WGM) optical microresonator biosensors are a powerful tool for targeted detection of analytes at extremely low concentrations. However, in complex environments, non-specific adsorption can significantly reduce their signal to noise ratio, limiting their accuracy. To overcome this, poly(ethylene glycol) (PEG) can be employed in conjunction with appropriate recognition elements to create a nonfouling surface capable of detecting targeted analytes. This paper investigates a general route for the addition of nonfouling elements to WGM optical biosensors to reduce non-specific adsorption, while also retaining high sensitivity. We use the avidin-biotin analyte-recognition element system, in conjunction with PEG nonfouling elements, as a proof-of-concept, and explore the extent of non-specific adsorption of lysozyme and fibrinogen at multiple concentrations, as well as the ability to detect avidin in a concentration-dependent fashion. Ellipsometry, contact angle measurement, fluorescence microscopy, and optical resonator characterization methods were used to study non-specific adsorption, the quality of the functionalized surface, and the biosensor’s performance. Using a recognition element ratio to nonfouling element ratio of 1:1, we showed that non-specific adsorption could be significantly reduced over the controls, and that high sensitivity could be maintained. Due to the frequent use of biotin-avidin-biotin sandwich complexes in functionalizing sensor surfaces with biotin-labeled recognition elements, this chemistry could provide a common basis for creating a non-fouling surface capable of targeted detection. This should improve the ability of WGM optical biosensors to operate in complex environments, extending their application towards real-world detection. PMID:26213937

  2. Biosensing operations based on whispering-gallery-mode optical cavities in single 1.0-µm diameter hexagonal GaN microdisks grown by radio-frequency plasma-assisted molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Kouno, Tetsuya; Sakai, Masaru; Kishino, Katsumi; Hara, Kazuhiko

    2016-05-01

    Biosensing operations based on a whispering-gallery-mode optical cavity in a single hexagonal GaN microdisk of approximately 1.0 µm diameter were demonstrated here. The sharp resonant peak in the photoluminescence spectrum obtained from the microdisk in aqueous sucrose solution redshifts with a change in sucrose concentration. The results indicate that an extremely small microdisk could be used as an optical transducer for sensing sugar, namely, as a biosensor. Furthermore, we investigate the relationship between the diameter of the microdisk and the sensitivity of the biosensor.

  3. Study of NTA-Nickel (II) Motif Functionalization for Binding of Histidine-Tagged Proteins by a Whispering Gallery Mode Resonator

    NASA Astrophysics Data System (ADS)

    Khuong, Anne Chudolij

    This work demonstrates the viability of the whispering gallery mode (WGM) photonic sensing method for use as a biosensor by demonstrating a surface immobilization strategy for histidine tagged biomolecules to the WGM sensor surface. The WGM resonator is a dielectric spherical microstructure that can sustain high-Q electromagnetic waves confined to the sphere by total internal reflection. Light circumnavigates the periphery of the WGM resonator and when the trapped light constructively superimposes onto itself on the round trip, a resonance condition is achieved. Because of minimal loss due to reflection, these modes can reach unusually high quality factors. When a change occurs in the evanescent field at the boundary of the resonator and surrounding environment, such as when a molecule binds to the resonator surface, a shift results in the resonance wavelength; this enables the WGM resonator to be used as a sensor. WGM optical biosensors offer a powerful alternative to conventional analytical techniques due to their high sensitivity, specificity and their ability to directly detect label-free events in real time. There has been considerable growth in this field over the last decade and potential applications to medical and biotechnological research are numerous; however, there are still obstacles limiting the widespread commercial use of these devices. The obstacle we address in this work relates to a general fundamental difficulty incorporating biomaterial into biosensors. We demonstrate a specific and controlled functionalization strategy intended for subsequent assimilation of biomolecules onto the WGM resonator surface. We have developed a general method which can be used to controllably immobilize recombinant proteins to WGM silica surfaces via their histidine tags. In the work presented herein we monitor by WGM, in real time, a two step functionalization strategy to incorporate an NTA-Ni2+ motif onto the surface of a WGM resonator. We estimated the

  4. Gallery of Planetary Nebula Spectra

    NASA Astrophysics Data System (ADS)

    Kwitter, Karen B.; Henry, Richard B. C.

