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1

Cooled echelle grating spectrometer. [for space telescope applications  

NASA Technical Reports Server (NTRS)

A cooled echelle grating spectrometer for detecting wavelengths between one micron and fifteen microns is disclosed. More specifically, the spectrometer has a cross-dispersing grating for ordering infrared energy and an echelle grating for further ordering of the infrared energy. Ordered radiation from the echelle grating is sensed by a detecting means. Also disclosed is use of a Schmidt camera for focusing the further ordered radiation from the echelle grating onto a detector array having individual detectors dispersed on a plane which substantially corresponds to a curved focal plane of the Schmidt camera. A spectrometer constructed according to the teachings of the present invention will continuously cover the spectrum between one micron and fifteen microns and have a resolution of 0.1/cm.

Beer, R. (inventor)

1980-01-01

2

Echelle grating multi-order imaging spectrometer utilizing a catadioptric lens  

DOEpatents

A cryogenically cooled imaging spectrometer that includes a spectrometer housing having a first side and a second side opposite the first side. An entrance slit is on the first side of the spectrometer housing and directs light to a cross-disperser grating. An echelle immersions grating and a catadioptric lens are positioned in the housing to receive the light. A cryogenically cooled detector is located in the housing on the second side of the spectrometer housing. Light from the entrance slit is directed to the cross-disperser grating. The light is directed from the cross-disperser grating to the echelle immersions grating. The light is directed from the echelle immersions grating to the cryogenically cooled detector on the second side of the spectrometer housing.

Chrisp, Michael P; Bowers, Joel M

2014-05-27

3

GRIS: The grating infrared spectrometer  

Microsoft Academic Search

The grating infrared spectrometer (GRIS) is an echelle grating, prism cross-dispersed, spectrometer designed for the 2.3-m Steward Observatory telescope. The cross-dispersed format utilizes a Near Infrared Camera and Multi-Object Spectrometer 3 (NICMOS 3) HgCdTe detector array for observations in the 0.86-2.5 micrometer spectral region. An echelle grating, ruled on both sides, provides resolutions of 3449 and 9439 per slit width,

Rodger I. Thompson; Harland W. Epps; Greg Winters; William Womack; Eric Mentzell

1994-01-01

4

Compact high-resolution spaceborne echelle grating spectrometer with acousto-optical tunable filter based order sorting for the infrared domain from 2.2 to 4.3 mum  

Microsoft Academic Search

A new compact spaceborne high-resolution spectrometer developed for the European Space Agency's Venus Express spacecraft is described. It operates in the IR wavelength range of 2.2 to 4.3 mum and measures absorption spectra of minor constituents in the Venusian atmosphere. It uses a novel echelle grating with a groove density of 4 lines\\/mm in a Littrow configuration in combination with

Dennis Nevejans; Eddy Neefs; Emiel van Ransbeeck; Sophie Berkenbosch; Roland Clairquin; Lieve de Vos; Wouter Moelans; Stijn Glorieux; Ann Baeke; Oleg Korablev; Imant Vinogradov; Yuri Kalinnikov; Benny Bach; Jean-Pierre Dubois; Eric Villard

2006-01-01

5

A Far Infrared Echelle Spectrometer for the Kuiper Airborne Observatory  

NASA Technical Reports Server (NTRS)

A liquid-helium-cooled grating spectrometer (CGS) is being developed as a facility instrument for the Kuiper Airborne Observatory (KAO), primarily to study for infrared lines originating in the interstellar medium. A maximum resolving power of approximately 6000 is achieved by means of a 45 cm long Echelle grating and is optically capable of operating in the spectral range from 25 to 300 microns. An array of detectors is used to simultaneously measure a line and the adjacent continuum from astronomical sources. Currently six detectors allow measurements in the 30 to 120 micron spectral band. The instrument, its operation, and its performance are described.

Erickson, E. F.; Houck, J. R.; Harwit, M. O.; Rank, D. M.; Haas, M. R.; Hollenbach, D. J.; Simpson, J. P.; Augason, G. C.; Mckibbin, D. D.

1984-01-01

6

Spherical grating spectrometers  

NASA Astrophysics Data System (ADS)

We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.

O'Donoghue, Darragh; Clemens, J. Christopher

2014-07-01

7

Integrated Grating Spectrometer  

NASA Technical Reports Server (NTRS)

Proposed integrated grating spectrometer made in waveguide layer on silicon wafer. Occupies area of about 2 centimeters to 2nd power on wafer 0.4 mm thick. Operates in visible spectrum (wavelengths of 400 to 700 nm) and blazed to diffract in first order. Array of integrated grating spectrometers performs spectral analysis of picture elements along line. Optical fiber couples light from each picture element into separate integrated spectrometer. Technique enables continous independent variation, along grating, of pitch, curvature, and blaze angle. Grating designed to have large numerical aperture, zero aberration at two selected wavelengths, and very low aberration at intermediate wavelengths.

Lang, Robert J.

1990-01-01

8

Optical Alignment and Diffraction Analysis for AIRES: An Airborne Infrared Echelle Spectrometer  

NASA Technical Reports Server (NTRS)

The optical design is presented for a long-slit grating spectrometer known as AIRES (Airborne InfraRed Echelle Spectrometer). The instrument employs two gratings in series: a small order sorter and a large steeply blazed echelle. The optical path includes four pupil and four field stops, including two narrow slits. A detailed diffraction analysis is performed using GLAD by Applied Optics Research to evaluate critical trade-offs between optical throughput, spectral resolution, and system weight and volume. The effects of slit width, slit length, oversizing the second slit relative to the first, on- vs off-axis throughput, and clipping at the pupil stops and other optical elements are discussed.

Haas, Michael R.; Fonda, Mark (Technical Monitor)

2002-01-01

9

Design considerations for AIRES, an airborne infrared echelle spectrometer for SOFIA  

NASA Technical Reports Server (NTRS)

The airborne infrared echelle spectrometer (AIRES) was proposed as a facility instrument for the stratospheric observatory for infrared astronomy (SOFIA) project. The preliminary AIRES design uses multiple two dimensional detector arrays and a 1.2 m long, 76 deg blaze angle echelle to combine high spectral resolution with diffraction limited imaging in the cross-dispersion direction. A preliminary optical design and the mechanical architecture are presented together with the analysis and prototyping of lightweight aluminum echelles. Instrument efficiencies are calculated and compared for different gratings, and the associated mechanical design tradeoffs are discussed.

Haas, Michael R.; Erickson, Edwin F.; Baltz, James A.; Colgan, Sean W. J.; Lynch, Dana H.; Sablan, Marita

1996-01-01

10

CHIRON -A Fiber-fed High-resolution Echelle Spectrometer At CTIO 1.5m Telescope  

E-print Network

CHIRON - A Fiber-fed High-resolution Echelle Spectrometer At CTIO 1.5m Telescope J.F.P. Spronck (1 is a highly stable cross-dispersed echelle spectrometer deployed at CTIO 1.5m telescope. It is fed by fiber-micron fiber (2.7" on sky) ·Image Slicer (3 slices) ·140-mm beam ·R2 grating ·Cross-disperser prism

Tokovinin, Andrei A.

11

The Cryogenic Grating Spectrometer  

NASA Technical Reports Server (NTRS)

The Cryogenic Grating Spectrometer (CGS) first flew on the KAO in 1982 December and has been open to guest investigators since 1984 October. In the past 12 years it has completed over 100 research flights supporting 13 different principal investigators studying a variety of objects. We briefly describe the instrument, its capabilities and accomplishments, and acknowledge the people who have contributed to its development and operation.

Erickson, Edwin F.; Haas, Michael R.; Colgan, Sean W. J.; Simpson, Janet P.; Rubin, Robert H.

1995-01-01

12

AOTF-echelle spectrometer for air-ICP-AES continuous emission monitoring of heavy metals and actinides  

NASA Astrophysics Data System (ADS)

A spectrometer system consisting of a quartz acousto-optic tunable filter (AOTF) and an echelle grating has been assembled and tested for ICP-AES continuous emission monitoring of heavy metal and actinide elements in stack exhaust offgases introduced into an air plasma. The AOTF is a rapidly tunable bandpass filter that is used to select a small wavelength range (0.1 to 0.6 nm) of optical emission from the air plasma; the echelle grating provides high dispersion, yielding a spectral resolution of approximately 0.004 to 0.008 nm from 200 to 425 nm. The AOTF-echelle spectrometer, equipped with a photodiode array or CCD, provides rapid sequential multielement analysis capabilities. It is much more compact and portable than commercial ICP-AES echelle spectrometers, allowing use of the system in field and on-line process monitoring applications. Data will be presented that detail the resolution, detection limits, capabilities, and performance of the AOTF-echelle spectrometer for continuous emission monitoring of heavy metals (As, Be, Cd, Cr, Hg, and Pb) and actinides (including U isotopes). The potential use of the AOTF-echelle spectrometer with other emission sources and for other monitoring applications will be discussed.

Baldwin, David P.; Zamzow, Daniel S.; Eckels, David E.; Miller, George P.

1999-02-01

13

Diffraction Effects in a Grating Spectrometer  

NASA Technical Reports Server (NTRS)

This paper describes a numerical study of diffraction effects in the AIRES optical system using GLAD by Applied Optics Research. AIRES (or Airborne Infrared Echelle Spectrometer) employs two gratings in series. The small, first-order (i.e., predisperser) grating sorts orders for the large, high-order echelle grating, thus providing moderately high spectral resolution over 3.6 octaves in wavelength. The AIRES' optical design includes three field stops (i.e., a circular aperture and two long, narrow slits) and four pupil stops. A detailed diffraction analysis is required to evaluate critical trade-offs between spectral resolution, optical throughput, detector background, scattered light, and system size and weight. Such an analysis must consider diffraction effects at the pupil stops (edge diffraction), at the field stops (spatial filtering), and at intermediate positions where other optical elements are located. The effects of slit width, slit length, oversizing of the second slit relative to the first, baffling at the Lyot stop and subsequent pupil stops, and the necessity for oversizing other optical elements are presented and discussed. It is found that for narrow slits, the downstream energy distribution is significantly broadened relative to that for large slits, where telescope diffraction dominates, leading to significantly more light loss than anticipated, unless other key optical elements are oversized. The importance of performing a proper diffraction analysis is emphasized and the suitability of GLAD for this task is discussed.

Haas, Michael R.; DeVincenzi, D. (Technical Monitor)

2002-01-01

14

The ORFEUS II Echelle Spectrometer: Instrument description, performance and data reduction  

E-print Network

During the second flight of the ORFEUS-SPAS mission in November/December 1996, the Echelle spectrometer was used extensively by the Principal and Guest Investigator teams as one of the two focal plane instruments of the ORFEUS telescope. We present the in-flight performance and the principles of the data reduction for this instrument. The wavelength range is 90 nm to 140 nm, the spectral resolution is significantly better than lambda/(Delta lambda) = 10000, where Delta lambda is measured as FWHM of the instrumental profile. The effective area peaks at 1.3 cm^2 near 110 nm. The background is dominated by straylight from the Echelle grating and is about 15% in an extracted spectrum for spectra with a rather flat continuum. The internal accuracy of the wavelength calibration is better than +/- 0.005 nm.

J. Barnstedt; N. Kappelmann; I. Appenzeller; A. Fromm; M. Goelz; M. Grewing; W. Gringel; C. Haas; W. Hopfensitz; G. Kraemer; J. Krautter; A. Lindenberger; H. Mandel; H. Widmann

2000-06-21

15

The design of an echelle spectrometer for diffuse extreme ultraviolet/far ultraviolet astronomy  

NASA Technical Reports Server (NTRS)

The novel, relatively high-resolution nebular spectrometer design presented incorporates a mechanical precollimator with an objective echelle grating that proceeds to a cross-dispensing Wadsworth configuration; the minimum feasible number of reflections is employed in order to maximize EUV sensitivity. The configuration, which is noted to be capable of yielding a comparatively large field of view for optimal diffuse emission sensitivity, is compact and employs conventionally fabricated optical components and available microchannel plate detectors. The sensitivities obtainable approach the limit stipulated by Liouville's theorem.

Martin, Christopher

1986-01-01

16

AOTF-echelle spectrometer for air-ICP-AES continuous emission monitoring of heavy metals and actinides  

Microsoft Academic Search

A spectrometer system consisting of a quartz acousto-optic tunable filter (AOTF) and an echelle grating has been assembled and tested for ICP-AES continuous emission monitoring of heavy metal and actinide elements in stack exhaust offgases introduced into an air plasma. The AOTF is a rapidly tunable bandpass filter that is used to select a small wavelength range (0.1 to 0.6

David P. Baldwin; Daniel S. Zamzow; David E. Eckels; George P. Miller

1999-01-01

17

Exploiting a transmission grating spectrometer  

SciTech Connect

The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

Bell, Ronald E. [Princeton Plasma Physics Laboratory, Princeton University, Princeton New Jersey 08543-0451 (United States)

2004-10-01

18

Exploiting a Transmission Grating Spectrometer  

SciTech Connect

The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

Ronald E. Bell

2004-12-08

19

AIRES: An Airborne Infra-Red Echelle Spectrometer for SOFIA  

NASA Technical Reports Server (NTRS)

SOFIA will enable astronomical observations with unprecedented angular resolution at infrared wavelengths obscured from the ground. To help open this new chapter in the exploration of the infrared universe, we are building AIRES, an Airborne Infra-Red Echelle Spectrometer. AIRES will be operated as a first generation, general purpose facility instrument by USRA, NASA's prime contractor for SOFIA. AIRES is a long slit spectrograph operating from 17 - 210 microns. In high resolution mode the spectral resolving power is approx. 10(exp 6) microns/A or approx. 10(exp 4) at 100 microns. Unfortunately, since the conference, a low resolution mode with resolving power about 100 times lower has been deleted due to budgetary constraints. AIRES includes a slit viewing camera which operates in broad bands at 18 and 25 microns.

Dotson, Jessie J.; Erickson, Edwin F.; Haas, Michael R.; Colgan, Sean W. J.; Simpson, Janet P.; Telesco, Charles M.; Pina, Robert K.; Wolf, Juergen; Young, Erick T.

1999-01-01

20

Chiron - A Fiber-fed High-resolution Echelle Spectrometer At Ctio 1.5m Telescope  

NASA Astrophysics Data System (ADS)

Small telescopes can play an important role in the search for exoplanets because they offer an opportunity for high cadence observations that are not possible with large aperture telescopes. CHIRON is a highly stable cross-dispersed echelle spectrometer deployed at CTIO 1.5m telescope. It is fed by fiber and intended primarily for precise radial velocities. It is currently mainly used to search for low mass planets around alpha Centauri A and B. An iodine cell is used for wavelength calibration. The optical layout is a classical echelle with 150 mm collimator size. The bench-mounted spectrometer is fiber-fed followed by an image slicer or a slit mask. For the grating, we used the existing R2 echelle grating (that has a throughput of about 50%). An apochromatic refractor is used as the camera. Image quality of the design is excellent over the full spectral range. The instrument has been commissioned in March 2011. It has four observing modes: (a) unsliced fiber (R = 25,000-30,000), (b) image slicer (3 slices, R=80,000), (c) wide slit (R = 80,000-90,000) and (d) narrow slit (R = 120,000). The spectral format spans 4200 to 8700 Angstroms. The total throughput of the telescope and spectrometer is 5-6%. Replacement of the grating and coating of the prism will further improve the efficiency. Furthermore, the spectrometer is in a closed temperature-stabilized environment and pressure stabilization is currently being implemented. An exposure meter to precisely calculate the photon-weighted mid-point time will be installed in June 2011.

Spronck, Julien; Schwab, C.; Tokovinin, A.; Giguere, M.; Szymkowiak, A.; Fischer, D.

2011-05-01

21

Imaging spectrometer/camera having convex grating  

NASA Technical Reports Server (NTRS)

An imaging spectrometer has fore-optics coupled to a spectral resolving system with an entrance slit extending in a first direction at an imaging location of the fore-optics for receiving the image, a convex diffraction grating for separating the image into a plurality of spectra of predetermined wavelength ranges; a spectrometer array for detecting the spectra; and at least one concave sperical mirror concentric with the diffraction grating for relaying the image from the entrance slit to the diffraction grating and from the diffraction grating to the spectrometer array. In one embodiment, the spectrometer is configured in a lateral mode in which the entrance slit and the spectrometer array are displaced laterally on opposite sides of the diffraction grating in a second direction substantially perpendicular to the first direction. In another embodiment, the spectrometer is combined with a polychromatic imaging camera array disposed adjacent said entrance slit for recording said image.

Reininger, Francis M. (Inventor)

2000-01-01

22

Convex Diffraction Grating Imaging Spectrometer  

NASA Technical Reports Server (NTRS)

A 1:1 Offner mirror system for imaging off-axis objects is modified by replacing a concave spherical primary mirror that is concentric with a convex secondary mirror with two concave spherical mirrors M1 and M2 of the same or different radii positioned with their respective distances d1 and d2 from a concentric convex spherical diffraction grating having its grooves parallel to the entrance slit of the spectrometer which replaces the convex secondary mirror. By adjusting their distances d1 and d2 and their respective angles of reflection alpha and beta, defined as the respective angles between their incident and reflected rays, all aberrations are corrected without the need to increase the spectrometer size for a given entrance slit size to reduce astigmatism, thus allowing the imaging spectrometer volume to be less for a given application than would be possible with conventional imaging spectrometers and still give excellent spatial and spectral imaging of the slit image spectra over the focal plane.

Chrisp, Michael P. (Inventor)

1999-01-01

23

Athermalized low-loss echelle-grating-based multimode dense wavelength division demultiplexer  

E-print Network

of increasing the capacity of long-haul fiber links. But the WDM for data com- munications has to be quite low of the fibers used in LANs, owing to its low-cost installation and maintenance. It was installed in LANsAthermalized low-loss echelle-grating-based multimode dense wavelength division demultiplexer Jie

Chen, Ray

24

Compact Imaging Spectrometer Utilizing Immersed Gratings  

DOEpatents

A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, a system for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through an optical element to the detector array.

Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

2006-03-21

25

An FIR cooled grating spectrometer for the Kuiper Airborne Observatory  

NASA Technical Reports Server (NTRS)

The design and performance of a liquid-He-cooled spectrometer being developed for the Kuiper Airborne Observatory (KAO) to study FIR lines originating in the interstellar medium are discussed. Currently, the spectrometer contains six Ge:Ga photoconductor detectors mounted in integrating cavities and cooled to about 3 K; the collimator focal plane has space for 39 such detectors. The instrument achieves a maximum resolving power of 6000 by means of a 45-cm long echelle grating and is optically capable of operating in the spectral range 25-300 microns. A laboratory spectrum of water vapor, an atmospheric water absorption feature measured from the KAO with Mars as a source, and the forbidden O(2+) emission from W51-IRS1 are shown.

Erickson, E. F.; Haas, M. R.; Hollenbach, D. J.; Simpson, J. P.; Augason, G. C.; Houck, J. R.; Harwit, M. O.; Rank, D. M.

1985-01-01

26

The Constellation-X reflection grating spectrometer  

Microsoft Academic Search

The Constellation-X Reflection Grating Spectrometer (RGS) is designed to provide high-throughput, high-resolution spectra in the long wavelength band of 6 to 50 angstrom. In the nominal design an array of reflection gratings is mounted at the exit of the Spectroscopy X-ray Telescope (SXT) mirror module. The gratings intercept and disperse light to a designated array of CCD detectors. To achieve

Jean Cottam; Webster Cash; Kathryn A. Flanagan; Ralf K. Heilmann; Gregory Y. Prigozhin; Andrew P. Rasmussen; George R. Ricker; Mark L. Schattenburg; Eric Schindhelm

2006-01-01

27

On the multiple grating spectrometer resolving power  

Microsoft Academic Search

The resolution for multiple grating spectrometers is obtained using the transfer function formalism. It is shown that the limiting resolving power for a system of n equal gratings in additive dispersion lambda\\/Delta lambda sub g (n) is overestimated by previous calculations even for low n values. It is also found that when n is increased this quantity reaches a limiting

V. Mazzacurati; G. Ruocco; G. Signorelli

1988-01-01

28

Compact imaging spectrometer utilizing immersed gratings  

DOEpatents

A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

2007-07-03

29

Compact reflective imaging spectrometer utilizing immersed gratings  

DOEpatents

A compact imaging spectrometer comprising an entrance slit for directing light, a first mirror that receives said light and reflects said light, an immersive diffraction grating that diffracts said light, a second mirror that focuses said light, and a detector array that receives said focused light. The compact imaging spectrometer can be utilized for remote sensing imaging spectrometers where size and weight are of primary importance.

Chrisp, Michael P. (Danville, CA)

2006-05-09

30

Micro Ring Grating Spectrometer with Adjustable Aperture  

NASA Technical Reports Server (NTRS)

A spectrometer includes a micro-ring grating device having coaxially-aligned ring gratings for diffracting incident light onto a target focal point, a detection device for detecting light intensity, one or more actuators, and an adjustable aperture device defining a circular aperture. The aperture circumscribes a target focal point, and directs a light to the detection device. The aperture device is selectively adjustable using the actuators to select a portion of a frequency band for transmission to the detection device. A method of detecting intensity of a selected band of incident light includes directing incident light onto coaxially-aligned ring gratings of a micro-ring grating device, and diffracting the selected band onto a target focal point using the ring gratings. The method includes using an actuator to adjust an aperture device and pass a selected portion of the frequency band to a detection device for measuring the intensity of the selected portion.

Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor); Choi, Sang H. (Inventor)

2012-01-01

31

Beam Shape Effects on Grating Spectrometer Resolution  

NASA Technical Reports Server (NTRS)

The collimated optical beam in a grating spectrometer may be circular or elliptical in cross section, so that different parts of the beam illuminate different numbers of grooves on the grating. Here we estimate the consequent loss in spectral resolution relative to that obtained with a beam which illuminates a fixed number of grooves. For representative diffraction resolution functions, the effect is to reduce the intrinsic resolving power of the spectrometer by about 13%, exclusive of other contributions such as finite entrance slit width.

Erickson, Edwin F.; Rabanus, David; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

32

New Convex Grating Types for Concentric Imaging Spectrometers  

NASA Technical Reports Server (NTRS)

The properties of convex gratings fabricated by electron-beam lithography are investigated. Three grating types are shown. These gratings allow the optical designer to fully realize the considerable advantages of concentric spectrometer forms.

Mouroulis, P.; Wilson, D. W.; Maker, P. D.; Maker, R. E.; Muller, R. E.

1998-01-01

33

Electro-optic Phase Grating Streak Spectrometer  

SciTech Connect

The electro-optic phase grating streak spectrometer (EOPGSS) generates a time-resolved spectra equivalent to that obtained with a conventional spectrometer/streak camera combination, but without using a streak camera (by far the more expensive and problematic component of the conventional system). The EOPGSS is based on a phase, rather than an amplitude grating. Further, this grating is fabricated of electro-optic material such as, for example, KD*P, by either etching grooves into an E-O slab, or by depositing lines of the E-O material onto an optical flat. An electric field normal to the grating alters the materials index of refraction and thus affects a shift (in angle) of the output spectrum. Ramping the voltage streaks the spectrum correspondingly. The streak and dispersion directions are the same, so a second (static, conventional) grating disperses the spectrum in the orthogonal direction to prevent different wavelengths from overwriting each other. Because the streaking is done by the grating, the streaked output spectrum is recorded with a time-integrating device, such as a CCD. System model, typical design, and performance expectations will be presented.

Goldin, F. J.

2012-08-02

34

Inflight calibration of the XMMNewton Reflection Grating Spectrometers  

E-print Network

In­flight calibration of the XMM­Newton Reflection Grating Spectrometers C. Erd a , M. Audard b , A The Reflection Grating Spectrometer (RGS) 1--3 on European Space Agency's (ESA) X­ray observatory XMM­ Newton 4 is a dispersive spectrometer which, for the first time in X­ray astronomy, uses reflection gratings as dispersive

Audard, Marc

35

The Constellation-X reflection grating spectrometer Jean Cottama  

E-print Network

The Constellation-X reflection grating spectrometer Jean Cottama , Webster Cashb , Kathryn A University, SLAC, Menlo Park, CA USA 94025 ABSTRACT The Constellation-X Reflection Grating Spectrometer (RGS. Keywords: X-ray, spectrometer, grating, CCD, Constellation-X 1. INTRODUCTION Constellation-X1 is one

36

Imaging Spectrometers Using Concave Holographic Gratings  

NASA Technical Reports Server (NTRS)

Imaging spectroscopy combines the spatial attributes of imaging with the compositionally diagnostic attributes of spectroscopy. For spacebased remote sensing applications, mass, size, power, data rate, and application constrain the scanning approach. For the first three approaches, substantial savings in mass and size of the spectrometer can be achieved in some cases with a concave holographic grating and careful placement of an order-sorting filter. A hologram etched on the single concave surface contains the equivalent of the collimating, dispersing, and camera optics of a conventional grating spectrometer and provides substantial wavelength dependent corrections for spherical aberrations and a flat focal field. These gratings can be blazed to improve efficiency when used over a small wavelength range or left unblazed for broadband uniform efficiency when used over a wavelength range of up to 2 orders. More than 1 order can be imaged along the dispersion axis by placing an appropriately designed step order-sorting filter in front of the one- or two-dimensional detector. This filter can be shaped for additional aberration corrections. The VIRIS imaging spectrometer based on the broadband design provides simultaneous imaging of the entrance slit from lambda = 0.9 to 2.6 microns (1.5 orders) onto a 128 x 128 HgCdTe detector (at 77 K). The VIRIS spectrometer was used for lunar mapping with the UH 24.in telescope at Mauna Kea Observatory. The design is adaptable for small, low mass, space based imaging spectrometers.

Gradie, J.; Wang, S.

1993-01-01

37

A set of innovative immersed grating based spectrometer designs for METIS  

NASA Astrophysics Data System (ADS)

We present innovative, immersed grating based optical designs for the SMO (Spectrograph Main Optics) module of the Mid-infrared E-ELT Imager and Spectrograph, METIS. The immersed grating allows a significant reduction of SMO volume compared to conventional echelle grating designs, because the diffraction takes place in high refractive index silicon. Additionally, using novel optimization techniques and technical solutions in silicon micromachining offered by the semiconductor industry, further improvements can be achieved. We show optical architectures based on compact, double-pass Three Mirror Anastigmat (TMA) designs, which appear advantageous in terms of one or several of the following: optical performance, reduction of volume, ease of manufacturing and testing. We explore optical designs, where the emphasis is put on manufacturability and we investigate optical solutions, where the ultimate goal is the highest possible optical performance. These novel, silicon immersed grating based design concepts are applicable for future earth and space based spectrometers.

Agcs, Tibor; Navarro, Ramon; Venema, Lars; van Amerongen, Aaldert H.; Tol, Paul J. J.; van Brug, Hedser; Brandl, Bernhard R.; Molster, Frank; Todd, Stephen

2014-07-01

38

The Constellation-X Reflection Grating Spectrometer  

NASA Technical Reports Server (NTRS)

The Reflection Grating Spectrometer on the Constellation-X mission will provide high sensitivity, high-resolution spectra in the soft x-ray band. The RGS performance requirements are specified as a resolving power of greater than 300 and an effective area of greater than 1000 sq cm across most of the 0.25 to 2.0 keV band. These requirements are driven by the science goals of the mission. We will describe the performance requirements and goals, the reference design of the spectrometer, and examples of science cases where we expect data from the RGS to significantly advance our current understanding of the universe.

Allen, Jean C.

2006-01-01

39

Streaked, x-ray-transmission-grating spectrometer  

SciTech Connect

A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/..delta..lambda of 4 to 50, limited primarily by source size and collimation effects.

Ceglio, N.M.; Roth, M.; Hawryluk, A.M.

1981-08-01

40

Lower order blaze grating spectrometer of large diffraction angle  

Microsoft Academic Search

A new kind of large dispersion lower order blaze grating spectrometer is built. The design is based on the use of uncustomary large angles of incidence and diffraction approaching 80. The double diffraction optical scheme is employed to fit the design conception. A set of compact size grating spectrometers of various focal lengths and grating ruled widths has been manufactured

Yu. S. Koshkin; E. E. Mukhin; G. T. Razdobarin; V. V. Semenov; A. N. Shilnikov; Yu. K. Mihailovskij; L. I. Bakh

1999-01-01

41

Calibration and efficiency of the Einstein objective grating spectrometer  

Microsoft Academic Search

The Einstein Observatory, a large satellite dedicated to X-ray astronomy, carried the first large X-ray telescope to be placed in orbit and an objective grating spectrometer with two sets of gratings. This paper lists prelaunch calibration results and describes the derivation of spectrometer efficiency and resolution. Several calibration spectra are shown, and theoretical grating parameters are derived from the calibration

F. D. Seward; T. Chlebowski; J. P. Delvaille; J. P. Henry; S. M. Kahn; L. van Speybroeck; J. Dijkstra; A. C. Brinkman; J. Heise; R. Mewe; J. Schrijver

1982-01-01

42

Single-detector micro-electro-mechanical scanning grating spectrometer  

Microsoft Academic Search

A compact, robust grating spectrometer based on an optimised micro-electro-mechanical grating mirror component has been developed,\\u000a built, and characterised. The application of an oscillating reflection grating micro-mirror component as scanning dispersive\\u000a element in a modified CzernyTurner monochromator layout enables the design of compact grating spectrometers capable of acquiring\\u000a full spectra using a single detector element. Designed for a wavelength range

M. Kraft; A. Kenda; A. Frank; W. Scherf; A. Heberer; T. Sandner; H. Schenk; F. Zimmer

2006-01-01

43

Continuum-source atomic absorption spectroscopy with an echelle spectrometer adapted to a charge injection device.  

PubMed

An instrumental system for continuum-source atomic absorption spectroscopy has been developed for simultaneous multielement determinations. The system consists of an electrothermal atomizer and a charge injection device adapted to an echelle spectrometer to achieve multiplex detection. A continuous 40-nm spectral range in the two-dimensional echelle spectrum was acquired simultaneously through the capability of the charge injection device to integrate signals in its MOS capacitors. Novel methods were developed to compute absorbances by "scanning" through all orders in the entire echelle spectrum or selecting absorption lines randomly. In the range 300-430 nm, characteristic concentrations (1% absorption) were 1.6, 2.6, 2.9, and 3.8 ng mL-1 respectively for Cu, Mn, and two Cr lines; these values are similar to those (1.3, 2.2, 1.2, and 3.6 ng mL-1) obtained for single-element detection with an image-dissector system. PMID:2240578

Hsiech, C; Petrovic, S C; Pardue, H L

1990-09-15

44

Cooled grating infrared spectrometer for astronomical observations  

NASA Technical Reports Server (NTRS)

A liquid helium-cooled infrared spectrometer for the 16 to 50 micron range is described. The instrument has six detectors, three each of Si:Sb and Ge:Ga and two diffraction gratings mounted back-to-back. Cold preoptics are used to match the spectrometer to the telescope. In its nominal configuration the system resolution is 0.03 micron from 16 to 30 microns and 0.07 micron from 28 to 50 microns. A cooled filter wheel is used to change order sorting filters. The gratings are driven by a steel band and gear train operating at 4 K. The detector outputs are amplified by a TIA, employing a matched pair of JFETs operating at 70 K inside the dewar. The external warm electronics include a gain stage for the TIA and dc-coupled gating circuit to remove charged-particle (cosmic-ray secondary)-induced noise spikes. The gating circuit reduces the overall system noise by a factor of two when the spectrometer is used on NASA's Kuiper Airborne Observatory. Sample spectra are presented and the deglitcher performance is illustrated.

Houck, J. R.; Gull, G. E.

1983-01-01

45

UNIVERSIT AT OSNABR UCK 1 Grating Spectrometer GRATING.TEX KB 20020119  

E-print Network

UNIVERSIT ¨AT ?OSNABR ¨UCK 1 Grating Spectrometer GRATING.TEX KB 20020119 KLAUS BETZLER1-known properties of spectrometers. As an addition to textbooks, it may present some help to students working over the field of spectroscopy. 1 Grating Mathematics 1.1 Transfer Function As a general rule

Osnabrück, Universität

46

A transmission grating spectrometer for plasma diagnostics  

SciTech Connect

Radiation temperature is an important parameter in characterizing the properties of hot plasmas. In most cases this temperature is time varying caused by the short lived and/or time dependent nature of the plasma. Thus, a measurement of the radiation flux as a function of time is quite valuable. To this end the authors have developed a spectrometer that can acquire spectra with a time resolution of less than 1 ns and covers the spectral energy range from {approximately} 60 to 1,000 eV. The spectrometer consists of an entrance slit placed relatively near the plasma, a thin gold film transmission grating with aperture, a micro channel plate (MCP) detector with a gold cathode placed at the dispersion plane and an electron lens to focus the electrons from the MCP onto a phosphor coated fiber optic plug. The phosphor (In:CdS) has a response time of {approximately} 500 ps. This detector system, including the fast phosphor is similar to one that has been previously described. The spectrometer is in a vacuum chamber that is turbo pumped to a base pressure of {approximately} 5 x 10{sup 7} torr. The light from the phosphor is coupled to two streak cameras through 100 m long fiber optic cables. The streak cameras with their CCD readouts provide the time resolution of the spectrum. The spectrometer has a built in alignment system that uses an alignment telescope and retractable prism.

Bartlett, R.J.; Hockaday, R.G. [Los Alamos National Lab., NM (United States); Gallegos, C.H.; Gonzales, J.M.; Mitton, V. [EG and G Energy Measurements, Los Alamos, NM (United States)

1995-09-01

47

Faceted grating prism for a computed tomographic imaging spectrometer  

E-print Network

Faceted grating prism for a computed tomographic imaging spectrometer Michael W. Kudenov Julia://opticalengineering.spiedigitallibrary.org/ on 02/04/2013 Terms of Use: http://spiedl.org/terms #12;Faceted grating prism for a computed tomographic disperser based on a 2-D grating prism and a division of aperture approach. Included is an optical design

Dereniak, Eustace L.

48

Micro-spectrometer based on flat field holographic concave grating  

NASA Astrophysics Data System (ADS)

A micro-spectrometer which adopts the holographic concave grating as imaging and dispersing element is introduced in the paper. Using ZEMAX soft ware tools, the optimal design of aberration correction of the concave grating which retains the image quality without sacrificing the resolution is coming up with. The portable micro-spectrometer with F/#4 is developed. During 350nm to 800nm wavelength range, the resolution of this kind of micro-spectrometer is better than 0.5nm. In addition, the diffraction efficiency of the concave grating, which is a very important indicator of the spectrometer and confines the detecting ability to the faintest spectrograph, is calculated by means of the rigorous coupled wave theory of the grating. The relationship between the diffraction efficiency of the concave grating and its profile parameters is discussed, too. The results obtained from these researches provide the necessary guidance in fabrication of the micro-spectrometer.

Li, Chaoming; Chen, Xinrong; Wu, Jianhong; Hu, Zhuyuan

2010-11-01

49

Immersion echelle spectrograph  

DOEpatents

A small spectrograph containing no moving components and capable of providing high resolution spectra of the mid-infrared region from 2 microns to 4 microns in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 10.sup.-5 cm.sup.2 sr. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first order transmission grating in a cross-dispersing configuration to provide a two-dimensional (2-D) spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a near aberration-free axially symmetric design. The spectrometer has wide use potential in addition to general research, such as monitoring atmospheric constituents for air quality, climate change, global warming, as well as monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

Stevens, Charles G. (Danville, CA); Thomas, Norman L. (Livermore, CA)

2000-01-01

50

Numerical optimization of spherical VLS grating X-ray spectrometers  

E-print Network

Operation of an X-ray spectrometer based on a spherical variable line spacing grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and spectrometer geometry. The analysis is illustrated with optical design of a model spectrometer to deliver a resolving power above 20400 at photon energy of 930 eV (Cu L-edge). With this energy taken as reference, the VLS coefficients are optimized to cancel the lineshape asymmetry (mostly from the coma aberrations) as well as minimize the symmetric aberration broadening at large grating illuminations, dramatically increasing the aberration-limited vertical acceptance of the spectrometer. For any energy away from the reference, we evaluate corrections to the entrance arm and light incidence angle on the grating to maintain the exactly symmetric lineshape. Furthermore, we evaluate operational modes when these corrections are coordinated to maintain either energy independent focal curve inclination or maximal aberration-lim...

Strocov, V N; Flechsig, U; Patthey, L; Chiuzb?ian, G S

2010-01-01

51

Imaging Spectrometer Designs Utilizing Immersed Gratings With Accessible Entrance Slit  

SciTech Connect

A compact imaging spectrometer comprises an entrance slit, a catadioptric lens with a mirrored surface, a grating, and a detector array. The entrance slit directs light to the mirrored surface of the catadioptric lens; the mirrored surface reflects the light back through the lens to the grating. The grating receives the light from the catadioptric lens and diffracts the light to the lens away from the mirrored surface. The lens transmits the light and focuses it onto the detector array.

Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR)

2006-03-21

52

Compact Catadioptric Imaging Spectrometer Designs Utilizing Immersed Gratings  

DOEpatents

An imaging spectrometer comprising an entrance slit for directing light, a lens that receives said light and reflects said light, a grating that defracts said light back onto said lens which focuses said light, and a detector array that receives said focused light. In one embodiment the grating has rulings immersed into a germanium surface.

Lerner, Scott A. (Livermore, CA)

2006-02-28

53

Hyphenation of a near-infrared Echelle spectrometer to a microplasma for element-selective detection in gas chromatography.  

PubMed

The coupling of a near-infrared Echelle spectrometer (NIRES) with a gas chromatograph for element-selective detection is introduced. The miniaturized capacitive plasma device is operated at a frequency of 40.68 MHz and is mounted directly on an Hewlett-Packard HP6890 GC. First results with a mixture of halogenated standard compounds are presented and discussed in terms of the advantages and problems with this system. PMID:11798094

Cziesla, K; Platzer, B; Okruss, M; Florek, S; Otto, M

2001-12-01

54

Compact echelle spectrometer for occultation sounding of the Martian atmosphere: design and performance.  

PubMed

The echelle spectrometer TIMM-2 is the instrument developed for the unsuccessful Russian mission Phobos-Grunt. The instrument was dedicated to solar occultation studies of the Martian atmosphere by measuring the amount of methane, by sensitive measuring of other minor constituents, and by profiling the D/H ratio and the aerosol structure. The spectral range of the instrument is 2300-4100 nm, the spectral resolving power ?/?? exceeds 25,000, and the field of view is 1.521 arc min. The spectra are measured in narrow spectral intervals, corresponding to discreet diffraction orders. One measurement cycle includes several spectral intervals. To study the vertical profiles of aerosol, the instrument incorporates four photometers in the UV to near-IR spectral range. The mass of the instrument is 2800 g, and its power consumption is 12 W. One complete flight model remains available after the Phobos-Grunt launch. We discuss the science objectives of the occultation experiment for the case of Mars, the implementation of the instrument, and the results of ground calibrations. PMID:23400068

Korablev, Oleg; Montmessin, Franck; Trokhimovsky, Alexander; Fedorova, Anna A; Kiselev, Alexander V; Bertaux, Jean-Loup; Goultail, Jean-Pierre; Belyaev, Denis A; Stepanov, Alexander V; Titov, Andrei Yu; Kalinnikov, Yurii K

2013-02-10

55

Variable line-space gratings - New designs for use in grazing incidence spectrometers  

NASA Technical Reports Server (NTRS)

An account is given of a fundamentally different approach to the use of variable line-space gratings for grazing incidence spectrometers. In the new approach, the gratings are flat and they are placed to intercept the converging beam from a collecting mirror rather than the diverging beam from a slit. This results in (1) small aberrations over a wide instantaneous range in wavelength, (2) a modest required variation in line spacing across the ruled width, (3) a simultaneous minimization of both the spectral and image height aberrations, and (4) a completely stigmatic zero order image. The slitless arrangement common to these designs is very compact, having no additional length behind the focal plane of the collecting mirror. In-plane and conical fan designs are considered. One combination design, in the form of an echelle spectrometer, is discussed. The designs are considered to represent ideal candidates for moderate to high resolution spectrometers on such missions as the Far Ultraviolet Spectroscopic Explorer (FUSE, now Columbus) and the Advanced X-ray Astrophysics Facility (AXAF).

Hettrick, M. C.; Bowyer, S.

1983-01-01

56

Comparison of a transmission grating spectrometer to a reflective grating spectrometer for standoff laser-induced breakdown spectroscopy measurements  

SciTech Connect

We evaluate a new transmission grating spectrometer for standoff laser-induced breakdown spectroscopy (LIBS) measurements. LIBS spectra collected from standoff distances are often weak, with smaller peaks blending into the background and noise. Scattered light inside the spectrometer can also contribute to poor signal-to-background and signal-to-noise ratios for smaller emission peaks. Further, collecting standoff spectra can be difficult because most spectrometers are designed for laboratory environments and not for measurements in the field. To address these issues, a custom-designed small, lightweight transmission grating spectrometer with no moving parts was built that is well suited for standoff LIBS field measurements. The performance of the spectrometer was quantified through 10 m standoff LIBS measurements collected from aluminum alloy samples and measurements from spectra of a Hg-Ar lamp. The measurements were compared to those collected using a Czerny-Turner reflective grating spectrometer that covered a similar spectral range and used the same ICCD camera. Measurements using the transmission grating spectrometer had a 363% improved signal-to-noise ratio when measured using the 669 nm aluminum emission peak.

Weisberg, Arel; Craparo, Joseph; De Saro, Robert; Pawluczyk, Romuald

2010-05-01

57

A field-portable thermal infrared grating spectrometer (THIRSPEC)  

Microsoft Academic Search

A thermal infrared grating spectrometer was developed for field studies in the Earth sciences. The design is based on a reflection grating and a 60-element HgCdTe detector array. The useful spectral range of the instrument covers 7.9-11.3 ?m with a Nyquist limited resolution of 0.16 ?m. The instrument averages over a 12 field of view and compares the exitance of

Benoit Rivard; Paul J. Thomas; D. Pollex; A. Hollinger; John R. Miller; R. Dick

1994-01-01

58

Compact Refractive Imaging Spectrometer Designs Utilizing Immersed Gratings  

DOEpatents

A compact imaging spectrometer comprising an entrance slit for directing light, a first means for receiving the light and focusing the light, an immersed diffraction grating that receives the light from the first means and defracts the light, a second means for receiving the light from the immersed diffraction grating and focusing the light, and an image plane that receives the light from the second means

Lerner, Scott A. (Livermore, CA); Bennett, Charles L. (Livermore, CA); Bixler, Jay V. (Oakland, CA); Kuzmenko, Paul J. (Livermore, CA); Lewis, Isabella T. (San Jose, CA)

2005-07-26

59

The polarisation correction for space-borne grating spectrometers  

NASA Astrophysics Data System (ADS)

Satellite measurements of backscattered sunlight contain essential information about the global distribution of atmospheric constituents. Light reflected from the Earth's atmosphere is linearly or partially linearly polarized because of scattering of unpolarized sunlight by air molecules and aerosols. In the ultraviolet and visible part of the spectrum, measurements of space-borne grating spectrometers are in general sensitive to the state of polarization of the observed light. The interaction of polarized light with polarization-sensitive optical devices yields a different radiance that is measured by the detectors than the radiance that enters the instrument. In the OMI and the SBUV/2 instruments the problem of instrument polarization sensitivity is avoided because the polarized backscattered sunlight is depolarized before it interacts with the polarization-sensitive optical components. For GOME, SCIAMACHY, and GOME-2 it is intended to eliminate the polarization response of the instrument from the polarization-sensitive measurement. This paper discusses the basic concept of the polarisation correction of the space-borne grating spectrometers by using Mueller matrix calculus. A model was developed using the Mueller Matrices formulation to evaluate the polarization sensitivity of the space-borne grating spectrometers. The optical components are treated as general diattenuators with phase retardance. The correction for this polarization sensitivity is based on broadband polarization measurements. Accurate preflight polarisation calibration of space-borne grating spectrometers is essential for the observational objectives of the instrument, and a special facility has been developed in order to allow the instrument to be calibrated.

Zhao, Fa-cai; Sun, Quan-she; Chen, Kun-feng; Zhu, Xing-bang; Wang, Shao-shui; Wang, Guo-quan; Zheng, Xiang-liang; Han, Zhong

2014-02-01

60

An X-ray Grating Spectrometer for the ISS  

NASA Astrophysics Data System (ADS)

We present the design approach for a X-ray grating spectrometer mission to be deployed on the International Space Station. The baseline design uses sub-apertured X-ray optics feeding into off-plane gratings to achieve both high spectral resolution with a large effective area; the read out is by high-TRL CCDs in the focal plane. The mission will use a pointing system with a novel technology to reduce vibrations from the ISS propagating into the telescope, and would be ready to be attached to the ISS in 2021. The mission parameters are similar to those of the IXO X-ray Grating Spectrometer of R=3000 and ~1000 sq. cm at 0.5 keV, with a bandpass from ~0.3-1 keV, enabling a wide range of science objectives.

Bookbinder, Jay A.; McEntaffer, Randall L.; Daigneau, Peter; Smith, Randall K.; Bautz, Mark W.; Burrows, David N.; Willingale, Richard; Petre, Robert; Wilms, Jrn; Falcone, Abraham; Brickhouse, Nancy S.; Ptak, Andrew; Foster, Adam; Bregman, Joel N.

2014-06-01

61

Spectrometer concept and design for X-ray astronomy using a blazed transmission grating  

E-print Network

Spectrometer concept and design for X-ray astronomy using a blazed transmission grating Kathryn grating schemes considered in the past1,2,3 . The spectrometer readout is based on conventional CCD high spectral resolution in the soft X-ray band, employing grating spectrometers of sufficient

62

A simple miniature optical spectrometer with a planar waveguide grating coupler in  

E-print Network

A simple miniature optical spectrometer with a planar waveguide grating coupler in combination: A miniature optical spectrometer with a thin-film planar waveguide grating coupler in combination, "Miniaturized spectrometer employing planar waveguides and grating couplers for chemical analysis," Appl. Opt

Avrutsky, Ivan

63

A filter free dual transmission grating spectrometer for the extreme-ultraviolet  

E-print Network

A filter free dual transmission grating spectrometer for the extreme- ultraviolet Seth R. Wieman of a prototype dual-grating filter-free extreme ultraviolet (EUV) spectrometer that has potential as a highly gratings of the type used in our spectrometer are the subject of considerable previous research4

Didkovsky, Leonid

64

"The Reflection Grating Spectrometer on Constellation-X"  

NASA Technical Reports Server (NTRS)

The Constellation-X Reflection Grating Spectrometer (RGS) is designed to provide high-throughput, high-resolution spectra in the long wavelength band of 6 to 50 angstrom. In the nominal design an array of reflection gratings is mounted at the exit of the Spectroscopy X-ray Telescope (SXT) mirror module. The gratings intercept and disperse light to a designated array of CCD detectors. To achieve the throughput (A_eff > 1000 cm2 below 0.6 keV) and resolution (R > 300 below 0.6 keV) requirements for the instrument we are investigating two possible grating designs. The first design uses in-plane gratings in a classical configuration that is very similar to the XMM-Newton RGS. The second design uses off-plane gratings in a conical configuration. The off-plane design has the advantage of providing higher reflectivity and potentially, a higher spectral resolution than the in-plane configuration. In our presentation we will describe the performance requirements and the current status of the technology development.

Cottam, J.

2006-01-01

65

Cooled grating array spectrometer for 0.6-5 microns  

NASA Technical Reports Server (NTRS)

A grating spectrometer, designed to illuminate an array of 122 InSb photodiodes with minimum aberrations and maximum speed, has been constructed. The instrument will be used on the 5 meter Hale telescope at Palomar Observatory, and is easily adaptable to telescopes of various focal ratios. A resolving power of 100-1000 can be obtained at wavelengths between 0.6 microns and 5 microns with remotely interchangeable gratings. The spectrometer is sufficiently compact to fit on the 8-inch work surface of a commercially available dewar, and uses simple on-axis spherical and paraboloidal optical elements. The camera mirror produces an f/2.5 beam which, with the 0.2 mm detectors, allows a 3-in. focal-plane aperture on the 5 meter telescope. All rays fall within a 100 microns blur circle at all points along the array. Distortions have been corrected with a tilted field flattening lens in front of the detector.

Nordholt, J. E.; Lacy, J. H.

1982-01-01

66

The Reflection Grating Spectrometer on board XMM-Newton  

Microsoft Academic Search

The ESA X-ray Multi Mirror mission, XMM-Newton, carries two identical Reflection Grating Spectrometers (RGS) behind two of its three nested sets of Wolter I type mirrors. The instrument allows high-resolution (E\\/Delta E = 100 to 500) measurements in the soft X-ray range (6 to 38 , or 2.1 to 0.3 keV) with a maximum effective area of about 140 cm2

J. W. den Herder; A. C. Brinkman; S. M. Kahn; G. Branduardi-Raymont; K. Thomsen; H. Aarts; M. Audard; J. V. Bixler; A. J. den Boggende; J. Cottam; T. Decker; L. Dubbeldam; C. Erd; H. Goulooze; M. Gdel; P. Guttridge; C. J. Hailey; K. Al Janabi; J. S. Kaastra; P. A. J. de Korte; B. J. van Leeuwen; C. Mauche; A. J. McCalden; R. Mewe; A. Naber; F. B. Paerels; J. R. Peterson; A. P. Rasmussen; K. Rees; I. Sakelliou; M. Sako; J. Spodek; M. Stern; T. Tamura; J. Tandy; C. P. de Vries; S. Welch; A. Zehnder

2001-01-01

67

Immersion echelle spectrograph  

SciTech Connect

A small spectrograph is disclosed containing no moving components and capable of providing high resolution spectra of the mid-infrared region from 2 microns to 4 microns in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 10{sup {minus}5}cm{sup 2}sr. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first order transmission grating in a cross-dispersing configuration to provide a two-dimensional (2-D) spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a near aberration-free axially symmetric design. The spectrometer has wide use potential in addition to general research, such as monitoring atmospheric constituents for air quality, climate change, global warming, as well as monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

Stevens, C.G.; Thomas, N.L.

