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1

Cooled Echelle Grating Spectrometer.  

National Technical Information Service (NTIS)

A cooled echelle grating spectrometer for detecting wavelengths between one micrometers and fifteen micrometers is described. More specifically, a spectrometer is disclosed, having a cross-dispersing grating for ordering infrared energy, and an echelle gr...

R. Beer

1978-01-01

2

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

3

Immersion grating development for the VLT high-resolution IR echelle spectrometer: status report  

Microsoft Academic Search

Infrared immersion gratings are a possible way to realize the very high-resolution option in the planned VLT IR echelle spectrograph. In addition, immersion gratings and particular aspects of their fabrication are of interest to other applications. This paper summarizes the present status of the development program.

G. Wiedemann

1995-01-01

4

Echelle gratings acting as one  

NASA Astrophysics Data System (ADS)

A new device for producing order-sortable echelle spectra by use of consecutive diffractions in several echelle grating surfaces is described. This echelle emulating device (EED) comprises a prism placed in the path between a pair of echelle grating surfaces. The refractive angle of the prism is fixed through a simple relation. The device reproduces all the main properties of a single virtual echelle, obtained from a simple grating equation describing the combined action of the gratings and the prism. The spectral order of the EED is the sum of the spectral orders of the individual gratings. A spectrograph that utilizes the device is described, and several applications are discussed.

Lindblom, Peter

2003-08-01

5

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

6

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

7

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

8

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

9

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

10

Volume phase holographic echelle grating: a theoretical study  

NASA Astrophysics Data System (ADS)

Volume phase holographic gratings (VPHGs) are becoming fundamental dispersing elements in astronomical instrumentation. Here it will be described the efficiency behavior of such dispersing elements at high diffraction orders for understanding the possible use as echelle gratings. The efficiency is calculated based on RCWA analysis and different parameters are changed/optimized, i.e film thickness, refractive index modulation and profile. The results show that the VPHGs are not suitable for working at high orders in the classical configurations.

Bianco, Andrea; Pariani, Giorgio

2010-07-01

11

Torus Grating Spectrometer.  

National Technical Information Service (NTIS)

Calculations are given for the design of a spectrometer having fixed slits and a concave grating of toroidal surface in which the grating is rotated to vary the wavelength. Conditions are stated to obtain minimum astigmatism, and from these the most favor...

H. Greiner, E. Schaffer

1977-01-01

12

Cryogenic Grating Spectrometer.  

National Technical Information Service (NTIS)

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 st...

E. F. Erickson, M. R. Haas, S. W. J. Colgan, J. P. Simpson, R. H. Rubin

1995-01-01

13

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

14

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

15

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

16

Exploiting a Transmission Grating Spectrometer.  

National Technical Information Service (NTIS)

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 foc...

R. E. Bell

2004-01-01

17

Infrared Grating Spectrometer for GIRL.  

National Technical Information Service (NTIS)

A grating spectrometer with medium spectral resolution was developed for the GIRL project (Experiment E3), for the determination of the emission of trace constituents in the Earth's atmosphere, and for planetary and astronomical measurements. The spectrom...

D. Offermann, G. Lange, K. Grossmann, P. Knieling

1986-01-01

18

Multiple Grating Spectrometer Resolving Power.  

National Technical Information Service (NTIS)

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 pr...

V. Mazzacurati, G. Ruocco, G. Signorelli

1988-01-01

19

High-throughput, high-resolution Echelle deep-UV Raman spectrometer.  

PubMed

We constructed an ultrahigh-throughput, high-resolution ultraviolet (UV) Raman spectrograph that utilizes a high-efficiency filter-stage monochromator and a high-dispersion Echelle spectrograph. The spectrograph utilizes a total of six mirrors and two gratings, with an overall efficiency at 229 nm of ~18%. The limiting resolution of our spectrometer is 0.6 cm?¹ full width half-maximum (FWHM), as measured for 229 nm Rayleigh scattering. Use of a 1 mm-wide entrance slit gives rise to an approximately 10 cm?¹ FWHM resolution at 229 nm. The ultrahigh spectrograph throughput enables ultrahigh signal-to-noise ratio, deep UV Raman spectra that allow us to monitor <1% changes in peptide bond composition. The throughput is measured to be 35-fold greater than conventional deep UV Raman spectrometers. PMID:23876726

Bykov, Sergei V; Sharma, Bhavya; Asher, Sanford A

2013-08-01

20

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

21

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

22

Balloon-Borne Grating Spectrometer.  