    In the course of our abundance studies over the past decade we have accumulated more than 120 high-quality, medium resolution spectra of planetary nebulae (PNe) from 3600-9600 Å using the KPNO 2.1m Goldcam CCD spectrograph and the CTIO 1.5m RC spectrograph. Results have been published in, e.g., Kwitter & Henry (1998); Henry, Kwitter & Balick (2004); and Milingo et al. (2006). We have created this website as a place where the spectra are available for graphical display, and where PN atlas information and image links are tabulated. The URL is: http://oit.williams.edu/nebulae

  5. The Museum and Gallery Corner.

    ERIC Educational Resources Information Center

    Romey, William

    1983-01-01

    Describes exhibits and activities at Field Museum of Natural History (Chicago), Oregon Museum of Science and Industry (Portland), Carnegie Museum of Natural History (Pittsburgh), and Museum of Sanibel Island (Florida). Such information as educational activities, admission costs, and hours of operation is included. (JN)

  6. A Gallery of Lifelong Achievers.

    ERIC Educational Resources Information Center

    Music Educators Journal, 1980

    1980-01-01

    As a reminder that creativity in music and learning go on through life, this article presents a portfolio of photographs and vignettes of musicians in their seventies, eighties, and nineties who continue to be outstandingly creative in composition and/or performance. (Author/SJL)

  7. The Horn Book Graphic Gallery.

    ERIC Educational Resources Information Center

    Horn Book Magazine, 1986

    1986-01-01

    Presents an annotated bibliography of 14 picture books with copyright dates from 1980 to 1984. David Macauley, Ed Young, and Richard Bartlett based their selections on illustration and design criteria that they most admired. (JK)

  8. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    STS-125 astronaut John Grunsfeld stands behind a display of Hubble memorabilia during a press briefing at the new "Moving Beyond Earth," a new exhibition at the National Air and Space Museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors “in orbit” in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  9. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    STS-125 astronaut John Grunsfeld speaks during a press briefing at the new "Moving Beyond Earth," a new exhibition at the National Air and Space Museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors “in orbit” in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  10. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    An unidentified member of the media tries out an interactive display during a press briefing at the new "Moving Beyond Earth," exhibition at the National Air and Space Museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors “in orbit” in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  11. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    Jack Dailey, director of the Smithsonian's National Air and Space Museum, speaks during a press briefing at the new "Moving Beyond Earth," a new exhibition at the museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors “in orbit” in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  12. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    Ed Weiler, associate administrator for the Science Mission Directorate at NASA, speaks during a press briefing at the new "Moving Beyond Earth," exhibition at the National Air and Space Museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors “in orbit” in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  13. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    David DeVorkin, Senior Curator, Collection: Astronomy and space sciences speaks during a press briefing at the new "Moving Beyond Earth," exhibition at the National Air and Space Museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors “in orbit” in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  14. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    Dr. Valerie Neal, a curator at the Smithsonian's National Air and Space Museum, speaks during a press briefing at the new "Moving Beyond Earth," exhibition at the museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors “in orbit” in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  15. Moving Beyond Earth Gallery Opening

    NASA Image and Video Library

    2009-11-18

    David H. DeVorkin, Senior Curator, Astronomy and the Space Sciences Division of Space History, at the Smithsonian's National Air and Space Museum, speaks during a press briefing at the new "Moving Beyond Earth," exhibition at the museum in Washingon, Wednesday, Nov. 18, 2009. Moving Beyond Earth is an immersive exhibition that places visitors "in orbit" in the shuttle and space-station era to explore recent human spaceflight and future possibilities. Photo Credit: (NASA/Paul E. Alers)

  16. Gallery of ESOL Lesson Plans.

    ERIC Educational Resources Information Center

    Literacy Assistance Center, New York, NY.

    This collection of lesson plans for teaching English as a Second Language includes the following: "You Scratched Me!" which has students examine verbs in three forms (base, past, and progressive) together with questions, accelerating the memorization and understanding of verb forms and tenses; "Getting Acquainted/Inferential Thinking," which…

  17. Heavy-metal contamination of rivers by mining gallery waters during the flood in 2002 in Saxony/Germany and low-cost rapid analysis of contaminated river sediments by XRF

    NASA Astrophysics Data System (ADS)

    Mucke, D.; Kumann, R.; Mucke, S.