2000-06-20

68

ZEUS-2: a second generation submillimeter grating spectrometer for exploring distant galaxies  

E-print Network

ZEUS-2, the second generation (z)Redshift and Early Universe Spectrometer, like its predecessor is a moderate resolution (R~1000) long-slit, echelle grating spectrometer optimized for the detection of faint, broad lines from distant galaxies. It is designed for studying star-formation across cosmic time. ZEUS-2 employs three TES bolometer arrays (555 pixels total) to deliver simultaneous, multi-beam spectra in up to 4 submillimeter windows. The NIST Boulder-built arrays operate at ~100mK and are readout via SQUID multiplexers and the Multi-Channel Electronics from the University of British Columbia. The instrument is cooled via a pulse-tube cooler and two-stage ADR. Various filter configurations give ZEUS-2 access to 7 different telluric windows from 200 to 850 micron enabling the simultaneous mapping of lines from extended sources or the simultaneous detection of the 158 micron [CII] line and the [NII] 122 or 205 micron lines from z = 1-2 galaxies. ZEUS-2 is designed for use on the CSO, APEX and possibly JCM...

Ferkinhoff, Carl; Parshley, Stephen C; Stacey, Gordon J; Irwin, Kent D; Cho, Hsiao-Mei; Halpern, Mark; 10.1117/12.857018

2010-01-01

69

Solar Imaging UV/EUV Spectrometers Using TVLS Gratings  

NASA Technical Reports Server (NTRS)

It is a particular challenge to develop a stigmatic spectrograph for UV, EUV wavelengths since the very low normal-incidence reflectance of standard materials most often requires that the design be restricted to a single optical element which must simultaneously provide both reimaging and spectral dispersion. This problem has been solved in the past by the use of toroidal gratings with uniform line-spaced rulings (TULS). A number of solar extreme ultraviolet (EUV) spectrometers have been based on such designs, including SOHO/CDS, Solar-B/EIS, and the sounding rockets Solar Extreme ultraviolet Research Telescope and Spectrograph (SERTS) and Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS). More recently, Kita, Harada, and collaborators have developed the theory of spherical gratings with varied line-space rulings (SVLS) operated at unity magnification, which have been flown on several astronomical satellite missions. We now combine these ideas into a spectrometer concept that puts varied-line space rulings onto toroidal gratings. Such TVLS designs are found to provide excellent imaging even at very large spectrograph magnifications and beam-speeds, permitting extremely high-quality performance in remarkably compact instrument packages. Optical characteristics of three new solar spectrometers based on this concept are described: SUMI and RAISE, two sounding rocket payloads, and NEXUS, currently being proposed as a Small-Explorer (SMEX) mission.

Thomas, Roger J.

2003-01-01

70

Description and performance of the reflection grating spectrometer on board of XMMNewton  

E-print Network

Description and performance of the reflection grating spectrometer on board of XMM­Newton J.W. den early 2000. First results for the Reflection Grating Spectrometers will be presented concentrating e Paul Sherrer Institute, CH­5232 Villigen, Switzerland ABSTRACT The Reflection Grating

Guedel, Manuel

71

New grating designs for a CTIS imaging spectrometer Nathan Hagena, Eustace L. Dereniaka  

E-print Network

New grating designs for a CTIS imaging spectrometer Nathan Hagena, Eustace L. Dereniaka a pattern is then replicated over the clear aperture to produce the final grating design.3 slit spectrometerOptical Sciences Center, University of Arizona, Tucson, AZ 85721 ABSTRACT We present some new grating designs

Dereniak, Eustace L.

72

Chirped holographic grating used as the dispersive element in an optical spectrometer  

SciTech Connect

We have developed a new design of optical spectrometer based on the use of a chirped holographic grating inscribed on a flat substrate. This type of grating has a surface modulation with a spatially varying period. The ability of the chirped grating to focus a beam is exploited to reduce significantly the physical dimensions of the instrument. Wavelength selection is achieved by a pure translation of the chirped grating. The properties of the chirped grating spectrometer have been characterized with different lasers and arc lamps and compared with those of two commercial spectrometers. A performance parameter has been defined, enabling the various instruments to be compared.

Fortin, Gilles; McCarthy, Nathalie

2005-08-10

73

Development of a Submillimeter-Wavelength Immersion Grating Spectrometer  

NASA Technical Reports Server (NTRS)

The broad goal of this project was to develop a broadband, moderate-resolution spectrometer for submillimeter wavelengths. Our original approach was to build an immersion grating spectrometer, and as such, the first step was to identify the best material (lowest loss, highest index) for the grating medium, and to characterize its properties at the foreseen optical-bench operating temperature of 1.5 K. To this end, we put our initial efforts into upgrading an existing laboratory submillimeter Fourier transform spectrometer, which allowed us to carry out the requisite materials measurements. The associated cryogenic detector dewar was also redesigned and rebuilt to carry out this work. This dewar houses the 1.5 K detector and the filter wheel used in the materials characterization. Our goal was to have the beam propagate through the samples as uniformly as possible, so the optics were redesigned to allow for the samples to be traversed by a well-defined collimated beam. The optics redesign also placed the samples at an image of the aperture stop located within the FTS. After the rebuild, we moved into the testing phase.

Phillips, T. G.

2001-01-01

74

The Spectrometer Objective: In this lab, you will calibrate a diffraction grating and use it to make a  

E-print Network

The Spectrometer Objective: In this lab, you will calibrate a diffraction grating and use and transmission grating. In this lab, we will use the transmission grating. However, most commercial spectrometers it to make a spectrometer. Once you have built the spectrometer, it's yours to keep! Someday when you have

Collins, Gary S.

75

The Reflection Grating Spectrometer on board XMM A. Brinkman, H. Aarts, A. den Boggende, T. Bootsma, L. Dubbeldam, J. den Herder, J. Kaastra,  

E-print Network

-- 1 -- The Reflection Grating Spectrometer on board XMM A. Brinkman, H. Aarts, A. den Boggende, T Scherrer Institute, CH­5232 Villigen, Switzerland ABSTRACT The Reflection Grating Spectrometer (RGS. Introduction While discussing the spectroscopic capabilities of the Reflection Grating Spectrometer (RGS

Guedel, Manuel

76

Design and early performance of IGRINS (Immersion Grating Infrared Spectrometer)  

NASA Astrophysics Data System (ADS)

The Immersion Grating Infrared Spectrometer (IGRINS) is a compact high-resolution near-infrared cross-dispersed spectrograph whose primary disperser is a silicon immersion grating. IGRINS covers the entire portion of the wavelength range between 1.45 and 2.45?m that is accessible from the ground and does so in a single exposure with a resolving power of 40,000. Individual volume phase holographic (VPH) gratings serve as cross-dispersing elements for separate spectrograph arms covering the H and K bands. On the 2.7m Harlan J. Smith telescope at the McDonald Observatory, the slit size is 1? x 15? and the plate scale is 0.27? pixel. The spectrograph employs two 2048 x 2048 pixel Teledyne Scientific and Imaging HAWAII-2RG detectors with SIDECAR ASIC cryogenic controllers. The instrument includes four subsystems; a calibration unit, an input relay optics module, a slit-viewing camera, and nearly identical H and K spectrograph modules. The use of a silicon immersion grating and a compact white pupil design allows the spectrograph collimated beam size to be only 25mm, which permits a moderately sized (0.96m x 0.6m x 0.38m) rectangular cryostat to contain the entire spectrograph. The fabrication and assembly of the optical and mechanical components were completed in 2013. We describe the major design characteristics of the instrument including the system requirements and the technical strategy to meet them. We also present early performance test results obtained from the commissioning runs at the McDonald Observatory.

Park, Chan; Jaffe, Daniel T.; Yuk, In-Soo; Chun, Moo-Young; Pak, Soojong; Kim, Kang-Min; Pavel, Michael; Lee, Hanshin; Oh, Heeyoung; Jeong, Ueejeong; Sim, Chae Kyung; Lee, Hye-In; Nguyen Le, Huynh Anh; Strubhar, Joseph; Gully-Santiago, Michael; Oh, Jae Sok; Cha, Sang-Mok; Moon, Bongkon; Park, Kwijong; Brooks, Cynthia; Ko, Kyeongyeon; Han, Jeong-Yeol; Nah, Jakyoung; Hill, Peter C.; Lee, Sungho; Barnes, Stuart; Yu, Young Sam; Kaplan, Kyle; Mace, Gregory; Kim, Hwihyun; Lee, Jae-Joon; Hwang, Narae; Park, Byeong-Gon

2014-07-01

77

In-flight calibration of the Chandra high-energy transmission grating spectrometer  

Microsoft Academic Search

We present results from in-flight calibration of the High Energy Transmission Grating Spectrometer (HETGS) on the Chandra X-ray Observatory. Basic grating assembly parameters such as orientation and average grating period were measured using emission line sources. These sources were also used to determine the locations of individual CCDs within the flight detector. The line response function (LRF) was modeled in

Herman L. Marshall; Daniel Dewey; Kazunori Ishibashi

2004-01-01

78

Calibration of an extreme-ultraviolet transmission grating spectrometer with synchrotron radiation  

Microsoft Academic Search

The responsivity of an extreme-ultraviolet transmission grating spectrometer with silicon photodiode detectors was measured with synchrotron radiation. The spectrometer was designed to record the absolute radiation flux in a wavelength bandpass centered at 30 nm. The transmission grating had a period of 200 nm and relatively high efficiencies in the 11 and the 21 diffraction orders that were dispersed on

John F. Seely; Charles M. Brown; Glenn E. Holland; Frederick Hanser; John Wise; James L. Weaver; Raj Korde; Rodney A. Viereck; Richard Grubb; Darrell L. Judge

2001-01-01

79

Initial Results From The Chandra High Energy Transmission Grating Spectrometer  

NASA Technical Reports Server (NTRS)

The High Energy Transmission Grating Spectrometer (HETGS) on the Chandra X-ray Observatory provides spectral resolving powers of 200-1000 over the range 0.4-8.0 keV (1.5-30 A) with effective area of 2-200 square centimeters. Initial observations during the activation and calibration phases of the mission show that the HETGS is performing as predicted prior to Chandra launch. The talk presented very preliminary results that illustrate the power of the HETGS for performing detailed studies of a wide range of celestial sources, including plasma diagnostics. This written version gives a brief summary of that talk with examples of preliminary spectra of Capella, the Crab pulsar, SS433 and the SNR E0102-72.

Canizares, C. R.; Davis, D. S.; Dewey, D.; Flanagan, K. A.; Houck, J.; Huenemoerder, D. P.; Marshall, H. L.; Schattenburg, M. L.; Schulz, N. S.; Wise, M.

2000-01-01

80

Next Generation Grating Spectrometer Sounders for LEO and GEO  

NASA Technical Reports Server (NTRS)

AIRS and MODIS are widely used for weather, climate, composition, carbon cycle, cross-calibration, and applications. The community asking for new capability in the 2020 timeframe, capabilities desired: (1) Hyperspectral UV to LWIR, High Spatial ?1km IFOV (2) Maximize Synergies of Solar Reflected and IR. Synergies with OCO-2. We expect more users and applications of next gen LEO IR Sounder than GEO. These include: weather, climate, GHG monitoring, aviation, disaster response. There is a new direction for imagers and sounders: (1) Separate Vis/NIR/SWIR from MWIR/LWIR instruments reduces technology risk and complexity. (2) Expect Costs to be lower than CrIS & VIIRS Some additional ideas to reduce costs include: (1) minimum set of requirements (2) mini-grating spectrometers. supports constellation for higher revisit (3) new technology to reduce instrument size (large format fpa's) (4) hosted payloads

Pagano, Thomas S.

2011-01-01

81

Design of a novel transmission-grating spectrometer for soft X-ray emission studies  

Microsoft Academic Search

The design of a transmission-grating spectrometer for high-resolution soft X-ray emission studies has been proposed. It is different from conventional types of soft X-ray emission spectrometers; that is, the spectrometer has a Wolter type I mirror, a free-standing transmission grating, and a back-illuminated CCD. A high collection angle up to 1.510?3sr is achieved by utilizing the Wolter mirror as a

Takaki Hatsui; Hiroyuki Setoyama; Eiji Shigemasa; Nobuhiro Kosugi

2005-01-01

82

A simple scanning spectrometer based on a stretchable elastomeric reflective grating  

SciTech Connect

We report a scanning optical spectrometer based on the use of a stretchable elastomeric reflective grating. The grating is obtained by supersonic cluster beam implantation of silver nanoparticles on polydimethylsiloxane previously grooved by molding to create a replica of a commercial digital versatile disk grating. The use of a stretchable grating allows the spectrometer spanning the whole optical wavelength range by solely extending the diffraction element by more than 100% of its original dimensions. The stretchable reflective optical grating shows excellent performances and stability upon thousands of stretching cycles. The use of this elastomeric element makes the optical layout and the mechanics of the spectrometer extremely simple and advantageous for those applications where spectral resolution is not a major requirement. As a proof of principle, we present the absorption spectrum of Rhodamine B in solution obtained by our spectrometer and compared to commercial instruments.

Ghisleri, C.; Milani, P., E-mail: paolo.milani@mi.infn.it [CIMAINA and Dipartimento di Fisica, Universit di Milano, via Celoria 16, 20133 Milano (Italy); WISE srl, Piazza Duse 2, 20122 Milano (Italy); Potenza, M. A. C.; Bellacicca, A. [CIMAINA and Dipartimento di Fisica, Universit di Milano, via Celoria 16, 20133 Milano (Italy); Ravagnan, L. [WISE srl, Piazza Duse 2, 20122 Milano (Italy)

2014-02-10

83

[EUV flat field grating spectrometer and performance measurement].  

PubMed

A high-resolution extreme ultraviolet (EUV) spectrometer has been developed to diagnose the magnetically confined plasmas. A holographic spherical varied line spacing concave grating which provides a flat focal plane is used as the diffraction element working with the grazing incidence angle of 3 degrees. The nominal groove density is 1200 lines x mm(-1). A deeply cooled back-illuminated CCD camera is used as the spectra detector and a mechanical shutter is used to control the time of exposure. It covers the wavelength range of 5-50 nm with the CCD cameral moving along the spectra focal plane to cover different wavelength range interested. Spectrometer design is presented and it was tested by a Penning discharge light source. By the wavelength calibration, the actual parameters of the optical system were calculated and the wavelength accuracy is 0.003 nm. Results show that the spectral resolution is about 0.015 nm at 20 nm with the width of entrance slit opened at 30 microm, which agrees with the design goal. PMID:23156796

Du, Xue-wei; Shen, Yong-cai; Li, Chao-yang; An, Ning; Shi, Yue-jiang; Wang, Qiu-ping

2012-08-01

84

A liquid-helium-cooled grating spectrometer for far infrared astronomical observations  

Microsoft Academic Search

A liquid-helium-cooled grating spectrometer has been developed for low-resolution far-infrared spectrometric measurements of astronomical sources conducted by the 30-cm NASA Lear Jet telescope. Simple MOSFET coupled transimpedance preamplifiers were adopted for the spectrometer design. The infrared spectrometer has resolving powers from 10 to 150 over the wavelength range from 45 to 115 microns.

J. R. Houck; D. Ward

1979-01-01

85

Development of a critical-angle transmission grating spectrometer for the International X-Ray Observatory  

E-print Network

We present a high-resolution soft x-ray grating spectrometer concept for the International X-Ray Observatory (IXO) that meets or exceeds the minimum requirements for effective area (> 1, 000 cm[superscript 2] for E < 1 ...

Smith, Matthew

86

Integrated arrayed waveguide grating spectrometer for on-chip optical coherence tomography  

Microsoft Academic Search

A silicon oxynitride based arrayed waveguide grating spectrometer was designed for on-chip spectral-domain optical coherence tomography systems. Transmission measurement results are promising for miniaturizing the current optical coherence tomography systems through integrated optics.

I. Akca; N. Ismail; F. Sun; V. D. Nguyen; J. Kalkman; T. G. van Leeuwen; A. Driessen; K. Worhoff; M. Pollnau; R. M. de Ridder

2010-01-01

87

A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating  

SciTech Connect

There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8 m and capable of 10{sup 5} resolving power.

Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA94720 (United States)

2010-06-23

88

A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating  

SciTech Connect

There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8m and capable of 10{sup 5} resolving power.

Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

2010-01-31

89

A high-resolution grating spectrometer for the infra-red region  

Microsoft Academic Search

A grating spectrometer designed on an Ebert mounting has been constructed which, with suitable photoconductive cells and a 6 6 in. N.P.L. grating, gives a resolution of 0.1 cm-1 in the range 6000 to 1700 cm-1. It covers the region 600 to 10 000 cm-1 with a single grating and is as simple to operate as a conventional prism

M A Ford; W C Price; G R Wilkinson

1958-01-01

90

Compact Reflective Imaging Spectrometer Design Utilizing An Immersed Grating And Anamorphic Mirror  

DOEpatents

A compact imaging spectrometer comprising an entrance slit, an anamorphic mirror, a grating, and a detector array. The entrance slit directs light to the anamorphic mirror. The anamorphic mirror receives the light and directs the light to the grating. The grating receives the light from the anamorphic mirror and defracts the light back onto the anamorphic mirror. The anamorphic mirror focuses the light onto a detector array.

Lerner, Scott A. (Corvalis, OR)

2006-01-10

91

Soft X-ray response of a CCD with a grating spectrometer  

Microsoft Academic Search

We calibrate the X-ray imaging spectrometers, which are CCD cameras installed on the ASTRO-E satellite, by using dispersed continuous soft X-rays from a grating spectrometer. We obtained the signal-pulse height and energy-resolution as a function of X-ray energies continuously. However, the wings of the line spread function of the grating distorts the center of the signal-pulse height derived by a

M. Shouho; K. Katayama; H. Katayama; T. Kohmura; H. Tsunemi; S. Kitamoto; K. Hayashida; E. Miyata; K. Hashimotodani; K. Yoshita; K. Koyama; G. Ricker; M. W. Bautz; R. Foster; S. Kissel

1999-01-01

92

High resolution Florida IR silicon immersion grating spectrometer and an M dwarf planet survey  

NASA Astrophysics Data System (ADS)

We report the system design and predicted performance of the Florida IR Silicon immersion grating spectromeTer (FIRST). This new generation cryogenic IR spectrograph offers broad-band high resolution IR spectroscopy with R=72,000 at 1.4-1.8 ?m and R=60,000 at 0.8-1.35 ?m in a single exposure with a 2kx2k H2RG IR array. It is enabled by a compact design using an extremely high dispersion silicon immersion grating (SIG) and an R4 echelle with a 50 mm diameter pupil in combination with an Image Slicer. This instrument is operated in vacuum with temperature precisely controlled to reach long term stability for high precision radial velocity (RV) measurements of nearby stars, especially M dwarfs and young stars. The primary technical goal is to reach better than 4 m/s long term RV precision with J<9 M dwarfs within 30 min exposures. This instrument is scheduled to be commissioned at the Tennessee State University (TSU) 2-m Automatic Spectroscopic Telescope (AST) at Fairborn Observatory in spring 2013. FIRST can also be used for observing transiting planets, young stellar objects (YSOs), magnetic fields, binaries, brown dwarfs (BDs), ISM and stars. We plan to launch the FIRST NIR M dwarf planet survey in 2014 after FIRST is commissioned at the AST. This NIR M dwarf survey is the first large-scale NIR high precision Doppler survey dedicated to detecting and characterizing planets around 215 nearby M dwarfs with J< 10. Our primary science goal is to look for habitable Super-Earths around the late M dwarfs and also to identify transiting systems for follow-up observations with JWST to measure the planetary atmospheric compositions and study their habitability. Our secondary science goal is to detect and characterize a large number of planets around M dwarfs to understand the statistics of planet populations around these low mass stars and constrain planet formation and evolution models. Our survey baseline is expected to detect ~30 exoplanets, including 10 Super Earths, within 100 day periods. About half of the Super-Earths are in their habitable zones and one of them may be a transiting planet. The AST, with its robotic control and ease of switching between instruments (in seconds), enables great flexibility and efficiency, and enables an optimal strategy, in terms of schedule and cadence, for this NIR M dwarf planet survey.

Ge, Jian; Powell, Scott; Zhao, Bo; Wang, Ji; Fletcher, Adam; Schofield, Sidney; Liu, Jian; Muterspaugh, Matthew; Blake, Cullen; Barnes, Rory

2012-09-01

93

Design of optical system for spectrometer involving a volume phase holographic transmission grating  

NASA Astrophysics Data System (ADS)

At present, spectrometer has popularly being used into varieties of fields including environment, food, medical health monitoring and metal industry because it has the advantages of noninvasive, high efficient and convenient etc. The performance of the spectrometer is determined by its optical system. Normally, according to the apparatus and principle of splitting-light, optical system of spectrometer can be classified into several categories, for example, filter-typed, dispersion typed, Fourier transform typed and acousto-optic tunable typed. The grating typed optical system has been popularly used into the spectrometer due to the features of higher diffraction efficiency, resolution and dispersion rate etc. In the grating-typed optical system, although the traditional plane and concave grating have usually been used into some spectrometers, some disadvantages of them still limit their applications, such as, large aberration, worse spectral flatness and low deficiency, etc. In this paper, to overcome these disadvantages of the traditional plane and concave grating, a novel optical system for spectrometer (OSS) based on volume phase holographic transmission (VPHT) grating was designed. For this novel grating, its manufacture and theories were investigated, and its diffraction efficiency was firstly numerically simulated according to different parameters. In order to prove the feasibility of this designed OSS, the spectral calibration experiment was performed and the spectral resolution reached 2nm.

Ren, Zhong; Liu, Guodong; Huang, Zhen

2014-08-01

94

Passive Spectroscopy Bolometers, Grating- And X-ray Imaging Crystal Spectrometers  

SciTech Connect

This tutorial gives a brief introduction into passive spectroscopy and describes the working principles of bolometers, a high-resolution grating spectrometer, and a novel X-ray imaging crystal spectrometer, which is also of particular interest for profile measurements of the ion temperature and plasma rotation velocity on ITER and future burning plasma experiments.

Bitter, M.; Hill, K. W.; Scott, S.; Paul, S. [Princeton Plasma Physics Laboratory, Princeton, NJ, 08543 (United States); Ince-Cushman, A.; Reinke, M.; Rice, J. E. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Beiersdorfer, P.; Gu, M. F. [Lawrence Livermore national Laboratory, Livermore, CA 94550-9234 (United States); Lee, S. G. [Korea Basic Science Institute, Taejeon 305-333 (Korea, Republic of); Broennimann, Ch.; Eikenberry, E. F. [Paul Scherrer Institut, CH5232 Villigen-PSI (Switzerland)

2008-03-12

95

Passive Spectroscopy Bolometers, Grating- And X-Ray Imaging Crystal Spectrometers  

SciTech Connect

This tutorial gives a brief introduction into passive spectroscopy and describes the working principles of bolometers, a high-resolution grating spectrometer, and a novel X-ray imaging crystal spectrometer, which is of particular interest for profile measurements of the ion temperature and plasma rotation velocity on ITER and future burning plasma experiments.

Bitter, M; Hill, K W; Scott, S; Paul, S; Ince-Cushmann, A; Reinke, M; Rice, J; Beiersdorfer, P; Gu, M F; Lee, S G; Broennimann, C; Eikenberry, E F

2007-11-07

96

Numerical optimization of spherical variable-line-spacing grating X-ray spectrometers.  

PubMed

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and spectrometer geometry. The analysis is illustrated with optical design of a model spectrometer to deliver a resolving power above 20400 at a photon energy of 930?eV (Cu L-edge). With this energy taken as reference, the VLS coefficients are optimized to cancel the lineshape asymmetry (mostly from the coma aberrations) as well as minimize the symmetric aberration broadening at large grating illuminations, dramatically increasing the aberration-limited vertical acceptance of the spectrometer. For any energy away from the reference, corrections to the entrance arm and light incidence angle on the grating are evaluated to maintain the exactly symmetric lineshape. Furthermore, operational modes when these corrections are coordinated are evaluated to maintain either energy-independent focal curve inclination or maximal aberration-limited spectrometer acceptance. The results are supported by analytical evaluation of the coma term of the optical path function. This analysis thus gives a recipe for designing a high-resolution spherical VLS grating spectrometer operating with negligible aberrations at large acceptance and over an extended energy range. PMID:21335898

Strocov, V N; Schmitt, T; Flechsig, U; Patthey, L; Chiuzb?ian, G S

2011-03-01

97

Fundamental limits to slow-light arrayed-waveguide-grating spectrometers.  

PubMed

We present an analytical model that describes the limiting spectral performance of arrayed-waveguide-grating (AWG) spectrometers that incorporate slow-light methods. We show that the loss-limited spectral resolution of a slow-light grating-based spectrometer scales as the loss-group-index ratio of the waveguide array. We further show that one can achieve a spectral resolution of a few GHz using currently available slow-light photonic crystal waveguides while greatly shrinking the on-chip footprint of the spectrometer. PMID:23546160

Shi, Zhimin; Boyd, Robert W

2013-03-25

98

Development of two-grating spectrometer for the charge exchange spectroscopy system on KSTAR  

SciTech Connect

The charge exchange spectroscopy (CES) system on Korea Superconducting Tokamak Advanced Research (KSTAR) was installed last year and had been applied to measure the C VI ion temperature and rotation velocity profiles. The ion temperature and rotation velocity profiles had been estimated from the C VI 5290.5 A (n = 8-7) charge-exchange spectrum signal measured by a Czerny-Turner type spectrometer and a thinned back-illuminated charge coupled device (CCD) camera. However, the Czerny-Turner type spectrometer used for the KSTAR CES system showed so low signal to noise ratio for KSTAR plasmas in the 2010 experimental campaign that the time resolution of the CES system had been limited to 100 ms due to the increased exposure time of the attached CCD camera. Then, new two-grating spectrometer had been developed in order to improve the time resolution of the CES system. The spectrometer consists of two gratings (1200 g/mm and 1800 g/mm each) with additive configuration, concave mirrors (f = 50 cm), and a cylindrical lens (f = 50 cm). The time resolution of the CES system increases by a factor of 2-4 with the two-grating spectrometer. The C VI ion temperature and rotation velocity profiles obtained by the two-grating spectrometer are compared to those by Czerny-Turner type spectrometer in this paper.

Lee, Hyungho [Department of Nuclear Fusion and Plasma Science, University of Science and Technology (UST), Gajungro 217, Daejeon 305-350 (Korea, Republic of); National Fusion Research Institute (NFRI), Gwahangno113, Daejeon 305-333 (Korea, Republic of); Song, Eun-ji; Oh, Soo-ghee [Division of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of); Park, Young-dong [Department of Chemistry, Ajou University, Suwon 443-749 (Korea, Republic of); Ko, Won-Ha [National Fusion Research Institute (NFRI), Gwahangno113, Daejeon 305-333 (Korea, Republic of)

2011-06-15

99

Design and optimization of optical system for a spectrometer based on VPHT grating  

NASA Astrophysics Data System (ADS)

To overcome some drawbacks of optical system for plane and concave grating typed spectrometer, including serious aberration, worse spectral fatness and low diffraction efficiency etc, a novel optical system based on volume phase holographic transmission (VPHT) grating was designed in this paper. For this grating, its manufacture and theories were investigated, and its diffraction efficiency was numerically simulated. In order to validate this designed optical system, the spectral scaling experiment was performed and the spectral resolution reached 2nm, the calibration equation between the scaling wavelength and corresponding pixels was gotten via linear least square fitting algorithm. It was proved that the wavelength absolute value reach 1.7nm on the wavelength of 635nm, the root-mean-square error (RMSE) of full scaling wavelengths was 0.3nm. These experimental results illustrated that the design of the optical system for spectrometer based on VPHT grating is good.

Ren, Zhong; Liu, Guodong; Huang, Zhen; Xiong, Zhihua

2014-11-01

100

A Novel Active Grating Monochromator - Active Grating Spectrometer Beamline System for Inelastic Soft-X-ray Scattering Experiments  

SciTech Connect

By using two aspherical variable-line-space active gratings and applying the energy compensation principle, we have designed a very efficient active grating monochromator -- active grating spectrometer (AGM-AGS) beamline system for the photon demanding inelastic soft-x-ray scattering experiments. During the energy scan, the defocus and coma aberrations of the AGM can be completely eliminated to make the focal point fixed at the sample position and to maintain high spectral resolution for the entire spectral range. The AGS, which has an optical system identical to that of the AGM, but positioned reversely along the optical path, collects the photons emitted from the sample with a nearly identical energy spread as the AGM and focus them onto a position sensitive detector located at the exit slit position. The ray tracing results show that the efficiency of the AGM-AGS is two orders of magnitudes higher than that of conventional design while maintaining a very high spectral resolution.

Fung, H.S.; Chen, C.T.; Huang, L.J.; Chang, C.H.; Chung, S.C.; Wang, D.J.; Tseng, T.C.; Tsang, K.L. [National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan (China)

2004-05-12

101

Hinge spectrometer - A grating Fabry-Perot instrument for far-infrared/submillimeter spectroscopy in space  

NASA Technical Reports Server (NTRS)

A compact submillimeter spectrometer can be constructed through the use of a combination of grating and Fabry-Perot techniques. The instrument has only one moving part, a grating that pivots about an accurately placed hinge. The entire optical train is cooled to liquid helium temperature for low-background low-noise operation and is designed for use in astronomical observations from aircraft, balloons, or space vehicles. Resolving power R about 20,000 at about 150 microns is demonstrated.

Harwit, Martin; Fuller, Charles; Viscuso, Paul J.; Stacey, Gordon J.

1987-01-01

102

Development of a novel spectrometer for tongue coating analyzer based on volume holography transmissive grating  

NASA Astrophysics Data System (ADS)

Tongue diagnosis (TD) is an important diagnostic methods in the traditional Chinese medicine (TCM). According to the viewpoint of TCM, the changes of the tongue coating (TC) can reflect the pathological state of the patient. And the nature or severity of diseasec can be determined by observing the TC. Over the years, TD is mostly depended on the subjective experience of the Chinese physician. And the diagnostic results will be impacted by.some factors, e.g. the different light sources or environmental brightness. Recently years, the method of digital image processing has been used into the TD. But its application is limited by the complicated algorithm, time-consuming and big error, etc. Therefore, a novel tongue coating analyzer(TCA) is designed in this paper. Meanwhile, a novel spectrometer for TCA based on the volume holography transmissive (VHT) grating is developed. In this spectrometer, since the VHT grating doesn't produce the stray-light due to the absence of the grooves of classical surface-embossed gratings, the VHT grating is used as the diffraction grating instead of the classical plane or concave grating. Experimental results show that the performances of the spectrometer for TCA have been improved by using the VHT grating, optimizing the light-path structure and software algorithm, etc. Compared with the others, this spectrometer for TCA has many advantages, such as, less diffraction, wider spectrum range, higher efficiency and resolution, etc. The spectrum range of the spectrometer for TCA can reach 300-1000nm, its resolution can reach 1nm and the optical density is larger than 3.

Ren, Zhong; Liu, Guodong; Dai, Longmin; Huang, Zhen; Zeng, Lvming

2010-11-01

103

The super-gratings: How to improve the limiting resolution of grating spectrometers  

Microsoft Academic Search

An array of two coplanar gratings gives rise to a single high-dispersion element, which is here called super-grating. The possibility of realizing practically a super-grating is analyzed from a theoretical point of view. It is shown that the most critical parameter, i.e. the phase matching between the two elements, may be satisfactorily adjusted using available micropositioning systems.

V. Mazzacurati; G. Ruocco

1990-01-01

104

Imaging extreme ultraviolet spectrometer employing a single toroidal diffraction grating - The initial evaluation  

NASA Technical Reports Server (NTRS)

The design and test results of a high-efficiency EUV imaging spectrometer employing a concave toroidal grating which is illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface are discussed. Photographic tests and initial photoelectric tests with a two-dimensional pulse-counting detector system demonstrate the excellent image quality of the grating at wavelengths near 600 A. Applications of the spectrometer for the study of nonsolar objects and solar regions (including the chromosphere, transition region, and corona) are considered.

Huber, M. C. E.; Timothy, J. G.; Morgan, J. S.; Lemaitre, G.; Tondello, G.

1988-01-01

105

[Study on far ultraviolet imaging spectrometer with grating dispersion for atmosphere remote sensing].  

PubMed

The far ultraviolet imaging spectrometer with grating dispersion is mainly used in the detection of the ionosphere, thermosphere, auroral zone and glow zone. It is important for the study and application of the remote sensing of atmosphere in China. We designed two optical systems for the far ultraviolet imaging spectrometer, and obtained the plane grating structure prototype based on the principles of nadir and limb atmospheric sounding. The prototype working at the waveband of 120-180 nm consists of an off-axis parabolic mirror and an advanced Czerny-Turner spectral imaging system. The far ultraviolet response back-illuminating CCD is adopted as the detector. The corresponding experiment system was built to calibrate the basic performances of the spectrometer prototype. The spectral and spatial resolutions are 2 nm and 0.5 mrad respectively. The far ultraviolet imaging spectrometer prototype plays an important role in the study and application of atmospheric remote sensing. PMID:22582666

Yu, Lei; Wang, Shu-rong; Lin, Guan-yu; Qu, Yi; Wang, Long-qi

2012-03-01

106

Transmission grating based extreme ultraviolet imaging spectrometer for time and space resolved impurity measurements.  

PubMed

A free standing transmission grating based imaging spectrometer in the extreme ultraviolet range has been developed for the National Spherical Torus Experiment (NSTX). The spectrometer operates in a survey mode covering the approximate spectral range from 30 to 700 A? and has a resolving capability of ??/? on the order of 3%. Initial results from space resolved impurity measurements from NSTX are described in this paper. PMID:21034035

Kumar, Deepak; Stutman, Dan; Tritz, Kevin; Finkenthal, Michael; Tarrio, Charles; Grantham, Steven

2010-10-01

107

Transmission grating based extreme ultraviolet imaging spectrometer for time and space resolved impurity measurements  

SciTech Connect

A free standing transmission grating based imaging spectrometer in the extreme ultraviolet range has been developed for the National Spherical Torus Experiment (NSTX). The spectrometer operates in a survey mode covering the approximate spectral range from 30 to 700 A and has a resolving capability of {delta}{lambda}/{lambda} on the order of 3%. Initial results from space resolved impurity measurements from NSTX are described in this paper.

Kumar, Deepak; Stutman, Dan; Tritz, Kevin; Finkenthal, Michael [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 (United States); Tarrio, Charles; Grantham, Steven [Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

2010-10-15

108

Z-Spec: a broadband millimeter-wave grating spectrometer: design, construction, and first cryogenic measurements  

Microsoft Academic Search

We present the design, integration, and first ryogenic testing of our new broad-band millimeter-wave spectrometer, Z-Spec. Z-Spec uses a novel architecture called WaFIRS (Waveguide Far-IR Spectrometer), which employs a curved diffraction grating in a parallel-plate waveguide propagation medium. The instrument will provide a resolving power betwee 200 and 350 across an instantaneous bandwidth of 190-310 GHz, all packaged within a

C. Matt Bradford; Peter A. R. Ade; James E. Aguirre; James J. Bock; Mark Dragovan; Lionel Duband; Lieko Earle; Jason Glenn; Hideo Matsuhara; Bret J. Naylor; Hien T. Nguyen; Minhee Yun; Jonas Zmuidzinas

2004-01-01

109

Study of Planck's Law with a Small USB Grating Spectrometer  

ERIC Educational Resources Information Center

In this paper an experiment to study Planck's radiation law is presented. The spectra of a heated furnace and of a halogen lamp under various conditions were measured with a small USB grating spectrometer and fitted using Planck's law. The temperature determined from the fit was then compared with the results of comparative temperature

Navratil, Zdenek; Dosoudilova, Lenka; Jurmanova, Jana

2013-01-01

110

A Long Look at NGC 3783 with the XMM-Newton Reflection Grating Spectrometer  

Microsoft Academic Search

A long 280 ks observation of the Seyfert 1 galaxy NGC 3783 with XMM-Newton is reported. We focus on the oxygen line complex between 17 and 24 as measured with the Reflection Grating Spectrometer. Accurate absorption column densities and emission-line fluxes are obtained. We explore several options for the geometry and physical form of the emitting and absorbing gas.

Ehud Behar; Andrew P. Rasmussen; Alexander J. Blustin; Masao Sako; Steven M. Kahn; Jelle S. Kaastra; Graziella Branduardi-Raymont; Katrien C. Steenbrugge

2003-01-01

111

Grating arrays for high--throughput soft X-ray spectrometers A. Rasmussena A. Aquilab j BookbinderC C. Chang E. Gulliksonb R. Heilmanne  

E-print Network

Grating arrays for high--throughput soft X-ray spectrometers A. Rasmussena A. Aquilab j Bookbinder keY, or 6 Angstroms. Consequently, grating spectrometers offer the current, best means by which describe grating spectrometer design candidates for the future mission Constellation--X, and how

112

JOT JRNAL DE PHYSIQUE Colloque C 2, suppliment GU no3-4, Tome 28, mars-avril1967, page C 2 -44 A MULTIPLEX GRATING SPECTROMETER  

E-print Network

A MULTIPLEX GRATING SPECTROMETER by J. F. GRAINGER,J. RINGand J. H. STELL Department of Applied Physics interferomstre a deux ondes sont discutes. Abstract. - A near infra-red grating spectrometer for telescope use GRATING SPECTROMETER C 2 - 4 5 As is well known [2], if cp is the flux through a spec- trometer whose

Paris-Sud XI, Université de

113

In-Flight Calibration of the Chandra High Energy Transmission Grating Spectrometer  

E-print Network

We present results from in-flight calibration of the High Energy Transmission Grating Spectrometer (HETGS) on the Chandra X-ray Observatory. Basic grating assembly parameters such as orientation and average grating period were measured using emission line sources. These sources were also used to determine the locations of individual CCDs within the flight detector. The line response function (LRF) was modeled in detail using an instrument simulator based on pre-flight measurements of the grating alignments and periods. These LRF predictions agree very well with in-flight observations of sources with narrow emission lines. Using bright continuum sources, we test the consistency of the detector quantum efficiencies by comparing positive orders to negative orders.

Herman L. Marshall; Daniel Dewey; Kazunori Ishibashi

2003-09-03

114

Design of a flat field concave-grating-based micro-Raman spectrometer for environmental applications.  

PubMed

In order to simplify the design process of microfabricated concave gratings, simplified algorithms for fast characterization of the concave grating were developed. These algorithms can be used to assist system designers using ray-tracing software in the determination of optimum design parameters considering the requirements and restrictions for specific applications. According to the algorithms, it is feasible to design a flat field microconcave grating with a 4 mm grating radius as a key component in a micro-Raman spectrometer system for inline environmental monitoring applications. This microspectrometer operates over the spectral wavelength band from 785 nm to 1000 nm and has a spectral resolution of 2 nm at 900 nm. The total size of the system is 1 mm4 mm3.7 mm, making it one of the smallest for this wavelength range and spectrum resolution. PMID:23033103

Li, Zhiyun; Deen, M Jamal; Fang, Qiyin; Selvaganapathy, P R

2012-10-01

115

Varied-space grazing incidence gratings in high resolution scanning spectrometers  

SciTech Connect

We discuss the dominant geometrical aberrations of a grazing incidence reflection grating and new techniques which can be used to reduce or eliminate them. Convergent beam geometries and the aberration correction possible with varied groove spacings are each found to improve the spectral resolution and speed of grazing incidence gratings. In combination, these two techniques can result in a high resolution (lambda/..delta..lambda > 10/sup 4/) monochromator or scanning spectrometer with a simple rotational motion for scanning wavelength or selecting the spectral band. 21 refs., 4 figs.

Hettrick, M.C.; Underwood, J.H.

1986-10-01

116

Design of a grating spectrometer from a 1:1 Offner mirror system  

NASA Technical Reports Server (NTRS)

A 1:1 Offner mirror system is modified to work as a grating spectrometer for the infrared by placing a grating on the secondary convex mirror of the system. Slight adjustment of the configuration combined with tilt of the secondary provide the necessary degrees of freedom to correct for astigmatism of the system. Additional control may be obtained by using a holographic optical element (HOE), constructed to add necessary compensating aberrations. Details of the best configuration and the limitations of performance are presented.

Kwo, Deborah; Lawrence, George; Chrisp, Michael

1987-01-01

117

Integrated X-ray testing of the electro-optical breadboard model for the XMM reflection grating spectrometer  

SciTech Connect

X-ray calibration of the Electro-Optical Breadboard Model (EOBB) of the XXM Reflection Grating Spectrometer has been carried out at the Panter test facility in Germany. The EOBB prototype optics consisted of a four-shell grazing incidence mirror module followed by an array of eight reflection gratings. The dispersed x-rays were detected by an array of three CCDs. Line profile and efficiency measurements where made at several energies, orders, and geometric configurations for individual gratings and for the grating array as a whole. The x-ray measurements verified that the grating mounting method would meet the stringent tolerances necessary for the flight instrument. Post EOBB metrology of the individual gratings and their mountings confirmed the precision of the grating boxes fabrication. Examination of the individual grating surface`s at micron resolution revealed the cause of anomalously wide line profiles to be scattering due to the crazing of the replica`s surface.

Bixler, J.V.; Craig, W.; Decker, T. [Lawrence Livermore National Lab., CA (United States); Aarts, H.; Boggende, T. den; Brinkman, A.C. [Space Research Organization Netherlands, Utrecht (Netherlands); Burkert, W.; Brauninger, H. [Max-Planck Institute fur Extraterrestische Physik, Testanlage (Germany); Branduardi-Raymont, G. [Univ. College London (United Kingdom); Dubbeldam, L. [Space Research Organization Netherlands, Leiden (Netherlands)] [and others

1994-07-12

118

Dispersive element based on grating and tunable Fabry-Perot filter in miniature spectrometer.  

PubMed

We present a new design for the integration of a tunable Fabry-Perot (FP) filter and the grating etched on top of the cavity (IGFP) in the miniature spectrometer. It is based on the predispersion of the grating with the capacity of spatial separation of the spectral component and filter effect of the tunable FP filter. The free spectral range (FSR) of the IGFP is determined by the FSR of the grating, and its resolution depends on the filtering capacity of the FP filter. In the experiment, the high-resolution and wavelength scanning process of the IGFP were demonstrated with a narrowband and broadband light source, respectively. The results of the sub-nanometer resolution agree well with those from a commercial optical spectrum analyzer. Further, the IGFP provides an effective approach to solve the problem of the decrease of spectral resolution in the miniaturization process. PMID:24513992

Shi, Zhendong; Fang, Liang; Zhou, Chongxi

2014-01-01

119

Calibration of a high resolution grating soft x-ray spectrometer  

SciTech Connect

The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10-50 A waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer. The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes, and x-ray sources.

Magee, E. W.; Dunn, J.; Brown, G. V.; Beiersdorfer, P. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); Cone, K. V.; Park, J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); Department of Applied Sciences, University of California, Davis, California 95616 (United States); Porter, F. S.; Kilbourne, C. A.; Kelley, R. L. [Goddard Space Flight Center, NASA, Greenbelt, Maryland 20770 (United States)

2010-10-15

120

Combined optical dispersion by prism and arrayed waveguide grating with multiple diffraction orders for Raman spectrometer  

NASA Astrophysics Data System (ADS)

A compact dispersive device for Raman spectrometer was proposed to achieve a spectrum resolution below 0.55 nm in the spectral range of 800 to 1000 nm. A 41-channel arrayed waveguide grating (AWG) with eleven different diffraction orders was designed, and each output channel of this AWG contained eleven light signals with periodically 20 nm spaced wavelength. These signals were further cross-dispersed by a prism, and finally form a 41 11 spots array on a CCD. The detailed theoretical analysis and simulation of this dispersive device were introduced in this paper. Compared with commercial dispersive modules composed of grating, lens, and mirrors, the proposed structure is able to provide a compact device with higher spectrum resolution, which is attractive for handheld Raman spectrometer.

Cheng, Ya-qin; Sun, Hong-da; Wu, Zhao; Deng, Sheng-feng; Lu, Miao

2014-09-01

121

A Low Cost and High Capability X-ray Grating Spectrometer on the ISS  

NASA Astrophysics Data System (ADS)

We present the scientific motivation for a X-ray grating spectrometer mission to be deployed on the International Space Station. The primary goals of this mission would be to address the "missing baryon" problem, finally detecting and characterizing the Warm-Hot Intergalactic Medium that should exist as filaments threading through intergalactic space. The mission parameters are similar to those of the IXO X-ray Grating Spectrometer of R=3000 and 1000 sq. cm at 0.5 keV and a bandpass from 0.3-1.0 keV. This would also enable studies of feedback from supermassive black holes, stellar coronae, and the structure of the interstellar medium and halo of the Milky Way, amongst other goals.

Smith, Randall K.; Bookbinder, Jay A.; Brickhouse, Nancy S.; Foster, Adam; Petre, Robert; Ptak, Andrew; McEntaffer, Randall L.; Bautz, Mark W.; Burrows, David N.; Falcone, Abraham; Bregman, Joel N.; Wilms, Jrn; Willingale, Richard

2014-06-01

122

Arcus: A Low Cost and High Capability X-ray Grating Spectrometer on the ISS  

NASA Astrophysics Data System (ADS)

We present the scientific motivation for Arcus, a proposed X-ray grating spectrometer SMEX mission to be deployed on the International Space Station. The primary goals of this mission are to understand structure formation via the imprint it leaves on hot gas in and around galaxies and clusters, to characterize feedback from supermassive black holes by observing highly ionized material coming from these sources, and to study the stellar life cycle from formation through death. The mission parameters are similar to those of the IXO X-ray Grating Spectrometer, with of R>2500 and > 600 sq. cm around the crucial O VII and O VIII lines, and a bandpass from 8-52 A (0.25-1.5 keV).

Smith, Randall K.

2014-08-01

123

An infrared high resolution silicon immersion grating spectrometer for airborne and space missions  

NASA Astrophysics Data System (ADS)

Broad-band infrared (IR) spectroscopy, especially at high spectral resolution, is a largely unexplored area for the far IR (FIR) and submm wavelength region due to the lack of proper grating technology to produce high resolution within the very constrained volume and weight required for space mission instruments. High resolution FIR spectroscopy is an essential tool to resolve many atomic and molecular lines to measure physical and chemical conditions and processes in the environments where galaxy, star and planets form. A silicon immersion grating (SIG), due to its over three times high dispersion over a traditional reflective grating, offers a compact and low cost design of new generation IR high resolution spectrographs for space missions. A prototype SIG high resolution spectrograph, called Florida IR Silicon immersion grating spectromeTer (FIRST), has been developed at UF and was commissioned at a 2 meter robotic telescope at Fairborn Observatory in Arizona. The SIG with 54.74 degree blaze angle, 16.1 l/mm groove density, and 50x86 mm2 grating area has produced R=50,000 in FIRST. The 1.4-1.8 um wavelength region is completely covered in a single exposure with a 2kx2k H2RG IR array. The on-sky performance meets the science requirements for ground-based high resolution spectroscopy. Further studies show that this kind of SIG spectrometer with an airborne 2m class telescope such as SOFIA can offer highly sensitive spectroscopy with R~20,000-30,000 at 20 to 55 microns. Details about the on-sky measurement performance of the FIRST prototype SIG spectrometer and its predicted performance with the SOFIA 2.4m telescope are introduced.