National Technical Information Service (NTIS)

A balloon-borne, 0.5-m, Czerny-Turner grating spectrometer has been designed and constructed at the University of Denver and has measured atmospheric transmittance in several spectral regions between 2 micron and 14 micron. These data have been obtained o...

D. G. Murcray, F. H. Murcray, W. J. Williams

1966-01-01

23

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

24

Development of the mid-IR echelle high-dispersion spectrograph employing the germanium immersion grating  

Microsoft Academic Search

We have developed a germanium immersion grating mid-infrared cryogenic spectrograph (GIGMICS) designed for the Nasmyth focus stage of NAOJ Subaru 8.2 m telescope, which operates at N-band (8-13 mum) in wavelength with the R ~ 50,000. A single crystal germanium immersion echelle grating (30 × 30 × 72 mm) for collimated beam size of Phi28 mm was fabricated by utilizing

Yasuhiro Hirahara; Tsuyoshi Hirao; Yoshio Tatamitani; Tomohisa Yonezu; Noboru Ebizuka; Kentaro Kawaguchi; Hitoshi Tokoro; Tomomichi N. Oka

2010-01-01

25

Testing of an Echelle Spectrometer as a LIBS Detector at Sandia  

SciTech Connect

Some useful information has been obtained regarding the potential use of the echelle spectrometer system for Laser-Induced Breakdown Spectroscopy (LIBS) monitoring applications, despite the AOTF-computer operational problems during the Sandia site-test. Currently, the use of the echelle spectrometer with the LIBS system is not suitable for trace-level analyte detection. This is due, in part, to the lower light throughput of the echelle spectrometer system compared to the SpectraPro-275. The low duty cycle of the LIBS system, which results from the use of a low-repetition-rate (but low-cost and portable) laser, also limits the detection sensitivity achievable using a high-resolution spectrometer. At high analyte concentrations, the echelle spectrometer is able to resolve spectral interferences including the Cd-As line pair at 228.8-nm and other LIBS emission features not resolved using the SpectraPro-275. A definite positive result obtained is the determination that at the high resolution of the echelle spectrometer, time-gating of the CCD detector is not necessary to discriminate analyte spectral signals from the LIBS background emission. The cost of the gated CCD and associated electronics is a significant portion of the cost of the Sandia LIBS system. Incorporation of a low-cost version of the echelle spectrometer for process monitoring applications not requiring trace-level detection could make LIBS a more viable technique where cost is a limiting factor. We hope to have the opportunity to perform additional collaborative work using the AOTF-echelle spectrometer for on-line LIBS monitoring applications, in order to demonstrate the advantage of rapid line-switching (using the AOTF) and simultaneous detection of multiple emission features across the spectral range of the echelle.

David P. Baldwin; Daniel S. Zamzow; David K. Ottesen; Howard A. Johnsen

2001-04-25

26

AIRES: an airborne infrared echelle spectrometer for SOFIA  

NASA Astrophysics Data System (ADS)

The Stratospheric Observatory for Infrared Astronomy (SOFIA) will enable unique astronomical observations from visible to millimeter wavelengths. AIRES, a long-slit spectrograph with a mid-infrared slit viewing camera, would enable spectral imaging of gas-phase spectral features between 17 and 210 ?m with resolving powers from ~60,000 to 5000. The Cryogenic Grating Spectrometer (CGS: AIRES' predecessor) which was flown on NASA's Kuiper Airborne Observatory (KAO) for 13 years, demonstrated the importance of this wavelength range. A 1997 proposal to develop AIRES was selected as the highest-ranked of 19 U.S. competitors for first-generation SOFIA science instruments. Funding was terminated in 2001 due to budget problems associated with an original under estimate and the advent of full cost accounting in NASA. Here we summarize AIRES' expected performance, its science potential, its status, and lessons learned. Highlighted are three successfully accomplished major technical developments: the world's largest monolithic cryogenic grating, cryogenic multiplexing amplifiers for far-infrared germanium photoconductor detectors, and an optical/mechanical design in a package suitable for installation on SOFIA. We show that AIRES would fill a unique role among other spectroscopic capabilities foreseen for space-borne missions. AIRES' capabilities remain a high but unfilled priority for SOFIA, and for the science community in general.