    2012-04-01

    Dieter Mucke, Rolf Kumann, Susanne Mucke GEOMONTAN Gesellschaft für Geologie und Bergbau mbH&Co.KG, Muldentalstrasse 56, 09603 Rothenfurth, Saxony/Germany The Ore Mountains between Bohemia and Saxony are effected by age-long mining for silver mining and winning of other ores. A lot of galleries were driven to keep water away from the mines. Today they still drain off water into the rivers which are used as receiving streams. Sulphide- and sulpharsenide-minerals are unstable. The decomposition of these minerals is caused by the influence of oxygenated drainage water. As a result of this process free cations of iron, copper, lead, zinc, cadmium and residuals of acid (sulphuric acid, acid sulphur, arsenous acid). Already during the transport in the gallery water transformations and precipitations proceed: iron precipitates as sol of iron-(III)-hydroxide-flocks and carries manganese and arsenic, as well as a part of zinc and copper along, on the other hand a bigger part of cadmium keeps in dissolution. From 1844 until 1877 in the silver mining area of Freiberg/Brand-Erbisdorf/Halsbrücke the gallery "Rothschönberger Stolln" was driven with a length of 50 km. In 1995/1996 we determined during four measuring cycles the loads of selected contaminants of five different measuring points in a gallery segment, which takes 29 km. As the annual input into the stream system Triebisch/Elbe with the mudflat of the North Sea as receiving stream we determined: • 19.000 t solid matter (hereof 10.400 t gypsum) • 820 kg cadmium • 420 kg arsenic • 1450 kg lead • 1140 kg copper • 111 t zinc During the flood in August 2002 occurred: • a total sinking of the Münzbach • a partial sinking of the Freiberger Mulde into the Rothschönberger Stolln. Thereby its flow increased from 600 l/sec in average to 10 m3/sec. Over three days during the flood in 2002 water samples were taken and analysed and the discharge was detected. So it was possible to calculate the loads. There was

  18. An Interactive Gallery of Planetary Nebula Spectra

    NASA Astrophysics Data System (ADS)

    Kwitter, K. B.; Henry, R. B. C.

    2002-12-01

    We have created a website containing high-quality moderate-resolution spectra of 88 planetary nebulae (PNe) from 3600 to 9600 Å, obtained at KPNO and CTIO. Spectra are displayed in a zoomable window, and there are templates available that show wavelength and ion identifications. In addition to the spectra themselves, the website also contains a brief discussion of PNe as astronomical objects and as contributors to our understanding of stellar evolution, and a table with atlas information for each object along with a link to an image. This table can be re-ordered by object name, galactic or equatorial coordinates, distance from the sun, the galactic center, or the galactic plane. We envision that this website, which concentrates a large amount of data in one place, will be of interest to a variety of users. PN researchers might need to check the spectrum of a particular object of interest; the non-specialist astronomer might simply be interested in perusing such a collection of spectra; and finally, teachers of introductory astronomy can use this database to illustrate basic principles of atomic physics and radiation. To encourage such use, we have written two simple exercises at a basic level to introduce beginning astronomy students to the wealth of information that PN spectra contain. We are grateful to Adam Wang of the Williams College OIT and to his summer student teams who worked on various apects of the implementation of this website. This work has been supported by NSF grant AST-9819123 and by Williams College and the University of Oklahoma.

  19. Instructor Gallery. Homage to the Laborer.

    ERIC Educational Resources Information Center

    Vanelli, Jill

    1991-01-01

    Discusses the life and paintings of Vincent van Gogh, focusing on "The Road Meanders," and describes how to teach students through the painting (e.g., analyzing colors, discussing feelings it evokes, and writing poems that speak to the people in the painting). A copy of the painting is included. (SM)