Ge, Jian; Zhao, Bo; Powell, Scott; Jiang, Peng; Uzakbaiuly, Berik; Tanner, David

2014-08-01

124

A far-infrared Fabry-Prot interferometer and grating spectrometer for balloon-borne astronomy  

Microsoft Academic Search

A far-infrared computer-controlled Fabry-Prot interferometer has been built for use on the UCL 60 cm stabilised balloon platform for the observation of fine structure and molecular lines at moderately high spectral resolution (lambda\\/deltalambda ? 1000). The interferometer is combined with a helium cooled grating spectrometer which allows operation anywhere in the 40-115 mum wavelength range whilst minimising the thermal background

G. Poulter; R. E. Jennings

1983-01-01

125

Multivariate Monte Carlo Methods for the Reflection Grating Spectrometers on XMM-Newton  

Microsoft Academic Search

We propose a novel multivariate Monte Carlo method as an efficient and\\u000aflexible approach to analyzing extended X-ray sources with the Reflection\\u000aGrating Spectrometer (RGS) on XMM Newton. A multi-dimensional interpolation\\u000amethod is used to efficiently calculate the response function for the RGS in\\u000aconjunction with an arbitrary spatially-varying spectral model. Several methods\\u000aof event comparison that effectively compare the

J. R. Peterson; J. G. Jernigan; S. M. Kahn

2004-01-01

126

Determining ngstrm's Turbidity Coefficients: An Analysis with a Wide-Range Grating Spectrometer  

Microsoft Academic Search

The dependence of ngstrom's turbidity parameters on the wavelength has been analyzed in the wavelength interval 0.450.70 ?m. Measurements of aerosol optical thicknesses in this range were obtained by a wide-range grating spectrometer with a resolution of ? 2.5 nm. Based on such measurements, two different methods for obtaining turbidity parameters have been validated and intercompared: (a) the ratio method

V. Cuomo; F. Esposito; G. Pavese; C. Serio

1993-01-01

127

Calibrated Time-Resolved Transmission Grating Spectrometer for the Study of Ultrafast X-Ray Sources  

Microsoft Academic Search

A transmission grating spectrometer has been coupled to a high-temporal-resolution soft x-ray streak camera for the study of picosecond laser-plasma x-ray sources. A procedure to deconvolve the overlapping contributions of diffraction orders and to calibrate the instrument has been established in order to obtain absolute time-resolved x-ray emission spectra in the 0.11.2 keV spectral region. The deconvolution and calibration techniques

J. F. Pelletier; M. Chaker; J. C. Kieffer

1996-01-01

128

Time-resolved x-ray transmission grating spectrometer for studying laser-produced plasmas  

Microsoft Academic Search

The development of a new time-resolved x-ray spectrometer is reported in which a free-standing x-ray transmission grating is coupled to a soft x-ray streak camera. The instrument measures continuous x-ray spectra with 20-psec temporal resolution and moderate spectral resolution (..delta..lambda> or =1 A) over a broad spectral range (0.1--5 keV) with high sensitivity and large information recording capacity. Its capabilities

N. M. Ceglio; R. L. Kauffman; A. M. Hawryluk; H. Medecki

1983-01-01

129

XMM-Newton Reflection Grating Spectrometer Observations of the Prototypical Starburst Galaxy M82  

Microsoft Academic Search

We present results from XMM-Newton Reflection Grating Spectrometer\\u000aobservations of the prototypical starburst galaxy M82. These high resolution\\u000aspectra represent the best X-ray spectra to date of a starburst galaxy. A\\u000acomplex array of lines from species over a wide range of temperatures is seen,\\u000athe most prominent being due to Lyman-alpha emission from abundant low Z\\u000aelements such as

Andrew M. Read; Ian R. Stevens

2002-01-01

130

Advanced statistical analysis of laser-induced breakdown spectroscopy data to discriminate sedimentary rocks based on Czerny-Turner and Echelle spectrometers  

NASA Astrophysics Data System (ADS)

The correct identification of rock types is critical for understanding the origins and history of any particular rock body. Laser-induced breakdown spectroscopy (LIBS) has developed into an excellent analytical tool for geological materials research because of its numerous technical advantages compared with traditional methods. The coupling of LIBS with advanced multivariate analysis has received increasing attention because it facilitates the rapid processing of spectral information to differentiate and classify samples. In this study, we collected LIBS datasets for 16 sedimentary rocks from Triassic strata in Sichuan Basin. We compared the performance of two types of spectrometers (Czerny-Turner and Echelle) for classification of rocks using two advanced multivariate statistical techniques, i.e., partial least squares discriminant analysis (PLS-DA) and support vector machines (SVMs). Comparable levels of performance were achievable when using the two systems in the best signal reception conditions. Our results also suggest that SVM outperformed PLS-DA in classification performance. Then, we compared the results obtained when using pre-selected wavelength variables and broadband LIBS spectra as variable inputs. They provided approximately equivalent levels of performance. In addition, the rock slab samples were also analyzed directly after being polished. This minimized the analysis time greatly and showed improvement of classification performance compared with the pressed pellets.

Zhu, Xiaoqin; Xu, Tao; Lin, Qingyu; Liang, Long; Niu, Guanghui; Lai, Hongjun; Xu, Mingjun; Wang, Xu; Li, Hua; Duan, Yixiang

131

Imaging spectrometer for high resolution measurements of stratospheric trace constituents in the ultraviolet  

Microsoft Academic Search

A high-resolution spectrometer has been developed for studies of minor constituents in the middle atmosphere at ultraviolet wavelengths. In particular, the instrument is intended for observations of upper stratospheric UV bands. The spectrometer has a slit width of 0.08 A obtained by means of an echelle grating and a cross-disperser grating. The image plane detector is an intensified CCD consisting

Marsha R. Torr; D. G. Torr

1988-01-01

132

The high energy transmission grating spectrometer for AXAF. [Advanced X-ray Astrophysics Facility  

NASA Technical Reports Server (NTRS)

Attention is given to a high energy transmission grating spectrometer that operates over the range 0.4-8 keV, giving resolving powers of 100-1000 and effective areas of 10-200 sq cm. The instrument, which is part of the MIT high resolution X-ray spectroscopy investigation, consists of a single array of grating facets of two types: medium energy gratings of 0.6-micron period, 0.5-micron thick silver mounted behind the outer three AXAF mirrors, and high energy gratings of 0.2-micron period, 1.0-micron thick gold mounted behind the inner three mirrors. The gratings are oriented so as to correct for coma and so that the medium and high energy spectra form a shallow 'X' at the AXAF focal plane. Likely targets include normal stars, binary X-ray sources, active galactic nuclei and quasars. The HETGS can also be used to give moderate resolution spectra of slightly extended sources and monochromatic images of sources with strong lines, such as supernova remnants in nearby galaxies.

Canizares, C. R.; Schattenburg, M. L.; Smith, H. I.

1986-01-01

133

Aberration analysis of a concentric imaging spectrometer with a convex grating  

NASA Astrophysics Data System (ADS)

We analyze the ray-optical aberrations in a concentric imaging spectrometer composed of one convex grating and two concave mirrors of different radii. We assume that the system is generally not telecentric. First we derive aberration functions of Seidel and Buchdahl types for a bundle of rays converging to dispersed Gaussian images. Next we discuss the conditions in which the third and fifth-order ray aberrations are balanced. Finally we show that a concentric imaging spectrometer for use with a CCD detector can be optimized effectively in the neighborhood of a stigmatic condition. The stigmatic condition derived here can be useful in rapidly creating an initial design of a concentric imaging spectrometer with minimal aberrations.

Kim, Seo Hyun; Kong, Hong Jin; Chang, Soo

2014-12-01

134

Optimizing and characterizing grating efficiency for a soft X-ray emission spectrometer.  

PubMed

The efficiency of soft X-ray diffraction gratings is studied using measurements and calculations based on the differential method with the S-matrix propagation algorithm. New open-source software is introduced for efficiency modelling that accounts for arbitrary groove profiles, such as those based on atomic force microscopy (AFM) measurements; the software also exploits multi-core processors and high-performance computing resources for faster calculations. Insights from these calculations, including a new principle of optimal incidence angle, are used to design a soft X-ray emission spectrometer with high efficiency and high resolution for the REIXS beamline at the Canadian Light Source: a theoretical grating efficiency above 10% and resolving power E/?E > 2500 over the energy range from 100 eV to 1000 eV are achieved. The design also exploits an efficiency peak in the third diffraction order to provide a high-resolution mode offering E/?E > 14000 at 280 eV, and E/?E > 10000 at 710 eV, with theoretical grating efficiencies from 2% to 5%. The manufactured gratings are characterized using AFM measurements of the grooves and diffractometer measurements of the efficiency as a function of wavelength. The measured and theoretical efficiency spectra are compared, and the discrepancies are explained by accounting for real-world effects: groove geometry errors, oxidation and surface roughness. A curve-fitting process is used to invert the calculations to predict grating parameters that match the calculated and measured efficiency spectra; the predicted blaze angles are found to agree closely with the AFM estimates, and a method of characterizing grating parameters that are difficult or impossible to measure directly is suggested. PMID:23412484

Boots, Mark; Muir, David; Moewes, Alexander

2013-03-01

135

Arcus:An X-ray Grating Spectrometer on the ISS: Mission Overview  

NASA Astrophysics Data System (ADS)

Arcus is an X-ray grating spectrometer mission to be deployed on the International Space Station in response to NASAs Astrophysics Division plan to announce a SMEX call in Fall 2014 with a cost cap of $125M (FY15). The baseline design uses sub-apertured X-ray silicon pore optics feeding into off-plane gratings to achieve both high spectral resolution with a large effective area. The detector focal plane uses Suzaku-type CCDs. The mission would be ready to be launched and mounted on the ISS in 2020. The mission parameters are R=2800 and ~800 sq. cm at the critical O VII wavelength near 21 0.5 keV), with an overall bandpass from 8-52 (0.25-1.5 keV), enabling a wide range of science objectives. These values are similar to those of the grating spectrometers considered as part of the proposed Constellation-X and IXO missions, which were highly ranked by two Decadal surveys.

Bookbinder, Jay A.

2014-08-01

136

Arcus: an ISS-attached high-resolution x-ray grating spectrometer  

NASA Astrophysics Data System (ADS)

We present the design and scientific motivation for Arcus, an X-ray grating spectrometer mission to be deployed on the International Space Station. This mission will observe structure formation at and beyond the edges of clusters and galaxies, feedback from supermassive black holes, the structure of the interstellar medium and the formation and evolution of stars. The mission requirements will be R>2500 and >600 cm2 of effective area at the crucial O VII and O VIII lines, values similar to the goals of the IXO X-ray Grating Spectrometer. The full bandpass will range from 8-52 (0.25-1.5 keV), with an overall minimum resolution of 1300 and effective area >150 cm2. We will use the silicon pore optics developed at cosine Research and proposed for ESA's Athena mission, paired with off-plane gratings being developed at the University of Iowa and combined with MIT/Lincoln Labs CCDs. This mission achieves key science goals of the New Worlds, New Horizons Decadal survey while making effective use of the International Space Station (ISS).

Smith, R. K.; Ackermann, M.; Allured, R.; Bautz, M. W.; Bregman, J.; Bookbinder, J.; Burrows, D.; Brenneman, L.; Brickhouse, N.; Cheimets, P.; Carrier, A.; Freeman, M.; Kaastra, J.; McEntaffer, R.; Miller, J.; Ptak, A.; Petre, R.; Vacanti, G.

2014-07-01

137

Design of spherical varied line-space gratings for a high-resolution EUV spectrometer  

NASA Technical Reports Server (NTRS)

A highly efficient EUV spectrograph is designed for high-resolution spectroscopic observation. The spectrograph is designed for point source astronomy in a 40-120 nm bandpass and is to be ORFEUS (Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer), scheduled for launch as the first payload of a German space platform Astro-SPAS (Astronomy Shuttle Pallet Satellite). The design uses spherical varied line-space (SVLS) grating to minimize astigmatism, coma, and spherical aberration. The effectiveness and practical feasibility of the design is proved by an SVLS grating for visible use. The image focusing properties of the SVLS grating for ORFEUS are compared to those with toroidal uniform line-space (TULS) design. The SVLS design is superior to the TULS, theoretically in resolution and image concentration, but also practically with not only fabrication ease. Four SVLS gratings with nominal groove densities of 6000, 4550, 3450, and 2616 gr./mm, and a 200 mm x 200 mm ruled area have been ruled using a numerically controlled ruling engine for use in ORFEUS.

Harada, Tatsuo; Kita, Toshiaki; Bowyer, Stuart; Hurwitz, Mark

1991-01-01

138

A compact immersion grating spectrometer with quantum capacitance detectors for space- borne far-IR spectroscopy  

NASA Astrophysics Data System (ADS)

We will develop a wafer-scale moderate-resolution (R~500) wideband immersion waveguide grating spectrometer with an integrated quantum capacitance detector (QCD) array to demonstrate a background-limited wideband spectrometer with detectors on a silicon wafer. Such a system is required for future cryogenic far-IR missions for which spectrometer scope is typically limited by cryogenic size and mass. This effort builds on the successes with the waveguide grating spectrometer technology (WaFIRS) as used in Z-Spec, as well as the recent demonstration of a world-record optical NEP in the far-IR of 2x10^-20W/Hz1/2 with the QCD. Here we will use silicon immersion to reduce the volume and mass by at least an order of magnitude. Unlike spectrometers based on superconducting transmission line or waveguide which are limited to frequencies below the 720 GHz niobium gap (e.g. SuperSpec and Microspec), the WaFIRS / QCD technology is applicable throughout the far-IR / THz. The Quantum Capacitance Detector is a small-volume superconducting device that exploits it s extreme susceptibility to the presence of quasiparticle excitations arising from pair-breaking radiation to enable background limited detection. With recent world-record NEP demonstrations, it is arguably the most promising device for low optical background loads 10^-22 through 10^-16W that are encountered in dispersed spectroscopy at space-borne and balloon-borne platforms. Our prototype will target the 200- 350 micron band, it will provide R~500 with a ~500 QCD pixel array. Optical characterization will verify system sensitivity, spectral performance, and beam characteristics.

Echternach, Pierre

139

Calibration of a Flat Field Soft X-ray Grating Spectrometer for Laser Produced Plasmas  

SciTech Connect

We have calibrated the x ray response of a variable line spaced grating spectrometer, known as the VSG, at the Fusion and Astrophysics Data and Diagnostic Calibration Facility at the Lawrence Livermore National Laboratory (LLNL). The VSG has been developed to diagnose laser produced plasmas, such as those created at the Jupiter Laser Facility and the National Ignition Facility at LLNL, and at both the Omega and Omega EP lasers at University of Rochester's Laboratory for Laser Energetics. The bandwidth of the VSG spans the range from {approx} 6 to 60 {angstrom}. The calibration results present here include the VSG's dispersion and quantum efficiency. The dispersion is determined by measuring the x rays emitted from hydrogen-like and helium-like ions of carbon, nitrogen, oxygen, neon, and aluminum. The quantum efficiency is calibrated to an accuracy of 30% or better by normalizing the x ray intensities recorded by the VSG to those simultaneously recorded by an x ray microcalorimeter spectrometer.

Park, J; Brown, G V; Schneider, M B; Baldis, H A; Beiersdorfer, P; Cone, K V; Kelley, R L; Kilbourne, C A; Magee, E; May, M J; Porter, F S

2010-05-12

140

Calibration of a flat field soft x-ray grating spectrometer for laser produced plasmas  

SciTech Connect

We have calibrated the x-ray response of a variable line spaced grating spectrometer, known as the VSG, at the Fusion and Astrophysics Data and Diagnostic Calibration Facility at the Lawrence Livermore National Laboratory (LLNL). The VSG has been developed to diagnose laser produced plasmas, such as those created at the Jupiter Laser Facility and the National Ignition Facility at LLNL and at both the Omega and Omega EP lasers at the University of Rochester's Laboratory for Laser Energetics. The bandwidth of the VSG spans the range of {approx}6-60 A. The calibration results presented here include the VSG's dispersion and quantum efficiency. The dispersion is determined by measuring the x rays emitted from the hydrogenlike and heliumlike ions of carbon, nitrogen, oxygen, neon, and aluminum. The quantum efficiency is calibrated to an accuracy of 30% or better by normalizing the x-ray intensities recorded by the VSG to those simultaneously recorded by an x-ray microcalorimeter spectrometer.

Park, J.; Cone, K. V. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); University of California, Davis, One Shields Avenue, Davis, California 95616 (United States); Brown, G. V.; Schneider, M. B.; Beiersdorfer, P.; Magee, E. W.; May, M. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); Baldis, H. A. [University of California, Davis, One Shields Avenue, Davis, California 95616 (United States); Kelley, R. L.; Kilbourne, C. A.; Porter, F. S. [NASA Goddard Space Flight Center, Greenbelt, Maryland 20770 (United States)

2010-10-15

141

High resolution transmission grating spectrometer for edge toroidal rotation measurements of tokamak plasmas  

SciTech Connect

We present a high throughput (f/3) visible (3500-7000 A) Doppler spectrometer for toroidal rotation velocity measurements of the Alcator C-Mod tokamak plasma. The spectrometer has a temporal response of 1 ms and a rotation velocity sensitivity of {approx}10{sup 5} cm/s. This diagnostic will have a tangential view and map out the plasma rotation at several locations along the outer half of the minor radius (r/a>0.5). The plasma rotation will be determined from the Doppler shifted wavelengths of D{sub {alpha}} and magnetic and electric dipole transitions of highly ionized impurities in the plasma. The fast time resolution and high spectral resolving power are possible due to a 6 in. diam circular transmission grating that is capable of {lambda}/{delta}{lambda}{approx}15 500 at 5769 A in conjunction with a 50 {mu}m slit.

Graf, A.; May, M.; Beiersdorfer, P.; Magee, E.; Lawrence, M.; Rice, J. [University of California, Davis, California 95616 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2004-10-01

142

High Resolution Transmission Grating Spectrometer for Edge Toroidal Rotation Measurements of Tokamak Plasmas  

SciTech Connect

We present a high throughput (f/3) visible (3500 - 7000 Angstrom) Doppler spectrometer for toroidal rotation velocity measurements of the Alcator C-Mod tokamak plasma. The spectrometer has a temporal response of 1 ms and a rotation velocity sensitivity of {approx}10{sup 5} cm/s. This diagnostic will have a tangential view and map out the plasma rotation at several locations along the outer half of the minor radius (r/a > 0.5). The plasma rotation will be determined from the Doppler shifted wavelengths of D{sub alpha} and magnetic and electric dipole transitions of highly ionized impurities in the plasma. The fast time resolution and high spectral resolving power are possible due to a 6' diameter circular transmission grating that is capable of {lambda}/{Delta}{lambda} {approx} 15500 at 5769 Angstrom in conjunction with a 50 {micro}m slit.

Graf, A; May, M; Beiersdorfer, P; Magee, E; Lawrence, M; Terry, J; Rice, J

2004-04-29

143

Calibration of a helium-cooled infrared spatial radiometer and grating spectrometer  

NASA Technical Reports Server (NTRS)

Methods used by the Space Dynamics Laboratory of Utah State University (SDL/USU) to calibrate infrared sensors are described, using the Infrared Background Signature Survey (IBSS) spatial radiometer and grating spectrometer as examples. A calibration equation and a radiometric model are given for each sensor to describe their responsivity in terms of individual radiometric parameters. The calibration equation terms include dark offset, linearity, absolute responsivity, and measurement uncertainty, and the radiometric model domains include spatial, spectral, and temporal domains. A portable calibration facility, designed and fabricated by SDL/USU, provided collimated, extended, diffuse scatter, and Jones sources in a single cryogenic dewar. This multi-function calibrator allowed calibration personnel to complete a full calibration of the IBSS infrared radiometer and spectrometer in two 15-day periods. A calibration data system was developed to control and monitor the calibration facility, and to record and analyze sensor data.

Jacobsen, Larry; Sargent, Steve; Wyatt, Clair L.; Steed, Allan J.

1992-01-01

144

Discovery of Narrow X-Ray Absorption Lines from NGC 3783 with the Chandra High Energy Transmission Grating Spectrometer  

Microsoft Academic Search

We present the first grating-resolution X-ray spectra of the Seyfert 1 galaxy NGC 3783, obtained with the High Energy Transmission Grating Spectrometer on the Chandra X-Ray Observatory. These spectra reveal many narrow absorption lines from the H-like and He-like ions of O, Ne, Mg, Si, S, and Ar as well as Fe XVII-Fe XXI L-shell lines. We have also identified

Shai Kaspi; W. N. Brandt; Hagai Netzer; Rita Sambruna; George Chartas; Gordon P. Garmire; John A. Nousek

2000-01-01

145

[Development of spectrometer for tongue diagnosis based on plane holography concave grating].  

PubMed

The traditional tongue inspection method should be urgently improved due to the relative large diagnosis error probability caused by the excessive dependence on the Chinese physician's experience and judgment. But the application of tongue diagnosis based on image processing is limited by some factors including the performance of light source, image acquisition device and the low recognition rate of similar color for different diseases. In order to overcome these drawbacks, the spectroscopy method was employed to analyze the tongue by using the unique fingerprint effect of tongue spectrum. A spectrometer for tongue diagnosis (STD) was developed to achieve this goal in this paper. Meanwhile, to overcome the shortcomings of traditional light-splitting devices, a plane holographic concave grating was used as the diffractive grating, which not only can improve the luminous flux efficiency and miniaturize system, but also improve the spectral imaging quality and resolution. Experimental results demonstrated that the spectral range of STD reached 340-850 nm, and its spectral resolution is better than 2 nm. And the result of simulation experiment validated the feasibility of spectrometer's system. PMID:24369678

Ren, Zhong; Liu, Guo-dong; Huang, Zhen

2013-09-01

146

Development of silicon immersed grating for METIS on E-ELT  

NASA Astrophysics Data System (ADS)

We have developed the technology to manufacture an immersed grating in silicon for the Mid-infrared E-ELT Imager and Spectrograph, METIS. We show that we can meet the required diffraction-limited performance at a resolution of 100000 for the L and M spectral bands. Compared to a conventional grating, the immersed grating drastically reduces the beam diameter and thereby the size of the spectrometer optics. As diffraction takes place inside the high-index medium, the optical path difference and angular dispersion are boosted proportionally, thereby allowing a smaller grating area and a smaller spectrometer size. The METIS immersed grating is produced on a 150 mm industry standard for wafers and replaces a classical 400 mm echelle. Our approach provides both a feasible path for the production of a grating with high efficiency and low stray light and improves the feasibility of the surrounding spectrometer optics. In this contribution we describe and compare the classical-grating solution for the spectrometer with our novel immersed-grating based design. Furthermore, we discuss the production route for the immersed grating that is based on our long-standing experience for space-based immersed gratings. We use standard techniques from the semiconductor industry to define grating grooves with nanometer accuracy and sub-nanometer roughness. We then use optical manufacturing techniques to combine the wafer and a prism into the final immersed grating. Results of development of the critical technology steps will be discussed.

van Amerongen, Aaldert H.; Agocs, Tibor; van Brug, Hedser; Nieuwland, Govert; Venema, Lars; Hoogeveen, Ruud W. M.

2012-09-01

147

Design and simulation of arrayed waveguide grating (AWG) for micro-Raman spectrometer  

NASA Astrophysics Data System (ADS)

Micro Raman spectrometer has broad applications for monitoring harmful chemicals in food, water and environment. Arrayed waveguide grating (AWG) is a promising device to build a dispersive micro Raman spectrometer. Comparing with the widely used demultiplexer in optical communication, AWG in spectrometer is unique due to its broad spectral range and low insert loss. In this paper, a computer algorithm routine was explored to accomplish the design of a broadband, arbitrary AWG structure. First, the focal length, length increment of adjacent waveguide and diffraction order of an AWG were figured out by a MATLAB program, the coordinates was then input into a VBScript program to generate the layout, and the layout was analyzed in OptiwaveBPM software for optical characterization. The proposed MATLAB and VBScript program was verified by the design and simulation of a 800-1000 nm range, 40 channels asymmetric AWG, a spectral resolution of 5 nm was demonstrated with insert loss of 5.03-7.16 dB. In addition, an approach to realize multimode input was introduced to reduce the optical coupling loss. Multimode light beam was firstly converted to a series of single mode beams by the methods proposed by S. G. Leon-Saval et al. in 2005. Next, these single mode beams were coupled into the input star coupler of an AWG. As a proof of this concept, a three inputs, 20 channel, 850-950 nm spectral range AWG was simulated, and merits and drawbacks of this approach were discussed.

Cheng, Yaqin; Deng, Shengfeng; Xu, Yingchao; Lu, Miao

2012-10-01

148

Low-energy inverse photoemission spectroscopy using a high-resolution grating spectrometer in the near ultraviolet range.  

PubMed

An inverse photoemission spectroscopy (IPES) apparatus using a Czerny-Turner grating spectrometer is demonstrated. Previous IPES instruments based on grating spectrometers used a concave grating and operated in the vacuum ultraviolet range. The reflectance of such gratings is lower than 20% and the aberration cannot be finely corrected leading to an energy resolution of up to 0.1 eV. In the present study, employing the low energy IPES regime [H. Yoshida, Chem. Phys. Lett. 539-540, 180 (2012)], incident electrons with a kinetic energy below 5 eV are used, while photon emission in the range of between 250 and 370 nm is analyzed with a 10-cm Czerny-Turner grating spectrometer. The signal intensity is at least 30 times higher than the previous apparatus. The resolution of photon detection is set at 0.07 eV though the ultimate resolution is one order of magnitude higher. The experiment is performed both by sweeping the electron energy (isochromat mode) and by simultaneously analyzing the photon of whole wavelength range (tunable photon energy mode). PMID:24182123

Yoshida, Hiroyuki

2013-10-01

149

Design of a transmission grating spectrometer and an undulator beamline for soft x-ray emission studies  

SciTech Connect

A soft x-ray undulator beamline and an x-ray emission spectrometer have been designed for soft x-ray emission studies. The beamline has a varied-line-spacing plane grating monochromator, which enables the energy resolution over 104 with a beam size down to 10 x 60 {mu}m2. The x-ray emission spectrometer has a Wolter type I mirror, a free-standing transmission grating, and a back-illuminated CCD. A high collection angle up to 1.5 x 10-3 sr is achieved by utilizing the Wolter mirror as a prefocusing system. The CCD is mounted at 1400 mm downstream of the grating on a Rowland torus mount. Diffracted x-rays are detected in the normal incidence geometry, resulting in high detection efficiency. The energy resolution is limited by the figure errors of the optical elements and the spatial resolution of the detector.

Hatsui, Takaki; Kosugi, Nobuhiro [Institute for Molecular Sciences, Myodaiji, Okazaki 444-8585 (Japan); Graduate University for Advanced Studies, Myodaiji, Okazaki 444-8585 (Japan); Shigemasa, Eiji [Institute for Molecular Sciences, Myodaiji, Okazaki 444-8585 (Japan)

2004-05-12

150

CALIBRATION OF THE REFLECTION GRATING SPECTROMETERS ON-BOARD J. W. den Herder 1 , A. C. Brinkman 1 , S. M. Kahn 2 , G. Branduardi-Raymont 3 , M. Audard 4 ,  

E-print Network

1 CALIBRATION OF THE REFLECTION GRATING SPECTROMETERS ON-BOARD XMM-NEWTON J. W. den Herder 1 , A. C The Re ection Grating Spectrometers allow high-reso- lution (E/#1;E = 100 to 500) measurements of the calibration of the Re ection Grating Spectrometers will be discussed. This includes a description of the main

Guedel, Manuel

151

A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility  

SciTech Connect

A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors (GXD) it records sixteen time-gated spectra between 250 and 1000eV with 100ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and VUV beamline at the National Synchrotron Light Source (NSLS), evidence a <100{micro}m spatial resolution in combination with a source-size limited spectral resolution that is <10eV at photon energies of 300eV.

Moore, A S; Guymer, T M; Kline, J L; Morton, J; Taccetti, M; Lanier, N E; Bentley, C; Workman, J; Peterson, B; Mussack, K; Cowan, J; Prasad, R; Richardson, M; Burns, S; Kalantar, D H; Benedetti, L R; Bell, P; Bradley, D; Hsing, W; Stevenson, M

2012-05-01

152

Multivariate Monte Carlo Methods for the Reflection Grating Spectrometers on XMM-Newton  

SciTech Connect

We propose a novel multivariate Monte Carlo method as an efficient and flexible approach to analyzing extended X-ray sources with the Reflection Grating Spectrometer (RGS) on XMM Newton. A multi-dimensional interpolation method is used to efficiently calculate the response function for the RGS in conjunction with an arbitrary spatially-varying spectral model. Several methods of event comparison that effectively compare the multivariate RGS data are discussed. The use of a multi-dimensional instrument Monte Carlo also creates many opportunities for the use of complex astrophysical Monte Carlo calculations in diffuse X-ray spectroscopy. The methods presented here could be generalized to other X-ray instruments as well.

Peterson, J.

2004-11-10

153

Multiwavelength campaign on Mrk 509. II. Analysis of high-quality Reflection Grating Spectrometer spectra  

E-print Network

We study the bright Seyfert 1 galaxy Mrk~509 with the Reflection Grating Spectrometers (RGS) of XMM-Newton using the RGS multi-pointing mode of XMM-Newton for the first time in order to constrain the properties of the outflow in this object. We want to obtain the most accurate spectral properties from the 600 ks spectrum of Mrk 509 which has excellent statistical quality. We derive an accurate relative calibration for the effective area of the RGS, derive an accurate absolute wavelength calibration, improve the method for adding time-dependent spectra and enhance the efficiency of the spectral fitting by two orders of magnitude. We show the major improvement of the spectral data quality due to the use of the new RGS multi-pointing mode of XMM-Newton. We illustrate the gain in accuracy by showing that with the improved wavelength calibration the two velocity troughs observed in UV spectra are resolved.

Kaastra, J S; Steenbrugge, K C; Detmers, R G; Ebrero, J; Behar, E; Bianchi, S; Costantini, E; Kriss, G A; Mehdipour, M; Paltani, S; Petrucci, P -O; Pinto, C; Ponti, G

2011-01-01

154

Multivariate Monte Carlo Methods for the Reflection Grating Spectrometers on XMM-Newton  

E-print Network

We propose a novel multivariate Monte Carlo method as an efficient and flexible approach to analyzing extended X-ray sources with the Reflection Grating Spectrometer (RGS) on XMM Newton. A multi-dimensional interpolation method is used to efficiently calculate the response function for the RGS in conjunction with an arbitrary spatially-varying spectral model. Several methods of event comparison that effectively compare the multivariate RGS data are discussed. The use of a multi-dimensional instrument Monte Carlo also creates many opportunities for the use of complex astrophysical Monte Carlo calculations in diffuse X-ray spectroscopy. The methods presented here could be generalized to other X-ray instruments as well.

J. R. Peterson; J. G. Jernigan; S. M. Kahn

2004-10-26

155

Towards a portable Raman spectrometer using a concave grating and a time-gated CMOS SPAD.  

PubMed

A low-cost, compact Raman spectrometer suitable for the on-line water monitoring applications is explored. A custom-designed concave grating for wavelength selection was fabricated and tested. The detection of the Raman signal is accomplished with a time-gated single photon avalanche diode (TG-SPAD). A fixed gate window of 3.5ns is designed and applied to the TG-SPAD. The temporal resolution of the SPAD was ~60ps when tested with a 7ps, 532nm solid-state laser. To test the efficiency of the gating in fluorescence signal suppression, different detection windows (3ns-0.25ns) within the 3.5ns gate window are used to measure the Raman spectra of Rhodamine B. Strong Raman peaks are resolved with this low-cost system. PMID:25089491

Li, Zhiyun; Deen, M Jamal

2014-07-28

156

A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility.  

PubMed

A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors it records 16 time-gated spectra between 250 and 1000 eV with 100 ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300 eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and vacuum ultraviolet beamline at the National Synchrotron Light Source, evidence a <100 ?m spatial resolution in combination with a source-size limited spectral resolution that is <10 eV at photon energies of 300 eV. PMID:23126953

Moore, A S; Guymer, T M; Kline, J L; Morton, J; Taccetti, M; Lanier, N E; Bentley, C; Workman, J; Peterson, B; Mussack, K; Cowan, J; Prasad, R; Richardson, M; Burns, S; Kalantar, D H; Benedetti, L R; Bell, P; Bradley, D; Hsing, W; Stevenson, M

2012-10-01

157

Multichannel Doppler transmission grating spectrometer at the Alcator C-Mod tokamak  

SciTech Connect

Upgrades to an existing transmission grating spectrometer for visible light used for Doppler velocity and temperature measurements at the Alcator C-Mod tokamak are given. These include a new Princeton Instruments Photonmax 512B charge-coupled device and a four channel fiber optic input. These together allow improvements to the signal level, time resolution, and the number of spatial channels. The fiber optic input allows four simultaneous spatial channels each of which offers a larger percentage of input light flux when compared to the standard fiber slit combination. The ''on chip'' amplification combined with versatile pixel binning further increases the signal to noise ratio allowing a continuous acquisition of spectra every 8 ms. The error bars for extracted velocity and temperature values are potentially smaller owing to the smaller pixel size and increased light flux which allow a more detailed line shape and simplifies line fitting. Examples of time and space resolved spectra are shown and further improvements are discussed.

Graf, A. [University of California at Davis, California 95616 (United States); May, M.; Beiersdorfer, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2008-10-15

158

A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility  

SciTech Connect

A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors it records 16 time-gated spectra between 250 and 1000 eV with 100 ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300 eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and vacuum ultraviolet beamline at the National Synchrotron Light Source, evidence a <100 {mu}m spatial resolution in combination with a source-size limited spectral resolution that is <10 eV at photon energies of 300 eV.

Moore, A. S.; Guymer, T. M.; Morton, J.; Bentley, C.; Stevenson, M. [Directorate Science and Technology, AWE Aldermaston, Reading, RG7 4PR (United Kingdom); Kline, J. L.; Taccetti, M.; Lanier, N. E.; Workman, J.; Peterson, B.; Mussack, K.; Cowan, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Prasad, R.; Richardson, M.; Burns, S.; Kalantar, D. H.; Benedetti, L. R.; Bell, P.; Bradley, D.; Hsing, W. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States)

2012-10-15

159

Reflection Grating Array Associated with the Reflection Grating Spectrometer Developed by the Space Research Organization of the Netherlands for the X-ray Multi-Mirror Mission (XMM)  

NASA Technical Reports Server (NTRS)

The University of California, Berkeley (UCB) served as the Principal Investigator institution for the United States participation in the development of the Reflection Grating Spectrometer (RGS) which included the design, development, fabrication, and testing of the Reflection Grating Assembly (RGA). UCB was assisted in this role by the Lawrence Livermore National Laboratory and Columbia University who provided the primary facilities, materials, services and personnel necessary to complete the development. UC Berkeley's Dr. Steven Kahn provided the technical and scientific oversight for the design. development and testing of the RGA units by monitoring the performance of the units at various stages in their development. Dr. Kahn was also the primary contact with the Space Research Organization of the Netherlands (SRON) and represented the RGA development at all SRON and European Space Agency (ESA) reviews of the RGA status. In accordance with the contract, the team designed and developed novel optical technology to meet the unique requirements of the RGS. The ESA XMM-Newton Mission carries two identical Reflection Grating Spectrometers (RGS) behind two of its three nested sets of Wolter I type mirrors. The instrument allows high-resolution measurements in the soft X-ray range (6 to 38 angstroms or 2.1 to 0.3 keV) with a maximum effective area of about 140 sq cm at 15 angstroms. Its design is optimized for the detection of the K-shell transitions of carbon, nitrogen, oxygen, neon, magnesium, and silicon. as well as the L shell transitions of iron. The RGA itself consists of two units. A structure for each unit was designed to hold up to 220 gratings. In its final configuration, one unit holds 182 gratings and the second hold 181 gratings.

Kahn, Steven M.

2001-01-01

160

Calibration of Xray CCDs with an ErectField Grating Spectrometer in the 0.2 1.5 keV band.  

E-print Network

Calibration of X­ray CCDs with an Erect­Field Grating Spectrometer in the 0.2 ­ 1.5 keV band. G been calibrated in the 0.25­1.5 keV spectral range using an erect­field grating spectrometer X­ray CCDs developed at MIT Lincoln Laboratories for the AXAF CCD Imaging Spectrometer (ACIS) have

161

AEGIS: An Astrophysics Experiment for Grating and Imaging Spectroscopy---a Soft X-ray, High-resolution Spectrometer  

NASA Astrophysics Data System (ADS)

AEGIS is a concept for a high-resolution soft X-ray spectroscopic observatory developed in response to NASA's request for definitions of the next X-ray astronomy mission. At a small fraction of the cost of the once-planned International X-ray Observatory (IXO), AEGIS has capabilities that surpass IXO grating spectrometer requirements, and which are far superior to those of existing soft X-ray spectrometers. AEGIS incorporates innovative technology in X-ray optics, diffraction gratings and detectors. The mirror uses high area-to-mass ratio segmented glass architecture developed for IXO, but with smaller aperture and larger graze angles optimized for high-throughput grating spectroscopy with low mass and cost. The unique Critical Angle Transmission gratings combine low mass and relaxed figure and alignment tolerances of Chandra transmission gratings but with high diffraction efficiency and resolving power of blazed reflection gratings. With more than an order of magnitude better performance over Chandra and XMM grating spectrometers, AEGIS can obtain high quality spectra of bright AGN in a few hours rather than 10 days. Such high resolving power allows detailed kinematic studies of galactic outflows, hot gas in galactic haloes, and stellar accretion flows. Absorption line spectroscopy will be used to study large scale structure, cosmic feedback, and growth of black holes in thousands of sources to great distances. AEGIS will enable powerful multi-wavelength investigations, for example with Hubble/COS in the UV to characterize the intergalactic medium. AEGIS will be the first observatory with sufficient resolution below 1 keV to resolve thermally-broadened lines in hot ( 10 MK) plasmas. Here we describe key science investigations enable by Aegis, its scientific payload and mission plan. Acknowledgements: Support was provided in part by: NASA SAO contract SV3-73016 to MIT for the Chandra X-ray Center and Science Instruments; NASA grant NNX08AI62G; and the MKI Instrumentation Development Fund.

Huenemoerder, David; Bautz, M. W.; Davis, J. E.; Heilmann, R. K.; Houck, J. C.; Marshall, H. L.; Neilsen, J.; Nicastro, F.; Nowak, M. A.; Schattenburg, M. L.; Schulz, N. S.; Smith, R. K.; Wolk, S.; AEGIS Team

2012-01-01

162

Different approaches to precise wavelength calibration of a flat-field grating spectrometer for laser-produced plasmas  

NASA Astrophysics Data System (ADS)

Accurate mathematical models called one-line calibration and parameter fitting are presented for wavelength calibration of a flat-field grating spectrometer. The models precisely establish the relationship between wavelength and pixel position of the detector, since geometry parameters and the grating equation of the spectrometer are taken into account. Compared with the commonly used polynomial fitting, the models presented here provide more reliable calibration results, especially in the extended region away from the calibration points. In addition to the high precision of calibration, the parameter fitting procedure provides a helpful way to obtain the actual parameters of the spectrometer. Supported by the National Natural Science Foundation of China under Grant Nos 10875109, 10874156, and 11105129.

Xiong, Gang; Zhang, Jiyan; Yang, Guohong; Yang, Jiamin; Li, Hang; Hu, Zhimin; Zhao, Yang; Wei, Minxi; Yi, Tao

2014-06-01

163

EGRAM- ECHELLE SPECTROGRAPH DESIGN AID  

NASA Technical Reports Server (NTRS)

EGRAM aids in the design of spectrographic systems that utilize an echelle-first order cross disperser combination. This optical combination causes a two dimensional echellogram to fall on a detector. EGRAM describes the echellogram with enough detail to allow the user to effectively judge the feasibility of the spectrograph's design. By iteratively altering system parameters, the desired echellogram can be achieved without making a physical model. EGRAM calculates system parameters which are accurate to the first order and compare favorably to results from ray tracing techniques. The spectrographic system modelled by EGRAM consists of an entrance aperture, collimator, echelle, cross dispersion grating, focusing options, and a detector. The system is assumed to be free of aberrations and the echelle, cross disperser, and detector should be planar. The EGRAM program is menu driven and has a HELP facility. The user is prompted for information such as minimum and maximum wavelengths, slit dimensions, ruling frequencies, detector geometry, and angle of incidence. EGRAM calculates the resolving power and range of order numbers covered by the echellogram. A numerical map is also produced. This tabulates the order number, slit bandpass, and high/middle/low wavelengths. EGRAM can also compute the centroid coordinates of a specific wavelength and order (or vice versa). EGRAM is written for interactive execution and is written in Microsoft BASIC A. It has been implemented on an IBM PC series computer operating under DOS. EGRAM was developed in 1985.

Dantzler, A. A.

1994-01-01

164

Spectroscopic comparison between 1200 grooves/mm ruled and holographic gratings of a flat-field spectrometer and its absolute sensitivity calibration using bremsstrahlung continuum  

SciTech Connect

A flat-field extreme ultraviolet (EUV) spectrometer with a varied line spacing groove grating (1200 grooves/mm at grating center) has been developed to study the emission spectra from highly ionized medium Z impurities in large helical device (LHD). It covers a wavelength range of 50-500 A using a mechanically ruled grating, which was later replaced by a newly developed laminar-type holographic grating for comparative studies. Differences in spectral resolution, intensities of higher order spectra, and sensitivities of the spectrometer were studied between the two gratings by observing the emission spectra of LHD plasmas. Although the achieved resolution was alike between them, i.e., {delta}{lambda}{approx}0.24 A ring at 200 A, the holographic grating was much superior in suppressing the higher order light than the ruled grating. The relative sensitivity between the two gratings was evaluated using continuum radiation from LHD plasmas. As a result, it was found that the holographic grating has a flat response in the full wavelength range, but the sensitivity of the ruled grating drops sharply below 200 A. A new technique for the absolute calibration of the EUV holographic grating spectrometer was tried by combining the continuum radiation with a branching ratio of C IV lines (3p-3s: 5800 A/3p-2s: 312 A), and an accurate absolute sensitivity has been successfully obtained.

Chowdhuri, Malay Bikas; Morita, Shigeru; Goto, Motoshi; Nishimura, Hiroaki; Nagai, Keiji; Fujioka, Shinsuke [Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan); National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Institute of Laser Engineering, Osaka University, Suita 565-0871, Osaka (Japan)

2007-02-15

165

Optical design for a breadboard high-resolution spectrometer for SIRTF/IRS  

NASA Astrophysics Data System (ADS)

The optical design of a breadboard high resolution infrared spectrometer for the IRS instrument on the SIRTF mission is discussed. The spectrometer uses a crossed echelle grating configuration to cover the spectral region from 10 to 20 micrometer with a resolving power of approximately equals 600. The all reflective spectrometer forms a nearly diffraction limited image of the two dimensional spectrum on a 128 multiplied by 128 arsenic doped silicon area array with 75 micrometer pixels. The design aspects discussed include, grating numerology, image quality, packaging and alignment philosophy.

Brown, Robert J.; Houck, James R.; van Cleve, Jeffrey E.

1996-11-01

166

Flat-field grating spectrometer for high-resolution soft x-ray and EUV measurements on an electron beam ion trap  

SciTech Connect

A R = 44.3 m grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Angstrom up to 50 Angstrom. The instrument uses a grating with variable line spacing (about 2400 l/mm) for a flat field of view. Spectra are recorded with a back-illuminated charge-coupled device detector. The new instrument greatly improves upon the resolution achieved with existing grating spectrometers and complements crystal spectrometers at the shorter wavelengths both in terms of wavelength coverage and polarization independent reflectivity response.

Beiersdorfer, P; Magee, E; Trabert, E; Chen, H; Lepson, J K; Gu, M F; Schmidt, M

2004-03-27

167

Flat-field grating spectrometer for high-resolution soft x-ray and extreme ultraviolet measurements on an electron beam ion trap  

SciTech Connect

A R=44.3 m grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 up to 50 A. The instrument uses a grating with variable line spacing (about 2400 l/mm for a flat field of view. Spectra are recorded with a back-illuminated charge-coupled device detector. The new instrument greatly improves upon the resolution achieved with existing grating spectrometers and complements crystal spectrometers at the shorter wavelengths both in terms of wavelength coverage and polarization independent reflectivity response.

Beiersdorfer, P.; Magee, E.W.; Traebert, E.; Chen, H.; Lepson, J.K.; Gu, M.-F.; Schmidt, M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); University of California, Berkeley, California 94720 (United States); Stanford University, Palo Alto, California 94305 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2004-10-01

168

NOTES: Reduction of residual coma and astigmatism in a 1.5 m Czerny-Turner spectrometer  

Microsoft Academic Search

Ray tracing calculations have been performed in order to evaluate the geometrical aberrations of a high resolution 15 m in-plane Czerny-Turner spectrometer using spherical mirrors and a high blaze angle Echelle grating. Results show that for minimum instrumental broadening the focusing mirror off-axis angle must satisfy the Rosendahl cos3 relation, that the astigmatism can be reduced by using divergent grating

R. C. Preston

1970-01-01

169

Calibration and in-orbit performance of the reflection grating spectrometer onboard XMM-Newton  

NASA Astrophysics Data System (ADS)

Context. XMM-Newton was launched on 10 December 1999 and has been operational since early 2000. One of the instruments onboard XMM-Newton is the reflection grating spectrometer (RGS). Two identical RGS instruments are available, with each RGS combining a reflection grating assembly and a camera with charge-coupled devices to record the spectra. Aims: We describe the calibration and in-orbit performance of the RGS instrument. By combining the preflight calibration with appropriate inflight calibration data including the changes in detector performance over time, we aim at profound knowledge about the accuracy in the calibration. This will be crucial for any correct scientific interpretation of spectral features for a wide variety of objects. Methods: Ground calibrations alone are not able to fully characterize the instrument. Dedicated inflight measurements and constant monitoring are essential for a full understanding of the instrument and the variations of the instrument response over time. Physical models of the instrument are tuned to agree with calibration measurements and are the basis from which the actual instrument response can be interpolated over the full parameter space. Results: Uncertainties in the instrument response have been reduced to <10% for the effective area and <6 m for the wavelength scale (in the range from 8 to 34 ). The remaining systematic uncertainty in the detection of weak absorption features has been estimated to be 1.5%. Conclusions: Based on a large set of inflight calibration data and comparison with other instruments onboard XMM-Newton, the calibration accuracy of the RGS instrument has been improved considerably over the preflight calibrations.

de Vries, C. P.; den Herder, J. W.; Gabriel, C.; Gonzalez-Riestra, R.; Ibarra, A.; Kaastra, J. S.; Pollock, A. M. T.; Raassen, A. J. J.; Paerels, F. B. S.

2015-01-01

170

High-Resolution Observations of the Elliptical Galaxy NGC 4636 with the Reflection Grating Spectrometer on Board XMM-Newton  

Microsoft Academic Search

We present the first high spectral resolution X-ray observation of the giant elliptical galaxy NGC 4636, obtained with the reflection grating spectrometer on board the XMM-Newton Observatory. The resulting spectrum contains a wealth of emission lines from various charge states of oxygen, neon, magnesium, and iron. Examination of the cross-dispersion profiles of several of these lines provides clear, unambiguous evidence

H. Xu; S. M. Kahn; J. R. Peterson; E. Behar; F. B. S. Paerels; R. F. Mushotzky; J. G. Jernigan; A. C. Brinkman; K. Makishima

2002-01-01

171

First Light Measurements of Capella with the Low-Energy Transmission Grating Spectrometer aboard the Chandra X-Ray Observatory  

Microsoft Academic Search

We present the first X-ray spectrum obtained by the Low-Energy Transmission Grating Spectrometer (LETGS) aboard the Chandra X-Ray Observatory. The spectrum is of Capella and covers a wavelength range of 5-175 (2.5-0.07 keV). The measured wavelength resolution, which is in good agreement with ground calibration, is Deltalambda~=0.06 (FWHM). Although in-flight calibration of the LETGS is in progress, the

A. C. Brinkman; C. J. T. Gunsing; J. S. Kaastra; R. Mewe; F. Paerels; A. J. J. Raassen; J. J. van Rooijen; H. Bruninger; W. Burkert; V. Burwitz; G. Hartner; P. Predehl; J.-U. Ness; J. H. M. M. Schmitt; J. J. Drake; O. Johnson; M. Juda; V. Kashyap; S. S. Murray; D. Pease; P. Ratzlaff; B. J. Wargelin

2000-01-01

172

XMM-Newton Reflection Grating Spectrometer Observations of Discrete Soft X-Ray Emission Features from NGC 1068  

Microsoft Academic Search

We present the first high-resolution, soft X-ray spectrum of the prototypical Seyfert 2 galaxy, NGC 1068. This spectrum was obtained with the XMM-Newton Reflection Grating Spectrometer (RGS). Emission lines from H-like and He-like low-Z ions (from C to Si) and Fe L-shell ions dominate the spectrum. Strong, narrow radiative recombination continua (RRCs) for several ions are also present, implying that

Ali Kinkhabwala; Masao Sako; Ehud Behar; Steven M. Kahn; Frits Paerels; Albert C. Brinkman; Jelle S. Kaastra; Ming Feng Gu; Duane A. Liedahl

2002-01-01

173

Absolute measurement of the spectral and angular properties of undulator radiation with a pinhole transmission grating spectrometer  

Microsoft Academic Search

Absolute measurements of undulator radiation in the soft x-ray region from 50 to 500 eV are presented. A dedicated compact pinhole transmission grating spectrometer has been built, which was calibrated with relative uncertainties between 5% (at 100 eV) and 20% (at 500 eV) in the calculable undispersed dipole radiation of the storage ring BESSY. We report measurements of the spectral

Karl Molter; Gerhard Ulm

1992-01-01

174

High-Resolution X-Ray Spectra of Capella: Initial Results from the Chandra High-Energy Transmission Grating Spectrometer  

Microsoft Academic Search

High-resolution spectra of the active binary Capella (G8 III + G1 III) covering the energy range of 0.4-8.0 keV (1.5-30 ) show a large number of emission lines, demonstrating the performance of the High-Energy Transmission Grating Spectrometer. A preliminary application of plasma diagnostics provides information on coronal temperatures and densities. Lines arising from different elements in a range of ionization

C. R. Canizares; D. P. Huenemoerder; D. S. Davis; D. Dewey; K. A. Flanagan; J. Houck; T. H. Markert; H. L. Marshall; M. L. Schattenburg; N. S. Schulz; M. Wise; J. J. Drake; N. S. Brickhouse

2000-01-01

175

High resolution X-ray spectroscopy of zeta Puppis with the XMM-Newton reflection grating spectrometer  

Microsoft Academic Search

We present the first high resolution X-ray spectrum of the bright O4Ief supergiant star zeta Puppis, obtained with the Reflection Grating Spectrometer on-board XMM-Newton. The spectrum exhibits bright emission lines of hydrogen-like and helium-like ions of nitrogen, oxygen, neon, magnesium, and silicon, as well as neon-like ions of iron. The lines are all significantly resolved, with characteristic velocity widths of

S. M. Kahn; M. A. Leutenegger; J. Cottam; G. Rauw; J.-M. Vreux; A. J. F. den Boggende; R. Mewe; M. Gdel

2001-01-01

176

XMM-Newton Reflection Grating Spectrometer Observations of the Prototypical Starburst Galaxy M82  

E-print Network

We present results from XMM-Newton Reflection Grating Spectrometer observations of the prototypical starburst galaxy M82. These high resolution spectra represent the best X-ray spectra to date of a starburst galaxy. A complex array of lines from species over a wide range of temperatures is seen, the most prominent being due to Lyman-alpha emission from abundant low Z elements such as N, O, Ne, Mg and Si. Emission lines from Helium-like charge states of the same elements are also seen in emission, as are strong lines from the entire Fe-L series. Further, the OVII line complex is resolved and is seen to be consistent with gas in collisional ionization equilibrium. Spectral fitting indicates emission from a large mass of gas with a differential emission measure over a range of temperatures (from 0.2 keV to 1.6 keV, peaking at 0.7 keV), and evidence for super-solar abundances of several elements is indicated. Spatial analysis of the data indicates that low energy emission is more extended to the south and east of the nucleus than to the north and west. Higher energy emission is far more centrally concentrated.