Erickson, Edwin F.; Haas, Michael R.; Colgan, Sean J. W.; Dotson, Jessie L.; Simpson, Janet P.; Young, Erick T.

2007-10-01

27

Compact imaging spectrometer utilizing immersed gratings  

Microsoft Academic Search

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

Michael P. Chrisp; Scott A. Lerner; Paul J. Kuzmenko; Charles L. Bennett

2007-01-01

28

Compact Imaging Spectrometer Utilizing Immersed Gratings  

Microsoft Academic Search

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

Michael P. Chrisp; Scott A. Lerner; Paul J. Kuzmenko; Charles L. Bennett

2006-01-01

29

Design of a mid-IR immersion echelle grating spectrograph for remote sensing  

Microsoft Academic Search

We describe the design of a silicon immersion grating spectrograph for the remote detection of chemicals in the atmosphere. The instrument is designed to operate in the two atmospheric windows from 2.3 to 2.5 and 2.8 to 4.2 microns at a resolution of 0.1 cm-1. This is achieved by cross dispersing a high order silicon immersion echelle (13.5 grooves\\/mm) and

Norman L. Thomas; Isabella T. Lewis; Charles G. Stevens

1995-01-01

30

Design of a mid-IR immersion echelle grating spectrograph for remote sensing  

SciTech Connect

We describe the design of a silicon immersion grating spectrograph for the remote detection of chemicals in the atmosphere. The instrument is designed to operate in the two atmospheric windows from 2.3 to 2.5 and 2.8 and 4.2 microns at a resolution of 0.1 cm{sup {minus}1}. This is achieved by cross dispersing a high order silicon immersion echelle (13.5 grooves/mm) and a first order concave grating operating in a reflective configuration to generate a two-dimensional spectrum in the image plane with diffraction limited performance.

Thomas, N.L.; Lewis, I.T.; Stevens, C.G.

1995-05-09

31

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

32

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

33

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

34

Compact reflective imaging spectrometer utilizing immersed gratings  

Microsoft Academic Search

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

Chrisp; Michael P

2006-01-01

35

Theory of a Concave Grating Spectrometer.  

National Technical Information Service (NTIS)

Apparatus constants for minimum defocussing of a concave grating spectrometer were determined. Equations were obtained relating apparatus constants, which were not obtainable in Seya theory. Numerical solutions were calculated by computer from an equation...

H. Greiner E. Schaeffer

1976-01-01

36

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

37

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

38

Proposal of a polarization-insensitive echelle grating demultiplexer based on a nanophotonic silicon-on-insulator platform through a dual-grating system.  

PubMed

In this Letter, we demonstrate theoretically the design of a polarization-insensitive echelle grating demultiplexer on a nanophotonic silicon-on-insulator platform. The polarization-insensitive performance is achieved through a dual-grating system, which utilizes different concave gratings for different polarizations. The first concave grating acts as a polarization to beam splitter as well, allowing light with the other polarization to pass through and be reflected by the second grating, which is designed separately; thus the same spectral responses are obtained for the two polarizations. PMID:20479821

Zhu, Ning

2010-05-15

39

AIRES: an Airborne InfraRed Echelle Spectrometer for SOFIA  

Microsoft Academic Search

The Stratospheric Observatory for Infrared Astronomy, SOFIA, is a 2.7 meter telescope which is scheduled to begin observations in a Boeing 747 in October 2001. Among other SOFIA science instruments recently selected for development is the facility spectrometer AIRES. AIRES is designed for studies of a broad range of phenomena occuring in the interstellar medium (ISM) which are uniquely enabled