  20. New 360 degree color gallery panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the first contiguous, uniform 360-degree color panorama taken by the Imager for Mars Pathfinder (IMP) over the course of sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama. At left is a lander petal and a metallic mast which is a portion of the low-gain antenna. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock Barnacle Bill, which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large rock Yogi. Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, and appeared more like the common basalts found on Earth. The tracks and circular pattern in the soil leading up to Yogi were part of Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the wheels in order to determine physical properties of the soil. During its traverse to Yogi the rover stirred the soil and exposed material from several centimeters in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer, the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to the rock Scooby Doo, and such white material may underlie much of the site. Deflated airbags are visible at the perimeter of all three lander petals.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' Its red, green, and blue filters were used to take this image. The IMP, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  1. Hubble Gallery of Jupiter's Galilean Satellites

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This is a Hubble Space Telescope 'family portrait' of the four largest moons of Jupiter, first observed by the Italian scientist Galileo Galilei nearly four centuries ago. Located approximately one-half billion miles away, the moons are so small that, in visible light, they appear as fuzzy disks in the largest ground-based telescopes. Hubble can resolve surface details seen previously only by the Voyager spacecraft in the early 1980s. While the Voyagers provided close-up snapshots of the satellites, Hubble can now follow changes on the moons and reveal other characteristics at ultraviolet and near-infrared wavelengths.

    Over the past year Hubble has charted new volcanic activity on Io's active surface, found a faint oxygen atmosphere on the moon Europa, and identified ozone on the surface of Ganymede. Hubble ultraviolet observations of Callisto show the presence of fresh ice on the surface that may indicate impacts from micrometeorites and charged particles from Jupiter's magnetosphere.

    Hubble observations will play a complementary role when the Galileo spacecraft arrives at Jupiter in December of this year.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  2. Framing Measurement: An Art Gallery Installation

    ERIC Educational Resources Information Center

    Bush, Sarah B.; Karp, Karen S.; Bennett, Victoria Miller; Popelka, Liz; Nadler, Jennifer

    2013-01-01

    In this article, the authors describe how mathematics teachers and art teachers were able to enthusiastically engage seventh- and eighth-grade students in an interdisciplinary activity focused on scaling, proportional reasoning, and measurement by recreating artwork on a famous private collection. Using the artwork from The Barnes Foundation in…

  3. Whispering Gallery Effects in the Troposphere

    DTIC Science & Technology

    1992-12-01

    InnlikMl ix,ti’ III tilt: 600l D S ie~go alica. Uhu’ti it 1tuid [’c .ioli lildcd ItiA thuc 060 DUJCT w I ~~~~~APPROX C\\d~ltiudc s. ostl u i’Inhk ’ 350 - 700

  4. Instructor Gallery. Still Life in Bloom.

    ERIC Educational Resources Information Center

    Darst, Diane W.

    1992-01-01

    The article presents ideas for using Van Gogh's painting, "Irises," to teach elementary students about floral still lifes and the use of space, light, and other aspects of composition. It includes a poster of "Irises" along with suggestions and activities for using it to explore the elements of art. (SM)

  5. Photo Gallery for Northwest Indiana Area (Indiana)

    EPA Pesticide Factsheets

    Northwest Indiana Area (Indiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

  6. Photo Gallery for South Platte Watershed

    EPA Pesticide Factsheets

    South Platte Watershed from the Headwaters to the Denver Metropolitan Area (Colorado) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating

  7. Thermal behavior of the SHOOT gallery arm

    NASA Technical Reports Server (NTRS)

    Nissen, J. A.; Van Sciver, S. W.

    1991-01-01

    The planned Superfluid Helium On-Orbit Transfer (SHOOT) experiment will show the feasibility of resupplying orbiting facilities with liquid helium. The SHOOT experiment, designed for transfer rates of 300 to 800 liters/hr, will use a thermomechanical pump and four screen covered flow channels for fluid acquisition. Cavitation and thermal behavior was examined in ground based tests of the pump and of a full sized channel. A model for estimating the temperature profile at the pump inlet is presented. Large temperature increases in this region can significantly degrade the performance of the fountain pump.

  8. Framing Measurement: An Art Gallery Installation

    ERIC Educational Resources Information Center

    Bush, Sarah B.; Karp, Karen S.; Bennett, Victoria Miller; Popelka, Liz; Nadler, Jennifer

    2013-01-01

    In this article, the authors describe how mathematics teachers and art teachers were able to enthusiastically engage seventh- and eighth-grade students in an interdisciplinary activity focused on scaling, proportional reasoning, and measurement by recreating artwork on a famous private collection. Using the artwork from The Barnes Foundation in…

  9. On the Horizon: Black Hole Experiment Gallery

    NASA Astrophysics Data System (ADS)

    Steel, Simon J.; Reinfeld, E. L.; Dussault, M. E.; Gould, R. R.