Andrew M. Read; Ian R. Stevens

2002-06-12

177

Fifteen years of experience with the Reflection Grating Spectrometer on XMM-Newton  

NASA Astrophysics Data System (ADS)

The RGS instrument is the X-ray spectrometer on board the XMM-Newton satellite, launched December 1999, and still fully operational. It consists of a reflection grating to disperse the incoming X-rays and a CCD camera as detector. In the past fifteen years a lot of experience has been gained in operating and calibrating this instrument. In this presentation we report on the calibration methods and status, new instrumental modes and detector performance, which were acquired and developed based on the in-flight experiences with the instrument. Selecting the proper operating modes, combined with careful data processing based on target characteristics and science goals, allows detection of weak spectral features, despite slowly degrading detectors due to radiation damage and contamination. At present the instrument has excellent health status and performance, and will be one of the few major instruments for X-ray spectroscopy in the coming years, until supplemented by new missions like ASTRO-H and, in particular, Athena.

de Vries, C. P.; den Herder, J. W.; Gonzalez-Riestra, R.; Gabriel, C.; Kaastra, J. S.; Raassen, A. J. J.; Paerels, F. B. S.; Pollock, A. M. T.; Ibarra, I.

2014-07-01

178

[Development of a high resolution simultaneous microwave plasma torch spectrometer].  

PubMed

A unique high resolution simultaneous microwave plasma torch (MPT) atomic emission spectrometer was developed and studied preliminarily. Some advanced technologies were applied to the spectrometer, such as echelle grating, UV-intensified CCD array detector, adjustable microwave generator, and water cooling system for the generator, etc. The detection limits of the spectrometer for some elements were determined, the spectral resolution and pixel resolution of the spectrometer were calculated, and an analysis of a practical sample was carried out. The preliminary results demonstrate that such simultaneous spectrometer has advantages of saving sample and time, possessing high sensitivity and resolution, and low-cost for the purchase and maintenance. Taking analytical figures of merit into consideration, the high resolution simultaneous MPT spectrometer will have extended application areas and greater competition potential as compared with sequential MPT spectrometers. PMID:18260435

Jiang, Jie; Huan, Yan-Fu; Jin, Wei; Feng, Guo-Dong; Fei, Qiang; Cao, Yan-Bo; Jin, Qin-Han

2007-11-01

179

Design of a novel multi-spectral imaging spectrometer for breast cancer detector based on VHT grating  

NASA Astrophysics Data System (ADS)

The ultrasonic imaging, X-mammography, CT imaging and MRI can be applied into the breast cancer diagnosis(BCD). But some factors such as the spatial resolution, contrast and price-performance ratio (PPR) limit their applications. So, a novel BCD technology, that is, multi-spectral imaging is adopted into this paper. It can get more information of the breast tumor and higher identity because it combines the advantages of the spectroscopy and the imaging technology. And in this paper, the multi-spectral light source induced the breast cancer imaging detector(BCID) is designed, the spectrum can cover from the UV to NIR. Meanwhile, a custom-built multi-spectral imaging spectrometer (MSIS) is also developed. And, in order to overcome the stray-light of the light-route system and improve the resolution and light-passing efficiency of the system, the novel volume holography transmissive (VHT) grating instead of the plane or concave grating is used as the diffraction grating in this MSIS. Experimental result show that the novel BCD technology is feasible, it can offer not only the spectral information but also the image of the tumor. The spectrum resolution of the MSIS for BCID based on VHT grating can reach 2nm. Compared with the others, this BCID has more compact structure, faster speed, higher PPR and higher resolution and accuracy. Therefore, this BCID has the potential value in the field of the BCD.

Ren, Zhong; Wu, Yan; Liu, Guodong; Huang, Zhen; Zeng, Lvming

2011-06-01

180

Reflection grating spectrometer for the x-ray multi-mirror (XMM) space observatory: design and calculated performance  

SciTech Connect

A spectrometer design candidate is presented for the X-ray Multi-Mirror (XMM) observatory, being planned by the European Space Agency (ESA) as a long-lived large-area of telescopes. The science requirement of moderate resolution (E/..delta..E approx.100) spectroscopy in a two octave region (0.5 to 2 keV) with extremely high throughput (effective area > 500 cm/sup 2/) results in the use of grazing incidence reflection gratings. Due to the low image quality of the telescopes (approx. 1 minute of arc), the grating dispersion must be maximized by use of the classical grating mount in which the spectrum is dispersed within the plane of incident radiation. Due to the small field of view by the x-ray telescopes, the gratings must be situated in the converging beam at the exit of the telescope. A spectrometer module consists of a thin-foil conical mirror telescope, a stack of plane varied-space reflection gratings and an imaging proportional counter. This system is analyzed on the basis of dispersion, geometric aberrations and efficiency. At a spectral resolution of 0.15 A, a twenty module XMM would attain an average effective area of approx.900 cm/sup 2/, reaching twice this value at the peak wavelength (15 A). Similar throughput is obtained in second order centered at 7.5 A, the two spectral orders separated by the non-dispersive energy resolution of the proportional counter. Continuous spectra are obtained in the 6-25 A band (0.5 to 2 keV), and can be extended to 45 A if desired by tuning of the grating. The instrument sensitivity is sufficient to allow the first spectral detection of soft x-ray features in external galaxies, with access to an estimated population of several hundred active galactic nuclei. Such observations will expand vastly the roles feasible for spectroscopy in x-ray astrophysics, marking the beginning of a new era in space astronomy.

Hettrick, M.C.; Kahn, S.M.

1985-10-01

181

High Resolution Soft X-ray Spectroscopy of M87 with the Reflection Grating Spectrometers on XMM-Newton  

Microsoft Academic Search

We present high-resolution X-ray spectroscopic observations of M87 with the\\u000aReflection Grating Spectrometers on XMM-Newton. We detect strong K-shell line\\u000aemission from N, O, Ne, Mg, some emission from He-like Si, a fully resolved set\\u000aof Fe L-shell emission spectra, and some emission from C. The angular intensity\\u000adistributions of the strong emission lines are detectably resolved on scales\\u000a(15-160)

I. Sakelliou; J. R. Peterson; T. Tamura; F. B. S. Paerels; J. S. Kaastra; E. Belsole; H. Boehringer; G. Branduardi-Raymont; C. Ferrigno; J. W. den Herder; J. Kennea; R. F. Mushotzky; W. T. Vestrand; D. M. Worrall

2002-01-01

182

A reflection grating spectrometer for the X-ray Multi-Mirror (XMM) space observatory - Design and calculated performance  

NASA Technical Reports Server (NTRS)

Attention is given to a spectrometer design candidate for the X-ray Multi-Mirror observatory, being planned by the European Space Agency as a long-lived large-area array of telescopes. The science requirement of moderate resolution spectroscopy in a two octave region with extremely high throughput leads to the use of grazing incidence reflection gratings. It is noted that the sensitivity of the instrument is sufficient to permit the first spectral detection of soft X-ray features in external galaxies.

Hettrick, Michael C.; Kahn, Steven M.

1986-01-01

183

Efficiency calibration of the four multilayer-coated holographic ion-etched flight gratings for a sounding rocket high-resolution spectrometer  

Microsoft Academic Search

We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-mm radius of curvature), large (160 mm x 90 mm), and have a laminar groove profile of high density (3600 grooves\\/mm). They have been coated with a high-reflectance multilayer of Mo5C\\/Si\\/Mo2Si. Using an atomic force microscope, we examined

Michael P. Kowalski; Herbert Gursky; Jack C. Rife; Daryl J. Yentis; Raymond G. Cruddace; Troy W. Barbee; William H. Goldstein; Joseph F. Kordas; Klaus F. Heidemann; Gilbert G. Fritz; William R. Hunter; Martin A. Barstow; George W. Fraser; Nigel P. Bannister; Jonathan S. Lapington; J. A. Tandy; B. S. Sanderson

2001-01-01

184

A Tower Concept for the Off-Plane X-ray Grating Spectrometer for the International X-ray Observatory  

NASA Astrophysics Data System (ADS)

An Off-Plane X-ray Grating Spectrometer (OP-XGS) concept is being developed to meet the needs of the International X-ray Observatory (IXO). The OP-XGS will provide the required spectral resolution of R >3000 over the 0.3 - 1 keV band with >1000 cm2 effective collecting area, using experience gained with the current generation of reflection gratings already flown on rocket experiments. We have developed several potential configurations that meet or exceed these requirements and the optical modeling of these designs is presented by Dr. Webster Cash elsewhere at this conference. This paper will focus on the mechanical design and requirements for one of these configurations, the "tower concept. This configuration mounts the grating modules to the instrument platform via a tower, allowing direct alignment with the camera module. This reduces the complexity of the alignment problem while also minimizing the overall mass of the XGS. We have developed an initial interface concept and resource requirements for this option to be reviewed by the mission teams for design drivers. We contrast the resource requirements for this concept with those required for other concepts which have been reviewed by the OP-XGS team. Further, we have identified those portions of the tower design concept that will require potential technology demonstration to reach TRL 6 prior to sensor Preliminary Design Review.

Casement, L. Suzanne; McEntaffer, R.; Cash, W.; Johnson, T.; Lillie, C.

2010-02-01

185

Spectrometer Based on a VLS Grating for Diagnostics of a Vacuum-Ultraviolet Free Electron Laser  

SciTech Connect

Photon beam diagnostics for vacuum-ultraviolet free electron lasers (VUV FEL) are critical to monitoring and understanding their performance characteristics. Due to the shot-to-shot fluctuations inherent in FELs based on the self amplified spontaneous emission (SASE) process, it is mandatory to use pulse-resolved diagnostics. We have designed a spectrograph based on a variable-line-spacing (VLS) plane grating and a phosphor/CCD to monitor single shot spectra of the free electron laser at DESY. The basic concept is to allow most of the beam to be reflected towards an experimental station while the first order light is dispersed and focused by the VLS grating onto the CCD. The spectrograph will cover the wavelength range 6.4-60 nm with the CCD accepting a bandwidth of {approx}10%. The grazing angle of incidence on the grating is 2 deg., the central line density is 1200 l/mm, and the distance grating-CCD is approximately 2 m. The linear variation of the grating line spacing combined with positioning the detector at the focal curve, allows zeroing the defocus in the full spectrograph wavelength range. The correction of higher order grating aberrations yields a theoretical resolving power greater than 20000 over the full length of the 20 mm CCD when the CCD is positioned tangent to the focal plane. Based on power considerations, a shallow blazed grating is the preferred profile. Efficiency calculations over the spectrograph range show that with a carbon coating the absolute efficiency for zeroth order is higher than 0.85 and the first order efficiency varies between 0.5% and 8%.

Reininger, R. [Scientific Answers and Solutions, 5708 Restal St., Madison, WI (United States); Feldhaus, J.; Ploenjes, E.; Treusch, R. [Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, D- 22607 Hamburg (Germany); Roper, M.D.; Quinn, F.M.; Bowler, M.A. [CLRC Daresbury Laboratory, Warrington, WA4 4AD (United Kingdom)

2004-05-12

186

X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility  

SciTech Connect

An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution {approx} 50. It has been used at the LULI-2000 laser facility at Ecole Polytechnique (France) to measure the {Delta}n = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

Reverdin, Charles; Caillaud, T.; Gilleron, F.; Pain, J. C.; Silvert, V.; Soullie, G.; Villette, B. [CEA, DAM, DIF, 91297 Arpajon (France); Thais, Frederic; Loisel, Guillaume; Blenski, T.; Poirier, M. [CEA, DSM, IRAMIS, Service Photons, Atomes et Molecules, 91191 Gif-sur-Yvette (France); Busquet, M. [ARTEP Inc, Ellicott City, Maryland 21042 (United States); Bastiani-Ceccotti, S.; Serres, F. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); Ducret, J. E. [CELIA, UMR5107, CEA, CNRS, Universite de Bordeaux, 33400 Talence (France); Foelsner, W. [Max Planck Instituet fuer Quantum Optik, 85748 Garching (Germany); Gilles, D.; Turck-Chieze, S. [CEA, DSM, IRFU, Service d'astrophysique, 91191 Gif-sur-Yvette (France)

2012-10-15

187

Optical design of a grazing incidence spectrometer\\/monochromater with varied line-space flat grating for high-order harmonic diagnostic  

Microsoft Academic Search

The optical design of an EUV spectrometer\\/monochromator for diagnostic of high-order harmonics generated by an ultra-short (less than 30 fs) pulsed laser focused onto a gas jet is presented. A grazing-incidence flat-field spectrometer for the 3 - 75 nm spectral region has been designed: it adopts a stigmatic toroidal mirror and a varied line-space flat grating mounted in converging light.

Luca Poletto; Giampiero Naletto; Giuseppe Tondello

1999-01-01

188

Measurement of spatial modes of broad-area diode lasers with 1GHz resolution grating spectrometer  

Microsoft Academic Search

A 1-GHz resolution double-pass grating spectroscopy of broad-area diode lasers is performed. Measurements of spatial and spectral distribution of emitting power are performed as a function of pumping current. Results are confronted with the mode structure of gain-guided waveguide. Nonlinear coupling of lateral modes has been observed and quantified

Nikolai Stelmakh; Max Flowers

2006-01-01

189

Silicon-on-insulator spectrometers with integrated GaInAsSb photodiodes for wide-band spectroscopy from 1510 to 2300 nm.  

PubMed

We present a silicon-on-insulator (SOI) based spectrometer platform for a wide operational wavelength range. Both planar concave grating (PCG, also known as echelle grating) and arrayed waveguide grating (AWG) spectrometer designs are explored for operation in the short-wave infrared. In addition, a total of four planar concave gratings are designed to cover parts of the wavelength range from 1510 to 2300 nm. These passive wavelength demultiplexers are combined with GaInAsSb photodiodes. These photodiodes are heterogeneously integrated on SOI with benzocyclobutene (DVS-BCB) as an adhesive bonding layer. The uniformity of the photodiode characteristics and high processing yield, indicate a robust fabrication process. We demonstrate good performance of the miniature spectrometers over all operational wavelengths which paves the way to on-chip absorption spectroscopy in this wavelength range. PMID:23482178

Ryckeboer, E; Gassenq, A; Muneeb, M; Hattasan, N; Pathak, S; Cerutti, L; Rodriguez, J B; Tourni, E; Bogaerts, W; Baets, R; Roelkens, G

2013-03-11

190

EXES: The Echelon-Cross-Echelle Spectrograph for SOFIA  

NASA Astrophysics Data System (ADS)

The Echelon-cross-Echelle Spectrograph (EXES) is one of the first generation instruments for the Stratospheric Observatory for Infrared Astronomy (SOFIA). It operates at high, medium, and low spectral resolution in the wavelength region 4.5 to 28.3 microns using a 1024x1024 Si:As detector array. From SOFIA, the high spectral resolution mode (R 100,000) will provide truly unique data given the improved atmospheric transmission. We present the current status of EXES including lab results with a new echelle grating, which enables the low resolution mode and a camera mode in addition to the previously available high and medium resolution modes.

DeWitt, Curtis N.; Richter, M. J.; McKelvey, M. E.; Seifahrt, A.

2012-01-01

191

A portable flat-field concave grating spectrometer with high resolution  

NASA Astrophysics Data System (ADS)

The resolution of spectrometer can be increased by using multiple detectors. But for the portable spectrometer, the relatively wide edge that used to fix the detector can seriously influence the imaging quality. And the multiple detectors will increase the difficulty of the circuit part. In this paper, a novel method is introduced to increase the resolution by using one detector. The whole waveband is divided into two wavebands in this new structure. And the long waveband will be reflected by a mirror to the definitely location in which the short wave is located. This structure will not only solve the influence of the detector's edge but also lower the cost of circuit part. By the simulation of the ZEMAX, the resolution of the spectrometer using the new method is better than the current works using one detector in the whole waveband.

Zhou, Qian; Pang, Jinchao; Ni, Kai

2014-11-01

192

Optical Transfer Function of Concave Grating Spectrometer Based on Wave Optical Method  

Microsoft Academic Search

Optical transfer functions (OTF) of two types of spectrometer --- Eagle mounting and Seya-Namioka mounting --- are calculated by the wave-optical method which defines the OTF as the autocorrelation function of the pupil. Results obtained are compared with previous results of the present authors and interpreted as effects of diffraction and aberration on the broadening of point image. The OTFs

Tsuneo Katayama; Akio Takahashi

1970-01-01

193

NIR spectroscopy on moving solids using a scanning grating spectrometerimpact on multivariate process analysis  

Microsoft Academic Search

The effect of sample movement on spectral response during fiber probe diffuse reflectance near-infrared spectrometry (NIR) sampling was characterized. This is of central importance in Process Analytical Chemistry (PAC) and Process Analytical Technology (PAT). The incitement to this study was the observation of spectral artifacts during measurements of powder samples in process streams when using a mechanically scanning spectrometer. Artifacts

M. Andersson; O. Svensson; S. Folestad; M. Josefson; K.-G. Wahlund

2005-01-01

194

Fully Automated Imaging Spectrometer  

E-print Network

Fully Automated Imaging Spectrometer User Manual Part Number 81092 ­ Revision 2 #12;Copyright................................................................................................................ 12 Installing the Grating)......................................................................................... 15 Installing the USB Spectrometer Utilities Software

Rubloff, Gary W.

195

Computed tomography imaging spectrometer (CTIS) with 2D reflective grating for ultraviolet to long-wave infrared detection especially useful for surveying transient events  

NASA Technical Reports Server (NTRS)

The optical system of this invention is an unique type of imaging spectrometer, i.e. an instrument that can determine the spectra of all points in a two-dimensional scene. The general type of imaging spectrometer under which this invention falls has been termed a computed-tomography imaging spectrometer (CTIS). CTIS's have the ability to perform spectral imaging of scenes containing rapidly moving objects or evolving features, hereafter referred to as transient scenes. This invention, a reflective CTIS with an unique two-dimensional reflective grating, can operate in any wavelength band from the ultraviolet through long-wave infrared. Although this spectrometer is especially useful for rapidly occurring events it is also useful for investigation of some slow moving phenomena as in the life sciences.

Wilson, Daniel W. (Inventor); Maker, Paul D. (Inventor); Muller, Richard E. (Inventor); Mouroulis, Pantazis Z. (Inventor)

2003-01-01

196

High resolution soft X-ray spectroscopy of the elliptical galaxy NGC 5044. Results from the reflection grating spectrometer on-board XMM-Newton  

Microsoft Academic Search

The results from an X-ray spectroscopic study of the giant elliptical galaxy NGC 5044 in the center of a galaxy group are presented. The line dominated soft X-ray spectra (mainly Fe-L and O Viii Lyalpha ) from the diffuse gas are resolved for the first time in this system with the Reflection Grating Spectrometers on-board XMM-Newton and provide a strong

T. Tamura; J. S. Kaastra; K. Makishima; I. Takahashi

2003-01-01

197

High-Resolution Spectroscopy of the X-Ray-photoionized Wind in Cygnus X-3 with the Chandra High-Energy Transmission Grating Spectrometer  

Microsoft Academic Search

We present a preliminary analysis of the 1-10 keV spectrum of the massive X-ray binary Cygnus X-3, obtained with the high-energy transmission grating spectrometer on the Chandra X-Ray Observatory. The source reveals a richly detailed discrete emission spectrum, with clear signatures of photoionization-driven excitation. Among the spectroscopic novelties in the data are the first astrophysical detections of a number of

Frits Paerels; Jean Cottam; Masao Sako; Duane A. Liedahl; A. C. Brinkman; J. S. Kaastra; P. Predehl

2000-01-01

198

First Light Measurements of Capella with the Low Energy Transmission Grating Spectrometer aboard the Chandra X-ray Observatory  

E-print Network

We present the first X-ray spectrum obtained by the Low Energy Transmission Grating Spectrometer (LETGS) aboard the Chandra X-ray Observatory. The spectrum is of Capella and covers a wavelength range of 5-175 A (2.5-0.07 keV). The measured wavelength resolution, which is in good agreement with ground calibration, is $\\Delta \\lambda \\simeq$ 0.06 A (FWHM). Although in-flight calibration of the LETGS is in progress, the high spectral resolution and unique wavelength coverage of the LETGS are well demonstrated by the results from Capella, a coronal source rich in spectral emission lines. While the primary purpose of this letter is to demonstrate the spectroscopic potential of the LETGS, we also briefly present some preliminary astrophysical results. We discuss plasma parameters derived from line ratios in narrow spectral bands, such as the electron density diagnostics of the He-like triplets of carbon, nitrogen, and oxygen, as well as resonance scattering of the strong Fe XVII line at 15.014 A.

A. C. Brinkman; C. J. T. Gunsing; J. S. Kaastra; R. L. J. van der Meer; R. Mewe; F. Paerels; A. J. J. Raassen; J. J. van Rooijen; H. Bruninger; W. Burkert; V. Burwitz; G. Hartner; P. Predehl; J. -U. Ness; J. H. M. M. Schmitt; J. J. Drake; O. Johnson; M. Juda; V. Kashyap; S. S. Murray; D. Pease; P. Ratzlaff; B. J. Wargelin

2000-01-04

199

High resolution X-Ray spectroscopy of Zeta Puppis with the XMM-Newton Reflection Grating Spectrometer  

E-print Network

We present the first high resolution X-ray spectrum of the bright O4Ief supergiant star Zeta Puppis, obtained with the Reflection Grating Spectrometer on-board XMM-Newton. The spectrum exhibits bright emission lines of hydrogen-like and helium-like ions of nitrogen, oxygen, neon, magnesium, and silicon, as well as neon-like ions of iron. The lines are all significantly resolved, with characteristic velocity widths of order 1000-1500 km s^{-1}. The nitrogen lines are especially strong, and indicate that the shocked gas in the wind is mixed with CNO-burned material, as has been previously inferred for the atmosphere of this star from ultraviolet spectra. We find that the forbidden to intercombination line ratios within the helium-like triplets are anomalously low for N VI, O VII, and Ne IX. While this is sometimes indicative of high electron density, we show that in this case, it is instead caused by the intense ultraviolet radiation field of the star. We use this interpretation to derive constraints on the location of the X-ray emitting shocks within the wind that are consistent with current theoretical models for this system.

S. M. Kahn; M. A. Leutenegger; J. Cottam; G. Rauw; J. -M. Vreux; A. J. F. den Boggende; R. Mewe; M. Guedel

2000-11-01

200

High Resolution Spectroscopy of 14 Cooling-Flow Clusters of Galaxies Using the Reflection Grating Spectrometers on XMM-Newton  

E-print Network

We present high resolution X-ray spectra of 14 cooling-flow X-ray clusters and groups obtained with the Reflection Grating Spectrometers (RGS) on XMM-Newton. The spectra exhibit line emission from a number of Fe L charge states as well as O VIII, Mg XII, Ne X, Si XIV & XIII, N VII, and C VI. All spectra show a deficit of soft X-ray lines predicted from the isobaric multi-phase spectral model as compared with morphological mass deposition rates from spatially-resolved spectroscopy with the European Photon Imaging Cameras (EPIC). We present some weak detections of plasma several times cooler than the ambient cluster temperatures. The results further suggest that either morphological mass deposition rates systematically overestimate the actual cooling rate or the emission measure of cooling-flows has a much steeper distribution than that predicted by a simple isobaric multi-phase model. We briefly discuss some modifications to the cooling-flow process.

J. R. Peterson; C. Ferrigno; J. S. Kaastra; F. B. S. Paerels; S. M. Kahn; J. G. Jernigan; J. A. M. Bleeker; T. Tamura

2002-02-05

201

High Resolution Observations of the Elliptical Galaxy NGC 4636 with the Reflection Grating Spectrometer On-Board XMM-Newton  

E-print Network

We present the first high spectral resolution X-ray observation of the giant elliptical galaxy NGC 4636, obtained with the Reflection Grating Spectrometer on-board the XMM-Newton Observatory. The resulting spectrum contains a wealth of emission lines from various charge states of oxygen, neon, magnesium, and iron. Examination of the cross-dispersion profiles of several of these lines provides clear, unambiguous evidence of resonance scattering by the highest oscillator strength lines, as well as a weak temperature gradient in the inner regions of the interstellar medium. We invoke a sophisticated new Monte Carlo technique which allows us to properly account for these effects in performing quantitative fits to the spectrum. Our spectral fits are not subject to many of the systematics that have plagued earlier investigations. The derived metal abundances are higher than have been inferred from prior, lower spectral resolution observations of this source (Awaki et al. 1994), but are still incompatible with conventional chemical enrichment models of elliptical galaxies. In addition, our data are incompatible with standard cooling flow models for this system - our derived upper limit to the mass deposition rate is below the predicted value by a factor of 3--5.

H. Xu; S. M. Kahn; J. R. Peterson; E. Behar; F. B. S. Paerels; R. F. Mushotzky; J. G. Jernigan; K. Makishima

2001-09-30

202

High Resolution Soft X-ray Spectroscopy of M87 with the Reflection Grating Spectrometers on XMM-Newton  

E-print Network

We present high-resolution X-ray spectroscopic observations of M87 with the Reflection Grating Spectrometers on XMM-Newton. We detect strong K-shell line emission from N, O, Ne, Mg, some emission from He-like Si, a fully resolved set of Fe L-shell emission spectra, and some emission from C. The angular intensity distributions of the strong emission lines are detectably resolved on scales (15-160) arcsec. The gas in the inner arcmin of M87 has a multi-phase structure, as indicated by the similarity of the emission line profiles of Fe L shell ions with widely separated ionization potentials. The global Fe L spectrum is approximately consistent with an isothermal plasma at kT_e ~ 1.8 keV, in addition to a component with a temperature distribution appropriate to an isobaric cooling flow, but with a minimum temperature cutoff of kT_min ~ 600 eV. The behaviour of this cooling-flow component is qualitatively similar to what is seen in other cooling flow clusters. Finally, we do not find any strong evidence for a spatial variation in abundances due to resonance scattering redistribution in the inner arcminute of the core.

I. Sakelliou; J. R. Peterson; T. Tamura; F. B. S. Paerels; J. S. Kaastra; E. Belsole; H. Boehringer; G. Branduardi-Raymont; C. Ferrigno; J. W. den Herder; J. Kennea; R. F. Mushotzky; W. T. Vestrand; D. M. Worrall

2002-06-14

203

A Long Look at NGC 3783 with the XMM-Newton Reflection Grating Spectrometers  

E-print Network

A long 280 ks observation of the Seyfert 1 galaxy NGC 3783 with XMM-Newton is reported. We focus on the oxygen line complex between 17 and 24 A as measured with the RGS spectrometers. Accurate absorption column densities and emission line fluxes are obtained. We explore several options for the geometry and physical form of the emitting and absorbing gas. The lack of change in ionization in the absorber despite an increase in continuum flux during the observation restricts the high-ionization (O-K) and the low-ionization (Fe-M) gas to distances of at least 0.5 pc and 2.8 pc, respectively, away from the central source. Given the P-Cygni type profiles in the resonance spectral lines and the similar velocity widths, column densities, and ionization structure inferred separately from the emission and absorption lines, it is tempting to relate the X-ray narrow-line emitting plasma with the X-ray absorbing gas. Under this assumption, the scenario of dense clumped clouds can be ruled out. Conversely, extended ionization cones (r > 10 pc) are consistent with the observation independent of this assumption. These findings are in stark contrast with the picture of numerous clumpy (n_e > 10^9 cm^-3) clouds drawn recently from UV spectra, but it is consistent with the extended X-ray emission cones observed directly in Seyfert 2 galaxies.

Ehud Behar; Andrew P. Rasmussen; Alexander J. Blustin; Masao Sako; Steven M. Kahn; Jelle S. Kaastra; Graziella Branduardi-Raymont; Katrien C. Steenbrugge

2003-07-27

204

Imaging spectrometer for high resolution measurements of stratospheric trace constituents in the ultraviolet  

NASA Technical Reports Server (NTRS)

A high-resolution spectrometer has been developed for studies of minor constituents in the middle atmosphere at ultraviolet wavelengths. In particular, the instrument is intended for observations of upper stratospheric UV bands. The spectrometer has a slit width of 0.08 A obtained by means of an echelle grating and a cross-disperser grating. The image plane detector is an intensified CCD consisting of a high gain proximity focused image intensifier that is fiber optically coupled to a two-dimensional CCD array. An instantaneous bandwidth of 9.2 A is resolved across 488 pixels at 0.018 A/pixel, permitting simultaneous acquisition of multiple lines of selected OH bands and the neighboring background. The spectrometer and the approach have been successfully demonstrated as a technique for measuring the concentration of OH on two high-altitude balloon flights. This paper reports the instrument design and its achieved performance.

Torr, Marsha R.; Torr, D. G.

1988-01-01

205

EXES: an echelon cross echelle spectrograph for SOFIA  

NASA Astrophysics Data System (ADS)

To study narrow features in quiescent molecular clouds, a high spectral resolution, high sensitivity instrument is required. We present the design and capabilities of a mid-IR spectrograph being built as a PI instrument for the Stratospheric Observatory for IR Astronomy. The Echelon- Cross-Echelle Spectrograph (EXES) will operate from 5.5-28.5 micrometers in three spectroscopic modes: R approximately 10(superscript 5), 10(superscript 4), and 1500. EXES is similar in concept to our ground based instrument, TEXES. EXES consists of three chambers. The first chamber contains focal-reducing optics. The second chamber houses the high resolution grating, an echelon. Discussion of the echelon can be found elsewhere in this volume. The third chamber contains an echelle grating and a first order grating mounted back-to-back. A flip mirror selects operating mode by either directing light into the echelon chamber or allowing the light to pass through to the grating chamber. Re-imaging optics upstream of the detector provide two plate scales. The detector, a 256 by 256 pixel Si:As IBC, is in a baffled subsection of the third chamber. Finally, the low resolution grating serves as a slit positioning camera when it is rotated face on.

Richter, Matthew J.; Lacy, John H.; Jaffe, Daniel T.; Hemenway, Mary Kay; Yu, Wanglong

1998-08-01

206

XMM-Newton Reflection Grating Spectrometer Observations of Discrete Soft-X-ray Emission Features from NGC 1068  

E-print Network

We present the first high-resolution, soft-X-ray spectrum of the prototypical Seyfert 2 galaxy, NGC 1068. This spectrum was obtained with the XMM-Newton Reflection Grating Spectrometer. Emission lines from H-like and He-like low-Z ions (from C to Si) and Fe-L-shell ions dominate the spectrum. Strong, narrow radiative recombination continua (RRC) for several ions are also present, implying that most of the observed soft-X-ray emission arises in low-temperature (few eV) plasma. This plasma is photoionized by the inferred nuclear continuum (obscured along our line of sight), as in the unified model of active galactic nuclei (AGN). We find excess emission (compared with pure recombination) in all resonance lines (np to 1s) up to the photoelectric edge, demonstrating the importance of photoexcitation as well. We introduce a simple model of a cone of plasma irradiated by the nuclear continuum; the line emission we observe along our line of sight perpendicular to the cone is produced through recombination/radiative cascade following photoionization and radiative decay following photoexcitation. A remarkably good fit is obtained to the H-like/He-like ionic line series, with inferred radial ionic column densities consistent with recent observations of warm absorbers in Seyfert 1 galaxies. Previous Chandra imaging revealed a large (extending out to 500 pc) ionization cone containing most of the X-ray flux, implying that the warm absorber in NGC 1068 is a large-scale outflow. To explain the ionic column densities, a broad, flat distribution in the logarithm of the ionization parameter ($\\xi=L_X/n_e r^2$) is necessary, spanning $\\log\\xi=0$--3. This suggests either radially-stratified ionization zones or the existence of a broad density distribution (spanning a few orders of magnitude) at each radius.

A. Kinkhabwala; M. Sako; E. Behar; S. M. Kahn; F. Paerels; A. C. Brinkman; J. S. Kaastra; M. F. Gu; D. A. Liedahl

2002-03-19

207

Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer  

SciTech Connect

We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-nm radius of curvature), large (160 mmx90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si. Using an atomic force microscope, we examined the surface characteristics of the first grating before and after multilayer coating. The average roughness is approximately 3 Aa rms after coating. Using synchrotron radiation, we completed in efficiency calibration map over the wavelength range 225-245 Aa. At an angle of incidence of 5 degree sign and a wavelength of 232 Aa, the average efficiency in the first inside order is 10.4{+-}0.5%, and the derived groove efficiency is 34.8{+-}1.6%. These values exceed all previously published results for a high-density grating. (c) 1999 Optical Society of America.

Kowalski, Michael P. [Naval Research Laboratory, Washington, D.C. 20375 (United States); Barbee, Troy W. Jr. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Heidemann, Klaus F. [Carl Zeiss, D-73446, Oberkochen, (Germany); Gursky, Herbert [Naval Research Laboratory, Washington, D.C. 20375 (United States); Rife, Jack C. [Naval Research Laboratory, Washington, D.C. 20375 (United States); Hunter, William R. [SFA Incorporated, 1401 McCormick Drive, Largo, Maryland 20774 (United States); Fritz, Gilbert G. [Naval Research Laboratory, Washington, D.C. 20375 (United States); Cruddace, Raymond G. [Naval Research Laboratory, Washington, D.C. 20375 (United States)

1999-11-01

208

Electrically-programmable diffraction grating  

DOEpatents

An electrically-programmable diffraction grating. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers).

Ricco, Antonio J. (Albuquerque, NM); Butler, Michael A. (Albuquerque, NM); Sinclair, Michael B. (Albuquerque, NM); Senturia, Stephen D. (Brookline, MA)

1998-01-01

209

A new grating X-ray spectrometer for 2-4 keV enabling a separate observation of In-L? and Sn-L? emissions of indium tin oxide.  

PubMed

A new multilayer-coated varied line-spaced grating, JS4000, was fabricated and tested for extending the upper limit of a grating X-ray spectrometer for electron microscopy. This grating was designed for 2-3.8 keV at a grazing incidence angle of 1.35. It was revealed that this new multilayer structure enables us to take soft-X-ray emission spectra continuously from 1.5 to 4.3 keV at the same optical setting. The full-width at half maximum of Te-L(?1,2) (3.8 keV) emission peak was 27 eV. This spectrometer was applied to indium tin oxide particles and clearly resolved Sn-L(?) (3444 eV) and In-L(?1) (3487 eV) peaks, which could not be resolved by a widely used energy-dispersive X-ray spectrometer. PMID:23307948

Terauchi, Masami; Takahashi, Hideyuki; Handa, Nobuo; Murano, Takanori; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Koeda, Masaru; Nagano, Tetsuya; Sasai, Hiroyuki; Oue, Yuki; Yonezawa, Zeno; Kuramoto, Satoshi

2013-06-01

210

Effective area calibration of the reflection grating spectrometers of XMM-Newton. II. X-ray spectroscopy of DA white dwarfs  

E-print Network

White dwarf spectra have been widely used as a calibration source for X-ray and EUV instruments. The in-flight effective area calibration of the reflection grating spectrometers (RGS) of XMM-Newton depend upon the availability of reliable calibration sources. We investigate how well these white dwarf spectra can be used as standard candles at the lowest X-ray energies in order to gauge the absolute effective area scale of X-ray instruments. We calculate a grid of model atmospheres for Sirius B and HZ 43A, and adjust the parameters using several constraints until the ratio of the spectra of both stars agrees with the ratio as observed by the low energy transmission grating spectrometer (LETGS) of Chandra. This ratio is independent of any errors in the effective area of the LETGS. We find that we can constrain the absolute X-ray spectrum of both stars with better than 5 % accuracy. The best-fit model for both stars is close to a pure hydrogen atmosphere, and we put tight limits to the amount of helium or the th...

Kaastra, J S; Hubeny, I; Paerels, F B S

2009-01-01

211

A radial velocity spectrometer for the Automated Planet Finder Telescope at Lick Observatory  

NASA Astrophysics Data System (ADS)

The Ken and Gloria Levy Spectrometer is being constructed at the Instrument Development Laboratory (Technical Facilities) of UCO/ Lick Observatory for use on the 2.4 meter Automated Planet Finder Telescope at Mt. Hamilton. The mechanical design of the instrument has been optimized for precision Doppler measurements. A key component of the design is the space-frame structure that contains passive thermal compensation. Determinate hexapod structures are used to mount the collimator, prism, and echelle grating. In this paper we describe the instrument mechanical design and some features that will help it detect rocky planets in the habitable zone.

Radovan, Matthew V.; Cabak, Gerald F.; Laiterman, Lee H.; Lockwood, Christopher T.; Vogt, Steven S.

2010-07-01

212

Spectroscopic evaluation of three different gratings used for a flat-field extreme ultraviolet spectrometer to monitor {delta}n=1 transitions from medium-Z impurities in 10-30 A  

SciTech Connect

Spectral characteristics of varied line spacing 2400 grooves/mm gratings used for a flat-field extreme ultraviolet spectrometer have been evaluated to monitor {delta}n=1 (n=2-3) transitions from medium-Z impurities in 10-30 A, where many spectral lines from metallic impurities closely exist. For this purpose emission spectra of the {delta}n=1 transitions from partially L-shell-ionized Ti and Fe have been measured in large helical device. At first, a ruled and a holographic grating were utilized for the comparative study. Both gratings suppressed higher order light effectively but spectral sensitivity was much higher for the holographic grating. The ruled grating, however, attained better spectral resolution (0.083 A at 18.97 A) in the 10-100 A range compared to that (0.130 A) of the holographic grating. After that a recently developed new holographic grating with different laminar shapes and line spacings has attempted to improve the spectral resolution. As a result, it has considerably improved the spectral resolution in the 10-30 A range, i.e., {approx}0.090 A. However, it is found that the experimentally obtained spectral resolution is quit poor compared to the computationally simulated one, suggesting a technical difficulty in manufacturing exactly the varied line spacing of the holographic grating at such a short wavelength range.

Chowdhuri, Malay Bikas [Department of Fusion Science, Graduate University for Advanced studies, Toki, Gifu 509-5292 (Japan); Morita, Shigeru; Goto, Motoshi [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Sasai, Hiroyuki [Shimadzu Corporation, Kyoto 604-8511 (Japan)

2008-10-15

213

Chandra\\/High Energy Transmission Grating Spectrometer Spectroscopy of the Galactic Black Hole GX 339-4: A Relativistic Iron Emission Line and Evidence for a Seyfert-like Warm Absorber  

Microsoft Academic Search

We observed the Galactic black hole GX 339-4 with the Chandra High Energy Transmission Grating Spectrometer (HETGS) for 75 ks during the decline of its 2002-2003 outburst. The sensitivity of this observation provides an unprecedented glimpse of a Galactic black hole at about a tenth of the luminosity of the outburst peak. The continuum spectrum is well described by a

J. M. Miller; J. Raymond; A. C. Fabian; J. Homan; M. A. Nowak; R. A. D. Wijnands; M. van der Klis; T. Belloni; J. A. Tomsick; D. M. Smith; P. A. Charles; W. H. G. Lewin

2004-01-01

214

High Resolution Spectroscopy of the X-ray Photoionized Wind in Cygnus X-3 with the Chandra High Energy Transmission Grating Spectrometer  

E-print Network

We present a preliminary analysis of the 1--10 keV spectrum of the massive X-ray binary Cyg X-3, obtained with the High Energy Transmission Grating Spectrometer on the Chandra X-ray Observatory. The source reveals a richly detailed discrete emission spectrum, with clear signatures of photoionization-driven excitation. Among the spectroscopic novelties in the data are the first astrophysical detections of a number of He-like 'triplets' (Si, S, Ar) with emission line ratios characteristic of photoionization equilibrium, fully resolved narrow radiative recombination continua of Mg, Si, and S, the presence of the H-like Fe Balmer series, and a clear detection of a ~ 800 km/s large scale velocity field, as well as a ~1500 km/s FWHM Doppler broadening in the source. We briefly touch on the implications of these findings for the structure of the Wolf-Rayet wind.

Frits Paerels; Jean Cottam; Masao Sako; Duane A. Liedahl; A. C. Brinkman; R. L. J. van der Meer; J. S. Kaastra; P. Predehl

2000-02-16

215

Grating spectrometer system for beam emission spectroscopy diagnostics using high-energy negative-ion-based neutral beam injection on LHD  

SciTech Connect

A beam emission spectroscopy (BES) system was developed for density gradient and fluctuation diagnostics in the Large Helical Device (LHD). In order to cover the large Doppler shift of the H{alpha} beam emission because of the high-energy negative-ion-based neutral beam atom (acceleration voltage V{sub acc}=90-170 kV) and the large motional Stark splitting due to the large vxB field (magnetic field B=3.0 T), a grating spectrometer was used instead of a conventional interference filter system. The reciprocal linear dispersion is about 2 nm/mm, which is sufficient to cover the motional Stark effect spectra using an optical fiber with a diameter of 1 mm.

Kado, S. [School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Oishi, T. [Graduate School/School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Yoshinuma, M.; Ida, K. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)

2010-10-15

216

The opto-mechanical design of the Colorado High-resolution Echelle Stellar Spectrograph (CHESS)  

NASA Astrophysics Data System (ADS)

We present the Colorado High-resolution Echelle Stellar Spectrograph (CHESS) sounding rocket payload. The design uses a mechanical collimator made from a grid of square tubing, an objective echelle grating, a holographically-ruled cross-disperser, a new 40 mm MCP with a cross strip anode or a delta-doped 3.5k x 3.5k CCD detector. The optics are suspended using carbon fiber rods epoxied to titanium inserts to create a space frame structure. A preliminary design is presented.

Kane, Robert; Beasley, Matthew; Green, James; Burgh, Eric; France, Kevin

2011-09-01

217

The Discovery of Broad P Cygni X-ray Lines from Circinus X-1 with the Chandra High Energy Transmission Grating Spectrometer  

E-print Network

We present the first grating-resolution X-ray spectra of the X-ray binary Cir X-1, obtained with the High Energy Transmission Grating Spectrometer on Chandra. These reveal a rich set of lines from H-like and/or He-like Ne, Mg, Si, S and Fe detected with a high signal-to-noise ratio. The lines are broad (+/- 2000 km/s) and show P Cygni profiles. The absorption components of the lines extend to low velocity, and they have about the same widths and strengths as the corresponding emission components. The widths of the X-ray P Cygni lines are comparable to that of the broad component of the strong, asymmetric H-alpha line from Cir X-1, suggesting that the two phenomena may be related. We discuss outflow models and propose that the P Cygni profiles may arise in the moderate temperature (5 x 10^6 K) region of the wind from an X-ray heated accretion disk. This basic picture strengthens the idea that the accretion disk in Cir X-1 is viewed in a relatively edge-on manner, and it suggests that Cir X-1 is the X-ray binary analog of a Broad Absorption Line quasar.

W. N. Brandt; N. S. Schulz

2000-07-26

218

High sensitivity transient infrared spectroscopy: a UV/Visible transient grating spectrometer with a heterodyne detected infrared probe.  

PubMed

We describe here a high sensitivity means of performing time resolved UV/Visible pump, infrared probe spectroscopy using optically Heterodyne Detected UV-IR Transient Gratings. The experiment design employed is simple, robust and includes a novel means of generating phase locked pulse pairs that relies on only mirrors and a beamsplitter. A signal to noise ratio increase of 24 compared with a conventional pump-probe arrangement is demonstrated. PMID:22714305

Donaldson, Paul M; Strzalka, Halina; Hamm, Peter

2012-06-01

219

Externally Dispersed Interferometry with the Lick Observatory Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

We demonstrate stellar and solar measurements of full-bandwidth echelle spectra using an externally dispersed interferometer (EDI). Spectral resolution of ~120k has been obtained using the ~60k resolution CAT facility at the Lick Observatory. The EDI is a series combination of a fixed delay interferometer and a grating spectrograph that increases the spectrograph's effective resolution by factors of 2 to 3. EDI uses a heterodyning effect to shift the input spectrum's high spectral resolution information to lower spatial frequencies that are less sensitive to the resolution limit caused by the spectrograph slit size and by the Nyquist limit of the detector. The resolution-boosted spectra is obtained by numerically reversing the heterodyning effect and combining these data with the ordinary spectrum simultaneously acquired within the EDI data. The interferometer fringes imprinted on the spectrum are exactly periodic in frequency space and acts as a fiducial net that uniformly covers the entire echelle bandwidth. Instrumental distortions that deviate the stellar signal also deviate these fiducial fringes, so the measurement, in comparison to a classical echelle data, is extremely robust to beam profile errors. Our method uses a uniform-phase interferometer fringe at the spectrograph entrance slit. Therefore the spectrograph may use either a 2d-echelle or slit-imaging format. The EDI has applications in Doppler radial velocimetry and high resolution spectroscopy. Work was partially supported by CalSpace/Lockheed, and NASA SARA research grants NAG5-9091 and NAG5-3051. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Erskine, D. J.; Edelstein, J.

2002-12-01

220

Far-ultraviolet imaging spectrograph and scanning grating spectrometers for the Remote Atmospheric and Ionospheric Detection System  

Microsoft Academic Search

The Remote Atmospheric and Ionospheric Detection System (RAIDS) experiment is an optical remote sensing platform consisting of eight sensors, (spectrographs, spectrometers, and photometers) covering the wavelength range 550 to 8744 [angstrom]. RAIDS employs a mechanical scan platform to view the Earth's limb and measure line-of-sight column emission from tangent altitudes from 50 to 750 km. These measurements provide vertical profiles

Robert P. McCoy; R. R. Meier; K. D. Wolfram; J. M. Picone; S. E. Thonnard; G. G. Fritz; J. S. Morrill; D. A. Hardin; A. B. Christensen; D. C. Kayser; J. B. Pranke; P. R. Straus

1994-01-01

221

An aureole-corrected Langley-plot method developed for the calibration of HiRES grating spectrometers  

Microsoft Academic Search

Ground-based sensors for the vicarious calibration of spaceborne Earth remote-sensing spectrometers must be Sun-calibrated for measurements of direct solar irradiance spectra. The best results for Sun calibration control gives the classical refined Langley-plot analysis at high altitude clean air sites. This analysis fails in general for near sea-level measurements due to unstable atmosphere and inhomogeneous layers during a calibration phase.

J. Nieke; B. Pflug; G. Zimmermann

1999-01-01

222

Broad-spectral-range synchronized flat-top arrayed-waveguide grating applied in a 225-channel cascaded spectrometer.  

PubMed

We present a new synchronized design for flattening the passband of an arrayed-waveguide grating (AWG) over a broad wavelength range of 90 nm. A wavelength-insensitive 3-dB balanced coupler is designed to be used in duplicate in a Mach-Zehnder interferometer (MZI); the phase deviation created by one of the balanced couplers is cancelled by flipping the other coupler around. This MZI is arranged in tandem with the AWG such that the output signal of the MZI is the input signal of the AWG. We demonstrate a 5-channel, 18-nm-spacing AWG with a 0.5-dB bandwidth of 12 nm over a 90-nm spectral range. A low-loss cascaded AWG system is demonstrated by using the MZI-synchronized flat-top AWG as a primary filter. PMID:23038381

Akca, B I; Doerr, C R; Sengo, G; Wrhoff, K; Pollnau, M; de Ridder, R M

2012-07-30

223

The Time-Dependent Sensitivity of the MAMA and CCD Long-Slit Gratings  

NASA Astrophysics Data System (ADS)

We present the results of observing flux standard stars used to determine trends in the sensitivities of the five STIS low-resolution, long-slit gratings between 1997 and 2013. Also, the assumption that the sensitivity trends for the medium-resolution and echelle gratings are the same as those for the corresponding low-resolution gratings is tested.

Holland, Stephen T.; Aloisi, Alessandra; Bostroem, Azalee; Oliveria, Cristina; Proffitt, Charles

2014-12-01

224

Optimal Extraction of Echelle Spectra  

NASA Astrophysics Data System (ADS)

The extraction of the echelle spectra registered with a CCD detector represents a big challenge because of three reasons: (1) the pixel sampling is often close or worse then optimal, (2) spectral orders are curved and tilted with respect to the CCD rows (or columns) and (3) every pixel contains additional noise coming from various sources as illustrated in Figure 1. The main goal of an optimal extraction is to recover as much of the science signal while minimizing the contribution of the noise. Here we present the Slit Function Decomposition algorithm which replaces the summation in a sliding window with a reconstruction of the slit illumination profile. The reconstruction is formulated as an inverse problem solved by iterations and it is robust against most of the systematic problems including cosmic rays and cosmetic defects.

Piskunov, Nikolai

225

Study of keV radiation properties of Mo and Ti X-pinch plasma sources using a pinhole transmission grating spectrometer  

SciTech Connect

The properties of keV x-ray radiations from Mo and Ti X-pinch plasma sources at the current of 800 kA were investigated by a pinhole transmission grating spectrometer. The spectrometer was characterized by a high linear dispersion rate (2.9 A/mm), and from its time-integrated diffraction images, rich information about the X-pinch sources (e.g., source number, source size, and absolute spectra) could be obtained. Multiple hot spots were produced in all the Mo tests with loads made of two or four 25 mum wires with or without a shunt wire, and obvious increases both in the radiation intensity and in the source size around the spectral region of 2.6 keV were observed. In Ti X-pinch tests, a single keV x-ray burst with a source size of approx200 mum and a time duration of approx200 ps in full width at half maximum was obtained using a load made of two 50 mum wires plus a shunt wire. The intensity of x-rays decreased sharply from approx10{sup 11} photon eV{sup -1} sr{sup -1} at 1 keV to approx10{sup 8} photon eV{sup -1} sr{sup -1} at 4 keV. The energy-dependent source size in the band of 1-4 keV is less than 100 mum and seemed to shrink quickly as x-ray energy increases.