E. F. Erickson; M. R. Haas; S. W. J. Colgan; T. Roellig; J. P. Simpson; C. M. Telesco; R. K. Pina; E. T. Young; J. Wolf

1997-01-01

40

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

41

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

42

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

43

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

44

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

45

Spectrometer with CMOS demodulation of fiber optic Bragg grating sensors  

Microsoft Academic Search

A CMOS imager based spectrometer is developed to interrogate a network containing a large number of Bragg grating sensors. The spectrometer uses a Prism-Grating- Prism (PGP) to spectrally separate serially multiplexed Bragg reflections on a single fiber. As a result, each Bragg grating produces a discrete spot on the CMOS imager that shifts horizontally as the Bragg grating experiences changes

Martin Brokner Christiansen

2001-01-01

46

Development of the mid-IR echelle high-dispersion spectrograph employing the germanium immersion grating  

NASA Astrophysics Data System (ADS)

We have developed a germanium immersion grating mid-infrared cryogenic spectrograph (GIGMICS) designed for the Nasmyth focus stage of NAOJ Subaru 8.2 m telescope, which operates at N-band (8-13 ?m) in wavelength with the R ~ 50,000. A single crystal germanium immersion echelle grating (30 × 30 × 72 mm) for collimated beam size of ?28 mm was fabricated by utilizing ultra precision micro-grinding method coupled with the ELID (ELectrolytic In-process Dressing) technique (Ohmori, H. 1992)1. All optical components are arranged on the 800 mm diameter cold optical base plate (~30 K) of the cryostat. By the Si:As IBC (Impurity Band Conductor) focal plane array (FPA) detector (412 × 512 pixels, unit pixel size 30 ?m) operated at 5 K simultaneously acquires ~13 % wavelength coverage for N-band. The instrument has been assembled and is now tested for the application to the gas-phase IR high-resolution spectroscopy.

Hirahara, Yasuhiro; Hirao, Tsuyoshi; Tatamitani, Yoshio; Yonezu, Tomohisa; Ebizuka, Noboru; Kawaguchi, Kentaro; Tokoro, Hitoshi; Oka, Tomomichi N.

2010-07-01

47

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 material’s 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

48

Seya'S Theory of the Concave Grating Spectrometer.  

National Technical Information Service (NTIS)

A survey was made of those spectrometers (monochromators) which use the concave grating employing single reflection, those which are suitable for wavelengths below 1000 A. A brief resume of Seya's theory is given. This theory provides the basis for the de...

H. Greiner E. Schaeffer

1976-01-01

49

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

50

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

51

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

52

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

53

Humidity-induced spectral shift in a cross-dispersion echelle spectrometer and its theoretical investigation.  

PubMed

The relationship between ambient relative humidity H and the position shift of a spectral line was investigated both experimentally and theoretically. An echelle-based ICP emission spectrometer equipped with a CID detector was used for experimental verification of the derived model. The shift of a spectral line is quantitatively described by two defined spectral shift functions: delta lambda x(x, lamda, H) (in the x direction of the CID detector) and delta lambda y(y, lambda, H) (in the y direction of the CID detector). Experimental results indicate that delta lamda x(x, lambda, H) does not change with a variation in ambient relative humidity, but delta lamda y(y, lambda, H) does. A spectral shift equation, i.e., an empirical second-order polynomial equation, can be used to describe the relationship between delta lamda y(y, lambda, H) and H. Based on the classical dipole model, classical mechanics and electrodynamics the empirical spectral-shift equation involving delta lambda y(y, lambda, H) and H was theoretically deduced. The theoretical result is in good agreement with the experimental findings. The theoretical results indicate that the coefficients of the empirical spectral-shift equation are related to the basic physical parameters of materials and the geometric configuration of the echelle CID ICP-AES, and also provide physical meaning to the coefficients of the empirical shift equation obtained experimentally. PMID:21090510

Liu, Ke-ling; Huang, Mao; Hieftje, Gary M

2010-09-01

54

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

55

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 Czerny–Turner 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

56

Carbon monoxide abundances and C12\\/C13 ratios of K and M stars obtained with an Echelle spectrometer  

Microsoft Academic Search

The spectra of 5 K and M stars in the 4200-4300\\/cm region were obtained by using a scanning echelle spectrometer. Although the spectrometer was not optimized for the 120 in. telescope, spectra of sufficient quality were obtained to derive CO molecular column densities and C12\\/C13 isotope ratios in the stellar atmospheres. The spectra were analyzed by means of a multilevel

G. C. Augason

1976-01-01

57

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

58

Basic angles in microelectromechanical system scanning grating spectrometers.  