    2006-09-01

    A new project is underway for engaging the museum-going public in the ongoing story of black hole science and the nature of scientific discovery. Following on the success of the Cosmic Questions traveling exhibition, the Smithsonian Astrophysical Observatory is initiating another museum project aimed at exploring the recent breakthroughs and current mysteries in our scientific understanding of black holes. High-energy astrophysicists and engineers are invited to learn more about this new proposal and to join in the development of a 2,500 square foot traveling exhibition, an associated web site and a supporting suite of educational materials and resources. This poster presents opportunities for scientist involvement, such as brainstorming of scientific priorities, input during the design process, and contributions of materials such as graphics and animations, and interviews with researchers. Following the opening, there will be opportunities for scientist participation in exhibit-related outreach, such as live presentations and content professional development for educators.

  10. Polarization Dependent Whispering Gallery Modes in Microspheres

    NASA Technical Reports Server (NTRS)

    Adamovsky, Grigory (Inventor); Wrbanek, Susan Y. (Inventor)

    2016-01-01

    A tunable resonant system is provided and includes a microsphere that receives an incident portion of a light beam generated via a light source, the light beam having a fundamental mode, a waveguide medium that transmits the light beam from the light source to the microsphere, and a polarizer disposed in a path of the waveguide between the light source and the microsphere. The incident portion of the light beam creates a fundamental resonance inside the microsphere. A change in a normalized frequency of the wavelength creates a secondary mode in the waveguide and the secondary mode creates a secondary resonance inside the microsphere.

  11. Photo Gallery for Anacostia Watershed (Washington, DC/Maryland)

    EPA Pesticide Factsheets

    Anacostia Watershed (Washington, DC/Maryland) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating

  12. Parity-Time-Symmetric Whispering-Gallery Microcavities

    DTIC Science & Technology

    2014-04-06

    lead to a new generation of synthetic optical systems enabling on-chip manipulation and control of light propagation. Parity–time-symmetric whispering...transmission is resonantly enhanced, a feature directly associated with the use of resonant structures. Our results could lead to a new generation of synthetic...100084, China, 3Department of Physics, W ashingtonUniversity, St Louis, Missouri 63130, USA, 4 Dipartimento di Matematica e Fisica Ennio De Giorgi

  13. Dazzling Physics Gallery Opens in Dallas Art Deco Building.

    ERIC Educational Resources Information Center

    Gifted Child Today (GCT), 1989

    1989-01-01

    The Dallas Science Place contains 55 interactive displays on observable phenomena, organized into 7 topic areas: motion, waves, matter, electromagnetism, energy, change, and entropy. Attempts were made to keep the exhibits' forms elemental, so that the underlying physical phenomena could be readily observed and experienced. (JDD)

  14. Integrated asymmetric whispering gallery mode resonator microcavity optomechanics

    NASA Astrophysics Data System (ADS)

    Soltani, Soheil; Hudnut, Alexa W.; Armani, Andrea M.

    2017-02-01

    Ultra high quality optical resonators have enabled accumulation of exceptionally high intensities of light from low input powers. This feature opens new horizons in low power observation of physical phenomena such as lasing, sensing and radiation pressure driven oscillations. Radiation pressure instability facilitates transfer of energy from photons to mechanical degree of freedom in optical resonators. In high quality toroidal micro cavities, radiation pressure is demonstrated in the form of "dynamic back action" and results mechanical oscillations with sub-Hz linewidth. Since the toroidal cavities are symmetrical in nature, the exerted radiation pressure can mainly excite radially symmetric modes such as the first cantilever mode and the radially breathing mode. Study of these modes reveals important information about interaction of light and mechanical mode as well as intrinsic properties of the resonator as a mechanical oscillator. However, there are some unexcited mechanical modes that in some cases have even higher mechanical quality factors compared to the usually excited ones. Most of the properties of these mechanical modes remain unknown because the radially symmetric force does not provide a component to excite them. In this research, we have developed a novel method to fabricate asymmetric toroidal resonators (minor and major diameters), which enables us to regeneratively excite unobserved asymmetric modes. One key feature is that the optical quality factor is relatively high despite the asymmetry. As a result, we are able to excite the asymmetric modes with sub-mW threshold powers. Complementary modeling is also performed, confirming the experimental findings.