Li Jing [Institute of Fluid Physics, CAEP, Mianyang 621900 (China); Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Deng Jianjun; Xie Weiping; Huang Xianbin; Yang Libing; Zhou Shaotong; Duan Shuchao; Zhang Siqun; Dan Jiakun [Institute of Fluid Physics, CAEP, Mianyang 621900 (China); Zhu Xiaoli [Key Laboratory of Nano-Fabrication and Novel Devices Integrated Technology, Institute of Microelectronics, CAS, Beijing 100029 (China)

2010-07-15

226

First Light Measurements with the XMM-Newton Reflection Grating Spectrometers: Evidence for an Inverse First Ionisation Potential Effect and Anomalous Ne A bundance in the Coronae of HR 1099  

Microsoft Academic Search

The RS CVn binary system HR 1099 was extensively observed by the XMM-Newton\\u000aobservatory in February 2000 as its first-light target. A total of 570 ks of\\u000aexposure time was accumulated with the Reflection Grating Spectrometers (RGS).\\u000aThe integrated X-ray spectrum between 5-35 Angstrom is of unprecedented quality\\u000aand shows numerous features attributed to transitions of the elements C, N,

A. C. Brinkman; E. Behar; M. Audard; A. J. F. den Boggende; G. Branduardi-Raymont; J. Cottam; C. Erd; J. W. den Herder; F. Jansen; J. S. Kaastra; S. M. Kahn; R. Mewe; F. B. S. Paerels; J. R. Peterson; A. P. Rasmussen; I. Sakelliou; C. de Vries

2000-01-01

227

First light measurements with the XMM-Newton reflection grating spectrometers: Evidence for an inverse first ionisation potential effect and anomalous Ne abundance in the Coronae of HR 1099  

Microsoft Academic Search

The RS CVn binary system HR 1099 was extensively observed by the XMM-Newton observatory in February 2000 as its first-light target. A total of 570 ks of exposure time was accumulated with the Reflection Grating Spectrometers (RGS). The integrated X-ray spectrum between 5-35 is of unprecedented quality and shows numerous features attributed to transitions of the elements C, N,

A. C. Brinkman; E. Behar; M. Gdel; M. Audard; A. J. F. den Boggende; G. Branduardi-Raymont; J. Cottam; C. Erd; J. W. den Herder; F. Jansen; J. S. Kaastra; S. M. Kahn; R. Mewe; F. B. S. Paerels; J. R. Peterson; A. P. Rasmussen; I. Sakelliou; C. de Vries

2001-01-01

228

Effective area calibration of the Reflection Grating Spectrometers of XMM-Newton. I. X-ray spectroscopy of the Crab nebula  

E-print Network

The Crab nebula and pulsar have been widely used as a calibration source for X-ray instruments. The in-flight effective area calibration of the Reflection Grating Spectrometers (RGS) of XMM-Newton depend upon the availability of reliable calibration sources. We investigate how the absolute effective area calibration of RGS can be obtained using Crab as a standard candle. We have analysed RGS observations of the Crab using different instrument configurations and spatial offsets, and made use of previous determinations of the continuum spectrum of the nebula plus pulsar. Due to the high spectral resolution of the RGS, we resolve the main absorption edges and detect the strong 1s-2p absorption lines of neutral oxygen. We get an excellent fit to the Crab spectrum using this fixed continuum and the absorption spectrum determined by RGS. We get accurate column densities for the neutral atoms of H, N, O, Ne, Mg, and Fe, as well as a clear detection of Fe II and firm upper limits for other ions. Our data are in good ...

Kaastra, J S; Costantini, E; Herder, J W A den

2009-01-01

229

High resolution soft X-ray spectroscopy of the elliptical galaxy NGC 5044. Results from the reflection grating spectrometer on-board XMM-Newton  

E-print Network

The results from an X-ray spectroscopic study of the giant elliptical galaxy NGC5044 in the center of a galaxy group are presented. The line dominated soft X-ray spectra (mainly Fe-L and O VIII Ly_a) from the diffuse gas are resolved for the first time in this system with the Reflection Grating Spectrometers on-board XMM-Newton and provide a strong constraint on the temperature structure. The spectra integrated over 2' (\\sim 20kpc) in full-width can be described by a two temperature plasma model of 0.7keV and 1.1keV. Most of the latter component is consistent with originating from off-center regions. Compared to the isobaric cooling flow prediction, the observation shows a clear cut-off below a temperature of 0.6 +-0.1keV. Furthermore, the Fe and O abundances within the central 10--20kpc in radius are accurately measured to be 0.55+-0.05 and 0.25+-0.1 times the solar ratios, respectively. The observed cut-off temperature of this galaxy and other central galaxies in galaxy groups and clusters are compared with the scale of the galaxy and properties of the surrounding intra-cluster medium. Based on this comparison, the origin of the lack of predicted cool emission is discussed.

T. Tamura; J. S. Kaastra; K. Makishima; I. Takahashi

2002-11-27

230

Measurement of the instrumental polarization of a high resolution ultraviolet spectrometer  

NASA Astrophysics Data System (ADS)

The polarization properties of a high-resolution echelle grating spectrometer have been characterized. Large variations of instrument response with incident polarization state at ultraviolet wavelengths were found. Measurements of the sensitivity of ISUS (Imaging Stratospheric Ultraviolet Spectrometer) to linearly polarized light at 312.6 nm showed a peak-to-peak variation of 72 percent as the plane of polarization is rotated. The results of these measurements are presented and nine elements of the 16-element system Mueller matrix which descibes the behavior of ISUS in partially linearized polarized light are measured. The implications of the observed instrumental polarization for remote sensing observations and its impact on a technique for discriminating against the polarized Rayleigh-scattered background to improve the measurement sensitivity are discussed.

Morgan, M. Frank; Chipman, Russell A.; Torr, Douglas G.

1990-02-01

231

Electrically-programmable diffraction grating  

DOEpatents

An electrically-programmable diffraction grating is disclosed. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers). 14 figs.

Ricco, A.J.; Butler, M.A.; Sinclair, M.B.; Senturia, S.D.

1998-05-26

232

Educational Multiwavelength Atomic Emission Spectrometer  

E-print Network

Educational Multiwavelength Atomic Emission Spectrometer Alexander Y. Nazarenko* Chemistry multiwavelength emission instrument utilizing a commercial grating monochromator, a fiber optic sensor to collect visualization makes the spectrometer a useful educational tool. Key Words: Atomic emission spectroscopy; CCD

Nazarenko, Alexander

233

MODELING THE TRIPLET SPECTRAL REGION CAPELLA WITH THE CHANDRA AND XMMNEWTON GRATINGS  

E-print Network

Transmission Grating Spectrometer (HETGS; 155 Energy Transmission Grating Spectrometer (LETGS; 219 and Reflection Grating Spectrometer (RGS; comparative analysis, focusing triplet around 13.5 , regionMODELING THE TRIPLET SPECTRAL REGION CAPELLA WITH THE CHANDRA AND XMM­NEWTON GRATINGS Jan

Ness, Jan-Uwe

234

Development of off-plane gratings for WHIMex and IXO Randall L. McEntaffer*a  

E-print Network

-plane grating spectrometers consist of an array of gratings capable of reaching resolutions above 3000 (/). Concept designs have been made for the International X-ray Observatory X-ray Grating Spectrometer. More) baseline configuration includes an X-ray Grating Spectrometer (XGS) instrument. The purpose of the IXO XGS

235

THE ACCRETION DISK CORONA AND DISK ATMOSPHERE OF 4U 1624-490 AS VIEWED BY THE CHANDRA-HIGH ENERGY TRANSMISSION GRATING SPECTROMETER  

SciTech Connect

We present a detailed spectral study (photoionization modeling and variability) of the 'Big Dipper' 4U 1624-490 based on a Chandra-High Energy Transmission Grating Spectrometer (HETGS) observation over the {approx}76 ks binary orbit of 4U 1624-490 . While the continuum spectrum can be modeled using a blackbody plus power law, a slightly better fit is obtained using a single {gamma} = 2.25 power-law partially (71%) covered by a local absorber of column density N{sub H,Local}=8.1{sub -0.6}{sup +0.7}x10{sup 22} cm{sup -2}. The data show a possible quasi-sinusoidal modulation with period 43{sup +13} {sub -9} ks that might be due to changes in local obscuration. Photoionization modeling with the XSTAR code and variability studies of the observed strong Fe XXV and Fe XXVI absorption lines point to a two-temperature plasma for their origin: a highly ionized component of ionization parameter {xi}{sub hot} {approx} 10{sup 4.3} erg cm s{sup -1} (T {approx} 3.0 x 10{sup 6} K) associated with an extended accretion disk corona of radius R {approx} 3 x 10{sup 10} cm, and a less-ionized more variable component of {xi} {approx} 10{sup 3.4} erg cm s{sup -1} (T {approx} 1.0 x 10{sup 6} K) and {xi}{approx}10{sup 3.1} erg cm s{sup -1} (T {approx} 0.9 x 10{sup 6} K) coincident with the accretion disk rim. We use this, with the observed Fe XXV and Fe XXVI absorption line variations (in wavelength, strength, and width) to construct a viewing geometry that is mapped to changes in plasma conditions over the 4U 1624-490 orbital period.

Xiang Jingen; Lee, Julia C. [Department of Astronomy (a part of the Harvard-Smithsonian Center for Astrophysics), Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Nowak, Michael A.; Schulz, Norbert S. [Massachusetts Institute of Technology, Kavli Center, 77 Massachusetts Avenue NE80, Cambridge, MA 02139 (United States); Wilms, Joern [Dr. Karl-Remeis-Observatory and Erlangen Centre for Astroparticle Physics, University of Erlangen-Nuremberg, Sternwartstrasse 7, 96049 Bamberg (Germany)], E-mail: jxiang@cfa.harvard.edu, E-mail: jclee@cfa.harvard.edu

2009-08-20

236

CHIRON - A Fiber Fed Spectrometer for Precise Radial Velocities  

NASA Astrophysics Data System (ADS)

The CHIRON optical high-resolution echelle spectrometer was commissioned at the 1.5 m telescope at CTIO in 2011. The instrument was designed for high throughput and stability, with the goal of monitoring radial velocities of bright stars with high precision and high cadence for the discovery of low-mass exoplanets. Spectral resolution of R = 79 000 is attained when using a slicer with a total (including telescope and detector) efficiency of 6% or higher, while a resolution of R = 136 000 is available for bright stars. A fixed spectral range of 415--880 nm is covered. The echelle grating is housed in a vacuum enclosure and the instrument temperature is stabilized to 0.2. Stable illumination is provided by an octagonal multimode fiber with excellent light-scrambling properties. An iodine cell is used for wavelength calibration. We describe the main optics, fiber feed, detector, exposure-meter, and other aspects of the instrument, as well as the observing procedure and data reduction.

Tokovinin, Andrei; Fischer, Debra A.; Bonati, Marco; Giguere, Matthew J.; Moore, Peter; Schwab, Christian; Spronck, Julien F. P.; Szymkowiak, Andrew

2013-11-01

237

Photoelectrochemical fabrication of spectroscopic diffraction gratings, phase 2  

NASA Technical Reports Server (NTRS)

This program was directed toward the production of Echelle diffraction gratings by a light-driven, electrochemical etching technique (photoelectrochemical etching). Etching is carried out in single crystal materials, and the differential rate of etching of the different crystallographic planes used to define the groove profiles. Etching of V-groove profiles was first discovered by us during the first phase of this project, which was initially conceived as a general exploration of photoelectrochemical etching techniques for grating fabrication. This highly controllable V-groove etching process was considered to be of high significance for producing low pitch Echelles, and provided the basis for a more extensive Phase 2 investigation.

Rauh, R. David; Carrabba, Michael M.; Li, Jianguo; Cartland, Robert F.; Hachey, John P.; Mathew, Sam

1990-01-01

238

MODELING THE Ne ix TRIPLET SPECTRAL REGION OF CAPELLA WITH THE CHANDRA AND XMM-NEWTON GRATINGS  

E-print Network

gathered together all available data of the High Energy Transmission Grating Spectrometer (HETGS; 155 ks), Low Energy Transmission Grating Spectrometer (LETGS; 219 ks), and Reflection Grating Spectrometer (RGSMODELING THE Ne ix TRIPLET SPECTRAL REGION OF CAPELLA WITH THE CHANDRA AND XMM-NEWTON GRATINGS Jan

Ness, Jan-Uwe

239

The assembly, calibration, and preliminary results from the Colorado high-resolution Echelle stellar spectrograph (CHESS)  

NASA Astrophysics Data System (ADS)

The Colorado High-resolution Echelle Stellar Spectrograph (CHESS) is a far ultraviolet (FUV) rocket-borne experiment designed to study the atomic-to-molecular transitions within translucent interstellar clouds. CHESS is an objective echelle spectrograph operating at f/12.4 and resolving power of 120,000 over a band pass of 100 - 160 nm. The echelle flight grating is the product of a research and development project with LightSmyth Inc. and was coated at Goddard Space Flight Center (GSFC) with Al+LiF. It has an empirically-determined groove density of 71.67 grooves/mm. At the Center for Astrophysics and Space Astronomy (CASA) at the University of Colorado (CU), we measured the efficiencies of the peak and adjacent dispersion orders throughout the 90 - 165 nm band pass to characterize the behavior of the grating for pre-flight calibrations and to assess the scattered-light behavior. The crossdispersing grating, developed and ruled by Horiba Jobin-Yvon, is a holographically-ruled, low line density (351 grooves/mm), powered optic with a toroidal surface curvature. The CHESS cross-disperser was also coated at GSFC; Cr+Al+LiF was deposited to enhance far-UV efficiency. Results from final efficiency and reflectivity measurements of both optics are presented. We utilize a cross-strip anode microchannel plate (MCP) detector built by Sensor Sciences to achieve high resolution (25 ?m spatial resolution) and data collection rates (~ 106 photons/second) over a large format (40mm round, digitized to 8k x 8k) for the first time in an astronomical sounding rocket flight. The CHESS instrument was successfully launched from White Sands Missile Range on 24 May 2014. We present pre-flight sensitivity, effective area calculations, lab spectra and calibration results, and touch on first results and post-flight calibration plans.

Hoadley, Keri; France, Kevin; Nell, Nicholas; Kane, Robert; Schultz, Ted; Beasley, Matthew; Green, James; Kulow, Jen; Kersgaard, Eliot; Fleming, Brian

2014-07-01

240

Development of lightweight blazed transmission gratings and large-area soft x-ray spectrographs  

E-print Network

-ray band can only be achieved with a state-of-the-art diffraction grating spectrometer, comprised of large of higher diffraction orders). Several new mission concepts containing CAT grating based spectrometers resolving power (R = / > 3000) x-ray grating spectrometer (XGS)4,5 with more than an order of magnitude

241

Precision Shaping, Assembly and Metrology of Foil Optics for X-ray Reflection Gratings  

E-print Network

cQED Technologies, Inc., Rochester, NY 14607 ABSTRACT The proposed Reflection Grating Spectrometer spectrometer flown on the X-ray Multi-Mirror (XMM) mission. Off-plane, or conical, gratings require much higher, wavefront sensing, magneto-rheologic finishing, MRF 1. INTRODUCTION The Reflection Grating Spectrometer (RGS

242

FIDEOS: a high resolution echelle spectrograph for the ESO 1m telescope at La Silla  

NASA Astrophysics Data System (ADS)

FIDEOS (FIbre Dual Echelle Optical Spectrograph) is a fibre-fed bench-mounted high-resolution echelle spec- trograph for the 1-m telescope at ESO in La Silla, Chile. It is based on a 44.41 lines/mm 70 blaze angle echelle grating in quasi-Littrow mode, providing spectral resolution of R ~ 42 000, covering the spectral range from 400 nm to 680 nm. The detector is a 2k2k CCD with 15 ?m pixels. The spectrograph will be fed by two 50 m core diameter fibres for the astronomical object and the simultaneous calibration lamp, respectively. Alter- natively, an iodine cell will be mounted on the telescope-spectrograph interface, providing a secondary spectral calibration source. In addition, the instrument will be mounted on a fixed optical-bench without movable parts rather than the CCD shutter and its enclosure will be thermally controlled to ensure opto-mechanical stability. Since the FIDEOS will deliver high resolution and spectral stability, it will be optimized for precision radial velocities.

Tala, Marcelo; Berdja, A.; Jones, M.; Vanzi, L.; Ropert, S.; Flores, M.; Viscasillas, C.

2014-07-01

243

FOCES - a fibre optics Cassegrain Echelle spectrograph  

Microsoft Academic Search

We have designed and built the echelle spectrograph FOCES fed by 100 mu m optical fibres to be mounted at the Cassegrain focus of either the 2.2 m or the 3.5 m telescope at the Calar Alto Observatory. The spectrograph itself follows a white-pupil design collimated with two off-axis parabolic mirrors. The 15 cm beam leaving the 31.6 lines\\/mm R2

M. J. Pfeiffer; C. Frank; D. Baumueller; K. Fuhrmann; T. Gehren

1998-01-01

244

First Light Measurements with the XMM-Newton Reflection Grating Spectrometers: Evidence for an Inverse First Ionisation Potential Effect and Anomalous Ne A bundance in the Coronae of HR 1099  

E-print Network

The RS CVn binary system HR 1099 was extensively observed by the XMM-Newton observatory in February 2000 as its first-light target. A total of 570 ks of exposure time was accumulated with the Reflection Grating Spectrometers (RGS). The integrated X-ray spectrum between 5-35 Angstrom is of unprecedented quality and shows numerous features attributed to transitions of the elements C, N, O, Ne, Mg, Si, S, Fe, and Ni. We perform an in-depth study of the elemental composition of the average corona of this system, and find that the elemental abundances strongly depend on the first ionisation potential (FIP) of the elements. But different from the solar coronal case, we find an inverse FIP effect, i.e., the abundances (relative to oxygen) increase with increasing FIP. Possible scenarios, e.g., selective enrichment due to Ne-rich flare-like events, are discussed.

A. C. Brinkman; E. Behar; M. Guedel; M. Audard; A. J. F. den Boggende; G. Branduardi-Raymont; J. Cottam; C. Erd; J. W. den Herder; F. Jansen; J. S. Kaastra; S. M. Kahn; R. Mewe; F. B. S. Paerels; J. R. Peterson; A. P. Rasmussen; I. Sakelliou; C. de Vries

2000-11-01

245

A soft X-ray study of type I active galactic nuclei observed with Chandra high-energy transmission grating spectrometer  

Microsoft Academic Search

We present the results of a uniform analysis of the soft X-ray spectra of 15 type I active galactic nuclei (AGN) observed with the high-resolution X-ray gratings onboard Chandra. We found that 10 out of the 15 AGN exhibit signatures of an intrinsic ionized absorber. The absorbers are photoionized and outflowing, with velocities in the range ~101 - 103 km

B. McKernan; T. Yaqoob; C. S. Reynolds

2007-01-01

246

Electromagnetic diffraction efficiencies for plane reflection diffraction gratings  

NASA Technical Reports Server (NTRS)

The theory and computer programs, based on electromagnetic theory, for the analysis and design of echelle gratings were developed. The gratings are designed for instruments that operate in the ultraviolet portion of the spectrum. The theory was developed so that the resulting computer programs will be able to analyze deep (up to 30 wavelengths) gratings by including as many as 100 real or homogeneous diffraction orders. The program calculates the complex amplitude coefficient for each of the diffracted orders. A check on the numerical method used to solve the integral equations is provided by a conservation of energy calculation.

Marathay, A. S.; Shrode, T. E.

1974-01-01

247

A new generation of spectrometer designs for ultraviolet astronomy  

Microsoft Academic Search

In grazing incidence reflecting grating spectrometers, a plane grating (or combination or plane gratings) directly intercepts, diffracts and focuses at grazing incidence the light collected by a preceding mirror. The common feature of the resulting gratings is a smooth spatial variation in the grooves spacings. Some grooves diffract within the plane of incidence, and are spaced quadratically with the distance

M. Hettrick; S. Bowyer

1984-01-01

248

XMM-Newton/Reflection Grating Spectrometer detection of the missing interstellar O VII K? absorption line in the spectrum of Cyg X-2  

NASA Astrophysics Data System (ADS)

The hot interstellar medium is an important part of the Galactic ecosystem and can be effectively characterized through X-ray absorption line spectroscopy. However, in a study of the hot medium using the accreting neutron star X-ray binary, Cyg X-2, as a background light source, a mystery came about when the putatively strong O VII K? line was not detected in Chandra grating observations, while other normally weaker lines such as O VII K? as well as O VI and O VIII K? are clearly present. We have investigated the grating spectra of Cyg X-2 from 10 XMM-Newton observations, in search of the missing line. We detect it consistently in nine of these observations, but the line is absent in the remaining one observation or is inconsistent with the detection in others at a 4? confidence level. This absence of the line resembles that seen in the Chandra observations. Similarly, the O VI K? line is found to disappear occasionally, but not in concert with the variation of the O VII K? line. All these variations are most likely due to the presence of changing O VII and O VI K? emission lines of Cyg X-2, which are blurred together with the absorption ones in the X-ray spectra. A re-examination of the Chandra grating data indeed shows evidence for a narrow emission line slightly off the O VI K? absorption line. We further show that narrow N V emission lines with varying centroids and fluxes are present in far-ultraviolet spectra from the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. These results provide new constraints on the accretion around the neutron star and on the X-ray-heating of the stellar companion. The understanding of these physical processes is also important to the fidelity of using such local X-ray binaries for interstellar absorption line spectroscopy.

Cabot, Samuel H. C.; Wang, Q. Daniel; Yao, Yangsen

2013-05-01

249

Engineering of the passband function of a generalized spectrometer  

E-print Network

engineering of a grating spectrometer. Through spatial masking of the input beam and translation of diffraction grating-based spectrometers [1], surprising new be- havior is found to arise in even the simplestEngineering of the passband function of a generalized spectrometer J.D. McKinney and A.M. Weiner

Purdue University

250

Efficiency of a grazing-incidence off-plane grating in the soft-x-ray region  

E-print Network

- Newton Reflection Grating Spectrometer and Chan- dra. Off-plane grating efficiencies were first measuredEfficiency of a grazing-incidence off-plane grating in the soft-x-ray region J. F. Seely, L. I-incidence diffraction grating in the off-plane mount were performed using polarized synchrotron radiation. The grating

251

Wavelength Calibration of the Hamilton Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

We present the wavelength calibration of the Hamilton Echelle Spectrograph at Lick Observatory. The main problem with the calibration of this spectrograph arises from the fact that thorium lines are absent in the spectrum of the presumed ThAr hollow-cathode lamp now under operation; numerous unknown strong lines, which have been identified as titanium lines, are present in the spectrum. We estimate the temperature of the lamp's gas which permits us to calculate the intensities of the lines and to select a large number of relevant Ti I and Ti II lines. The resulting titanium line list for the Lick hollow-cathode lamp is presented. The wavelength calibration using this line list was made with an accuracy of about 0.006 .

Pakhomov, Yu. V.; Zhao, G.

2013-10-01

252

NRES: The Network of Robotic Echelle Spectrographs  

NASA Astrophysics Data System (ADS)

Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by two 1 meter telescopes and a thorium argon calibration source, one at each of our observatory sites in the Northern and Southern hemispheres. Thus, NRES will be a single, globally-distributed, autonomous observing facility using twelve 1-m telescopes. Simulations suggest we will achieve long-term radial velocity precision of better than 3 m/s in less than an hour for stars brighter than V = 12. We have been funded with NSF MRI and ATI grants, and expect our first spectrograph to be deployed in mid 2015, with the full network operation of all 6 units beginning in 2016. We will discuss the NRES design, goals, robotic operation, and status, as well as the early results from our prototype spectrograph.

Siverd, Robert; Eastman, Jason D.; Brown, Timothy M.; Hygelund, John; Henderson, Todd; Tufts, Joseph; Van Eyken, Julian C.; Barnes, Stuart

2015-01-01

253

WAVELENGTH CALIBRATION OF THE HAMILTON ECHELLE SPECTROGRAPH  

SciTech Connect

We present the wavelength calibration of the Hamilton Echelle Spectrograph at Lick Observatory. The main problem with the calibration of this spectrograph arises from the fact that thorium lines are absent in the spectrum of the presumed ThAr hollow-cathode lamp now under operation; numerous unknown strong lines, which have been identified as titanium lines, are present in the spectrum. We estimate the temperature of the lamp's gas which permits us to calculate the intensities of the lines and to select a large number of relevant Ti I and Ti II lines. The resulting titanium line list for the Lick hollow-cathode lamp is presented. The wavelength calibration using this line list was made with an accuracy of about 0.006 .

Pakhomov, Yu. V. [Institute of Astronomy, Russian Academy of Sciences, Moscow (Russian Federation); Zhao, G., E-mail: pakhomov@inasan.ru [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2013-10-01

254

NRES: the network of robotic Echelle spectrographs  

NASA Astrophysics Data System (ADS)

Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by two 1 meter telescopes and a thorium argon calibration source, one at each of our observatory sites in the Northern and Southern hemispheres. Thus, NRES will be a single, globally-distributed, autonomous observing facility using twelve 1-m telescopes. Simulations suggest we will achieve long-term precision of better than 3 m/s in less than an hour for stars brighter than V = 12. We have been fully funded with an NSF MRI grant, and expect our first spectrograph to be deployed in Spring of 2015, with the full network operation of all 6 units beginning in Spring of 2016. We discuss the NRES design, goals, and robotic operation, as well as the early results from our prototype spectrograph.

Eastman, Jason D.; Brown, Timothy M.; Hygelund, John; van Eyken, Julian; Tufts, Joseph R.; Barnes, Stuart

2014-07-01

255

Color Perception with Diffraction Gratings.  

ERIC Educational Resources Information Center

Describes an experiment enabling students to apply concept of diffraction, determine limits of their color perception, learn how to measure wavelength with a simple apparatus, observe continuous and line spectra, and associate colors with corresponding wavelengths. The homemade diffraction-grating spectrometer used is easily constructed. (JN)

Kruglak, Haym; Campbell, Don

1983-01-01

256

High-resolution grazing-incidence grating spectrometer for temperature measurements of low-Z ions emitting in the 100300 spectral band  

SciTech Connect

We have constructed a high-resolution grazing-incidence spectrometer designed for measuring the ion temperature of low-Z elements, such as Li{sup +} or Li{sup 2+}, which radiate near 199 and 135 , respectively. Based on measurements at the Livermore Electron Beam Ion Trap we have shown that the instrumental resolution is better than 48 m at the 200 setting and better than 40 m for the 135- range. Such a high spectral resolution corresponds to an instrumental limit for line-width based temperature measurements of about 45 eV for the 199 Li{sup +} and 65 eV for the 135 Li{sup 2+} lines. Recently obtained survey spectra from the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory show the presence of these lithium emission lines and the expected core ion temperature of approximately 70 eV is sufficiently high to demonstrate the feasibility of utilizing our high-resolution spectrometer as an ion-temperature diagnostic.

Widmann, K., E-mail: widmann1@llnl.gov; Beiersdorfer, P.; Magee, E. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Boyle, D. P.; Kaita, R.; Majeski, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-11-15

257

High-resolution grazing-incidence grating spectrometer for temperature measurements of low-Z ions emitting in the 100-300 spectral band.  

PubMed

We have constructed a high-resolution grazing-incidence spectrometer designed for measuring the ion temperature of low-Z elements, such as Li(+) or Li(2 +), which radiate near 199 and 135 , respectively. Based on measurements at the Livermore Electron Beam Ion Trap we have shown that the instrumental resolution is better than 48 m at the 200 setting and better than 40 m for the 135- range. Such a high spectral resolution corresponds to an instrumental limit for line-width based temperature measurements of about 45 eV for the 199 Li(+) and 65 eV for the 135 Li(2 +) lines. Recently obtained survey spectra from the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory show the presence of these lithium emission lines and the expected core ion temperature of approximately 70 eV is sufficiently high to demonstrate the feasibility of utilizing our high-resolution spectrometer as an ion-temperature diagnostic. PMID:25430206

Widmann, K; Beiersdorfer, P; Magee, E W; Boyle, D P; Kaita, R; Majeski, R

2014-11-01

258

High-resolution grazing-incidence grating spectrometer for temperature measurements of low-Z ions emitting in the 100-300 spectral banda)  

NASA Astrophysics Data System (ADS)

We have constructed a high-resolution grazing-incidence spectrometer designed for measuring the ion temperature of low-Z elements, such as Li+ or Li2 +, which radiate near 199 and 135 , respectively. Based on measurements at the Livermore Electron Beam Ion Trap we have shown that the instrumental resolution is better than 48 m at the 200 setting and better than 40 m for the 135- range. Such a high spectral resolution corresponds to an instrumental limit for line-width based temperature measurements of about 45 eV for the 199 Li+ and 65 eV for the 135 Li2 + lines. Recently obtained survey spectra from the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory show the presence of these lithium emission lines and the expected core ion temperature of approximately 70 eV is sufficiently high to demonstrate the feasibility of utilizing our high-resolution spectrometer as an ion-temperature diagnostic.

Widmann, K.; Beiersdorfer, P.; Magee, E. W.; Boyle, D. P.; Kaita, R.; Majeski, R.

2014-11-01

259

Varied line-space grating for flat spectral response of coupling to single-mode fiber.  

PubMed

We use a planar linear grating with varied line-space grooves to introduce a tailored one-dimensional phase variation profile that results in an aberrated point-spread function at the focal plane. A design procedure for the period chirp map for such gratings is developed. As an example, we present theoretical and experimental results on a mechanically ruled, varied line-space echelle grating in single-mode fiber-coupled optical multiplexers in the wavelength region of 1545 nm. The varied line-space grating changes the multiplexer's Gaussian spectral response function to a flat-top dependence with reduced sensitivity to source laser wavelength drift. PMID:17268556

Huang, X-P; Spuler, Scott M; Sappey, Andrew D

2007-01-10

260

Performance of a laser frequency comb calibration system with a high-resolution solar echelle spectrograph  

NASA Astrophysics Data System (ADS)

Laser frequency combs (LFC) provide a direct link between the radio frequency (RF) and the optical frequency regime. The comb-like spectrum of an LFC is formed by exact equidistant laser modes, whose absolute optical frequencies are controlled by RF-references such as atomic clocks or GPS receivers. While nowadays LFCs are routinely used in metrological and spectroscopic fields, their application in astronomy was delayed until recently when systems became available with a mode spacing and wavelength coverage suitable for calibration of astronomical spectrographs. We developed a LFC based calibration system for the high-resolution echelle spectrograph at the German Vacuum Tower Telescope (VTT), located at the Teide observatory, Tenerife, Canary Islands. To characterize the calibration performance of the instrument, we use an all-fiber setup where sunlight and calibration light are fed to the spectrograph by the same single-mode fiber, eliminating systematic effects related to variable grating illumination.

Doerr, H.-P.; Kentischer, T. J.; Steinmetz, T.; Probst, R. A.; Franz, M.; Holzwarth, R.; Udem, Th.; Hnsch, T. W.; Schmidt, W.

2012-09-01

261

Balloon-borne ultraviolet stellar echelle spectrograph.  

PubMed

During the nights of 19, 20 May 1976 and 16, 17 September 1976, an 800-kg astronomical payload, developed by the NASA Johnson Space Center at Houston and the Astronomical Institute at Utrecht, was floating at 40-km altitude and recorded high-resolution uv spectra of stars. The spectral region of 200-340 am was covered with a spectral resolution of 0.01 nm. The optical system consisted of a 40-cm diam telescope with 1-sec of arc pointing capabilities, an echelle spectrograph working in spectral orders 66 to 112 and a SEC-vidicon integrating detector. Due to the high spectral simultaneity gain of the system 53 complete spectra of thirty-three different stars, with spectral types between 09.5 and M2 and with visual magnitudes between 0 and 4.5, could be obtained during the two nights of observation. Ozone in the residual atmosphere above 40 km reduces the atmospheric transmission around 250 nm to approximately 0.1, but with suitable integration times also in this region stars can be studied spectroscopically from balloon altitudes. PMID:20197835

Hoekstra, R; Kamperman, T M; Wells, C W; Werner, W

1978-02-15

262

Fiber-coupled high resolution infrared array spectrometer for the Kuiper Airborne Observatory  

NASA Technical Reports Server (NTRS)

A novel cryogenic grating spectrometer (FCAS) is being designed for observations of volatiles in cometary and planetary atmospheres, and in newly forming planetary systems. The instrument features two-dimensional detector arrays coupled to a high-dispersion echelle by infrared fibers, and will achieve a spectral resolving power of about 40,000. The primary observational platform for this instrument will be the Kuiper Airborne Observatory, but it will also be configured for use at ground-based observatories. Initially, the spectrometer will use a 58 x 62, 1- to 5-micron InSb array. Larger-format IR arrays and arrays of different composition, will later be incorporated as they become available. The instrument will be used in two modes. The first uses a large format IR array in the spectral image plane for the customary one-dimensional spectral-one-dimensional spatial coverage. In the second mode, a massive, coherent bundle of infrared transmitting ZrF4 fibers will be installed after the dispersive element, to reformat the two-dimensional array into an elongated one-dimensional array for wide spectral coverage, allowing multiple lines to be measured in a single integration with high sensitivity. The overall instrument design is discussed, and the system sensitivity is estimated.

Glenar, D. A.; Reuter, D.; Mumma, M. J.; Chin, G.; Wiedemann, G.; Jennings, D.

1990-01-01

263

Photonic Crystal Slot Waveguide Optical Absorption Spectrometer for Highly sensitive  

E-print Network

Photonic Crystal Slot Waveguide Optical Absorption Spectrometer for Highly sensitive Near · With photonic band gaps: "optical insulators" 1-D grating =1-D PhC 2-D PhC =2-D grating 3-D PhC =3-D grating

Texas at Austin, University of

264

Generation-X Grating Array Technology Development A White Paper submitted to the Electromagnetic Observations from Space (EOS) Discipline in  

E-print Network

will heavily leverage the development for the IXO X-ray Grating Spectrometer. However, there are several areas of a Grating Spectrometer (GS) that will be used for high resolution spectroscopy (E/E > 10,000) at energiesGeneration-X Grating Array Technology Development A White Paper submitted to the Electromagnetic

265

IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 52, NO. 3, MARCH 2005 419 Silicon-Based Micro-Fourier Spectrometer  

E-print Network

concepts were transferred from the macro to the microscale like grating spectrometers [1], [2], Fabry on a sensor chip. Grating spectrometers and classical Fourier spectrometer do not allow for the dense-Fourier Spectrometer Dietmar Knipp, Member, IEEE, Helmut Stiebig, Sameer R. Bhalotra, Student Member, IEEE, Eerke Bunte

Miller, David A. B.

266

Wide-range CCD spectrometer  

NASA Astrophysics Data System (ADS)

The utilization of wide range spectrometers is a very important feature for the design of optical diagnostics. This paper describes an innovative approach, based on charged coupled device, which allows to analyze different spectral intervals with the same diffraction grating. The spectral interval is varied by changing the position of the entrance slit when the grating is stationary. The optical system can also include a spherical mirror. In this case the geometric position of the mirror is calculated aiming at compensating the first order astigmatism and the meridional coma of the grating. This device is planned to be used in Thomson scattering diagnostic of the TOKAMAK of Instituto Superior Tecnico, Lisbon (ISTTOK).

Sokolova, Elena A.; Reyes Cortes, Santiago D.

1996-08-01

267

Fiber grating sensors  

Microsoft Academic Search

We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors

Alan D. Kersey; Michael A. Davis; Heather J. Patrick; Michel LeBlanc; K. P. Koo; C. G. Askins; M. A. Putnam; E. Joseph Friebele

1997-01-01

268

The Polychromator: A programmable MEMS diffraction grating for synthetic spectra  

SciTech Connect

The authors report here the design, fabrication and demonstration of an electrostatically actuated MEMS diffractive optical device, the Polychromator grating. The Polychromator grating enables a new type of correlation spectrometer for remote detection of a wide range of chemical species, offering electronic programmability, high specificity and sensitivity, fast response and ruggedness. Significant results include: (1) The first demonstrations of user-defined synthetic spectra in the 3-5 {micro}m wavelength regime based upon controlled deflection of individual grating elements in the Polychromator grating; (2) The first demonstration of gas detection by correlation spectroscopy using synthetic spectra generated by the Polychromator grating.

HOCKER,G.B.; YOUNGNER,D.; BUTLER,MICHAEL A.; SINCLAIR,MICHAEL B.; PLOWMAN,THOMAS E.; DEUTSCH,E.; VOLPICELLI,A.; SENTURIA,S.; RICCO,A.J.

2000-04-17

269

An Extreme Ultraviolet Spectrometer Leonid V. Didkovsky, Darrell L. Judge, and Andrew R. Jones  

E-print Network

Grating Spectrometer (EGS) is a normal incidence Rowland circle spectrograph with a spectral range of 25. A typical transmission grating spectrometer for EUV measurements from a sounding rocket was basedAn Extreme Ultraviolet Spectrometer Leonid V. Didkovsky, Darrell L. Judge, and Andrew R. Jones

Didkovsky, Leonid

270

Development of Off-Plane Reflection Grating Alignment Fixtures  

NASA Astrophysics Data System (ADS)

Currently, grating spectrometers are used onboard the Chandra X-ray Observatory and XMM-Newton in orbit around the Earth. However, future goals of greater spectral resolving power and greater effective areas necessitate a new generation of high-quality spectrometers. Off-plane reflection gratings can be used to provide high throughput and spectral resolution in the 0.3-2.0 keV band, allowing for unprecedented diagnostics of energetic astrophysical processes. A grating spectrometer consists of multiple aligned gratings intersecting the converging beam of a Wolter-I telescope. Each grating will be aligned such that the diffracted spectra overlap at the focal plane. Misalignments will degrade both spectral resolution and effective area. With analytical alignment tolerances calculated, laboratory techniques to achieve these tolerances for flight-like optics must be developed. We present the results from our first and second generation alignment fixtures, as well as wavefront stitching methods.

Donovan, Benjamin D; Allured, Ryan; McEntaffer, Randall L.

2014-06-01

271

Development of the Colorado High-resolution Echelle Stellar Spectrograph (CHESS)  

NASA Astrophysics Data System (ADS)

A key astrophysical theme that will drive future UV/optical space missions is the life cycle of cosmic matter, from the flow of intergalactic gas into galaxies to the formation and evolution of exoplanetary systems. Spectroscopic systems capable of delivering high resolution with low backgrounds will be essential to addressing these topics. Towards this end, we are developing a rocket-borne instrument that will serve as a pathfinder for future high-sensitivity, highresolution UV spectrographs. The Colorado High-resolution Echelle Stellar Spectrograph (CHESS) will provide 2 km s-1 velocity resolution (R = 150,000) over the 100 - 160 nm bandpass that includes key atomic and molecular spectral diagnostics for the intergalactic medium (H I Lyman-series, O VI, N V, and C IV), exoplanetary atmospheres (H I Lyman-alpha, O I, and C II), and protoplanetary disks (H2 and CO electronic band systems). CHESS uses a novel mechanical collimator comprised of an array of 10 mm x 10 mm stainless steel tubes to feed a low-scatter, 69 grooves mm-1 echelle grating. The cross-disperser is a holographically ruled toroid, with 351 grooves mm-1. The spectral orders can be recorded with either a 40 mm cross-strip microchannel plate detector or a 3.5k x 3.5k ?-doped CCD. The microchannel plate will deliver 30 ?m spatial resolution and employs new 64 amp/axis electronics to accommodate high count rate observations of local OB stars. CHESS is scheduled to be launched aboard a NASA Terrier/Black Brant IX sounding rocket from White Sands Missile Range in the summer of 2013.

France, Kevin; Beasley, Matthew; Kane, Robert; Nell, Nicholas; Burgh, Eric B.; Green, James C.

2012-09-01

272

A simple, low-cost, versatile charge-coupled device spectrometer for plasma spectroscopy  

E-print Network

line surveys from the ultraviolet to the near infrared. Measurements have been made on a low is a compact and robust CCD detector developed for amateur astronomy by Santa Barbara Instrument Group. The CCD- flectivity in the ultraviolet. A wide variety of gratings, in- cluding echelles, is available

Wisconsin at Madison, University of

273

High-throughput accurate-wavelength lens-based visible spectrometer  

Microsoft Academic Search

A scanning visible spectrometer has been prototyped to complement fixed-wavelength transmission grating spectrometers for charge exchange recombination spectroscopy. Fast f\\/1.8 200 mm commercial lenses are used with a large 2160 mm-1 grating for high throughput. A stepping-motor controlled sine drive positions the grating, which is mounted on a precision rotary table. A high-resolution optical encoder on the grating stage allows

Ronald E. Bell; Filippo Scotti

2010-01-01

274

Ultraviolet spectrometer experiment for the Voyager mission  

Microsoft Academic Search

The Voyager Ultraviolet Spectrometer (UVS) is an objective grating spectrometer covering the wavelength range of 5001700 with 10 resolution. Its primary goal is the determination of the composition and structure of the atmospheres of Jupiter, Saturn, Uranus and several of their satellites. The capability for two very different observational modes have been combined in a single instrument. Observations

A. L. Broadfoot; B. R. Sandel; D. E. Shemansky; S. K. Atreya; T. M. Donahue; H. W. Moos; J. L. Bertaux; J. E. Blamont; J. M. Ajello; D. F. Strobel; J. C. McConnell; A. Dalgarno; R. Goody; M. B. McElroy; Y. L. Yung

1977-01-01

275

Imaging spectrometer wide field catadioptric design  

DOEpatents

A wide field catadioptric imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The catadioptric design has zero Petzval field curvature. The imaging spectrometer comprises an entrance slit for transmitting light, a system with a catadioptric lens and a dioptric lens for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through the system for receiving the light to the detector array.

Chrisp; Michael P. (Danville, CA)

2008-08-19

276

The AXAF CCD imaging spectrometer  

NASA Technical Reports Server (NTRS)

The current status of the instrument design and the status of the CCDs being fabricated for the AXAF CCD Imaging Spectrometer (ACIS) are summarized. The instrument consists of an image recording array of CCDs and a linear arrangement of CCDs to record the spectra formed by the objective grating spectrometer. Both arrays employ CCDs with pixel dimensions which correspond to about 0.5 arcsec samples of the image. The CCDs provide moderate spectral resolution and good detection efficiency over the energy range 0.5 to 10 keV. Spectral resolution of 200 or more is achievable using the objective grating with the grating array. Radiation damage effects are shown to degrade the energy resolution of CCDs. Specially designed CCD pixel architecture is employed together with shielding and low temperature operation to slow the effects of radiation damage.

Garmire, G. P.; Ricker, G. R.; Bautz, M. W.; Burke, B.; Burrows, D. N.; Collins, S. A.; Doty, J. P.; Gendreau, K.; Lumb, D. H.; Nousek, J. A.

1992-01-01

277

Temporal Dispersion of a Spectrometer  

SciTech Connect

The temporal dispersion of an optical spectrometer has been characterized for a variety of conditions related to optical diagnostics to be fielded at the National Ignition Facility (e.g., Full-Aperture Backscatter Station, Thomson Scattering). Significant time smear is introduced into these systems by the path length difference through the spectrometer. The temporal resolution can be calculated to depend only on the order of the grating, wavelength, and the number of grooves illuminated. To enhance the temporal dispersion, the spectral gratings can be masked limiting the number of grooves illuminated. Experiments have been conducted to verify these calculations. The size and shape of masks are investigated and correlated to the exact shape of the temporal instrument function, which is required when interpreting temporally resolved data. The experiments used a 300fs laser pulse and a picosecond optical streak camera to determine the temporal dispersion. This was done for multiple spectral orders, gratings, and optical masks.

Visco, A; Drake, R P; Froula, D H; Glenzer, S H

2008-05-08

278

Multiple order common path spectrometer  

NASA Technical Reports Server (NTRS)

The present invention relates to a dispersive spectrometer. The spectrometer allows detection of multiple orders of light on a single focal plane array by splitting the orders spatially using a dichroic assembly. A conventional dispersion mechanism such as a defraction grating disperses the light spectrally. As a result, multiple wavelength orders can be imaged on a single focal plane array of limited spectral extent, doubling (or more) the number of spectral channels as compared to a conventional spectrometer. In addition, this is achieved in a common path device.

Newbury, Amy B. (Inventor)

2010-01-01

279

Off-plane grating mount tolerances for Constellation-X Webster Cash and Ann Shipley  

E-print Network

Off-plane grating mount tolerances for Constellation-X Webster Cash and Ann Shipley University-plane approach to the Reflection Grating Spectrometer of the Constellation-X Mission. In this paper we discuss: Off-plane mount, holographic grating, x-ray spectroscopy 1. Introduction 1.1 Constellation

Cash, Webster

280

The Constellation-X RGS options: Raytrace Modeling of the Off-plane Gratings  

E-print Network

The Constellation-X RGS options: Raytrace Modeling of the Off-plane Gratings K.A. Flanagan, J The Reflection Grating Spectrometer of the Constellation-X mission has two strong candidate configurations-ray, spectrometer, high resolution, CCD 1. INTRODUCTION Constellation-X is a high-throughput high

281

Mathematical Simulation for Integrated Linear Fresnel Spectrometer Chip  

NASA Technical Reports Server (NTRS)

A miniaturized solid-state optical spectrometer chip was designed with a linear gradient-gap Fresnel grating which was mounted perpendicularly to a sensor array surface and simulated for its performance and functionality. Unlike common spectrometers which are based on Fraunhoffer diffraction with a regular periodic line grating, the new linear gradient grating Fresnel spectrometer chip can be miniaturized to a much smaller form-factor into the Fresnel regime exceeding the limit of conventional spectrometers. This mathematical calculation shows that building a tiny motionless multi-pixel microspectrometer chip which is smaller than 1 cubic millimter of optical path volume is possible. The new Fresnel spectrometer chip is proportional to the energy scale (hc/lambda), while the conventional spectrometers are proportional to the wavelength scale (lambda). We report the theoretical optical working principle and new data collection algorithm of the new Fresnel spectrometer to build a compact integrated optical chip.

Park, Yeonjoon; Yoon, Hargoon; Lee, Uhn; King, Glen C.; Choi, Sang H.

2012-01-01

282

Snapshot dual-band visible hyperspectral imaging spectrometer  

E-print Network

systems. A whisk broom imaging spectrometer uses a diffraction grating in front of a line of detectorsSnapshot dual-band visible hyperspectral imaging spectrometer John Hartke, MEMBER SPIE United hyperspectral imaging spectrometer. A commercially available digital camera was integrated into a computed

Dereniak, Eustace L.

283

H.O.R.S. a new visiting instrument for G.T.C. based on the Utrecht Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

The High Optical Resolution Spectrograph (HORS) is a proposed high-resolution spectrograph for the 10-m Gran Telescopio Canarias (GTC) based on components from UES, a spectrograph which was in use at the 4.2-m William Herschel Telescope (WHT) between 1992 and 2001. HORS is designed as a cross-dispersed echelle spectrograph to observe in the range 380-800 nm with a FWHM resolving power of about 50,000. HORS would operate on the GTC as a general-purpose high-resolution spectrograph, and it would serve as a test-bed for some of the technologies proposed for ESPRESSO - an ultra-high stability spectrograph planned for the Very Large Telescope (VLT) of the European Southern Observatory. The HORS spectrograph will be placed in the Coud room, where it can enjoy excellent thermal and mechanical stability, fiber fed from the Nasmyth focus, which is shared with OSIRIS. Inside the spectrograph, incoming light will hit a small folder mirror before reaching the collimator. After a second folder, the light will go through a set of three prisms and an Echelle grating before entering the spectrograph camera and, finally, reaching the detector. This manuscript contains a summary of the whole process that has transformed UES into HORS, with all the mechanical and optical modifications that have been introduced to reach the final layout.

Peate, Jos; Gracia, Felix; Allende, Carlos; Calvo, Juan; Santana, Samuel

2014-07-01

284

Holographic optical grating and method for optimizing monochromator configuration  

DOEpatents

This invention comprises a novel apparatus for recording a holographic groove pattern on a diffraction grating blank. The recording apparatus is configured using newly developed groups of analytical equations. The invention further comprises the novel holographic diffraction grating made with the inventive recording apparatus. The invention additionally comprises monochromators and spectrometers equipped with the inventive holographic diffraction grating. Further, the invention comprises a monochromator configured to reduce aberrations using a newly developed group of analytical equations. Additionally, the invention comprises a method to reduce aberrations in monochromators and spectrometers using newly developed groups of analytical equations.

Koike, Masato (Moraga, CA)

1999-01-01

285

Chemical composition of the Orion nebula derived from echelle spectrophotometry  

Microsoft Academic Search

We present echelle spectroscopy in the 3500- to 7060- range for two positions of the Orion nebula. The data were obtained using the 2.1-m telescope at Observatorio Astrnmico Nacional in San Pedro Mrtir, Baja California. We have measured the intensities of about 220 emission lines, in particular 81 permitted lines of C+, N+, N++, 0, 0+, Ne0, Si+, Si++ and

C. Esteban; M. Peimbert; S. Torres-Peimbert; V. Escalante

1998-01-01

286

Advances in reflection grating technology for Constellation-X Ralf K. Heilmann, Mireille Akilian, Chih-Hao Chang, Carl G. Chen, Craig R. Forest, Chulmin  

E-print Network

Advances in reflection grating technology for Constellation-X Ralf K. Heilmann, Mireille Akilian The Reflection Grating Spectrometer (RGS) on Constellation-X will require thousands of large gratings with very submicron assembly repeatability. Keywords: x-ray optics, Constellation-X, in-plane gratings, off

287

[The integrative design for imaging spectrometer].  