PubMed

Modern miniaturized scanning grating spectrometers (SGSs) are often based on microelectromechanical system devices. In contrast to classical spectrometers, such systems exhibit additional design constraints, like a symmetrical motion of the grating with a limited deflection. A detailed mathematical analysis of typical SGS configurations based on the grating equation considering these constraints is presented. Equations that relate the basic angles on a scanning grating to the grating properties and the attainable wavelength range of a spectrometer are derived, and the solution set is examined. Furthermore, the analytical description can be used to optimize SGSs with symmetrically moving gratings. The attainable spectral range for a given deflection amplitude of the grating can be calculated. Alternatively, the required grating properties can be determined for a given spectral range. PMID:21857714

Puegner, Tino; Knobbe, Jens; Lakner, Hubert

2011-08-20

59

Development of a Submillimeter-Wavelength Immersion Grating Spectrometer.  

National Technical Information Service (NTIS)

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 ...

T. G. Phillips

2001-01-01

60

Imaging Spectrometer Designs Utilizing Immersed Gratings With Accessible Entrance Slit  

Microsoft Academic Search

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

Michael P. Chrisp; Scott A. Lerner

2006-01-01

61

Manufacturing of silicon immersion gratings for infrared spectrometers  

Microsoft Academic Search

Silicon immersion gratings have been a promising future technology for high resolution infrared spectroscopy for over 15 years. We report here on our current immersion grating research, including extensive measurements of the performance of micromachined silicon devices. We are currently producing gratings for two high resolution spectrometers: iSHELL at the University of Hawaii and IGRINS at the University of Texas

Weisong Wang; Michael Gully-Santiago; Casey Deen; Douglas J. Mar; Daniel T. Jaffe

2010-01-01

62

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

63

Comparative study of two new commercial echelle spectrometers equipped with intensified CCD for analysis of laser-induced breakdown spectroscopy.  

PubMed

The purpose of this paper is to provide the reader with comparative information about two new commercial echelle spectrometers equipped with intensified CCD (ICCD) detectors for laser-induced breakdown spectroscopy analysis. We carried out a performance comparison between two commercial ICCD/echelle spectrometers [ESA 3000 (LLA Instruments GmbH, Berlin-Adlershof, Germany) and a Mechelle 7500 (Multichannel Instruments, Stockholm, Sweden)] for the determination of the concentrations of Be, Mg, Si, Mn, Fe, and Cu in the same Al alloy samples adopting the same experimental conditions. The results show that both systems, despite their differences in terms of resolution, have similar performance in terms of sensitivity and precision of measurements for these elements in an Al alloy matrix at least for the range of wavelength 280-400 nm studied in this work. PMID:14594071

Sabsabi, Mohamad; Detalle, Vincent; Harith, Mohamed A; Tawfik, Walid; Imam, Hisham

2003-10-20

64

ZEUS: A Submillimeter Grating Spectrometer for Exploring Distant Galaxies  

NASA Astrophysics Data System (ADS)