  15. Intuitive Exploration of Volumetric Data Using Dynamic Galleries.

    PubMed

    Jönsson, Daniel; Falk, Martin; Ynnerman, Anders

    2016-01-01

    In this work we present a volume exploration method designed to be used by novice users and visitors to science centers and museums. The volumetric digitalization of artifacts in museums is of rapidly increasing interest as enhanced user experience through interactive data visualization can be achieved. This is, however, a challenging task since the vast majority of visitors are not familiar with the concepts commonly used in data exploration, such as mapping of visual properties from values in the data domain using transfer functions. Interacting in the data domain is an effective way to filter away undesired information but it is difficult to predict where the values lie in the spatial domain. In this work we make extensive use of dynamic previews instantly generated as the user explores the data domain. The previews allow the user to predict what effect changes in the data domain will have on the rendered image without being aware that visual parameters are set in the data domain. Each preview represents a subrange of the data domain where overview and details are given on demand through zooming and panning. The method has been designed with touch interfaces as the target platform for interaction. We provide a qualitative evaluation performed with visitors to a science center to show the utility of the approach.

  16. Whispering-gallery mode micro-kylix resonators.

    PubMed

    Ghulinyan, Mher; Pitanti, Alessandro; Pucker, Georg; Pavesi, Lorenzo

    2009-05-25

    Owing to their ability to confine electromagnetic energy in ultrasmall dielectric volumes, micro-disk, ring and toroid resonators hold interest for both specific applications and fundamental investigations. Generally, contributions from various loss channels within these devices lead to limited spectral windows (Q-bands) where highest mode Q-factors manifest. Here we describe a strategy for tuning Q-bands using a new class of micro-resonators, named micro-kylix resonators, in which engineered stress within an initially flat disk results in either concave or convex devices. To shift the Q-band by 60 nm towards short wavelengths in flat micro-disks a 50% diameter reduction is required, which causes severe radiative losses suppressing Q's. With a micro-kylix, we achieve similar tuning and even higher Q's by two orders of magnitude smaller diameter modification (0.4%). The phenomenon relies on geometry-induced smart interplay between modified dispersions of material absorption and radiative loss-related Q-factors. Micro-kylix devices can provide new functionalities and novel technological solutions for photonics and micro-resonator physics.

  17. Polarization Dependent Coupling of Whispering Gallery Modes in Microspheres

    NASA Technical Reports Server (NTRS)

    Adamovsky, G.; Wrbanek, S.; Floyd, B.; Crotty, M.

    2010-01-01

    Two sets of resonances in glass microspheres attached to a standard communication-grade single-mode optical fiber have been observed. It has been found that the strength of the resonances depends strongly on the polarization of the coupled light. Furthermore, the position of the resonances in the wavelength domain depends on the polarization of light in the optical fiber with maximum magnitudes shifted by approximately 45 .

  18. Photo Gallery for Lake Pontchartrain Area/New Orleans (Louisiana)

    EPA Pesticide Factsheets

    Lake Pontchartrain Area/New Orleans (Louisiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

  19. From Classroom to Gallery: Building Community and Preserving Heritage

    ERIC Educational Resources Information Center

    Barron, Kate

    2012-01-01

    When the levees broke during Hurricane Katrina in 2005, eighty percent of New Orleans flooded, and the citizens who returned to the evacuated city had to rebuild their homes, cultural institutions, and school system. This article records how The Ogden Museum of Southern Art, University of New Orleans, was able to collaborate with a charter school…

  20. From Classroom to Gallery: Building Community and Preserving Heritage

    ERIC Educational Resources Information Center

    Barron, Kate

    2012-01-01

    When the levees broke during Hurricane Katrina in 2005, eighty percent of New Orleans flooded, and the citizens who returned to the evacuated city had to rebuild their homes, cultural institutions, and school system. This article records how The Ogden Museum of Southern Art, University of New Orleans, was able to collaborate with a charter school…