PubMed

The hyperspectrum imaging spectrometer will achieve miniaturization and high spectrum resolution and high space resolution along with development of the hyperspectrum imaging technology that is becoming a trend. This trend requires the designers to improve and optimize their designing constantly in designing the instruments. The present paper carried out a method of integrative design for imaging spectrometer. This method suggested that the design and optimization work of the disperse systems of imaging spectrometers would take into account the whole systems, but not consider themselves only. It would get a perfect result by using this method. This paper also explained in details how the method can be used in the design course of imaging spectrometer with convex grating which has been used widely recently. Finally, this paper validated the method by testing the imaging spectrometer with convex grating, which was developed using this method. PMID:22582665

Cui, Ji-cheng; Liu, Yu-juan; Pan, Ming-zhong; Tang, Yu-guo

2012-03-01

288

November 1, 2001 / Vol. 26, No. 21 / OPTICS LETTERS 1645 Transform spectrometer based on measuring the periodicity  

E-print Network

spectrometer, including Fabry­Perot inter- ferometers,1 grating-based spectrometers,2 Michelson spectrometers,3November 1, 2001 / Vol. 26, No. 21 / OPTICS LETTERS 1645 Transform spectrometer based on measuring a compact transform spectrometer based on measuring the periodicity of Talbot self-images. The system has

Miller, David A. B.

289

High performance diffraction gratings made by e-beam lithography  

NASA Astrophysics Data System (ADS)

Gratings are essential components in different high performance optical set-ups such as spectrometers in space missions or ultrashort-pulse laser compression arrangements. Often such kinds of applications require gratings operating close to the technological accessible limits of today's fabrication technology. Typical critical parameters are the diffraction efficiency and its polarization dependency, the wave-front error introduced by the grating, and the stray-light performance. Additionally, space applications have specific environmental requirements and laser application typically demand a high damage threshold. All these properties need to be controlled precisely on rather large grating areas. Grating sizes of 200 mm or even above are not unusual anymore. The paper provides a review on how such high performance gratings can be realized by electron-beam lithography and accompanying technologies. The approaches are demonstrated by different examples. The first example is the design and fabrication of the grating for the Radial-Velocity-Spectrometer of the GAIA-mission of the ESA. The second grating is a reflective pulse compression element with no wavelength resonances due to an optimized design. The last example shows a three level blazed grating in resonance domain with a diffraction efficiency of approximately 86 %.

Zeitner, Uwe D.; Oliva, Maria; Fuchs, Frank; Michaelis, Dirk; Benkenstein, Tino; Harzendorf, Torsten; Kley, Ernst-Bernhard

2012-12-01

290

Narrowband Fiber Grating Filters  

Microsoft Academic Search

Two techniques for the fabrication of fiber gratings with a narrowband filter response are reported. In the first technique, the reflection bandwidth is reduced by increasing the grating length. Fiber gratings 10 mm long have been made with a bandwidth of ~0.3 nm. In the second technique, a phase shift is incorporated into the grating to form a resonant structure.

Catherine M. Ragdale; Douglas Reid; D. J. Robbins; Jens Buus; Ian Bennion

1990-01-01

291

A compact multichannel spectrometer for Thomson scattering  

SciTech Connect

The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T{sub e} < 100 eV are achieved by a 2971 l/mm VPH grating and measurements T{sub e} > 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated ({approx}2 ns) ICCD camera for detection. A Gen III image intensifier provides {approx}45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2012-10-15

292

A compact multichannel spectrometer for Thomson scattering.  

PubMed

The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T(e) < 100 eV are achieved by a 2971 l?mm VPH grating and measurements T(e) > 100 eV by a 2072 l?mm VPH grating. The spectrometer uses a fast-gated (~2 ns) ICCD camera for detection. A Gen III image intensifier provides ~45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction. PMID:23126988

Schoenbeck, N L; Schlossberg, D J; Dowd, A S; Fonck, R J; Winz, G R

2012-10-01

293

MEMS-based Ultra-Spectrometer (MEMUS): Status Report  

NASA Technical Reports Server (NTRS)

Micro-electromechanical system technology (MEMS) is allowing the development of a radical new design for compact spectrometers that provide both a survey and high resolution spectrograph in one instrument without mechanically changing gratings.

Castracane, J.; Schultz, P. H.; Gutin, M. A.; Gutin, O. N.

2000-01-01

294

Monolithic spectrometer  

DOEpatents

A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays. 6 figs.

Rajic, S.; Egert, C.M.; Kahl, W.K.; Snyder, W.B. Jr.; Evans, B.M. III; Marlar, T.A.; Cunningham, J.P.

1998-05-19

295

Monolithic spectrometer  

DOEpatents

A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

Rajic, Slobodan (Knoxville, TN); Egert, Charles M. (Oak Ridge, TN); Kahl, William K. (Knoxville, TN); Snyder, Jr., William B. (Knoxville, TN); Evans, III, Boyd M. (Oak Ridge, TN); Marlar, Troy A. (Knoxville, TN); Cunningham, Joseph P. (Oak Ridge, TN)

1998-01-01

296

Pseudoslit Spectrometer  

NASA Technical Reports Server (NTRS)

The pseudoslit spectrometer is a conceptual optoelectronic instrument that would offer some of the advantages, without the disadvantages, of prior linear-variable etalon (LVE) spectrometers and prior slit spectrometers. The pseudoslit spectrometer is so named because it would not include a slit, but the combined effects of its optical components would include a spatial filtering effect approximately equivalent to that of a slit. Like a prior LVE spectrometer, the pseudoslit spectrometer would include an LVE (essentially, a wedge-like narrowband- pass filter, the pass wavelength of which varies linearly with position in one dimension) in a focal plane covering an imaging planar array of photodetectors. However, the pseudoslit spectrometer would be more efficient because unlike a prior LVE spectrometer, the pseudoslit spectrometer would not have to be scanned across an entire field of view to obtain the spectrum of an object of interest that may occupy only a small portion of the field of view. Like a prior slit spectrometer, the pseudoslit spectrometer could acquire the entire spectrum of such a small object without need for scanning. However, the pseudoslit spectrometer would be optically and mechanically simpler: it would have fewer components and, hence, would pose less of a problem of alignment of components and would be less vulnerable to misalignment.

Reuter, Dennis C.; McCabe, George H.

2004-01-01

297

Photonic Crystal Slot Waveguide Spectrometer for Detection of Methane  

E-print Network

Photonic Crystal Slot Waveguide Spectrometer for Detection of Methane 1 Funded by Environmental Spectroscopy (33lbs, ~ 1cu.ft) Our Device 300 µµµµm 10µµµµm Photonic Crystal Slot Waveguide Spectrometer ( to wavelength · With photonic band gaps: "optical insulators" 1-D grating =1-D PhC 2-D PhC =2-D grating 3-D Ph

Texas at Austin, University of

298

High-throughput accurate-wavelength lens-based visible spectrometer.  

PubMed

A scanning visible spectrometer has been prototyped to complement fixed-wavelength transmission grating spectrometers for charge exchange recombination spectroscopy. Fast f/1.8 200 mm commercial lenses are used with a large 2160?mm(-1) grating for high throughput. A stepping-motor controlled sine drive positions the grating, which is mounted on a precision rotary table. A high-resolution optical encoder on the grating stage allows the grating angle to be measured with an absolute accuracy of 0.075 arc? sec, corresponding to a wavelength error ?0.005?A?. At this precision, changes in grating groove density due to thermal expansion and variations in the refractive index of air are important. An automated calibration procedure determines all the relevant spectrometer parameters to high accuracy. Changes in bulk grating temperature, atmospheric temperature, and pressure are monitored between the time of calibration and the time of measurement to ensure a persistent wavelength calibration. PMID:21033924

Bell, Ronald E; Scotti, Filippo

2010-10-01

299

High Resolution Coude Echelle Spectroscopy of IX Per  

NASA Astrophysics Data System (ADS)

High resolution (R = 45000) Coude-Echelle spectra of IX Per has been obtained at TB?TAK National Observatory (TUG) of Turkey. IX Per has been known to be a single lined (SB1) spectroscopic binary having chromospheric activity. However, analyzed spectra of IX Per by KOREL disentangling method indicated that the system is a double lined (SB2) spectroscopic binary. Weaker lines from the secondary are discovered on the decomposed spectra. A preliminary orbit indicates that the mass ratio of the system is 0.64. The light contribution of the secondary is up to 10% in investigated spectral region. Circular orbit is sufficient to explain radial velocity variations.

Ak, N. Filiz; Eker, Z.; Ak, H.; Kk, I.

2009-02-01

300

A treatment for background correction on the Hamilton Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

A method for background-illumination correction for the Hamilton Echelle Spectrograph is presented. The background is parametrized as (1) a global two-dimensional polynomial of scattered light, and (2) a local contamination of spectral features from adjacent orders modeled as a power law in the cross dispersion. The latter component corrects the overlap of closely packed adjacent orders. The significance of the local component is verified by statistical tests and interorder inspection. A software tool useful with the Image Reduction Analysis Facility has been made publicly available.

Churchill, Christopher W.; Allen, S. L.

1995-02-01

301

Multilayer diffraction grating  

DOEpatents

This invention is for a reflection diffraction grating that functions at X-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3,000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages.

Barbee, Jr., Troy W. (Palo Alto, CA)

1990-01-01

302

Varied line-space gratings: past, present and future  

SciTech Connect

A classically ruled diffraction grating consists of grooves which are equidistant, straight and parallel. Conversely, the so-called ''holographic'' grating (formed by the interfering waves of coherent visible light), although severely constrained by the recording wavelength and recording geometry, has grooves which are typically neither equidistant, straight nor parallel. In contrast, a varied line-space (VLS) grating, in common nomenclature, is a design in which the groove positions are relatively unconstrained yet possess sufficient symmetry to permit mechanical ruling. Such seemingly exotic gratings are no longer only a theoretical curiosity, but have been ruled and used in a wide variety of applications. These include: (1) aberration-corrected normal incidence concave gratings for Seya-Namioka monochromators and optical de-multiplexers, (2) flat-field grazing incidence concave gratings for plasma diagnostics, (3) aberration-corrected grazing incidence plane gratings for space-borne spectrometers, (4) focusing grazing incidence plane grating for synchrotron radiation monochromators, and (5) wavefront generators for visible interferometry of optical surfaces (particularly aspheres). Future prospects of VLS gratings as dispersing elements, wavefront correctors and beamsplitters appear promising. The author discusses the history of VLS gratings, their present applications, and their potential in the future. 61 refs., 24 figs.

Hettrick, M.C.

1985-08-01

303

A moderate-resolution, wide-band, astronomical echelle spectrograph  

NASA Technical Reports Server (NTRS)

An echelle spectrograph is described which is specifically designed for use on a 52-in. f/7.6 telescope as an instrument optimally suited for studying spectra of the faint optical counterparts to X-ray stars at moderate spectral resolution. The spectrograph is also able to accomodate a two-dimensional photon-tagging panoramic image detector so that high-time-resolution studies of the spectra of variable stars can be carried out. The equations for echelle spectrographs are summarized, and some features of the present instrument are discussed. These include its prism cross-disperser, small elliptical flat mirror, and unusually high efficiency. An iron-argon calibration spectrum obtained by pressing the film against the output fiber optics of a three-stage electrostatically focused image intensifier, a spectrum of P Cygni taken by placing the film directly in the image plane of the spectrograph, and a photon-counted image of a small section of an echellogram produced during an observation of the Ring nebula in Lyra are provided to illustrate the performance of the instrument.

Bardas, D.

1977-01-01

304

The Polar Environment Atmospheric Research Laboratory UVvisible Ground-Based Spectrometer: First measurements of O3, NO2, BrO,  

E-print Network

­visible, triple-grating spectrometer and is very similar to the UT-GBS (University of Toronto- GBS), which has of the refurbishment of PEARL, a UV­visible diffraction grating spectrometer, the PEARL-GBS (PEARL-Ground- BasedThe Polar Environment Atmospheric Research Laboratory UV­visible Ground-Based Spectrometer: First

Strong, Kimberly

305

Spectrometer and scanner with optofluidic configuration.  

PubMed

We present a spectrometer and scanner based on optofluidic configurations. The main optical component of the spectrometer is a compound optical element consisting of an optofluidic lens and standard blazed diffraction grating. The spectrum size can be changed by filling the lens cavity with different liquids. The scanner comprises two hollow 45 angle prisms oriented at 90 to each other. By changing the liquid inside the prisms, two-dimensional light beam scanning can be performed. PMID:23338199

Calixto, Sergio; Rosete-Aguilar, Martha; Sanchez-Morales, Maria Eugenia; Calixto-Solano, Margarita

2013-01-20

306

Transmission Grating Measurements of Undulator K  

SciTech Connect

This study was undertaken to understand the practicalities of determine K differences in the undulator modules by measuring single-shot x-ray spectra of the spontaneous radiation with a transmissive grating spectrometer under development to measure FEL spectra. Since the quality of the FEL is dependent on a uniform K value in all the undulator modules, being able to measure the relative undulator K values is important. Preliminary results were presented in a presentation, ''Use of FEL Off-Axis Zone Plate Spectrometer to Measure Relative K by the Pinhole/Centroid Method'', at the ''LCLS Beam-Based Undulator K Measurements Workshop'' on November 14, 2005 (UCRL-PRES-217281). This study applies equally well to reflective gratings of the appropriate period and inclinations.

Bionta, R M; Ott, L L

2006-05-15

307

Correlation spectrometer  

DOEpatents

A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.

Sinclair, Michael B. (Albuquerque, NM); Pfeifer, Kent B. (Los Lunas, NM); Flemming, Jeb H. (Albuquerque, NM); Jones, Gary D. (Tijeras, NM); Tigges, Chris P. (Albuquerque, NM)

2010-04-13

308

Catwalk grate lifting tool  

DOEpatents

A device for lifting catwalk grates comprising an elongated bent member with a handle at one end and a pair of notched braces and a hook at the opposite end that act in conjunction with each other to lock onto the grate and give mechanical advantage in lifting the grate.

Gunter, Larry W. (615 Sandpit Rd., Leesville, SC 29070)

1992-01-01

309

Catwalk grate lifting tool  

DOEpatents

A device is described for lifting catwalk grates comprising an elongated bent member with a handle at one end and a pair of notched braces and a hook at the opposite end that act in conjunction with each other to lock onto the grate and give mechanical advantage in lifting the grate. 10 figs.

Gunter, L.W.

1992-08-11

310

High accuracy wavelength calibration for a scanning visible spectrometer  

Microsoft Academic Search

Spectroscopic applications for plasma velocity measurements often require wavelength accuracies <=0.2 A˚. An automated calibration, which is stable over time and environmental conditions without the need to recalibrate after each grating movement, was developed for a scanning spectrometer to achieve high wavelength accuracy over the visible spectrum. This method fits all relevant spectrometer parameters using multiple calibration spectra. With a

Filippo Scotti; Ronald E. Bell

2010-01-01

311

Sub-nm resolution cavity enhanced micro-spectrometer  

E-print Network

Sub-nm resolution cavity enhanced micro- spectrometer Bernardo B. C. Kyotoku1,2 , Long Chen1: A novel on-chip spectrometer device using combined functionalities of a micro-ring resonator and a planar diffraction grating is proposed. We investigate the performance of this architecture by implementing

Lipson, Michal

312

Deep-etched fused silica gratings and applications  

NASA Astrophysics Data System (ADS)

Deep-etched fused silica grating is a kind of high density phase gratings whose surface are etched into an optimized depth for achieving a series of novel functions, such as high efficient diffraction at the -1 order, polarizing beam splitting, 1x2, 1x3 beam splitting, etc.. Since deep-etched fused silica grating is made of pure dielectric material of fused silica, so it has a high laser damage threshold for high power laser applications. We fabricated the polarizing beam splitter of the fused silica grating and realized the even and odd modes for analysis of fused silica grating. We gave the generalized equations for describing the performance of polarizing beam splitting and high efficient diffraction at the -1 order. We gave the analytic equation of 1x3 diffraction, which is impossible to obtain with the previous rigorously coupled wave method. For fabrication of deep-etched fused silica gratings, holographic recording, lithographic technique, and inductively coupled plasma etching are used to make the deep-etched gratings. Deep-etched gratings have a variety of practical applications. It can be used for demultiplexing optical signals in DWDM optical fiber communications. It can also be used as a pulse compressor of femtosecond or picosecond laser pulses. It can also be used as polarizing beam splitter, high efficient diffraction for spectrometer, etc.. Deep-etched fused silica gratings have a bright future for practical applications.

Zhou, Changhe

2010-11-01

313

Multilayer dielectric diffraction gratings  

DOEpatents

The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described. 7 figs.

Perry, M.D.; Britten, J.A.; Nguyen, H.T.; Boyd, R.; Shore, B.W.

1999-05-25

314

Multilayer dielectric diffraction gratings  

DOEpatents

The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described.

Perry, Michael D. (Livermore, CA); Britten, Jerald A. (Oakley, CA); Nguyen, Hoang T. (Livermore, CA); Boyd, Robert (Livermore, CA); Shore, Bruce W. (Livermore, CA)

1999-01-01

315

Toroidal Varied-Line Space (TVLS) Gratings  

NASA Technical Reports Server (NTRS)

It is a particular challenge to develop a stigmatic spectrograph for XUV wavelengths since the very low normal-incidence reflectance of standard materials most often requires that the design be restricted to a single optical element which must simultaneously provide both re-imaging and spectral dispersion. This problem has been solved in the past by the use of toroidal gratings with uniform line-spaced rulings (TULS). A number of solar EUV (Extreme Ultraviolet) spectrometers have been based on such designs, including SOHO/CDS, Solar-B/EIS, and the sounding rockets SERTS and EUNIS. More recently, Kita, Harada, and collaborators have developed the theory of spherical gratings with varied line-space rulings (SVLS) operated at unity magnification, which have been flown on several astronomical satellite missions. We now combine these ideas into a spectrometer concept that puts varied-line space rulings onto toroidal gratings. Such TVLS designs are found to provide excellent imaging even at very large spectrograph magnifications and beam-speeds, permitting extremely high-quality performance in remarkably compact instrument packages. Optical characteristics of two solar spectrometers based on this concept are described: SUMI, proposed as a sounding rocket experiment, and NEXUS, proposed for the Solar Dynamics Observatory mission.

Thomas, Roger J.; Oegerle, William (Technical Monitor)

2002-01-01

316

Multidimensional spectrometer  

DOEpatents

A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

Zanni, Martin Thomas (Madison, WI); Damrauer, Niels H. (Boulder, CO)

2010-07-20

317

CD Spectrometer  

NSDL National Science Digital Library

In this activity, learners use a compact disc to make a spectrometer, an instrument used to measure properties of light. Learners use their spectrometer to view a continuous spectrum produced by fluorescent light. This lesson guide also includes instructions on how to build a spectroscope from a cereal box.

Doherty, Paul

2000-01-01

318

Performance of the CHIRON high-resolution Echelle spectrograph  

NASA Astrophysics Data System (ADS)

CHIRON is a fiber-fed Echelle spectrograph with observing modes for resolutions from 28,000 to 120,000, built primarily for measuring precise radial velocities (RVs). We present the instrument performance as determined during integration and commissioning. We discuss the PSF, the effect of glass inhomogeneity on the cross-dispersion prism, temperature stabilization, stability of the spectrum on the CCD, and detector characteristics. The RV precision is characterized, with an iodine cell or a ThAr lamp as the wavelength reference. Including all losses from the sky to the detector, the overall efficiency is about 6%; the dominant limitation is coupling losses into the fiber due to poor guiding.

Schwab, Christian; Spronck, Julien F. P.; Tokovinin, Andrei; Szymkowiak, Andrew; Giguere, Matthew; Fischer, Debra A.

2012-09-01

319

The Echelon-cross-Echelle Spectrograph for SOFIA  

NASA Astrophysics Data System (ADS)

The Echelon-cross-Echelle Spectrograph (EXES), one of the first generation instruments for the Statospheric Observatory for Infrared Astronomy (SOFIA) will provide a unique tool for examining the ISM and star formation. The EXES high spectral resolution mode, R ? 120 000 from 4.5 ?m to 28.3 ?m, is designed for line observations of gas-phase molecules. The improved atmospheric transmission guaranteed by SOFIA will make observations of molecules such as H2O and CH4 fairly routine. EXES will also have medium and low resolution modes to enable a wide range of science projects. EXES is a PI instrument open for collaborative proposals following the model of the successful TEXES instrument (Lacy et al. 2002). It is currently scheduled for first science flights on SOFIA in 2013.

Richter, M. J.; Seifahrt, A.; McKelvey, M.; Zell, P.

2011-11-01

320

[Design of concave grating for ultraviolet-spectrum].  

PubMed

Ultraviolet-spectrum technology is a kind of low signal and multianalysis technology. For taking full advantage of spectral information and reducing the volume of spectrometer, we used high efficiency spectroscopy structure based on concave grating. Based on concave grating theory and optic design software ZEMAX, a flat field concave grating for ultraviolet spectrophotometer was designed from primary structure, which relied on global optimization of the software. The contradiction between wide spectrum bound and limited spectrum extension was resolved, aberrations were reduced successfully, spectrum information was utilized fully, and the optic structure of spectrometer was highly efficient. For better preference of this spectrophotometer, after get the structure parameter, combine grating fabrication condition with practice working condition, grating diffractive theory, holographic optics theory and software PCG rate was used for diffraction efficiency design and improve. A paradigm of flat field concave grating is given, it works between 190 nm to 410 nm, the diameter of the concave grating is 20 mm, and F/# is 0.21. The design result was analyzed and evaluated. It was showed that if the slit source, whose width is 50 microm, is used to reconstruction, the theoretic resolution capacity is better than 3 nm. PMID:22870673

Luo, Biao; Wen, Zhi-Yu; Wen, Zhong-Quan; Zeng, Tian-Ling

2012-06-01

321

Noise analysis of spectrometers based on speckle pattern reconstruction.  

PubMed

Speckle patterns produced by a disordered medium or a multimode fiber can be used as a fingerprint to uniquely identify the input light frequency. Reconstruction of a probe spectrum from the speckle pattern has enabled the realization of compact, low-cost, and high-resolution spectrometers. Here we investigate the effects of experimental noise on the accuracy of the reconstructed spectra. We compare the accuracy of a speckle-based spectrometer to a traditional grating-based spectrometer as a function of the probe signal intensity and bandwidth. We find that the speckle-based spectrometers provide comparable performance to a grating-based spectrometer when measuring intense or narrowband probe signals, whereas the accuracy degrades in the measurement of weak or broadband signals. These results are important to identify the applications that would most benefit from this new class of spectrometer. PMID:24514126

Redding, Brandon; Popoff, Sebastien M; Bromberg, Yaron; Choma, Michael A; Cao, Hui

2014-01-20

322

Mariner 10 ultraviolet spectrometer - Airglow experiment  

NASA Technical Reports Server (NTRS)

An extreme ultraviolet airglow spectrometer was flown on Mariner 10 to examine the atmosphere of Venus and Mercury. An objective grating spectrometer was used with channel electron multipliers at fixed positions in the image plane to continuously monitor the resonance-scattered emission rate of expected atomic atmospheric constituents He, H, A, Ne, O and C. A mechanical collimator placed in the entrance aperture of the spectrometer provided spectral separation of 19 A over the wavelength range from He/+/ at 304 A to C at 1657 A and provided spatial separation of 0.125 deg consistent with the spacecraft and trajectory capabilities. The calibration techniques are discussed.

Broadfoot, A. L.; Clapp, S. S.; Stuart, F. E.

1977-01-01

323

High Resolution VUV Spectrometer at the INDUS-1 Synchrotron Source  

SciTech Connect

An indigenously developed high-resolution vacuum ultraviolet (VUV) spectrometer has recently been commissioned at the INDUS-1 Synchrotron Source, Indore, India for carrying out spectroscopic research of atomic and molecular gases. The spectrometer uses a 6.65-meter concave grating in off-plane Eagle mounting and a photomultiplier tube (PMT) for recording the intensity profile of various spectral lines. Experimental performance of the spectrometer has been tested using laboratory sources and 1200 grooves/mm and 4800 grooves/mm concave gratings. Wavelength resolutions of 0.08 Aa and 0.01 Aa have been achieved when 1200 grooves/mm and 4800 grooves/mm concave gratings have been mounted successfully in the spectrometer. The instrument has been integrated with the high resolution VUV beamline at INDUS-1 and its performance is being evaluated with synchrotron radiation.

Das, Nimai C.; Shukla, Ram P.; Udupa, Dinesh V.; Sahoo, Naba K.; Bhattacharyya, Dibyendu; Sunanda, K.; Saraswathy, P. [Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai -400 085 (India)

2007-01-19

324

Modeling the Chandra High Energy Transmission Gratings below 2 keV  

E-print Network

Modeling the Chandra High Energy Transmission Gratings below 2 keV K.A. Flanagana, T.H. Markerta, J The High Energy Transmission Grating Spectrometer of the Chandra X-Ray Observatory is a high spectral it below 2 keV to complete the coverage over the Chandra energy range. We investigate the carbon, nitrogen

325

The fabrication of toroidal and coma-corrected toroidal diffraction gratings from spherical master gratings using elastically-deformable substrates - A progress report  

NASA Technical Reports Server (NTRS)

A technique has been developed which permits toroidal, and coma-corrected toroidal, diffraction gratings to be replicated from spherical master gratings by the use of elastically-deformable substrates. Toroidal gratings correct for astigmatism and, thus, make it possible to construct stigmatic spectrometers that employ a single reflective diffraction grating. These spectrometers are particularly useful for the extreme-ultraviolet (EUV) wavelength range, where reflection coefficients are low, since the single optical surface provides for dispersion, focusing, and astigmatism correction. The fabrication procedures for the pure toroidal, and coma-corrected toroidal, gratings are described, and initial test results are presented. The use of the toroidal gratings in a high-resolution sounding-rocket EUV spectroheliometer, and in both the coronal diagnostics spectrometer and the ultraviolet coronagraph spectrometer on the ESA/NASA solar and heliospheric observatory mission, is described briefly, and the use of this technique for the fabrication of a coma-corrected toroidal grating for the prime Rowland spectrograph of the FUSE/Lyman mission is briefly discussed.

Huber, Martin C. E.; Timothy, J. G.; Morgan, Jeffrey S.; Lemaitre, Gerard; Tondello, Giuseppe; Naletto, Giampiero

1991-01-01

326

Galileo Ultraviolet Spectrometer experiment  

NASA Technical Reports Server (NTRS)

The Galileo ultraviolet spectrometer experiment uses data obtained by the Ultraviolet Spectrometer (UVS) mounted on the pointed orbiter scan platform and from the Extreme Ultraviolet Spectrometer (EUVS) mounted on the spinning part of the orbiter with the field of view perpendicular to the spin axis. The UVS is a Ebert-Fastie design that covers the range 113-432 nm with a wavelength resolution of 0.7 nm below 190 and 1.3 nm at longer wavelengths. The UVS spatial resolution is 0.4 deg x 0.1 deg for illuminated disk observations and 1 deg x 0.1 deg for limb geometries. The EUVS is a Voyager design objective grating spectrometer, modified to cover the wavelength range from 54 to 128 nm with wavelength resolution 3.5 nm for extended sources and 1.5 nm for point sources and spatial resolution of 0.87 deg x 0.17 deg. The EUVS instrument will follow up on the many Voyager UVS discoveries, particularly the sulfur and oxygen ion emissions in the Io torus and molecular and atomic hydrogen auroral and airglow emissions from Jupiter. The UVS will obtain spectra of emission, absorption, and scattering features in the unexplored, by spacecraft, 170-432 nm wavelength region. The UVS and EUVS instruments will provide a powerful instrument complement to investigate volatile escape and surface composition of the Galilean satellites, the Io plasma torus, micro- and macro-properties of the Jupiter clouds, and the composition structure and evolution of the Jupiter upper atmosphere.

Hord, C. W.; Mcclintock, W. E.; Stewart, A. I. F.; Barth, C. A.; Esposito, L. W.; Thomas, G. E.; Sandel, B. R.; Hunten, D. M.; Broadfoot, A. L.; Shemansky, D. E.

1992-01-01

327

Tunable, fiber coupled spectrometer based on difference-frequency generation in periodically poled lithium niobate  

E-print Network

1 Tunable, fiber coupled spectrometer based on difference-frequency generation in periodically by rotation of its diffraction grating relative to the optical axis of the laser cavity. Fine tuning tunable Fig. 2: Conversion efficiency and tuning DFG spectrometer characteristics of a DFG spectrometer

328

High-resolution crystal spectrometer for the 1060 extreme ultraviolet region  

E-print Network

in the soft x-ray region below 25 ?. Above this wavelength grating spectrometers have been used, but oftenHigh-resolution crystal spectrometer for the 10­60 ? extreme ultraviolet region P. Beiersdorfer spectrometer with nominal resolving power approaching 1000 is described for measuring emission lines

Wargelin, Bradford J.

329

In situ calibration of an extreme ultraviolet spectrometer for attosecond transient  

E-print Network

- periments. Generally, an XUV spectrometer consists of a grazing incidence flat-field grating (FFGIn situ calibration of an extreme ultraviolet spectrometer for attosecond transient absorption January 2013 We report a method for calibrating an extreme ultraviolet spectrometer based on a flat

Van Stryland, Eric

330

Reflective diffraction grating  

DOEpatents

Reflective diffraction grating. A focused ion beam (FIB) micromilling apparatus is used to store color images in a durable medium by milling away portions of the surface of the medium to produce a reflective diffraction grating with blazed pits. The images are retrieved by exposing the surface of the grating to polychromatic light from a particular incident bearing and observing the light reflected by the surface from specified reception bearing.

Lamartine, Bruce C. (Los Alamos, NM)

2003-06-24

331

Deformed ellipsoidal diffraction grating blank  

NASA Technical Reports Server (NTRS)

The Deformed Ellipsoidal Grating Blank (DEGB) is the primary component in an ultraviolet spectrometer. Since one of the major concerns for these instruments is throughput, significant efforts are made to reduce the number of components and subsequently reflections. Each reflection results in losses through absorption and scattering. It is these two sources of photon loss that dictated the requirements for the DEGB. The first goal is to shape the DEGB in such a way that the energy at the entrance slit is focused as well as possible on the exit slit. The second goal is to produce a surface smooth enough to minimize the photon loss due to scattering. The program was accomplished in three phases. The first phase was the fabrication planning. The second phase was the actual fabrication and initial testing. The last phase was the final testing of the completed DEGB.

Decew, Alan E., Jr.

1994-01-01

332

The Constellation-X RGS options: raytrace modeling of the off-plane gratings  

NASA Astrophysics Data System (ADS)

The Reflection Grating Spectrometer of the Constellation-X mission has two strong candidate configurations. The first configuration, the in-plane grating (IPG), is a set of reflection gratings similar to those flown on XMM-Newton and has grooves perpendicular to the direction of incident light. In the second configuration, the off-plane grating (OPG), the grooves are closer to being parallel to the incident light, and diffract along a cone. It has advantages of higher packing density, and higher reflectivity. Confinement of these gratings to sub-apertures of the optic allow high spectral resolution. We have developed a raytrace model and analysis technique for the off-plane grating configuration. Initial estimates indicate that first order resolving powers in excess of 1000 (defined with half-energy width) are achievable for sufficiently long wavelengths (? >= 12), provided separate accommodation is made for gratings in the subaperture region farther from the zeroth order location.

Flanagan, Kathryn A.; Davis, John E.; Heilmann, Ralf K.; Levine, Alan M.; McGuirk, Michael; Ricker, George R.; Schattenburg, Mark L.; Wise, Michael; Rasmussen, Andrew; Bookbinder, Jay A.; Freeman, Mark D.; Gaetz, Terrance J.; Jerius, Diab; Nguyen, Dan; Podgorski, William A.; Reid, P. B.; Cash, Webster C.; Shipley, Ann F.; Gallagher, Dennis J.; Huang, Pei; Jordan, Steve P.

2004-10-01

333

High resolution fiber-fed echelle spectrograph for the Southern African Large Telescope  

Microsoft Academic Search

The design of the Canterbury Extremely Large Echelle Spectrograph on the Telescope In Africa (CELESTIA) is currently in progress. This high-resolution fiber-fed echelle spectrograph will be used with the Southern African Large Telescope (SALT) which is currently under construction at the South African Astronomical Observatory, near Sutherland, South Africa. CELESTIA uses a mechanically aligned mosaic of two 304 x 408-mm

Stuart I. Barnes; John B. Hearnshaw; Peter Cottrell; M. D. Albrow; Graeme Kershaw

2003-01-01

334

Fabrication and Performance of Silicon Immersion Gratings for Infrared Spectroscopy  

E-print Network

Fabrication and Performance of Silicon Immersion Gratings for Infrared Spectroscopy Jasmina P. Marsh, Douglas J. Mar, Daniel T. Jaffe Department of Astronomy, Univ. of Texas at Austin, 1 University infrared spectrometers with high throughput, high spectral resolution, and extensive instantaneous coverage

Jaffe, Daniel T.

335

AVES: an adaptive optics visual echelle spectrograph for the VLT  

NASA Astrophysics Data System (ADS)

We present the preliminary study of a low cost, high performance spectrograph for the VLT, for observations in the V, R and I bands. This spectrograph is meant for intermediate (R equals 16,000) resolution spectroscopy of faint (sky and/or detector limited) sources, with particular emphasis on the study of solar-type (F-G) stars belonging to the nearest galaxies and to distant (or highly reddened) galactic clusters. The spectrograph is designed to use the adaptive optics (AO) systems at the VLT Telescope. Even if these AO systems will not provide diffraction limited images in the V, R and I bands, the photon concentration will still be above approximately 60% of the flux in an 0.3 arcsecond aperture for typical Paranal conditions. This makes the construction of a compact, cheap and efficient echelle spectrograph possible. AVES will outperform comparable non adaptive optic instruments by more than one magnitude for sky- and/or detector-limited observations, and it will be very suitable for observations in crowded fields.

Pasquini, Luca; Delabre, Bernard; Avila, Gerardo; Bonaccini, Domenico

1998-07-01

336

The diffraction grating in the Ivory optomechanical modeling tools  

NASA Astrophysics Data System (ADS)

In imaging spectrometers it is important that both the image of the far-field object and the image of the slit be stable on the detector plane. Lenses and mirrors contribute to the motions of these images but motions of the diffraction grating also have their own influences on these image motions. This paper develops the vector equations for the images (spectra) of the diffraction grating and derives their optomechanical influence coefficients from them. The Ivory Optomechanical Modeling Tools integrates the diffraction grating into the larger optical imaging system and formats the whole system's influence coefficients suitably for both spreadsheet and finite element analysis methods. Their application is illustrated in an example of a spectrometer exposed to both static and dynamic disturbances.

Hatheway, Alson E.

2013-09-01

337

Properties of the ionized gas in HH 202 - II. Results from echelle spectrophotometry with Ultraviolet Visual Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

We present results of deep echelle spectrophotometry of the brightest knot of the Herbig-Haro object HH 202 in the Orion Nebula - HH 202-S - using the Ultraviolet Visual Echelle Spectrograph in the spectral range from 3100 to 10400 . The high spectral resolution of the observations has permitted to separate the component associated with the ambient gas from that associated with the gas flow. We derive electron densities and temperatures from different diagnostics for both components, as well as the chemical abundances of several ions and elements from collisionally excited lines, including the first determinations of Ca+ and Cr+ abundances in the Orion Nebula. We also calculate the He+, C2+, O+ and O2+ abundances from recombination lines. The difference between the O2+ abundances determined from collisionally excited and recombination lines - the so-called abundance discrepancy factor - is 0.35 and 0.11 dex for the shock and nebular components, respectively. Assuming that the abundance discrepancy is produced by spatial variations in the electron temperature, we derive values of the temperature fluctuation parameter, t2, of 0.050 and 0.016 for the shock and nebular components, respectively. Interestingly, we obtain almost coincident t2 values for both components from the analysis of the intensity ratios of HeI lines. We find significant departures from case B predictions in the Balmer and Paschen flux ratios of lines of high principal quantum number n. We analyse the ionization structure of HH 202-S, finding enough evidence to conclude that the flow of HH 202-S has compressed the ambient gas inside the nebula trapping the ionization front. We measure a strong increase of the total abundances of nickel and iron in the shock component, the abundance pattern and the results of photoionization models for both components are consistent with the partial destruction of dust after the passage of the shock wave in HH 202-S. Based on observations collected at the European Southern Observatory, Chile, proposal number ESO 70.C-0008(A). E-mail: amd@iac.es

Mesa-Delgado, A.; Esteban, C.; Garca-Rojas, J.; Luridiana, V.; Bautista, M.; Rodrguez, M.; Lpez-Martn, L.; Peimbert, M.

2009-05-01

338

Transmitted wavefront error of a volume phase holographic grating at cryogenic temperature.  

PubMed

This paper describes the results of transmitted wavefront error (WFE) measurements on a volume phase holographic (VPH) grating operating at a temperature of 120 K. The VPH grating was mounted in a cryogenically compatible optical mount and tested in situ in a cryostat. The nominal root mean square (RMS) wavefront error at room temperature was 19 nm measured over a 50 mm diameter test aperture. The WFE remained at 18 nm RMS when the grating was cooled. This important result demonstrates that excellent WFE performance can be obtained with cooled VPH gratings, as required for use in future cryogenic infrared astronomical spectrometers planned for the European Extremely Large Telescope. PMID:22660099

Lee, David; Taylor, Gordon D; Baillie, Thomas E C; Montgomery, David

2012-06-01

339

Precise angular positioning at 6K: the FIFI-LS grating assembly  

NASA Astrophysics Data System (ADS)

The Field Imaging Far Infrared Line Spectrometer (FIFI-LS) obtains spectral data within two wavelength ranges. The observed wavelengths are set by rotating the two diffraction gratings to specific angles. This paper describes on the grating assemblies, designed to rotate and stabilize the gratings. First the assembly itself and its special environment inside FIFI-LS is explained. Then a method is layed out how to monitor the performance of the drive and how to detect upcoming failures before they happen. The last chapter is dedicated to first inflight measurements of the position stability of the grating.

Rebell, Felix; Raab, Walfried; Colditz, Sebastian; Beckmann, Simon; Bryant, Aaron; Fischer, Christian; Fumi, Fabio; Geis, Norbert; Hnle, Rainer; Klein, Randolf; Krabbe, Alfred; Looney, Leslie; Poglitsch, Albrecht; Ragan, Sarah; Savage, Maureen

2014-07-01

340

HISS spectrometer  

SciTech Connect

This talk describes the Heavy Ion Spectrometer System (HISS) facility at the Lawrence Berkeley Laboratory's Bevalac. Three completed experiments and their results are illustrated. The second half of the talk is a detailed discussion of the response of drift chambers to heavy ions. The limitations of trajectory measurement over a large range in incident particle charge are presented.

Greiner, D.E.

1984-11-01

341

Spectrometer gun  

DOEpatents

A hand-holdable, battery-operated, microprocessor-based spectrometer gun is described that includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

Waechter, D.A.; Wolf, M.A.; Umbarger, C.J.

1981-11-03

342

Spectrometer gun  

DOEpatents

A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

Waechter, David A. (Los Alamos, NM); Wolf, Michael A. (Los Alamos, NM); Umbarger, C. John (Los Alamos, NM)

1985-01-01

343

Ultra-Compact, Superconducting Spectrometer-on-a-Chip at Submillimeter Wavelengths  

NASA Technical Reports Server (NTRS)

Small size, wide spectral bandwidth, and highly multiplexed detector readout are required to develop powerful multi-beam spectrometers for high-redshift observations. Currently available spectrometers at these frequencies are large and bulky. The grating sizes for these spectrometers are prohibitive. This fundamental size issue is a key limitation for space-based spectrometers for astrophysics applications. A novel, moderate-resolving-power (R-700), ultra-compact spectrograph-on-a-chip for millimeter and submillimeter wavelengths is the solution.

Chattopadhyay, Goutam; Zmuidzinas, Jonas; Bradford, Charles M.; Leduc, Henry G.; Day, Peter K.; Swenson, Loren; Hailey-Dunsheath, Steven; O'Brient, Roger C.; Padin, Stephen; Shirokoff, Erik D.; McKenney, Christopher; Reck, Theodore; Siles, Jose V.; Barry, Peter; Doyle, Simon; Mauskopf, Philip; Llombart, Nuria; Kovacs, Attila; Marrone, Dan P.

2013-01-01

344

Performance of high spatial frequency X-ray transmission gratings  

NASA Technical Reports Server (NTRS)

The performance of high spatial frequency 'phased' X-ray transmission gratings developed for the High Energy Transmission Grating Spectrometer on the Advanced X-ray Astrophysics FAcility (AXAF) is examined. The gratings tested here nominally consist of 1-micron-thick gold lines of 0.2 micron period covering approximately 5 sq cm of a polyimide membrane. A table-top setup at MIT employs the gratings in reflection to diffract UV (325 nm) laser light. It is used to measure grating periods and indicates that period variations within and between gratings are a few parts in 10,000. Tests performed at the Marshall Space Flight Center 304 m X-ray Facility using 1.5 keV X-rays in transmission corroborate the UV measurements and demonstrate geometrically-limited resolving powers of E/Delta E about 750. Finally, X-ray transmission tests performed in the MIT 25 m X-ray facility provide measurements of period, line thickness, space-to-period ratio, tilt of grating lines, and efficiency.

Fischbach, K. F.; Levine, A. M.; Schattenburg, M. L.; Dewey, D.; Renshaw, R. L.

1988-01-01

345

Ultraviolet spectrometer experiment for the Voyager mission  

NASA Technical Reports Server (NTRS)

An objective grating spectrometer covering the wavelength range of 500 to 1700 A with a 10-A resolution is employed for the Voyager ultraviolet spectrometer experiment. In determining the composition and structure of the atmospheres of Saturn, Jupiter and several satellites, the ultraviolet spectrometer will rely on airglow mode observations to measure radiation from the atmospheres due to resonant scattering of solar flux, and the occultation mode for assessments of the atmospheric extinction of solar or stellar radiation as the spacecraft enters shadow zones. Since it is capable of prolonged stellar observations in the 500 to 1000 A wavelength range, the spectrometer is expected to make important contributions to exploratory studies of UV sources.

Broadfoot, A. L.; Sandel, B. R.; Shemansky, D. E.; Atreya, S. K.; Donahue, T. M.; Moos, H. W.; Bertaux, J. L.; Blamont, J. E.; Ajello, J. M.; Strobel, D. F.

1977-01-01

346

Imaging IR spectrometer, phase 2  

NASA Technical Reports Server (NTRS)

The development is examined of a prototype multi-channel infrared imaging spectrometer. The design, construction and preliminary performance is described. This instrument is intended for use with JPL Table Mountain telescope as well as the 88 inch UH telescope on Mauna Kea. The instrument is capable of sampling simultaneously the spectral region of 0.9 to 2.6 um at an average spectral resolution of 1 percent using a cooled (77 K) optical bench, a concave holographic grating and a special order sorting filter to allow the acquisition of the full spectral range on a 128 x 128 HgCdTe infrared detector array. The field of view of the spectrometer is 0.5 arcsec/pixel in mapping mode and designed to be 5 arcsec/pixel in spot mode. The innovative optical design has resulted in a small, transportable spectrometer, capable of remote operation. Commercial applications of this spectrometer design include remote sensing from both space and aircraft platforms as well as groundbased astronomical observations.

Gradie, Jonathan; Lewis, Ralph; Lundeen, Thomas; Wang, Shu-I

1990-01-01

347

The Bragg crystal spectrometer for AXAF  

NASA Technical Reports Server (NTRS)

The goal of MIT's high resolution X-ray spectrometry investigation on the Advanced X-ray Astrophysics Facility is to study the physical conditions in celestial sources by means of detailed measurements of their X-ray spectra. The investigation involves two complimentary dispersive instruments, a Bragg crystal spectrometer (BCS) and a high energy transmission grating spectrometer. Particular attention is given to the BCS which will be used to measure the strengths of individual lines from both point and extended objects in order to apply plasma diagnostic techniques to the study of cosmic X-ray sources.

Canizares, C. R.; Markert, T. H.; Clark, G. W.

1986-01-01

348

An Extreme Ultraviolet Optics-Free Spectrometer With Improved Spectral Resolution and High Signal-to-Noise Ratio  

E-print Network

the spectral resolution of typical EUV grating spectrometers designed for spaceflight applications. ModeledAn Extreme Ultraviolet Optics-Free Spectrometer With Improved Spectral Resolution and High Signal (EUV) spectrometer based on a gas ionization chamber and on flight experience of the Optics Free

Didkovsky, Leonid

349

Alignment of the grating wheel mechanism for a ground-based cryogenic near-infrared astronomy instrument  

Microsoft Academic Search

We describe the population, optomechanical alignment, and alignment verification of near-infrared gratings on the grating wheel mechanism (GWM) for the Infrared Multi-Object Spectrometer (IRMOS). IRMOS is a cryogenic (80 K), principle investigator-class instrument for the 2.1 m and Mayall 3.8 m telescopes at Kitt Peak National Observatory, and a MEMS spectrometer concept demonstrator for the James Webb Space Telescope. The

Sharon M. Gutkowski; Raymond G. Ohl; Jason E. Hylan; John G. Hagopian; Stephen E. Kraft; J. E. Mentzell; Joseph A. Connelly; Joseph P. Schepis; Leroy M. Sparr; Matthew A. Greenhouse; John W. MacKenty

2003-01-01

350

Pupil aberrations in Offner spectrometers.  

PubMed

The light path function (LPF) of an Offner spectrometer is presented. The evaluation of the LPF of this spectrometer enables its imaging properties to be studied for arbitrary object and image positions, while avoiding the more complicated analysis of intermediate images generated by the diffraction grating, which is often involved. A power series expansion of the LPF on the grating coordinates directly determines pupil aberrations of the generated spectrum and facilitates the search for configurations with small low-order aberrations. This analysis not only confirms the possibility of reducing low-order aberrations in Rowland-type mounts, namely astigmatism and coma, as predicted in previous studies, but also proves that all third-order terms in the series expansion of the aberration function can be canceled at the image of the design point and for the corresponding design wavelength, when the design point is located on a plane orthogonal to the optical axis. Furthermore, fourth-order terms are computed and shown to represent the most relevant contribution to image blurring. Third- and fourth-order aberrations are also evaluated for Rowland mounts with the design point located outside the aforementioned plane. The study described in this manuscript is not restricted to small angles of incidence, and, therefore, it goes beyond Seidel and Buchdahl aberrations. PMID:22472819

Gonzlez-Nez, Hctor; Prieto-Blanco, Xess; de la Fuente, Ral

2012-04-01

351

IP Pegasi in outburst: Echelle spectroscopy and Modulation Doppler Tomography  

NASA Astrophysics Data System (ADS)

We analyse a unique set of time-resolved echelle spectra of the dwarf nova IP Peg, obtained at ESO's NTT with EMMI on the 4th of August 1999, just one day after the peak of an outburst. The dataset covers the wavelength range of 4000-7500A and shows Balmer, HeI, HeII and heavier elements in emission. IP Peg was observed one day after the peak of an outburst. The trailed spectra, spectrograms and Doppler maps show characteristics typical of IP Pegasi during the early stages of its outburst, such as prograde rotation from the accretion disc flow, chromospheric emission from the secondary and spiral arms. The high-ionisation line of HeII 4686A is the most centrally located line and its formation region has the greatest radial extension compared to the HeI lines. The Balmer lines extend from close to the white dwarf up to approximately 0.45 R_L, with the outer radius gradually increasing when moving from H delta to H alpha. The application, for the first time, of the modulation Doppler tomography technique, maps any harmonically varying components present in the system configuration, and this variability information is not considered in standard Doppler tomography studies. We find, as expected, that part of the strong secondary star emission in Balmer and HeI lines is modulated predominantly with the cosine term, consistent with the emission originating from the irradiated front side of the mass-donor star, facing the accreting white dwarf. For the Balmer lines the level of the modulation, compared to the average emission, decreases when moving to higher series. Emission from the extended accretion disk appears to be only weakly modulated, with amplitudes of at most a few percent of the non-varying disk emission. We find no evidence of modulated emission in the spiral arms, which if present, is relatively weak at that our signal-to-noise ratio was good enough to put an upper detection limit of any modulated emission at 5-6 percent. Only in one arm of the HeII 4686A line, is there a possibility of modulated emission, but again, we cannot be sure this is not caused by blending with the nearby Bowen complex of lines.

Papadaki, C.; Boffin, H. M. J.; Steeghs, D.

2008-09-01

352

Calibration of a High Resolution Soft X-ray Spectrometer  

SciTech Connect

A high resolution grating spectrometer (HRGS) with 2400 line/mm variable line spacing grating for the 10-50 {angstrom} wavelength range has been designed for laser-produced plasma experiments at the Lawrence Livermore National Laboratory (LLNL). The spectrometer has a large radius of curvature, R=44.3 m, is operated at a 2{sup o} grazing angle and can record high signal-to-noise spectra when used with a low-noise, cooled, charge-coupled device detector. The instrument can be operated with a 10-25 {micro}m wide slit to achieve the best spectral resolving power on laser plasma sources, approaching 2000, or in slitless mode with a small symmetrical emission source. Results will be presented for the spectral response of the spectrometer cross-calibrated at the LLNL Electron Beam Ion Trap facility using the broadband x-ray energy EBIT Calorimeter Spectrometer (ECS).

Dunn, J; Beiersdorfer, P; Brown, G V; Magee, E W

2010-01-26

353

Adapting a very high resolution echelle spectrograph to an 8 meter class telescope  

NASA Astrophysics Data System (ADS)

The Adaptively Corrected Echelle Spectrograph (ACES) high resolution echelle spectrograph was originally developed at Steward Observatory to couple adaptively-corrected stellar images to the instrument using a near single mode optical fiber to give R~190,000 at V band. We explore here the feasibility of using the spectrograph with the 2x8.4m Large Binocular Telescope (LBT), preserving the fiber coupling for instrument isolation and illumination stability, but employing either a narrow slit or image slicer to offset the smaller component size and thereby preserve high resolution. Such a combination could offer simultaneously higher resolution with greater wavelength coverage per exposure than the configuration of alternate instruments.

Reynolds, Robert O.; Dettmann, Lee

2014-07-01

354

High Accuracy Wavelength Calibration For A Scanning Visible Spectrometer  

Microsoft Academic Search

Spectroscopic applications for plasma velocity measurements often require wavelength accuracies 0.2. An automated calibration for a scanning spectrometer has been developed to achieve a high wavelength accuracy overr the visible spectrum, stable over time and environmental conditions, without the need to recalibrate after each grating movement. The method fits all relevant spectrometer paraameters using multiple calibration spectra. With a steping-motor

Ronald Bell Filippo Scotti

2010-01-01

355

Fiber laser FBG sensor system by using a spectrometer demodulation  

NASA Astrophysics Data System (ADS)

We suggest a spectrometer demodulation method of FBG sensors for the possible uses in wind power generator's blade monitoring. High signal-to-noise ratio outputs and linear demodulation were obtained by combining a fiber laser light source and a spectrometer which used a holographic volume grating and a 512-pixel PD array. Preliminary experimental results are presented to show the feasibility of the suggested FBG demodulation system.

Kim, Hyunjin; Song, Minho

2011-05-01

356

An EUV spectrometer for mapping the heliopause and solar wind , J.Edelsteina  

E-print Network

An EUV spectrometer for mapping the heliopause and solar wind M.Lamptona , J.Edelsteina , T limitation on the mapping rate at high signal-to-noise ratio. We have developed a spectrometer configuration combines a conventional normal-incidence Rowland mount grating and an efficient multilayer coating

California at Berkeley, University of

357

PRELIMINARY RESULTS FROM THE HAYABUSA NEAR INFRARED SPECTROMETER (NIRS) OF ASTEROID (25143) ITOKAWA. M. Abe1  

E-print Network

PRELIMINARY RESULTS FROM THE HAYABUSA NEAR INFRARED SPECTROMETER (NIRS) OF ASTEROID (25143) ITOKAWA Bay Area Blvd., Houston, TX 77058, USA). Introduction: NIRS is a near-infrared spectrometer on,000 spectra of Itokawa. NIRS has a 64-channel InGaAs photodiode array detector and a grism grating system [2

Hiroi, Takahiro

358

CHARACTERISTICS AND CURRENT STATUS OF NEAR INFRARED SPECTROMETER FOR HAYABUSA MISSION. M. Abe1  

E-print Network

CHARACTERISTICS AND CURRENT STATUS OF NEAR INFRARED SPECTROMETER FOR HAYABUSA MISSION. M. Abe1 , Y materials. Combining with the data from asteroid multiband imaging camera (AMICA) and X-ray spectrometer as a detec- tor and a grism (grating ­ prism) system. Spectral reso- lution is 23.6nm/channel. The second

Hiroi, Takahiro

359

OBSERVATIONS WITH NEAR INFRARED SPECTROMETER FOR HAYABUSA MISSION IN THE CRUISING PHASE. M. Abe1  

E-print Network

OBSERVATIONS WITH NEAR INFRARED SPECTROMETER FOR HAYABUSA MISSION IN THE CRUISING PHASE. M. Abe1@ithaca.edu). Introduction: NIRS is a near infrared spectrometer on-board the spacecraft HAYABUSA, which aims to return (grating ­ prism) system. Spectral resolution is 23.6nm/channel. The field of view is 0.1 x 0.1 degrees

Hiroi, Takahiro

360

FIES: A high resolution FIber fed Echelle Spectro-graph for NOT  

E-print Network

FIES: A high resolution FIber fed Echelle Spectro- graph for NOT S. Frandsen 1 and B. Lindberg 2 1 was a bench mounted, high resolution spectrograph, coupled to the telescope by an optical #12;ber. Due to #12. With a slit size of 88#22;m (transmitting 75% of the light imaged onto the #12;ber), the average resolution

Frandsen, Søren

361

Unexpected effects of a trap in CCD echelle spectra of B-type stars  

NASA Technical Reports Server (NTRS)

Because of the nature of echelle spectra, cosmetic defects such as traps may mimic real spectral features. An example from spectra taken at CTIO with a GEC CCD is presented, and it is shown how the affected pixels can be eliminated from the reduced spectrum, at a slight cost in signal-to-noise ratio.

Morrison, Nancy D.; Zimba, Jason R.

1990-01-01

362

Optical system for high resolution spectrometer/monochromator  

DOEpatents

An optical system for use in a spectrometer or monochromator employing a mirror which reflects electromagnetic radiation from a source to converge with same in a plane. A straight grooved, varied-spaced diffraction grating receives the converging electromagnetic radiation from the mirror and produces a spectral image for capture by a detector, target or like receiver.

Hettrick, Michael C. (Berkeley, CA); Underwood, James H. (Walnut Creek, CA)

1988-01-01

363

Optical system for high resolution spectrometer/monochromator  

DOEpatents

An optical system for use in a spectrometer or monochromator employing a mirror which reflects electromagnetic radiation from a source to converge with same in a plane is disclosed. A straight grooved, varied-spaced diffraction grating receives the converging electromagnetic radiation from the mirror and produces a spectral image for capture by a detector, target or like receiver. 11 figs.

Hettrick, M.C.; Underwood, J.H.

1988-10-11

364

Developing Tools for Undergraduate Spectroscopy: An Inexpensive Visible Light Spectrometer  

ERIC Educational Resources Information Center

The design and implementation of an inexpensive, high-resolution Littrow-type visible light spectrometer is presented. The instrument is built from low-cost materials and interfaced with the program RSpec for real-time spectral analysis, making it useful for classroom and laboratory exercises. Using a diffraction grating ruled at 1200 lines/mm and

Vanderveen, Jesse R.; Martin, Brian; Ooms, Kristopher J.

2013-01-01

365

Charged particle accelerator grating  

DOEpatents

A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

Palmer, Robert B. (Shoreham, NY)

1986-01-01

366

Circular Fibonacci gratings.  

PubMed

We introduce circular Fibonacci gratings (CFGs) that combine the concept of circular gratings and Fibonacci structures. Theoretical analysis shows that the diffraction pattern of CFGs is composed of fractal distributions of impulse rings. Numerical simulations are performed with two-dimensional fast Fourier transform to reveal the fractal behavior of the diffraction rings. Experimental results are also presented and agree well with the numerical results. The fractal nature of the diffraction field should be of great theoretical interest, and shows potential to be further developed into practical applications, such as in laser measurement with wideband illumination. PMID:22086040

Gao, Nan; Zhang, Yuchao; Xie, Changqing

2011-11-01

367

Extreme ultraviolet spectroscopy diagnostics of low-temperature plasmas based on a sliced multilayer grating and glass capillary optics  

Microsoft Academic Search

New extreme ultraviolet (EUV) spectroscopic diagnostics of relatively low-temperature plasmas based on the application of an EUV spectrometer and fast EUV diodes combined with glass capillary optics is described. An advanced high resolution dispersive element sliced multilayer grating was used in the compact EUV spectrometer. For monitoring of the time history of radiation, filtered fast EUV diodes were used in

V. L. Kantsyrev; A. S. Safronova; K. M. Williamson; P. Wilcox; N. D. Ouart; M. F. Yilmaz; K. W. Struve; D. L. Voronov; R. M. Feshchenko; I. A. Artyukov; A. V. Vinogradov

2008-01-01

368

High accuracy wavelength calibration for a scanning visible spectrometer.  

PubMed

Spectroscopic applications for plasma velocity measurements often require wavelength accuracies ?0.2?A?. An automated calibration, which is stable over time and environmental conditions without the need to recalibrate after each grating movement, was developed for a scanning spectrometer to achieve high wavelength accuracy over the visible spectrum. This method fits all relevant spectrometer parameters using multiple calibration spectra. With a stepping-motor controlled sine drive, an accuracy of ?0.25?A? has been demonstrated. With the addition of a high resolution (0.075?arc? sec) optical encoder on the grating stage, greater precision (?0.005?A?) is possible, allowing absolute velocity measurements within ?0.3?km/s. This level of precision requires monitoring of atmospheric temperature and pressure and of grating bulk temperature to correct for changes in the refractive index of air and the groove density, respectively. PMID:21033925

Scotti, Filippo; Bell, Ronald E

2010-10-01

369

High accuracy wavelength calibration for a scanning visible spectrometer  

SciTech Connect

Spectroscopic applications for plasma velocity measurements often require wavelength accuracies {<=}0.2 A. An automated calibration, which is stable over time and environmental conditions without the need to recalibrate after each grating movement, was developed for a scanning spectrometer to achieve high wavelength accuracy over the visible spectrum. This method fits all relevant spectrometer parameters using multiple calibration spectra. With a stepping-motor controlled sine drive, an accuracy of {approx}0.25 A has been demonstrated. With the addition of a high resolution (0.075 arc sec) optical encoder on the grating stage, greater precision ({approx}0.005 A) is possible, allowing absolute velocity measurements within {approx}0.3 km/s. This level of precision requires monitoring of atmospheric temperature and pressure and of grating bulk temperature to correct for changes in the refractive index of air and the groove density, respectively.

Scotti, Filippo; Bell, Ronald E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2010-10-15

370

Degradation Free Spectrometers for Solar EUV Measurements  

NASA Astrophysics Data System (ADS)

Solar EUV observations will be made using two new degradation-free EUV spectrometers on a sounding rocket flight scheduled for summer 2012. The two instruments, a rare gas photoionization-based Optics-Free Spectrometer (OFS) and a Dual Grating Spectrometer (DGS), are filter-free and optics-free. OFS can measure the solar EUV spectrum with a spectral resolution comparable to that of grating-based EUV spectrometers. The DGS selectable spectral bandwidth is designed to provide solar irradiance in a 10 nm band centered on the Lyman-alpha 121.6 nm line and a 4 nm band centered on the He-II 30.4 nm line to overlap EUV observations from the SDO/EUV Variability Experiment (EVE) and the SOHO/Solar EUV Monitor (SEM). A clone of the SOHO/SEM flight instrument and a Rare Gas Ionization Cell (RGIC) absolute EUV detector will also be flown to provide additional measurements for inter-comparison. Program delays related to the sounding rocket flight termination system, which was no longer approved by the White Sands Missile Range prevented the previously scheduled summer 2011 launch of these instruments. During this delay several enhancements have been made to the sounding rocket versions of the DFS instruments, including a lighter, simplified vacuum housing and gas system for the OFS and an improved mounting for the DGS, which allows more accurate co-alignment of the optical axes of the DGS, OFS, and the SOHO/SEM clone. Details of these enhancements and results from additional lab testing of the instruments are reported here. The spectrometers are being developed and demonstrated as part of the Degradation Free Spectrometers (DFS) project under NASA's Low Cost Access to Space (LCAS) program and are supported by NASA Grant NNX08BA12G.

Wieman, S. R.; Didkovsky, L. V.; Judge, D. L.; McMullin, D. R.

2011-12-01

371

First Results of ISO-SWS Grating Observations of Jupiter  

Microsoft Academic Search

The spectrum of Jupiter has been recorded on April 12, 1996, between 2.75 and 14.5 mu m, with the grating mode of the Short-Wavelength Spectrometer of ISO (Infrared Space Observatory). The resolving power is 1500 and the sensitivity limit is better than 1 Jy. The corresponding S\\/N ratio is better than 1000 at 2.75 mu m, 4000 at 5 mu

Th. Encrenaz; Th. de Graauw; S. Schaeidt; E. Lellouch; H. Feuchtgruber; D. A. Beintema; B. Bezard; P. Drossart; M. Griffin; A. Heras; M. Kessler; K. Leech; A. Morris; P. R. Roelfsema; M. Roos-Serote; A. Salama; B. Vandenbussche; E. A. Valentijn; G. R. Davies; D. A. Naylor

1996-01-01

372

The evaluation of a deformable diffraction grating for a stigmatic EUV spectroheliometer  

NASA Technical Reports Server (NTRS)

A high-efficiency, extreme ultraviolet (EUV) imaging spectrometer is constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically-deformable sub-master grating replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a two-dimensional, pulse-counting detector system verify the image quality of the toroidal grating at wavelengths near 600 A. The results of these tests and the basic designs of two instruments which could employ the imaging spectrometer for astrophysical investigations in space are described; i.e., a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona; and an EUV spectroscopic telescope for studies of non-solar objects.

Timothy, J. G.

1987-01-01

373

Bragg grating rogue wave  

E-print Network

We derive the rogue wave solution of the classical massive Thirring model, that describes nonlinear optical pulse propagation in Bragg gratings. Combining electromagnetically induced transparency with Bragg scattering four-wave mixing, may lead to extreme waves at extremely low powers.

Degasperis, Antonio; Aceves, Alejandro B

2015-01-01

374

Dynamic holographic gratings  

NASA Astrophysics Data System (ADS)

The work presented in this thesis is divided into two related areas. The first area of research was a study of photoanisotropic materials to record dynamic gratings. The second area was a study of stimulated diffusion backscattering in photorefractive crystals. The two areas are related by the fact that in the two cases we studied dynamic gratings. We studied reversible photochemical mechanisms using dye molecules suspended in polymer hosts that could record dynamic holograms. The self-developing refractive index changes in dye-doped or dye-attached polymer materials, in particularly azo-dye-doped polymer systems make them promising candidates for many applications (because of the large photoinduced birefringence). The mechanism of photoanisotropic recording in azo-dye-doped polymer materials is based on orientationally dependent photoisomerization of dye molecules that may be macroscopically described in terms of photoinduced linear dichroism and linear birefringence. We proposed a technique for the fabrication of thick photosensitized polymer materials for real-time (self- developing) holographic applications. Cross modulation experiments to study the photoinduced dichroism are then described and the discussion of photophysical mechanisms involved is given. We used azo-dye doped polymer materials to record thin and thick holograms (scalar and vector). We theoretically and experimentally demonstrated that one could successfully store (using a linearly and an elliptically polarized beams) and reconstruct an elliptical polarization state of light using photoanisotropic materials, even if a plane polarized reference beam is used for the recording and readout. Using photoanisotropic materials, we demonstrated experimentally and theoretically that macroscopic optical chirality may be generated in such systems with a proper choice of excitation beam polarization state. Linear diffraction gratings, that provide strongly asymmetric diffraction without surface modulation were also created and studied. Asymmetric diffraction may be achieved using blazed gratings. But in our case the spatial phase shift of the refractive index grating relative to the absorption grating is the origin of asymmetric behaviour. Experimental results made with thin mixed phase and absorption gratings in azo-dye-doped polymer films are in agreement with our theoretical results. In the second part of the thesis we analysed the stimulated diffusion backscattering (SDS) in photorefractive crystals based on the advantages of the reflection photorefractive gratings. The material research, which is the most acute direction, was studied. We believe that optimal crystal (its processing procedure and doping density) is still unknown even for visible range. We discussed the general analysis of the stimulated diffusion backscattering. We studied the relevant parameters for the sample, which demonstrated the most interesting stimulated diffusion backscattering response: measurements of gain, reflectivity, response rate, dark conductivity and grating decay. We clarified the principal possibilities to obtain self-phase conjugation at backward SDS in steady-state conditions. We also made the comparison of sensitivities of different geometries with respect to pump energy. Finally, we experimentally studied double-phase-conjugation geometry at double-loop reflection gratings.

Birabassov, Rouslan

2001-10-01

375

Test of prototype ITER vacuum ultraviolet spectrometer and its application to impurity study in KSTAR plasmas.  

PubMed

To optimize the design of ITER vacuum ultraviolet (VUV) spectrometer, a prototype VUV spectrometer was developed. The sensitivity calibration curve of the spectrometer was calculated from the mirror reflectivity, the grating efficiency, and the detector efficiency. The calibration curve was consistent with the calibration points derived in the experiment using the calibrated hollow cathode lamp. For the application of the prototype ITER VUV spectrometer, the prototype spectrometer was installed at KSTAR, and various impurity emission lines could be measured. By analyzing about 100 shots, strong positive correlation between the O VI and the C IV emission intensities could be found. PMID:25430310

Seon, C R; Hong, J H; Jang, J; Lee, S H; Choe, W; Lee, H H; Cheon, M S; Pak, S; Lee, H G; Biel, W; Barnsley, R

2014-11-01

376

The Chandra High Energy Transmission Grating: Design, Fabrication, Ground Calibration and Five Years in Flight  

E-print Network

Details of the design, fabrication, ground and flight calibration of the High Energy Transmission Grating, HETG, on the Chandra X-ray Observatory are presented after five years of flight experience. Specifics include the theory of phased transmission gratings as applied to the HETG, the Rowland design of the spectrometer, details of the grating fabrication techniques, and the results of ground testing and calibration of the HETG. For nearly six years the HETG has operated essentially as designed, although it has presented some subtle flight calibration effects.

Claude R. Canizares; John E. Davis; Daniel Dewey; Kathryn A. Flanagan; Eugene B. Galton; David P. Huenemoerder; Kazunori Ishibashi; Thomas H. Markert; Herman L. Marshall; Michael McGuirk; Mark L. Schattenburg; Norbert S. Schulz; Henry I. Smith; Michael Wise

2005-07-01

377

Pinhole transmission grating spectrometer of X-ray picosecond frame  

Microsoft Academic Search

The structure principle and performance of the measure system of three-dimensional resolution of time, space and spectrum\\u000a for laser-produced plasma are presented. The typical experimental results are also given.

Jinxiu Cheng; Tianshu Wen; Cunbang Yang; Zhijian Zheng; Jiabin Chen; Shuping Liu; Shaojun Fu; Yiling Hong

1998-01-01

378

Compact transform spectrometer based on sampling a standing wave H. L. Kung, S. R. Bhalotra, J. D. Mansell and D. A. B. Miller  

E-print Network

, including Fabry-Perot interferometers,1 grating based spectrometers2 and Michelson FourierCompact transform spectrometer based on sampling a standing wave H. L. Kung, S. R. Bhalotra, J. D demonstrate a Fourier-transform spectrometer based on a large-displacement MEMS mirror and sampling an optical

Miller, David A. B.

379

High-efficiency blazed transmission gratings for high-resolution soft x-ray spectroscopy  

NASA Astrophysics Data System (ADS)

High-resolution spectroscopy of astrophysical sources is the key to gaining a quantitative understanding of the history, dynamics, and current conditions of the cosmos. A large-area (> 1,000 cm2), high resolving power (R = ?/?? > 3,000) soft x-ray spectrometer that covers the lines of C, N, O, Ne and Fe ions is the ideal tool to address a number of high-priority sciences questions from the 2010 Decadal Survey, such as the connection between super-massive black holes and large-scale structure via cosmic feedback, the evolution of large-scale structure, the behavior of matter at high densities, and the conditions close to black holes. Numerous mission concepts that meet these requirements have been studied and proposed over the last few years, including grating instruments for the International X-ray Observatory. Nevertheless, no grating missions are currently approved. To improve the chances for future soft x-ray grating spectroscopy missions, grating technology has to progress and be advanced to higher TRLs. We have developed Critical-Angle Transmission (CAT) gratings that combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (low mass, relaxed alignment tolerances and temperature requirements, transparent at higher energies). A CAT grating-based spectrometer can provide performance 1-2 orders of magnitude better than current grating instruments on Chandra and Newton-XMM with minimal resource requirements. We have fabricated large-area free-standing CAT gratings with minimal integrated support structures from silicon-on-insulator wafers using advanced lithography and a combination of deep reactive-ion and wet etching, and will present our latest x-ray test results showing record high diffraction efficiencies in blazed orders.

Heilmann, Ralf K.; Bruccoleri, Alexander R.; Schattenburg, Mark L.

2015-01-01

380

CHIRON - A new high resolution spectrometer for CTIO  

NASA Astrophysics Data System (ADS)

Small telescopes can play an important role in the search for exoplanets because they offer an opportunity for high cadence observations that are not possible with large aperture telescopes. However, there is a shortage of high resolution spectrometers for precision Doppler planet searches. We report on an innovative design for CHIRON, an inexpensive spectrometer that we are building for the 1.5-m telescope at CTIO in Chile. The resolution will be R >80.000, the spectral format spanning 410 to 880 nm. The total throughput of the telescope and spectrometer will be better than 12%, comparable with the efficiency of state-of-the-art spectrometers. The design is driven by the requirements for precision Doppler searches for exoplanets using an iodine cell. The optical layout is a classical echelle with 140 mm beam size. The bench-mounted spectrometer will be fibre-fed followed by an image slicer. An apochromatic refractor is used as the camera. Image quality and throughput of the design are excellent over the full spectral range. Extensive use of commercially available components and avoidance of complicated custom optics are key for quick and resource-efficient implementation.

Schwab, C.; Spronck, J. F. P.; Tokovinin, A.; Fischer, D. A.; Marcy, G. W.

2011-07-01

381

The double grating monochromator's design for pure rotational Raman lidar  

NASA Astrophysics Data System (ADS)

The pure rotational Raman lidar temperature measurement system is usually used for retrieval of atmospheric temperature according to the echo signal ratio of high and low-level quantum numbers of N2 molecules which are consistent with the exponential relationship. An effective method to detect the rotational Raman spectrum is taking a double grating monochromator. In this paper the detection principle and the structure of the dual-grating monochromator are described, with analysis of rotational Raman's Stokes and anti-Stokes spectrums of N2 molecule, the high order and lower order quantum number of the probe spectrum are resolved, then the specific design parameters are presented. Subsequently spectral effect is simulated with Zemax software. The simulation result indicates that under the condition of the probe laser wavelength of 532nm and using double-grating spectrometer which is comprised by two blazed gratings, Raman spectrums of 529.05nm, 530.40nm, 533.77nm, 535.13nm can be separated well, and double-grating monochromator has high diffraction efficiency.

Ge, Xian-ying; Chen, He; Zhang, Yin-chao; Chen, Si-ying; Guo, Pan; Mu, Tao-tao; Bu, Zhi-chao; Yang, Jian

2013-09-01

382

Inexpensive photonic crystal spectrometer for colorimetric sensing applications.  

PubMed

Photonic crystal spectrometers possess significant size and cost advantages over traditional grating-based spectrometers. In a previous work [Pervez, et al, Opt. Express 18, 8277 (2010)] we demonstrated a proof of this concept by implementing a 9-element array photonic crystal spectrometer with a resolution of 20 nm. Here we demonstrate a photonic crystal spectrometer with improved performance. The dependence of the spectral recovery resolution on the number of photonic crystal arrays and the width of the response function from each photonic crystal is investigated. A mathematical treatment, regularization based on known information of the spectrum, is utilized in order to stabilize the spectral estimation inverse problem and achieve improved spectral recovery. Colorimetry applications, the measurement of CIE 1931 chromaticities and the color rendering index, are demonstrated with the improved spectrometer. PMID:23481975

Bryan, Kurt M; Jia, Zhang; Pervez, Nadia K; Cox, Marshall P; Gazes, Michael J; Kymissis, Ioannis

2013-02-25

383

Aspheric concave grating spectrographs  

NASA Technical Reports Server (NTRS)

The design of aspheric concave gratings for high-resolution spectroscopes is examined theoretically, using the requirements of the proposed Far-UV Spectroscopic Explorer (effective area 100 sq cm and lambda/delta lambda = 30,000 in the 90-120-nm range) as a concrete example and taking the limitations of current fabrication technology (straight grooves only and maximum density 6000 lines/mm) into account. The total-path function derived by Namioka (1961) for an ellipsoidal grating is subjected to aberration analysis to obtain the optical surface best suited to the design requirements; expressions for corrections to the conventional stigmatic Rowland-circle mount are obtained and shown to produce significant performance improvements; and the design advantages of coma-corrected non-Rowland geometries are explored. Ray tracings and deviation contours are provided.

Cash, W. C., Jr.

1984-01-01

384

Charged particle accelerator grating  

DOEpatents

A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

Palmer, R.B.

1985-09-09

385

[Optimum design of imaging spectrometer based on toroidal uniform-line-spaced (TULS) spectrometer].  

PubMed

Based on the geometrical aberration theory, a optimum-design method for designing an imaging spectrometer based on toroidal uniform grating spectrometer is proposed. To obtain the best optical parameters, twice optimization is carried out using genetic algorithm(GA) and optical design software ZEMAX A far-ultraviolet(FUV) imaging spectrometer is designed using this method. The working waveband is 110-180 nm, the slit size is 50 microm x 5 mm, and the numerical aperture is 0.1. Using ZEMAX software, the design result is analyzed and evaluated. The results indicate that the MTF for different wavelengths is higher than 0.7 at Nyquist frequency 10 lp x mm(-1), and the RMS spot radius is less than 14 microm. The good imaging quality is achieved over the whole working waveband, the design requirements of spatial resolution 0.5 mrad and spectral resolution 0.6 nm are satisfied. It is certificated that the optimum-design method proposed in this paper is feasible. This method can be applied in other waveband, and is an instruction method for designing grating-dispersion imaging spectrometers. PMID:23905368

Xue, Qing-Sheng; Wang, Shu-Rong

2013-05-01

386

Diffraction Gratings WDM Components  

NASA Astrophysics Data System (ADS)

Diffraction grating WDM components have tremendous capability in number of channels (160 channel components and more with bi-directionality are commercially available and components with two times more channels have been demonstrated experimentally). They have a high free spectral range (typically 775 nm with gratings working in the first order). Small spacing such as 25 GHz is commercially available and 5 GHz feasibility has been demonstrated. Athermal glass components down to 25 GHz spacing are manufactured with uncontrolled drifts as low as 0.35 pm/C using commonly available glasses. These solutions are based on the traditional and mature optics technology used to manufacture millions of diffractionlimited reliable optics at low cost. The unique three-dimensional nature of these components can be exploited for advanced features requested by network designers such as add/drops, crossconnects, and routing devices. Cyclic passive routers accurately matched to the ITU frequencies in DWDM or to ITU wavelengths in CWDM have been proposed for advanced networks. Diffraction grating components can be used for high quality bidirectional links. For mono-directional or bi-directional links they have virtually unlimited numbers of channels and provide the lowest crosstalk for the higher number of channels. For low cost mass production the problems of fibre handling, that are the same with any solution, remain to be solved.

Laude, Jean-Pierre

387

First application close measurements applying the new hybrid integrated MEMS spectrometer  

NASA Astrophysics Data System (ADS)

Grating spectrometers have been designed in many different configurations. Now potential high volume applications ask for extremely miniaturized and low cost systems. By the use of integrated MEMS (micro electro mechanical systems) scanning grating devices a less expensive single detector can be used in the NIR instead of the array detectors required for fixed grating systems. Meanwhile the design of a hybrid integrated MEMS scanning grating spectrometer has been drawn. The MEMS device was fabricated in the Fraunhofer IPMS own clean room facility. This chip is mounted on a small circuit board together with the detector and then stacked with spacer and mirror substrate. The spectrometer has been realized by stacking several planar substrates by sophisticated mounting technologies. The spectrometer has been designed for the 950nm - 1900nm spectral range and 9nm spectral resolution with organic matter analysis in mind. First applications are considered in the food quality analysis and food processing technology. As example for the use of a spectrometer with this performance the grill process of steak was analyzed. Similar measurement would be possible on dairy products, vegetables or fruit. The idea is a mobile spectrometer for in situ and on site analysis applications in or attached to a host system providing processing, data access and input-output capabilities, disregarding this would be a laptop, tablet, smart phone or embedded platform.

Grger, Heinrich; Pgner, Tino; Knobbe, Jens; Schenk, Harald

2013-05-01

388

The Berkeley EUV spectrometer for ORFEUS  

NASA Technical Reports Server (NTRS)

A novel EUV spectrometer is presented for the ORFEUS-SPAS mission. It uses a set of four varied line-space spherical diffraction gratings to obtain high-resolution spectra of point sources at wavelengths between 390 and 1200 A. The spectra are recorded with two detector units, each containing curved-surface microchannel plates and a delay-line anode-readout system. An independent optical system detects the image of the source in the entrance aperture and tracks the source as it drifts during an observation, enabling a reconstruction of the spectra postflight. The overall system performance is discussed and illustrated by synthetic spectra.

Hurwitz, M.; Bowyer, S.

1991-01-01

389

Electrically tunable diffraction grating  

NASA Astrophysics Data System (ADS)

We report on electrically-driven diffraction grating, where refractive index of a liquid crystal (LC) was modulated periodically at an interval of 700 nm by applying an external DC bias to a metallic nanograting (NG). The LC-NG structure exhibited a maximum refractive index variation (?n) of 0.088 and a diffraction efficiency (?) change of 0-16% with a large diffraction angle of 64 for incident light of 633 nm wavelength. This approach, with the help of faster electronics, provides an opportunity of developing active holograms for real 3D display

Kim, Sun Il; Choi, Jun Hee; Ahn, Ho Young; Baik, Chan Wook; An, Jungkwuen; Choi, Chil-Sung; Pyun, Kyungsuk; Lee, Hong-Seok

2013-09-01

390

Normal incidence spectrophotometer using high density transmission grating technology and highly efficiency silicon photodiodes for absolute solar EUV irradiance measurements  

NASA Technical Reports Server (NTRS)

New developments in transmission grating and photodiode technology now make it possible to realize spectrometers in the extreme ultraviolet (EUV) spectral region (wavelengths less than 1000 A) which are expected to be virtually constant in their diffraction and detector properties. Time dependent effects associated with reflection gratings are eliminated through the use of free standing transmission gratings. These gratings together with recently developed and highly stable EUV photodiodes have been utilized to construct a highly stable normal incidence spectrophotometer to monitor the variability and absolute intensity of the solar 304 A line. Owing to its low weight and compactness, such a spectrometer will be a valuable tool for providing absolute solar irradiance throughout the EUV. This novel instrument will also be useful for cross-calibrating other EUV flight instruments and will be flown on a series of Hitchhiker Shuttle Flights and on SOHO. A preliminary version of this instrument has been fabricated and characterized, and the results are described.

Ogawa, H. S.; Mcmullin, D.; Judge, D. L.; Korde, R.

1992-01-01

391

A new spectrometer concept for Mars exploration  

NASA Astrophysics Data System (ADS)

The Raman Laser Spectrometer instrument is included in ExoMars program Pasteur payload and it is focused on the Mars samples analytical analysis of the geochemistry content and elemental composition of the observed crushed samples obtained by the Rover. One of the most critical Units of the RLS is the Spectrometer unit (SPU) that performs Raman spectroscopy technique and operates in a very demanding environment (operative temperature: from -40 C to 6 C) with very restrictive design constraints. It is a very small optical instrument capable to cope with 0.09 nm/pixel of resolution. The selected solution is based on a single transmisive holographic grating. At this stage of the project SPU Team is preparing the Conceptual Design Review that will take place at the end of October 2011.

Rull, F.; Sansano, A.; Daz, E.; Colombo, M.; Belenguer, T.; Fernndez, M.; Guembe, V.; Canchal, R.; Dvila, B.; Snchez, A.; Laguna, H.; Ramos, G.; Gonzlez, C.; Fraga, D.; Gallego, P.; Hutchinson, I.; Ingley, R.; Snchez, J.; Canora, C. P.; Moral, A. G.; Ibarmia, S.; Prieto, J. A. R.; Manfredi, J. A. R.; Cabo, P.; Daz, C.; Jimnez, A.; Pla, J.; Margoills, R.

2011-10-01

392

[Current status and prospects of portable NIR spectrometer].  

PubMed

Near-infrared spectroscopy (NIRS) is a reliable, rapid, and non-destructive analytical method widely applied in as a number of fields such as agriculture, food, chemical and oil industry. In order to suit different applications, near-infrared spectrometers are now varied. Portable near-infrared spectrometers are needed for rapid on-site identification and analysis. Instruments of this kind are rugged, compact and easy to be transported. In this paper, the current states of portable near-infrared spectrometers are reviewed. Portable near-infrared spectrometers are built of different monochromator systems: filter, grating, Fourier-transform methods, acousto-optic tunable filter (AOTF) and a large number of new methods based on micro-electro-mechanical systems (MEMS). The first part focuses on working principles of different monochromator systems. Advantages and disadvantages of different systems are also briefly mentioned. Descriptions of each method are given in turn. Typical spectrometers of each kind are introduced, and some parameters of these instruments are listed. In the next part we discuss sampling adapters, display, power supply and some other parts, which are designed to make the spectrometer more portable and easier to use. In the end, the current states of portable near-infrared spectrometers are summarized. Future trends of development of portable near-infrared spectrometers in China and abroad are discussed. PMID:24555365

Yu, Xin-Yang; Lu, Qi-Peng; Gao, Hong-Zhi; Peng, Zhong-Qi

2013-11-01

393

[Small imaging spectrometer for the inspection of fruit quality].  

PubMed

Imaging spectrometer can acquire spatial and spectral information of the target at the same time, achieve high-precision, non-destructive, non-contamination and large area instantaneous inspection of the fruit. In order to get the imaging spectrum of the fruit, compact imaging spectrometer with convex grating produced by self was designed, it has the advantages of good performance, small volume and low weight, its resolution at 578 nm is 2.1 nm, and spectral line bend and chromatic distortion are both smaller than 0.6%. Laboratory test of the imaging spectrometer and the experiment of getting the imaging spectrum of apple were done, and the result shows that the imaging spectrometer satisfies the design requirement and can acquire the imaging spectrum of apple rapidly with high precision for inspection of fruit quality. PMID:22497177

Liu, Yu-juan; Tang, Yu-guo; Cui, Ji-cheng; Bayanheshig

2012-01-01

394

Galileo Ultraviolet Spectrometer experiment  

Microsoft Academic Search

The Galileo ultraviolet spectrometer experiment uses data obtained by the Ultraviolet Spectrometer (UVS) mounted on the pointed orbiter scan platform and from the Extreme Ultraviolet Spectrometer (EUVS) mounted on the spinning part of the orbiter with the field of view perpendicular to the spin axis. The UVS is a Ebert-Fastie design that covers the range 113432 nm with a wavelength

C. W. Hord; A. I. F. Stewart; C. A. Barth; L. W. Esposito; G. E. Thomas; B. R. Sandel; D. M. Hunten; A. L. Broadfoot; D. E. Shemansky; J. M. Ajello; R. A. West

1992-01-01

395

High resolution extreme ultraviolet spectrometer for an electron beam ion trap  

SciTech Connect

An extreme ultraviolet spectrometer has been developed for spectroscopic studies of highly charged ions with an electron beam ion trap. It has a slit-less configuration with a spherical varied-line-spacing grating that provides a flat focal plane for grazing incidence light. Alternative use of two different gratings enables us to cover the wavelength range 1-25 nm. Test observations with the Tokyo electron beam ion trap demonstrate the high performance of the present spectrometer such as a resolving power of above 1000.

Ohashi, Hayato; Yatsurugi, Junji; Nakamura, Nobuyuki [Institute for Laser Science, University of Electro-Communications, Chofu, Tokyo 182-8585 (Japan); Sakaue, Hiroyuki A. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

2011-08-15

396

Time- and frequency-domain models for Smith-Purcell radiation from a two-dimensional charge moving above a finite length grating.  

PubMed

Smith-Purcell radiation (SPR), formed by an electron beam traveling above a grating, is a very promising source of coherent radiation from the THz to the optical regime. We present two theoretical calculations of the SPR from a two-dimensional bunch of relativistic electrons passing above a grating of finite length. The first calculation uses the finite-difference time-domain approach with the total-field/scattered-field procedure for fields incident on the grating. This calculation allows good physical insight into the radiation process and also allows arbitrary geometries to be treated. The second calculation uses an electric-field integral equation method. Good agreement is obtained between these two calculations. The results of these theoretical calculations are then compared with a theoretical formalism based on an infinite-length grating. The latter formalism allows periodic boundary conditions to be rigorously applied. For gratings with less than approximately 50 periods, a significant error in the strength of the radiated field is introduced by the infinite-grating approximation. It is shown that this error disappears asymptotically as the number of periods increases. The Wood-Rayleigh anomalies, predicted in the infinite-grating approximation, were not seen in our finite-grating calculations. The SPR resonance condition is the same in all three formalisms. Numerical examples are presented for an approximately 18 MeV, 50 nC/m, 200 microm bunch traveling 0.6 mm above a ten-period echelle grating having a 2.-mm periodicity. PMID:15697740

Kesar, Amit S; Hess, Mark; Korbly, Stephen E; Temkin, Richard J

2005-01-01

397

[A two-dimensional double dispersed hadamard transform spectrometer].  

PubMed

A kind of two-dimensional hadamard transform spectrometer was developed. A grating was used for chromatic dispersion of orders and a prism was used for spectral dispersion. Quite different from traditional CCD detection method, a digital micromirror device (DMD) was applied for optical modulation, and a simple point detector was used as the sensor. Compared with traditional two-dimensional spectrometer, it has the advantage of high resolution and signal-noise-ratio, which was proved by theoretical calculation and computer simulation. PMID:22870674

Liu, Jia; Shi, Lei; Li, Kai; Zheng, Xin-Wen; Zeng, Li-Bo; Wu, Qiong-Shui

2012-06-01

398

A spectrometer to measure the diffuse, astronomical extreme ultraviolet background  

NASA Technical Reports Server (NTRS)

The present grazing incidence spectrometer for measuring the diffuse astronomical background between 80 and 650 A uses a wire grid collimator to define a 40-arcmin by 15-deg field of view. After passing through the collimator, radiation impinges on an array of plane reflection gratings. An array of mirrors then focuses the diffracted light through a thin filter onto a microchannel plate detector. The resulting system focuses to a few arcmin and produces spectra with 10 to 20 A resolution. Performance characteristics of the spectrometer are discussed.

Labov, Simon; Bowyer, Stuart; Martin, Christopher

1986-01-01

399

Planar Rowland spectrometer for fiber-optic wavelength demultiplexing  

NASA Astrophysics Data System (ADS)

A planar Rowland spectrometer was fabricated and characterized as a wavelength demultiplexer for multimode fiber-optic applications. The spectrometer consisted of a planar multimode glass waveguide with two curved end faces and a cylindrical concave attached to one of the end faces. Semiconductor lasers with wavelengths between 0.825 and 0.845 micron were used for the measurements. Cross-talk isolation between two adjacent fibers with center-to-center separation of 175 microns (100 A in wavelength difference) was measured to be 18 dB. The device's performance was limited by grating diffraction efficiency, optical aberration, waveguide dispersion, and waveguide losses.

Yen, H. W.; Friedrich, H. R.; Morrison, R. J.; Tangonan, G. L.

1981-12-01

400

High Accuracy Wavelength Calibration For A Scanning Visible Spectrometer  

SciTech Connect

Spectroscopic applications for plasma velocity measurements often require wavelength accuracies ? 0.2. An automated calibration for a scanning spectrometer has been developed to achieve a high wavelength accuracy overr the visible spectrum, stable over time and environmental conditions, without the need to recalibrate after each grating movement. The method fits all relevant spectrometer paraameters using multiple calibration spectra. With a steping-motor controlled sine-drive, accuracies of ~0.025 have been demonstrated. With the addition of high resolution (0.075 aresec) optical encoder on the grading stage, greater precision (~0.005 ) is possible, allowing absolute velocity measurements with ~0.3 km/s. This level of precision requires monitoring of atmospheric temperature and pressure and of grating bulk temperature to correct for changes in the refractive index of air and the groove density, respectively.

Filippo Scotti and Ronald Bell

2010-07-29

401

A visible-infrared imaging spectrometer for planetary missions  

NASA Technical Reports Server (NTRS)

This final report summarizes the design effort for the construction of a visible-infrared imaging spectrometer for planetary missions, funded by NASA under the Planetary Instrument Definition and Development Program. The goal was to design and develop a prototype brassboard pushbroom imaging spectrometer covering the 0.35 gm to 2.5 gm spectral region using a simplified optical layout that would minimize the size, mass and parts count of the instrument by using a single holographic grating to disperse and focus light from a single slit onto both the infrared and visible focal plane arrays. Design approaches are presented and analyzed, along with problems encountered and recommended solutions to those problems. In particular, a new type of grating, incorporating two sets of rulings and a filter in a layered structure, is presented for further development.

McCord, Thomas (Principal Investigator); Voelker, Mark; Owensby, Pam; Warren, Cris; Mooradian, Greg

1996-01-01

402

Approaching ultimate resolution for soft x-ray spectrometers.  

PubMed

We explore the potential performance of soft x-ray spectrometers based on the use of varied-line-spacing spherical diffraction gratings (VLS-SG). The quantitative assessment is based on an optimization procedure to obtain both negligible optical aberrations at full illumination of the grating and a quasi linear focal curve. It involves high-order optical aberration cancellation to calculate the focal curves. We also examine the validity of small divergence closed-form formulas describing the light path function. Optimizing the optical and geometric parameters gives an ultimate resolving power, at 930 eV, of between 10,800 for a 3 m long instrument and 34,000 for an 11 m spectrometer according to the Rayleigh criterion. Typical fabrication tolerances would scale these values down by about 10%. The findings are validated by ray-tracing simulations. PMID:22781243

Chiuzb?ian, Sorin G; Hague, Coryn F; Lning, Jan

2012-07-10

403

ORFEUS focal plane instrumentation: The Berkeley spectrometer  

NASA Technical Reports Server (NTRS)

A spectrograph for the ORFEUS mission that incorporates four varied line-space, spherically figured diffraction gratings was designed. The ORFEUS, a 1-m normal incidence telescope is equipped with 2 focal plane spectrographs. The Berkeley spectrograph was developed with an optimizing raytracing computer code. Each grating accepts the light from 20 percent of the aperture of the telescope primary mirror and has a unique set of characteristics to cover a sub-bandpass within the 390 to 1200 A spectral range. Two photon-counting detectors incorporating a time delay readout system are used to record the spectra from all four gratings simultaneously. The nominal design achieves a spectral resolution (FWHM) in excess of 5500 at all wavelengths within the bandpass. The resolution is limited primarily by the detector spatial resolution. The 1 sigma astigmatism of this design varies between 13 and 150 micrometer on the same focal surface. An independent, direct imaging system tracks the drift of the target within the spectrometer aperture and allows measurement of the misalignment between the telescope optical axis and that of the external star tracker. The resolution and astigmatism achievable with this design are superior to those of a standard Rowland spectrograph designed with the same constraints.

Hurwitz, Mark; Bowyer, Stuart

1988-01-01

404

Compact Two-Dimensional Spectrometer Optics  

NASA Technical Reports Server (NTRS)

The figure is a simplified depiction of a proposed spectrometer optical unit that would be suitable for incorporation into a remote-sensing instrumentation system. Relative to prior spectrometer optical assemblies, this unit would be compact and simple, largely by virtue of its predominantly two-dimensional character. The proposed unit would be a combination of two optical components. One component would be an arrayed-waveguide grating (AWG) an integrated-optics device, developed for use in wavelength multiplexing in telecommunications. The other component would be a diffraction grating superimposed on part of the AWG. The function of an AWG is conceptually simple. Input light propagates along a single-mode optical waveguide to a point where it is split to propagate along some number (N) of side-by-side waveguides. The lengths of the optical paths along these waveguides differ such that, considering the paths in a sequence proceeding across the array of waveguides, the path length increases linearly. These waveguides launch quasi-free-space waves into a planar waveguide-coupling region. The waves propagate through this region to interfere onto an array of output waveguides. Through proper choice of key design parameters (waveguide lengths, size and shape of the waveguide coupling region, and lateral distances between waveguides), one can cause the input light to be channeled into wavelength bins nominally corresponding to the output waveguides.

Hong, John

2008-01-01

405

A Compact, Fast, Wide-Field Imaging Spectrometer System  

NASA Technical Reports Server (NTRS)

We present test results from a compact, fast (F/1.4) imaging spectrometer system with a 33 degree field of view, operating in the 450-1650 nm wavelength region with an extended response InGaAs detector array. The system incorporates a simple two-mirror telescope and a steeply concave bilinear groove diffraction grating made with gray scale x-ray lithography techniques. High degree of spectral and spatial uniformity (97%) is achieved.

Mouroulis, Pantazis; VanGorp, Byron E.; White, Victor E.; Mumolo, Jason M.; Hebert, Daniel; Feldman, Martin

2011-01-01

406

Distributedfeedback pulse generator based on nonlinearfibre grating  

E-print Network

Distributedfeedback pulse generator based on nonlinearfibre grating B.J. Eggleton, C.M. de Sterke, R.E. Slusher and J.E. Sipe Indexing terms: Gratings injbres, Nonlinear optics, Solitons observed nonlinear compression and the formation of Bragg grating solitons [l, 21 in gratings, which rely

Sipe,J. E.

407

Diffractive Optics of Anisotropic Polarization Gratings  

Microsoft Academic Search

Diffraction gratings are being used to manipulate light in many different applications, such as in flat panel display systems, modern lighting systems, and optical recording. Diffraction gratings can be made polarization selective due to form birefringence. An alternative approach to polarization selective gratings is to use birefringent materials. In this thesis, diffraction gratings consisting of at least one birefringent material

M. Xu

2009-01-01

408

The characteristics of grating structure in magnetic field measurements based on polarization properties of fiber gratings  

Microsoft Academic Search

In this paper the characteristics of grating structure in magnetic field measurements based on differential group delay of fiber gratings are analyzed. Theoretical simulations are realized using the coupled-mode theory and transfer matrix method. The effects of grating parameters of uniform Bragg grating on measurement range and sensitivity are analyzed. The impacts of chirped, phase-shifted and apodized gratings on DGD

Yang Su; Hui Peng; Kui Feng; Yu-quan Li

2009-01-01

409

COS NUV Grating Efficiency Test  

NASA Astrophysics Data System (ADS)

We will perform two more grating efficiency tests to enable better comparison of results of grating efficiency tests done on the ground with external target spectroscopic sensitivity monitoring on orbit.The GETS contains 10 NUV exposures designed to get the same S/N of various emission lines throughout the NUV band. The sequence and duration of exposures in this NUV GET are the same as used by the IDT on the ground from 2004-2009 to monitor the relative efficiencies of the NUV gratings. The sequence starts with a 20-minute wait, to ensure that the lamp has cooled from any usage in a previous visit.

Osten, Rachel

2009-07-01

410

Durable silver thin film coating for diffraction gratings  

DOEpatents

A durable silver film thin film coated non-planar optical element has been developed to replace Gold as a material for fabricating such devices. Such a coating and resultant optical element has an increased efficiency and is resistant to tarnishing, can be easily stripped and re-deposited without modifying underlying grating structure, improves the throughput and power loading of short pulse compressor designs for ultra-fast laser systems, and can be utilized in variety of optical and spectrophotometric systems, particularly high-end spectrometers that require maximized efficiency.

Wolfe, Jesse D. (Discovery Bay, CA); Britten, Jerald A. (Oakley, CA); Komashko, Aleksey M. (San Diego, CA)

2006-05-30

411

The Joint Astrophysical Plasmadynamic Experiment (J-PEX): a high-resolution rocket spectrometer  

Microsoft Academic Search

We report on the successful sounding rocket flight of the high resolution (R=3000-4000) J-PEX EUV spectrometer. J-PEX is a novel normal incidence instrument, which combines the focusing and dispersive elements of the spectrometer into a single optical element, a multilayer-coated grating. The high spectral resolution achieved has had to be matched by unprecedented high spatial resolution in the imaging microchannel

Martin A. Barstow; Nigel P. Bannister; Raymond G. Cruddace; Michael P. Kowalski; Kent S. Wood; Daryl J. Yentis; Herbert Gursky; Troy W. Barbee Jr.; William H. Goldstein; Joseph F. Kordas; Gilbert G. Fritz; J. Leonard Culhane; Jonathan S. Lapington; J. S. Lapingtone

2003-01-01

412

On-chip spectrometer with a circular-hole defect for optical sensing applications.  

PubMed

We propose an optical sensor by integrating a circular-hole defect with an etched diffraction grating spectrometer based on amorphous silicon photonic platforms. There are some superiorities of this device, such as high sensitivity (~10000 nm/RIU), and ability to deliver component analysis from the near-infrared spectrum by using the integrated spectrometer. As application example, the chip is used for distinguishing similar biodiesel types and accurately determining their concentrations in a diesel oil mixture. PMID:23038564

Song, Jun; Zhou, Xiang; Li, Yuan-zhou; Li, Xuan

2012-08-13

413

Monitoring of Laser Material Welding Process Using UV-Visible Spectrometer  

SciTech Connect

UV-Visible spectrometer is used to record emission from magnesium and titanium metal plates during laser welding processing. Geometrically corrected Czerny-Turner configurations nearly eliminate defocusing problem. The Optikwerks software is used to find the optimum Czerny-Turner configuration and to choose optical elements such as grating types, mirrors focal length and diameter, and slit width. The design parameters of the uv-visible spectrometer in the wavelength range 200-1100 nm for monitoring laser material welding processing.

Genc, B.; Kacar, E.; Akman, E.; Demir, A. [University of Kocaeli, Laser Technologies Research and Application Center, Kocaeli (Turkey)

2007-04-23

414

Ray tracing method for the grazing incidence flat-field imaging soft X-ray spectrometer  

NASA Astrophysics Data System (ADS)

A ray tracing method is introduced for helping adjustment and spectra analysis of the grazing incidence flat-field imaging soft X-ray spectrometer. For a single point source, the spectra images obtained by separate components, the toroidal mirror, and the grazing incidence flat-field concave grating with varied line spaces are given respectively. The calculated spectral images of the single point source by the spectrometer are also given for comparison with measurements with different experimental alignments.

Dong, Quan-Li; Liu, Yun-Quan; Teng, Hao; Li, Ying-Jun; Zhang, Jie

2014-06-01

415

Fiber Grating Environmental Sensing System  

DOEpatents

Fiber grating environmental measurement systems are comprised of sensors that are configured to respond to changes in moisture or chemical content of the surrounding medium through the action of coatings and plates inducing strain that is measured. These sensors can also be used to monitor the interior of bonds for degradation due to aging, cracking, or chemical attack. Means to multiplex these sensors at high speed and with high sensitivity can be accomplished by using spectral filters placed to correspond to each fiber grating environmental sensor. By forming networks of spectral elements and using wavelength division multiplexing arrays of fiber grating sensors may be processed in a single fiber line allowing distributed high sensitivity, high bandwidth fiber optic grating environmental sensor systems to be realized.

Schulz, Whitten L. (Fairview, OR); Udd, Eric (Fairview, OR)

2003-07-29

416

A high-throughput, high-resolution spectrometer for mapping the heliopause and 3-D Solar Wind using He+ 30.4nm  

E-print Network

A high-throughput, high-resolution spectrometer for mapping the heliopause and 3-D Solar Wind using Entrance slit farm with ~ 1000 slits Photon counting imager Concave grating used near normal incidence Rowland mount spectrometer with improvements for high throughput 1. Entrance slit => 1-D coded aperture 2

California at Berkeley, University of

417

Extreme ultraviolet imaging spectrometer for thermospheric emissions  

NASA Technical Reports Server (NTRS)

One of the instruments that has been developed to fly on the Space Shuttle is the Imaging Spectrometric Observatory, an array of five imaging spectrometers to cover the 300-12,000-A wavelength range. In this paper the spectrometer designed to operate in the extreme ultraviolet is described. The instrument is intended for studies of the thermosphere and magnetosphere and support of various plasma experiments to be performed from the Shuttle. The design is modular so that various components such as gratings and detectors can be changed and optimized for a range of specific studies following the first survey mission. The detector is an intensified 2-D CCD which permits simultaneous spectral and spatial imaging. The spectral multiplexing gives the spectrometer a considerable speed advantage. The instrument has a small field of view and is thus capable of obtaining much needed scale height information on the atmospheric EUV emissions. Operating from the Shuttle, global and temporal coverage will be obtained, and the EUV data will be enhanced by the simultaneously acquired UV, visible, and near-IR observations.

Torr, M. R.; Vitz, R. C.

1982-01-01

418

Alignment of the Grating Wheel Mechanism for a Ground-Based, Cryogenic, Near-Infrared Astronomy Instrument  

NASA Technical Reports Server (NTRS)

We describe the population, optomechanical alignment, and alignment verification of near-infrared gratings on the grating wheel mechanism (GWM) for the Infrared Multi-Object Spectrometer (IRMOS). IRMOS is a cryogenic (80 K), principle investigator-class instrument for the 2.1 m and Mayall 3.8 m telescopes at Kitt Peak National Observatory, and a MEMS spectrometer concept demonstrator for the James Webb Space Telescope. The GWM consists of 13 planar diffraction gratings and one flat imaging mirror (58 x 57 mm), each mounted at a unique compound angle on a 32 cm diameter gear. The mechanism is predominantly made of Al 6061. The grating substrates are stress relieved for enhanced cryogenic performance. The optical surfaces are replicated from off-the-shelf masters. The imaging mirror is diamond turned. The GWM spans a projected diameter of approx. 48 cm when fully assembled, utilizes several flexure designs to accommodate potential thermal gradients, and is controlled using custom software with an off-the-shelf controller. Under ambient conditions, each grating is aligned in six degrees of freedom relative to a coordinate system that is referenced to an optical alignment cube mounted at the center of the gear. The local tip/tilt (Rx/Ry) orientation of a given grating is measured using the zero-order return from an autocollimating theodolite. The other degrees of freedom are measured using a two-axis cathetometer and rotary table. Each grating's mount includes a one-piece shim located between the optic and the gear. The shim is machined to fine align each grating. We verify ambient alignment by comparing grating difractive properties to model predictions.

Gutkowski, Sharon M.; Ohl, Raymond G.; Hylan, Jason E.; Hagopian, John G.; Kraft, Stephen E.; Mentzell, J. Eric; Connelly, Joseph A.; Schepis, Joseph P.; Sparr, Leroy M.; Greenhouse, Matthew A.

2003-01-01

419

Near-perfect diffraction grating rhomb  

DOEpatents

A near-perfect grating rhomb enables an output beam to be diffracted to an angle offset from the input beam. The correcting grating is tipped relative to the dispersing grating to provide the offset angle. The correcting grating is further provided with a groove spacing which differs from the dispersing grating groove space by an amount effective to substantially remove angular dispersion in the output beam. A near-perfect grating rhomb has the capability for selective placement in a FEL to suppress sideband instabilities arising from the FEL.

Wantuck, Paul J. (Santa Fe, NM)

1990-01-01

420

Study on the feasibility of measuring relief grating parameters through the transmission spectrum  

NASA Astrophysics Data System (ADS)

A nondestructive, accurate and fast method for measuring the grating parameters of relief gratings is proposed in this paper. At first, the 0th diffractive transmission efficiency spectrum from 600nm to 700nm is obtained according to a certain relief grating model with the rigorous coupled-wave analysis (RCWA). Under the condition of normal incidence, the 0th diffractive transmission efficiency will behave as a function of duty cycles, depths and profiles of grooves for both TE and TM polarization. Then the data of the 0th diffractive transmission efficiency spectrum for TE polarization is regarded as measured values of simulation. Finally, grating parameters are obtained with the library matching method. Theoretical analysis and numerical simulation results demonstrate the feasibility and validity of the proposed method. Being accurate, repeatable and nondestructive, this kind of method will obtain the grating parameters quickly in practice without comprehensive and expensive but only commonly spectrometer that will be convenient for measurement of grating parameters in situ.

Liu, Linyue; Chen, Xinrong; Li, Lin; Li, Chaoming; Wu, Jianhong

2014-12-01

421

[Study on an optical system of small ultraviolet imaging spectrometer with high resolution in broadband].  

PubMed

An ultraviolet imaging spectrometer was studied based on the principle of the small scale ultraviolet spectral instrument. The scheme composed of an off-axis parabolic mirror telescope and a single toroidal grating spectral imaging system was designed. The optimization of the optical system is the optimum processing for the parameters of the toroidal grating. The optical path function and the aberration equations of the grating were analyzed. The perfect anastigmatism conditions and imaging conditions of the single toroidal grating system were obtained. These two conditions that cannot be satisfied by the algebra calculation method limit the field of view and waveband of the spectrometer. The genetic algorithm was introduced to solve the problem. A solar-blind ultraviolet imaging spectrometer for 200-280 nm was designed to verify the design method. The optimum initial configuration was calculated and simulated. A system with F/# 5.7, focal length 102 mm and high spatial resolution was designed. The modulation transfer functions (MTF) of all fields of view are more than 0.65 in the waveband in the required Nyquist frequency (20 1p x mm(-1)). The design results indicate that the optical system theory can be applied to the small scale ultraviolet imaging spectrometer with high resolution and spectral broadband. PMID:23697155

Cong, Hai-Fang; Wang, Chun-Hui; Wang, Yu

2013-02-01

422

Grazing-incidence flat-field spectrometer for high-order harmonic diagnostics  

Microsoft Academic Search

The design and performances of an EUV spectrometer for diagnostics of high-order harmonics generated by an ultrashort (< 30 fs) pulsed laser focused onto a gas jet are presented. The system consists of a toroidal mirror, an entrance slit, a spherical variable-line-spaced grating and a bidimensional detector. The mirror focuses astigmatically the radiation from the gas jet, with the tangential

Luca Poletto; Giampiero Naletto; Giuseppe Tondello

2001-01-01

423

A Laser Frequency Comb System for Absolute Calibration of the VTT Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

A wavelength calibration system based on a laser frequency comb (LFC) was developed in a co-operation between the Kiepenheuer-Institut fr Sonnenphysik, Freiburg, Germany and the Max-Planck-Institut fr Quantenoptik, Garching, Germany for permanent installation at the German Vacuum Tower Telescope (VTT) on Tenerife, Canary Islands. The system was installed successfully in October 2011. By simultaneously recording the spectra from the Sun and the LFC, for each exposure a calibration curve can be derived from the known frequencies of the comb modes that is suitable for absolute calibration at the meters per second level. We briefly summarize some topics in solar physics that benefit from absolute spectroscopy and point out the advantages of LFC compared to traditional calibration techniques. We also sketch the basic setup of the VTT calibration system and its integration with the existing echelle spectrograph.

Doerr, H.-P.; Steinmetz, T.; Holzwarth, R.; Kentischer, T.; Schmidt, W.

2012-10-01

424

Optical Design of a Compact Imaging Spectrometer for Planetary Mineralogy  

NASA Technical Reports Server (NTRS)

We present the design of a compact, wide-angle pushbroom imaging spectrometer suitable for exploration of solar system bodies from low orbit. The spectrometer is based on a single detector array with a broadband response that covers the range 400 to 3000 nm and provides a spectral sampling of 10 nm. The telescope has a 24-deg field of view with 600 spatially resolved elements (detector pixels). A specially designed convex diffraction grating permits optimization of the signal-to-noise ratio through the entire spectral band. Tolerances and design parameters permit the achievement of high uniformity of response through field and wavelength. The spectrometer performance is evaluated in terms of predicted spectral and spatial response functions and from the point of view of minimizing their variation through field and wavelength. The design serves as an example for illustrating the design principles specific to this type of system.

Mouroulis, Pantazis; Sellar, R. Glenn; Wilson, Daniel W.; Shea, James J.; Green, Robert O.

2007-01-01

425

Grazing-incidence spectrometer on the SSPX spheromak  

SciTech Connect

The Silver Flat Field Spectrometer (SFFS) is a high-resolution grazing-incidence diagnostic for magnetically confined plasmas. It covers the wavelength range of 25-450 {angstrom} with a resolution of {Delta}{lambda} = 0.3 {angstrom} FWHM. The SFFS employs a spherical 1200 lines/mm grating for flat-field focusing. The imaging is done using a back-illuminated Photometrics CCD camera allowing a bandwidth of around 200 {angstrom} per spectrum. The spectrometer has been used for atomic spectroscopy on electron beam ion traps and for plasma spectroscopy on magnetic confinement devices. The design of the SFFS and the spectrometer setup at the Sustained Spheromak Physics Experiment (SSPX) in Livermore will be presented.

Clementson, J; Beiersdorfer, P; Magee, E W

2008-05-02

426

The localized chemical pollution in NGC 5253 revisited: Results from deep echelle spectrophotometry  

E-print Network

We present echelle spectrophotometry of the blue compact dwarf galaxy (BCDG) NGC 5253. The data have been taken with the Very Large Telescope UVES echelle spectrograph in the 3100 to 10400 angstroms range. We have measured the intensities of a large number of permitted and forbidden emission lines in four zones of the central part of the galaxy. In particular, we detect faint C II and O II recombination lines (RLs). This is the first time that these lines are unambiguously detected in a dwarf starburst galaxy. The physical conditions of the ionized gas have been derived using a large number of different line intensity ratios. Chemical abundances of He, N, O, Ne, S, Cl, Ar, and Fe have been determined following the standard methods. In addition, C^{++} and O^{++} abundances have been derived from pure RLs. These abundances are larger than those obtained from collisionally excited lines, (CELs) (from 0.30 to 0.40 dex for C^{++} and from 0.19 to 0.28 dex for O^{++}). This result is consistent with a temperature fluctuations parameter (t^2) between 0.050 and 0.072. We confirm previous results that indicate the presence of a localized N enrichment in certain zones of the center of the galaxy. Moreover, our results also indicate a possible slight He overabundance in the same zones. The enrichment pattern agrees with that expected for the pollution by the ejecta of massive stars in the Wolf-Rayet (WR) phase. The amount of enriched material needed to produce the observed overabundance is consistent with the mass lost by the number of WR stars estimated in the starbursts. Finally, we discuss the possible origin of the difference between abundances derived from RLs and CELs in H II regions, finding that a recent hypothesis based on the delayed enrichment by SNe ejecta inclusions seems not to explain the observed features.

A. R. Lopez-Sanchez; C. Esteban; J. Garcia-Rojas; M. Peimbert; M. Rodriguez

2006-09-18

427

Modified Schwarzschild imaging spectrometer with a low F-number and a long slit.  

PubMed

A modified Schwarzschild imaging spectrometer utilizing three nonconcentric aspheric mirrors and a plane grating is designed that can handle low F-number, long slit, and broad spectral range. Based on the geometrical aberration theory and Rowland circle condition, the astigmatism-correcting method of the Schwarzschild imaging spectrometer is analyzed. The design procedure of initial parameters is programmed using Matlab software. As an example, a modified Schwarzschild imaging spectrometer operating in 400-1000 nm waveband with F-number of 2.5 and slit length of 13 mm is designed, and good imaging quality is obtained. PMID:24085210

Xue, Qingsheng

2013-10-01

428

Fabrication of extremely smooth blazed diffraction gratings  

E-print Network

High efficiency diffraction gratings are important in a variety of applications, such as optical telecommunications, lithography, and spectroscopy. Special interest has been placed on blazed diffraction gratings for their ...

Chang, Chih-Hao, 1980-

2004-01-01

429

Three-dimensional grating image display  

NASA Astrophysics Data System (ADS)

The paper describes the principle of a 3D grating image display which is different from the real objective 3D hologram. This 3D grating image uses the cues that normally present in everyday human stereo perception and is based on the theory of grating patterns. Two methods are described and analyzed. The result is that the two methods are same in nature. The architecture for realizing full-color 3D grating image display is also given.

Wang, Zhao; Pei, ShuBao; Tan, Yushan

1996-12-01

430

Dual transmission grating based imaging radiometer for tokamak edge and divertor plasmas.  

PubMed

The designs of single transmission grating based extreme ultraviolet (XUV) and vacuum ultraviolet (VUV) imaging spectrometers can be adapted to build an imaging radiometer for simultaneous measurement of both spectral ranges. This paper describes the design of such an imaging radiometer with dual transmission gratings. The radiometer will have an XUV coverage of 20-200 A? with a ?10 A? resolution and a VUV coverage of 200-2000 A? with a ~50 A? resolution. The radiometer is designed to have a spatial view of 16, with a 0.33 resolution and a time resolution of ~10 ms. The applications for such a radiometer include spatially resolved impurity monitoring and electron temperature measurements in the tokamak edge and the divertor. As a proof of principle, the single grating instruments were used to diagnose a low temperature reflex discharge and the relevant data is also included in this paper. PMID:23127018

Kumar, Deepak; Clayton, Daniel J; Parman, Matthew; Stutman, Dan; Tritz, Kevin; Finkenthal, Michael

2012-10-01

431

Sub-wavelength GaN-based membrane high contrast grating reflectors.  

PubMed

The GaN-based membrane high contrast grating (HCG) reflectors have been fabricated and investigated. The structural parameters including grating periods, grating height, filling factors and air-gap height were calculated to realize high reflectivity spectra with broad bandwidth by the rigorous coupled-wave analysis and finite-difference time-domain method. Based on the optimized simulation results, the GaN-based membrane HCGs were fabricated by e-beam lithography and focused-ion beam process. The fabricated GaN-based membrane HCG reflectors revealed high reflectivity at 460 nm band with large stopband width of 60 nm in the TE polarization measured by using the micro-reflectivity spectrometer. The experimental results also showed a good agreement with simulated ones. We believe this study will be helpful for development of the GaN-based novel light emitting devices in the blue or UV region. PMID:23037102

Wu, Tzeng Tsong; Syu, Yu Cheng; Wu, Shu Hsien; Chen, Wei Ting; Lu, Tien Chang; Wang, Shing Chung; Chiang, Hai Pang; Tsai, Din Ping

2012-08-27

432

High resolution instrumentation system for fibre-Bragg grating aerospace sensors  

NASA Astrophysics Data System (ADS)

A passive technique for high-resolution detection of the wavelength of peak reflection from fibre Bragg grating (FBG) sensors is presented. The approach, based on a de-convolution of the FBG spectrum and the spectrometer resolution, essentially overcomes the low spectral resolution (?0.1 nm) associated with commercial spectrometers employing CCD detection. The performance of two algorithms, the Centroid Detection algorithm (CDA) and the least squares method (LSQ), are compared. The LSQ algorithm offers resolution enhancement of at least two orders of magnitude and is shown to be independent of the FBG intensity and bandwidth over a broad range.

Ezbiri, A.; Kanellopoulos, S. E.; Handerek, V. A.

1998-05-01

433

[Study and design on Dyson imaging spectrometer in spectral broadband with high resolution].  

PubMed

The paper designs and improves a telecentric imaging spectrometer, the Dyson imaging spectrometer. The optical structure of the imaging spectrometer is simple and compact, which is only composed of a hemispherical lens and a concave grating. Based on the Rowland circle and refraction theory, the broadband anastigmatic imaging condition of Dyson imaging spectrometer which is the ratio of the grating radius and hemispherical lens radius has been analyzed. By imposing this condition for two different wavelengths, the parameters of the optical system presenting low aberrations and excellent imaging quality are obtained. To make the design spectrometer more suitable for the engineering application, the paper studies the method making the detector not to attach the surface of the hemispherical lens. A design example using optimal conditions was designed to prove our theory. The Dyson imaging spectrometer of which the imaging RMS radii are less than 2.5 microm and the advanced spectrometer of which the imaging RMS radii are less than 8 microm, with NA 0.33, waveband 0.38-1.7 microm and the slit length 15 mm, have been obtained. The design method and results are more feasible and predominant, and can be applied in the areas of the industry and remote sensing. PMID:25007644

Yan, Ling-Wei

2014-04-01

434

Reflecting Schmidt imaging spectrometers.  

PubMed

A new very wide angle imaging spectrometer optical configuration which uses an all-reflecting Schmidt camera with a prism spectrometer to give a strip field of view is presented. Three complete systems (15 degrees, 8.5 degrees, 2.6 degrees FOV), including fore optics and spectrometer optics, were designed. These slit fields of view are pushbroomed across object space to create a 2-D image. The performance of each near diffraction-limited system and optical prescriptions is detailed. An all-reflecting Schmidt camera fore-optics system with a 60 degree field of view is also given. PMID:18195937

Breckinridge, J B; Page, N A; Shannon, R R; Rodgers, J M

1983-04-15

435

Ranging-imaging spectrometer  

NASA Astrophysics Data System (ADS)

An imaging spectrometer that can simultaneously obtain 3-D spatial and hyperspectral data has been developed. The Ranging-Imaging Spectrometer (RIS) is based on the Computed Tomographic Imaging Spectrometer (CTIS) developed at the Optical Science Center, and the Scannerless Laser Radar (LADAR) architecture developed at Sandia National Labs. The instrument acquires hyperspectral data in a single snapshot and spatial data in a series of snapshots. The system has 29 spectral bands, 1024 range samples, and approximately 80 x 80 spatial sampling. The RIS is discussed along with analysis of test data.

Kinder, Brian A.; Garcia, John P.; Habbit, Robert D.; Dereniak, Eustace L.

2003-12-01

436

Tunable micro-electromechanical grating in silicon  

Microsoft Academic Search

In this paper, we propose a solution for simple, fast and easily controllable way of tuning silicon gratings using Micro Electro Mechanical Systems (MEMS) to deform the grating itself. Basically the idea is to deform mechanically a silicon grating using electrostatic actuators, enabling pitch tuning over a large proportion (more than 50% is easily achievable with our approach). Moreover we

Yves-Alain Peter; Fatou Binetou Kon; Jonathan Masson; Nicolas Godbout

2006-01-01

437

Diffraction gratings used as identifying markers  

DOEpatents

A finely detailed defraction grating is applied to an object as an identifier or tag which is unambiguous, difficult to duplicate, or remove and transfer to another item, and can be read and compared with prior readings with relative ease. The exact pattern of the defraction grating is mapped by diffraction moire techniques and recorded for comparison with future readings of the same grating.

Deason, Vance A. (Idaho Falls, ID); Ward, Michael B. (Idaho Falls, ID)

1991-01-01

438

Symmetry properties of anisotropic dielectric gratings  

Microsoft Academic Search

This paper describes a theoretical analysis of liquid crystal grating structures and their properties based on the symmetry of the constitutive equations. Exact equations derived by using Bloch-Floquet theorem for one-dimensional anisotropic gratings are discussed. Scattering efficiency of the gratings is analyzed using the method of coupled plane waves having well defined parallel components of the wave vector to decompose

P. Galatola; C. Oldano; P. B. Sunilkumar

1994-01-01

439

Embedded high-contrast distributed grating structures  

DOEpatents

A new class of fabrication methods for embedded distributed grating structures is claimed, together with optical devices which include such structures. These new methods are the only known approach to making defect-free high-dielectric contrast grating structures, which are smaller and more efficient than are conventional grating structures.

Zubrzycki, Walter J. (Albuquerque, NM); Vawter, Gregory A. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM)

2002-01-01

440

Birefringent snapshot imaging spatial heterodyne spectrometer  

NASA Astrophysics Data System (ADS)

High speed spectral imaging is useful for a variety of tasks spanning industrial monitoring, target detection, and chemical identification. To better meet these needs, compact hyperspectral imaging instrumentation, capable of high spectral resolution and real-time data acquisition and processing, are required. In this paper, we describe the first snapshot imaging spatial heterodyne Fourier transform spectrometer based on birefringent crystals and polarization gratings. This includes details about its architecture, as well as our preliminary proof of concept. Finally, we discuss details related to the calibration of the sensor, including our preliminary investigations into high speed data reconstruction and calibration using neural networks. With such an approach, it may be feasible to reconstruct and calibrate an entire interferogram cube in one step with minimal Fast Fourier Transform (FFT) processing.

Maione, Bryan D.; Luo, David A.; Kudenov, Michael W.; Escuti, Michael J.; Miskiewicz, Matthew N.

2014-05-01

441

Advanced Fibre Bragg Grating and Microfibre Bragg Grating Fabrication Techniques  

NASA Astrophysics Data System (ADS)

Fibre Bragg gratings (FBGs) have become a very important technology for communication systems and fibre optic sensing. Typically, FBGs are less than 10-mm long and are fabricated using fused silica uniform phase masks which become more expensive for longer length or non-uniform pitch. Generally, interference UV laser beams are employed to make long or complex FBGs, and this technique introduces critical precision and control issues. In this work, we demonstrate an advanced FBG fabrication system that enables the writing of long and complex gratings in optical fibres with virtually any apodisation profile, local phase and Bragg wavelength using a novel optical design in which the incident angles of two UV beams onto an optical fibre can be adjusted simultaneously by moving just one optical component, instead of two optics employed in earlier configurations, to vary the grating pitch. The key advantage of the grating fabrication system is that complex gratings can be fabricated by controlling the linear movements of two translation stages. In addition to the study of advanced grating fabrication technique, we also focus on the inscription of FBGs written in optical fibres with a cladding diameter of several ten's of microns. Fabrication of microfibres was investigated using a sophisticated tapering method. We also proposed a simple but practical technique to filter out the higher order modes reflected from the FBG written in microfibres via a linear taper region while the fundamental mode re-couples to the core. By using this technique, reflection from the microfibre Bragg grating (MFBG) can be effectively single mode, simplifying the demultiplexing and demodulation processes. MFBG exhibits high sensitivity to contact force and an MFBG-based force sensor was also constructed and tested to investigate their suitability for use as an invasive surgery device. Performance of the contact force sensor packaged in a conforming elastomer material compares favourably to one of the best-performing commercial contact force sensors in catheterization applications. The proposed sensor features extremely high sensitivity up to 1.37-mN, miniature size (2.4-mm) that meets standard specification, excellent linearity, low hysteresis, and magnetic resonance imaging compatibility.

Chung, Kit Man

442

Optical apparatus for forming correlation spectrometers and optical processors  

DOEpatents

Optical apparatus is disclosed for forming correlation spectrometers and optical processors. The optical apparatus comprises one or more diffractive optical elements formed on a substrate for receiving light from a source and processing the incident light. The optical apparatus includes an addressing element for alternately addressing each diffractive optical element thereof to produce for one unit of time a first correlation with the incident light, and to produce for a different unit of time a second correlation with the incident light that is different from the first correlation. In preferred embodiments of the invention, the optical apparatus is in the form of a correlation spectrometer; and in other embodiments, the apparatus is in the form of an optical processor. In some embodiments, the optical apparatus comprises a plurality of diffractive optical elements on a common substrate for forming first and second gratings that alternately intercept the incident light for different units of time. In other embodiments, the optical apparatus includes an electrically-programmable diffraction grating that may be alternately switched between a plurality of grating states thereof for processing the incident light. The optical apparatus may be formed, at least in part, by a micromachining process. 24 figs.

Butler, M.A.; Ricco, A.J.; Sinclair, M.B.; Senturia, S.D.

1999-05-18

443

A cryogenically cooled, multidetector spectrometer for infrared astronomy  

NASA Technical Reports Server (NTRS)

A liquid helium-cooled, 24 detector grating spectrometer was developed and used for low resolution astronomical observations in the 5 to 14 micron spectral range. The instrument operated on the 91 cm Kuiper Airborne Observatory, the 3 m IRTF (Mauna Kea), the 3 m Shane telescope (Lick Observatory), and the 152 cm NASA and University of Arizona telescope. The detectors are discrete Si:Bi photoconductors with individual metal oxide semiconductor field effect transistor preamplifiers operating at 4 K. The system uses a liquid helium-cooled slit, order-sorter filter, collimator mirror, grating, and camera mirror arranged in a Czerny-Turner configuration with a cold stop added between the collimator mirror and the grating. The distances between components are chosen so that the collimator mirror images the secondary mirror of the telescope onto the cold stop, thus providing a very effective baffle. Scattered radiation is effectively reduced by using liquid helium-cooled, black baffles to divide the spectrometer into three separate compartments. The system noise-equivalent flux density, when used on the 152 cm telescope from 8 to 13 microns with a resolving power of 50, is 4.4 x 10 to the minus 17th power W/sq cm micron square root of Hz. The main applications are for measuring continuum radiation levels and solid state emission and absorption features in regions of star and planet formation.

Witteborn, F. C.; Bregman, J. D.

1985-01-01

444

A cryogenically cooled, multidetector spectrometer for infrared astronomy  

NASA Technical Reports Server (NTRS)

A liquid helium-cooled, 24 detector grating spectrometer was developed and used for low resolution astronomical observations in the 5 to 14 micron spectral range. The instrument operated on the 91 cm Kuiper Airborne Observatory, the 3 m IRTF (Mauna Kea), the 3 m Shane telescope Observatory, the 3 m Shane telescope (Lick Observatory), and the 152 cm NASA and University of Arizona telescope. The detectors are discrete Si:Bi photoconductors with individual metal oxide semiconductor field effect transistor preamplifiers operating at 4 K. The system uses a liquid helium-cooled slit, order-sorter filter, collimator mirror, grating, and camera mirror arranged in a Czerny-Turner configuration with a cold stop added between the collimator mirror and the grating. The distances between components are chosen so that the collimator mirror images the secondary mirror of the telescope onto the cold stop, thus providing a very effective baffle. Scattered radiation is effectively reduced by using liquid helium-cooled, black baffles to divide the spectrometer into three separate compartments. The system noise-equivalent flux density, when used on the 152 cm telescope from 8 to 13 microns with a resolving power of 50, is 4.4 x 10 to the minus 17th power W/sq cm micron square root of Hz. The main applications are for measuring continuum radiation levels and solid state emission and absorption features in regions of star and planet formation.

Witteborn, F. C.; Bregman, J. D.

1984-01-01

445

Optical apparatus for forming correlation spectrometers and optical processors  

DOEpatents

Optical apparatus for forming correlation spectrometers and optical processors. The optical apparatus comprises one or more diffractive optical elements formed on a substrate for receiving light from a source and processing the incident light. The optical apparatus includes an addressing element for alternately addressing each diffractive optical element thereof to produce for one unit of time a first correlation with the incident light, and to produce for a different unit of time a second correlation with the incident light that is different from the first correlation. In preferred embodiments of the invention, the optical apparatus is in the form of a correlation spectrometer; and in other embodiments, the apparatus is in the form of an optical processor. In some embodiments, the optical apparatus comprises a plurality of diffractive optical elements on a common substrate for forming first and second gratings that alternately intercept the incident light for different units of time. In other embodiments, the optical apparatus includes an electrically-programmable diffraction grating that may be alternately switched between a plurality of grating states thereof for processing the incident light. The optical apparatus may be formed, at least in part, by a micromachining process.

Butler, Michael A. (Albuquerque, NM); Ricco, Antonio J. (Albuquerque, NM); Sinclair, Michael B. (Albuquerque, NM); Senturia, Stephen D. (Brookline, MA)

1999-01-01

446

Calibration of a microchannel plate based extreme ultraviolet grazing incident spectrometer at the Advanced Light Source  

SciTech Connect

We present the design and calibration of a microchannel plate based extreme ultraviolet spectrometer. Calibration was performed at the Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL). This spectrometer will be used to record the single shot spectrum of radiation emitted by the tapered hybrid undulator (THUNDER) undulator installed at the LOASIS GeV-class laser-plasma-accelerator. The spectrometer uses an aberration-corrected concave grating with 1200 lines/mm covering 11-62 nm and a microchannel plate detector with a CsI coated photocathode for increased quantum efficiency in the extreme ultraviolet. A touch screen interface controls the grating angle, aperture size, and placement of the detector in vacuum, allowing for high-resolution measurements over the entire spectral range.

Bakeman, M. S. [Department of Physics, University of Nevada Reno, Reno, Nevada 89557 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Tilborg, J. van; Sokollik, T.; Baum, D.; Ybarrolaza, N.; Duarte, R.; Toth, C.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2010-10-15

447

Development, characterization and application of compact spectrometers based on MEMS with in-plane capacitive drives  

NASA Astrophysics Data System (ADS)

With a trend towards the use of spectroscopic systems in various fields of science and industry, there is an increasing demand for compact spectrometers. For UV/VIS to the shortwave near-infrared spectral range, compact hand-held polychromator type devices are widely used and have replaced larger conventional instruments in many applications. Still, for longer wavelengths this type of compact spectrometers is lacking suitable and affordable detector arrays. In perennial development Carinthian Tech Research AG together with the Fraunhofer Institute for Photonic Microsystems endeavor to close this gap by developing spectrometer systems based on photonic MEMS. Here, we review on two different spectrometer developments, a scanning grating spectrometer working in the NIR and a FT-spectrometer accessing the mid-IR range up to 14 ?m. Both systems are using photonic MEMS devices actuated by in-plane comb drive structures. This principle allows for high mechanical amplitudes at low driving voltages but results in gratings respectively mirrors oscillating harmonically. Both systems feature special MEMS structures as well as aspects in terms of system integration which shall tease out the best possible overall performance on the basis of this technology. However, the advantages of MEMS as enabling technology for high scanning speed, miniaturization, energy efficiency, etc. are pointed out. Whereas the scanning grating spectrometer has already evolved to a product for the point of sale analysis of traditional Chinese medicine products, the purpose of the FT-spectrometer as presented is to demonstrate what is achievable in terms of performance. Current developments topics address MEMS packaging issues towards long term stability, further miniaturization and usability.

Kenda, A.; Kraft, M.; Tortschanoff, A.; Scherf, Werner; Sandner, T.; Schenk, Harald; Luettjohann, Stephan; Simon, A.

2014-05-01

448

Ultraviolet-Infrared Mapping Interferometic Spectrometer  

NASA Technical Reports Server (NTRS)

Prism and grating spectrometers have been the defacto devices for spectral mapping and imaging (hereafter referred to as hyperspectra). We have developed a new, hybrid instrument with many superior capabilities, the Digital Array Scanned Interferometer, DASI. The DASI performs the hyperspectral data acquisition in the same way as a grating or prism spectrograph, but retains the substantial advantages of the two-beam (Michelson) interferometer with additional capabilities not possessed by either of the other devices. The DASI is capable of hyperspectral studies in virtually any space or surface environment at any wavelength from below 50 nm to beyond 12 microns with available array detectors. By our efforts, we have defined simple, low cost, no-moving parts DASI's capable of carrying out hyperspectral science measurements for solar system exploration missions, e.g. for martian, asteroid, lunar, or cometary surveys. DASI capabilities can be utilized to minimize cost, weight, power, pointing, and other physical requirements while maximizing the science data return for spectral mapping missions. Our success in the development of DASI's has become and continues to be an important influence on the efforts of the best research groups developing remote sensing instruments for space and other applications.

1994-01-01

449

Composite Spectrometer Prisms  

NASA Technical Reports Server (NTRS)

Efficient linear dispersive element for spectrometer instruments achieved using several different glasses in multiple-element prism. Good results obtained in both two-and three-element prisms using variety of different glass materials.

Breckinridge, J. B.; Page, N. A.; Rodgers, J. M.

1985-01-01

450

Mass spectrometer calibration standard  

NASA Technical Reports Server (NTRS)

Inert perfluorinated alkane and alkyl ethers mixture is used to calibrate mass spectrometer. Noncontaminating, commercially-available liquid provides series of reproducible reference peaks over broad mass spectrum that ranges over mass numbers from 1 to 200.

Ross, D. S.

1978-01-01

451

One-dimensional space resolving flat-field holographic grating soft x-ray framing camera spectrograph for laser plasma diagnostics  

SciTech Connect

A 1D space resolving x-ray spectrum diagnostic system has been developed to study the radiation opacity of hot plasma on SG-II laser facility. The diagnostic system consists of a 2400 lines/mm flat-field holographic grating and a gated microchannel plate coupled with an optical CCD and covers the wavelength range of 5-50 A. The holographic grating was compared with a ruled one by measuring the emission spectra from a laser-produced molybdenum plasma. The results indicate that the holographic grating possesses better sensitivity than the ruled grating having nearly similar spectral resolution. The spectrograph has been used in radiative opacity measurement of Fe plasma. Simultaneous measurements of the backlight source and the transmission spectrum in appointed time range in one shot have been accomplished successfully with the holographic grating spectrometer. The 2p-3d transition absorption of Fe plasma near 15.5A in has been observed clearly.

Xiong Gang; Hu Zhimin; Li Hang; Zhao Yang; Shang Wanli; Zhu Tuo; Wei Minxi; Yang Guohong; Zhang Jiyan; Yang Jiamin [Research Center of Laser Fusion, China Academy of Engineering Physics, P.O. Box 919-986, Mianyang 621900 (China)

2011-04-15

452

Electromagnetically induced grating with maximal atomic coherence  

SciTech Connect

We describe theoretically an atomic diffraction grating that combines an electromagnetically induced grating with a coherence grating in a double-{Lambda} atomic system. With the atom in a condition of maximal coherence between its lower levels, the combined gratings simultaneously diffract both the incident probe beam as well as the signal beam generated through four-wave mixing. A special feature of the atomic grating is that it will diffract any beam resonantly tuned to any excited state of the atom accessible by a dipole transition from its ground state.

Carvalho, Silvania A.; Araujo, Luis E. E. de [Instituto de Fisica ''Gleb Wataghin'', Universidade Estadual de Campinas, Campinas-SP, 13083-859 Sao Paulo (Brazil)

2011-10-15

453

Thermal behavior of waveguide gratings  

NASA Astrophysics Data System (ADS)

We investigate the design of binary grating structures, e.g. resonance waveguide filters (RWFs), with subwavelength feature sizes, taking the temperature dependence of different material parameters into account. Our final goal is to demonstrate devices with athermal operation. We design the binary grating structures to be made in polymer substrates, such as polycarbonate (PC), due to their potential for low cost, mass fabrication. The high thermal expansion coefficient (TEC) of polymers, compared to inorganic optical materials, enhances the thermal sensitivity of the grating structures. The gratings are designed using Fourier Model Method (FMM) by considering both thermal expansion and thermo-optic effects on the resonance wavelength shift. The fabrication of RWF structures is proposed by e-beam lithography, creating a master stamp and copying the structures into a polymer substrate by some replication techniques, followed by an ALD deposition of TiO2. When the resonance waveguide grating RWG is designed for nearly room temperature operation at a peak wavelength of 633 nm with a full width half maximum FWHM of 3 nm (TM mode reflectance), the peak wavelength shifts 0.2 nm /50C when only the TEC is taken into account. However, taking into account also the thermo-optic coefficients TOCs of PC and TiO2, the peak position shifts to 0.4 nm/ 50C on the opposite side of spectral central wavelength. Thus the overall shift reduces to 0.2 nm /5 0C, illustrating partial athermalization. It was also observed that thermo-optic coefficient TOC contributed more significantly than TEC effect. The wavelengths shift was almost linear with respect to temperature for both effects and showed slopes of 0.0673, 0.0422 and 0.02352 for TOC, TEC and combined effects, respectively.

Saleem, M. R.; Khan, M. B.; Khan, Z. M.; Stenberg, P. A.; Alasaarela, T.; Honkanen, S.; Bai, B.; Turunen, J.; Vahimaa, P.

2011-05-01

454

Extreme ultraviolet spectroscopy diagnostics of low-temperature plasmas based on a sliced multilayer grating and glass capillary optics  

SciTech Connect

New extreme ultraviolet (EUV) spectroscopic diagnostics of relatively low-temperature plasmas based on the application of an EUV spectrometer and fast EUV diodes combined with glass capillary optics is described. An advanced high resolution dispersive element sliced multilayer grating was used in the compact EUV spectrometer. For monitoring of the time history of radiation, filtered fast EUV diodes were used in the same spectral region (>13 nm) as the EUV spectrometer. The radiation from the plasma was captured by using a single inexpensive glass capillary that was transported onto the spectrometer entrance slit and EUV diode. The use of glass capillary optics allowed placement of the spectrometer and diodes behind the thick radiation shield outside the direction of a possible hard x-ray radiation beam and debris from the plasma source. The results of the testing and application of this diagnostic for a compact laser plasma source are presented. Examples of modeling with parameters of plasmas are discussed.

Kantsyrev, V. L.; Safronova, A. S.; Williamson, K. M.; Wilcox, P.; Ouart, N. D.; Yilmaz, M. F. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States); Struve, K. W. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Voronov, D. L. [Kharkiv Polytechnical University, Kharkiv 61002 (Ukraine); Feshchenko, R. M.; Artyukov, I. A.; Vinogradov, A. V. [Physical Lebedev Institute, Moscow 119991 (Russian Federation)

2008-10-15

455

Extreme ultraviolet spectroscopy diagnostics of low-temperature plasmas based on a sliced multilayer grating and glass capillary opticsa)  

NASA Astrophysics Data System (ADS)

New extreme ultraviolet (EUV) spectroscopic diagnostics of relatively low-temperature plasmas based on the application of an EUV spectrometer and fast EUV diodes combined with glass capillary optics is described. An advanced high resolution dispersive element sliced multilayer grating was used in the compact EUV spectrometer. For monitoring of the time history of radiation, filtered fast EUV diodes were used in the same spectral region (>13nm) as the EUV spectrometer. The radiation from the plasma was captured by using a single inexpensive glass capillary that was transported onto the spectrometer entrance slit and EUV diode. The use of glass capillary optics allowed placement of the spectrometer and diodes behind the thick radiation shield outside the direction of a possible hard x-ray radiation beam and debris from the plasma source. The results of the testing and application of this diagnostic for a compact laser plasma source are presented. Examples of modeling with parameters of plasmas are discussed.

Kantsyrev, V. L.; Safronova, A. S.; Williamson, K. M.; Wilcox, P.; Ouart, N. D.; Yilmaz, M. F.; Struve, K. W.; Voronov, D. L.; Feshchenko, R. M.; Artyukov, I. A.; Vinogradov, A. V.

2008-10-01

456

Advanced astigmatism-corrected tandem Wadsworth mounting for small-scale spectral broadband imaging spectrometer.  

PubMed

Tandem gratings of double-dispersion mount make it possible to design an imaging spectrometer for the weak light observation with high spatial resolution, high spectral resolution, and high optical transmission efficiency. The traditional tandem Wadsworth mounting is originally designed to match the coaxial telescope and large-scale imaging spectrometer. When it is used to connect the off-axis telescope such as off-axis parabolic mirror, it presents lower imaging quality than to connect the coaxial telescope. It may also introduce interference among the detector and the optical elements as it is applied to the short focal length and small-scale spectrometer in a close volume by satellite. An advanced tandem Wadsworth mounting has been investigated to deal with the situation. The Wadsworth astigmatism-corrected mounting condition for which is expressed as the distance between the second concave grating and the imaging plane is calculated. Then the optimum arrangement for the first plane grating and the second concave grating, which make the anterior Wadsworth condition fulfilling each wavelength, is analyzed by the geometric and first order differential calculation. These two arrangements comprise the advanced Wadsworth mounting condition. The spectral resolution has also been calculated by these conditions. An example designed by the optimum theory proves that the advanced tandem Wadsworth mounting performs excellently in spectral broadband. PMID:23292378

Lei, Yu; Lin, Guan-yu

2013-01-01

457

The PRL Stabilized High Resolution Echelle Fiber-fed Spectrograph: Instrument Description & First Radial Velocity Results  

E-print Network

We present spectrograph design details and initial radial velocity results from the PRL optical fiber-fed high-resolution cross-dispersed echelle spectrograph (PARAS), which has recently been commissioned at the Mt Abu 1.2 m telescope, in India. Data obtained as part of the post-commissioning tests with PARAS show velocity precision better than 2m/s over a period of several months on bright RV standard stars. For observations of sigma-Dra we report 1.7m/s precision for a period of seven months and 2.1m/s for HD 9407 over a period of 2 months. PARAS is capable of a single-shot spectral coverage of 3800A - 9500A at a resolution of about 67,000. The RV results were obtained between 3800A and 6900A using simultaneous wavelength calibration with a Thorium-Argon (ThAr) hollow cathode lamp. The spectrograph is maintained under stable conditions of temperature with a precision of 0.01 - 0.02C (rms) at 25.55C, and enclosed in a vacuum vessel at pressure of 0.1 +/-0.03 mbar. The blaze peak efficiency of the spectrograp...

Chakraborty, Abhijit; Roy, Arpita; Dixit, Vaibhav; Richardson, Eric Harvey; Dongre, Varun; Pathan, F M; Chaturvedi, Priyanka; Shah, Vishal; Ubale, Girish P; Anandarao, B G

2013-01-01

458

A search for lithium in Pleiades brown dwarf candidates using the Keck hires echelle  

NASA Technical Reports Server (NTRS)

We report Keck Observatory high-resolution echelle spectra of lithium at 670.8 nm in two of the lowest luminosity brown dwarf candidates in the Pleiades. These objects have estimated masses of 0.055 to 0.059 solar mass from their location on a color-magnitude diagram relative to theoretical isochrones. Stellar interior models predict that Li has not burned in them. However, we find no evidence of the Li line, at limits 100 to 1000 times below the initial abundance. This indicates that Li has in fact been depleted, presumably by nuclear processing as occurs in Pleiades stars. Interior models suggest that such large Li depletion occurs only for objects with M greater than 0.09 solar mass at the age of the Pleiades. Thus, it is unlikely that the candidates are brown dwarfs. The brown dwarf candidates present a conflict: either they have masses greater than suggested from their placement on the H-R diagram, or they do have the very low suggested masses but are nonetheless capable of destroying Li, in only 70 Myr. Until this dilemma is resolved, the photometric identification of brown dwarfs will remain difficult. Resolution may reside in higher T(sub eff) derived from optical and IR colors or in lower T(sub eff) in the interior models.

Marcy, Geoffrey W.; Basri, Gibor; Graham, James R.

1994-01-01

459

Calibration facility for airborne imaging spectrometers  

NASA Astrophysics Data System (ADS)

A new facility designed to perform calibration measurements of airborne imaging spectrometers was established at the German Aerospace Center (DLR) in Oberpfaffenhofen. This Calibration Home Base (CHB) is optimized to characterize radiometrically, spectrally, and geometrically the APEX (Airborne Prism Experiment) imaging spectrometer, which is currently being developed under the authority of the European Space Agency (ESA). It however can be used for other optical sensors as well. Computer control of major laboratory equipment allows automation of time consuming measurements. In APEX configuration (wavelength range: 380 to 2500 nm, instantaneous field of view: 0.48 mrad, field of view: 14 ?) spectral measurements can be performed to a wavelength uncertainty of 0.15 nm, geometric measurements at increments of 0.0017 mrad across track and 0.0076 mrad along track, and radiometric measurements to an uncertainty of 3% relative to national standard. The CHB can be adapted to similar sensors (including those with thermal infrared detectors) by exchanging the monochromator's lamp, the gratings and the filters, and by adjusting the distance between the sensor and folding mirror.

Gege, Peter; Fries, Jochen; Haschberger, Peter; Schtz, Paul; Schwarzer, Horst; Strobl, Peter; Suhr, Birgit; Ulbrich, Gerd; Jan Vreeling, Willem

460

The characteristics of grating structure in magnetic field measurements based on polarization properties of fiber gratings  

NASA Astrophysics Data System (ADS)

In this paper the characteristics of grating structure in magnetic field measurements based on differential group delay of fiber gratings are analyzed. Theoretical simulations are realized using the coupled-mode theory and transfer matrix method. The effects of grating parameters of uniform Bragg grating on measurement range and sensitivity are analyzed. The impacts of chirped, phase-shifted and apodized gratings on DGD peak values are also monitored. FBG transmitted spectrums and DGD spectrums are recorded by means of an optical vector analyzer (OVA). Both the simulations and experiments demonstrate that the phase-shifted gratings can obviously improve the sensitivity.

Su, Yang; Peng, Hui; Feng, Kui; Li, Yu-quan

2009-11-01

461

Cross-fiber Bragg grating transducer  

NASA Technical Reports Server (NTRS)

A transducer has been invented that uses specially-oriented gratings in waveguide a manner that allows the simultaneous measurement of physical phenomena (such as shear force, strain and temperature) in a single sensing element. The invention has a highly sensitive, linear response and also has directional sensitivity with regard to strain. The transducer has a waveguide with a longitudinal axis as well as two Bragg gratings. The transducer has a first Bragg grating associated with the waveguide that has an angular orientation .theta..sub.a relative to a perpendicular to the longitudinal axis such that 0.degree.<.theta..sub.a <.theta..sub.max. The second Bragg grating is associated with the waveguide in such a way that the angular orientation .theta..sub.b of the grating relative to a perpendicular to the longitudinal axis is (360.degree.-.theta..sub.max)<.theta..sub.b <360.degree.. The first Bragg grating can have a periodicity .LAMBDA..sub.a and the second Bragg grating can have a periodicity .LAMBDA..sub.b such that the periodicity .LAMBDA..sub.a of the first Bragg grating does not equal the periodicity .LAMBDA..sub.b of the second Bragg grating. The angle of the gratings can be such that .theta..sub.a =360.degree.-.theta..sub.b. The waveguide can assume a variety of configurations, including an optical fiber, a rectangular waveguide and a planar waveguide. The waveguide can be fabricated of a variety of materials, including silica and polymer material.

Albin, Sacharia (Inventor); Zheng, Jianli (Inventor); Lavarias, Arnel (Inventor)

2000-01-01

462

Design of Emission Spectrometers with Resolving Power of 10,000  

SciTech Connect

A systematic design procedure is outlined which allows the achievement of maximum resolving power of a grating spectrometer for soft X-ray emission. Starting with a finite overall size the source size limit is balanced against the detector limited resolving power to find the optimal distance between entrance slit or image, focusing mirror, varied line space grating, and detector. An example is given showing ray traces of an instrument of 2.5 meter overall size and a resolving power of 10,000. A tangential elliptical mirror permits an optimal design to be achieved.

McKinney, Wayne R. [Lawrence Berkeley National Laboratory, Berkeley CA 94720 (United States)

2004-05-12

463

Electron-proton spectrometer  

NASA Technical Reports Server (NTRS)

An electron-proton spectrometer was designed to measure the geomagnetically trapped radiation in a geostationary orbit at 6.6 earth radii in the outer radiation belt. This instrument is to be flown on the Applications Technology Satellite-F (ATS-F). The electron-proton spectrometer consists of two permanent magnet surface barrier detector arrays and associated electronics capable of selecting and detecting electrons in three energy ranges: (1) 30-50 keV, (2) 150-200 keV, and (3) 500 keV and protons in three energy ranges. The electron-proton spectrometer has the capability of measuring the fluxes of electrons and protons in various directions with respect to the magnetic field lines running through the satellite. One magnet detector array system is implemented to scan between EME north and south through west, sampling the directional flux in 15 steps. The other magnet-detector array system is fixed looking toward EME east.

Winckler, J. R.

1973-01-01

464

Graphene Bragg gratings on microfiber.  

PubMed

Graphene Bragg gratings (GBGs) on microfiber are proposed and investigated in this paper. Numerical analysis and simulated results show that the mode distribution, transmission loss, and central wavelength of the GBG are controllable by changing the diameter of the microfiber or the refractive index of graphene. Such type of GBGs with tunability may find important applications in optical fiber communication and sensing as all-fiber in-line devices. PMID:25321961

Yao, B C; Wu, Y; Zhang, A Q; Wang, F; Rao, Y J; Gong, Y; Zhang, W L; Wang, Z G; Chiang, K S; Sumetsky, M

2014-10-01

465

Broad band waveguide spectrometer  

DOEpatents

A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

Goldman, Don S. (Folsom, CA)

1995-01-01

466

An X-ray grazing incidence phase multilayer grating  

Microsoft Academic Search

An X-ray grazing incidence phase multilayer grating, representing a thin grating placed on a multilayer mirror, is proposed. A high efficiency of grating diffraction can be obtained by the possibility of changing the phase shift of the wave diffracted from the multilayer under the Bragg and total external reflection conditions. A grazing incidence phase multilayer grating consisting of Pt grating

V. A. Chernov; N. V. Kovalenko; S. V. Mytnichenko

2001-01-01