The redshift (Z) and Early Universe Spectrometer (ZEUS) is a long slit echelle grating spectrometer that we are constructing for use in the submillimeter atmospheric transmission windows (350 ? m, 450 ? m, and 610 ? m) on the James Clerk Maxwell Telescope (JCMT). ZEUS has a resolving power of R ? ? /? ? ˜ 1000, optimized for detecting broad, faint lines from extragalactic sources. The detector will be a 4×64 pixel array of pop-up bolometers (PUD) equipped with superconducting transition edge sensors (TES) linked into a SQUID multiplexed readout. The expected point source sensitivities of the TES PUD at 370 ? m and 444 ? m are 4.3 × 10-17 W m-2Hz-1/2 and 2.4 × 10-17 W m-2Hz-1/2. For our lab testing we are using a 1×32 pixel array of thermistor sensed bolometers from GSFC. This array has delivered the requisite sensitivity and spectral coverage for a successful first light at the JCMT in the 350 ? m and 450 ? m windows. We hope to put ZEUS on the JCMT in the spring of 2005. ZEUS is optimized to quickly obtain spectra of point sources over very broad bands in the submillimeter windows. In the 350 ? m window, ZEUS will provide an instantaneous 53 resolution element spectrum, for each of 4 spatial elements on the sky. The roughly 10% bandwidth 350 ? m window can therefore be covered with just two settings of the grating. Each pixel is mapped into 5'' on the sky (roughly ? /D at 350 ? m), so that the field of view is 5''×20''. At 610 ? m, the slit is opened to 10'' (2 pixels) resulting in a resolving power of around 500. ZEUS can quickly change wavelength or telluric window, adapting well to the demanding weather conditions in the short submillimeter windows. Our primary scientific objectives are to (1) Investigate Ultraluminous Infrared Galaxies (ULIGs) via their [C I] and mid-J CO line emission -- what are the origins of their tremendous infrared (IR) luminosities? Why are some ULIGs weak in the 158 ? m [C II] line? (2) Probe star formation in the early Universe using highly redshifted far-IR fine-structure line emission -- especially that of the 158 ? m [C II] line. How strong are starbursts in the early Universe? and (3) Provide redshifts for all 850 ? m SCUBA sources, providing source distance, luminosity, and number counts as a function of redshift. What is the evolutionary history of starformation in the early Universe? This project is supported by NSF grant AST-0096881.

Hailey-Dunsheath, S.; Nikola, T.; Stacey, G. J.; Oberst, T.; Parshley, S.; Benford, D. J.; Moseley, S. H.; Staguhn, J. G.

2004-12-01

65

Large-area silicon immersion echelle gratings and grisms for IR spectroscopy  

Microsoft Academic Search

We present design examples for instruments making use of micromachined silicon grisms and immersion gratings. The capabilities of high index grisms, transmission grating-prism hybrids, open up new possibilities in compact IR spectrograph design with spectral resolving power, R~500-5000. Coarsely grooved immersion gratings will provide for unique high resolution spectrograph designs in the near and mid-infrared (resolving power, R~104-105). The high

Luke D. Keller; Daniel T. Jaffe; Oleg A. Ershov; Jasmina P. Marsh

2002-01-01

66

Study on spectrometer based upon volume holographic transmission grating  

NASA Astrophysics Data System (ADS)

In this present paper, a spectrometer based upon axial transmissive optical structure with the volume-phase holographic (VPH) transmission grating technology is introduced. We give a physical insight for the structure and mechanism of photorefractive volume holographic gratings and theoretically analyze some important performance parameters of the spectrometer device using the coupled wave theory, which should be considered in the process of the following design for the device with volume phase holographic transmission gratings. The experimental results show, owing to its axial transmissive optical geometry and the perfect performance of the VPH transmission grating, the spectrometer based on the volume-phase holographic transmission grating has satisfactory high resolution and wavelength accuracy. It has great promise to be widely used in the future.

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

2010-05-01

67

Accurate wavelength calibration method using system parameters for grating spectrometers  

NASA Astrophysics Data System (ADS)

In this paper, an accurate method is proposed for wavelength calibration in grating spectrometers. The analytical calibration model of the Czerny-Turner optical system, which describes the relationship between the wavelengths and the pixel numbers with function of the system parameters, is established on the basis of the grating equation and geometric optics. An optimization fitting algorithm is introduced to calculate the practical system parameter values in this model. Experimental tests are conducted in our manufactured spectrometer. The results show that this method has higher calibration accuracy in a broadband spectrometer system and less dependence on the spectral lines chosen compared to the traditional polynomial method. This novel wavelength calibration method also can be applied to other plane-grating or concave-grating spectrometers.

Liu, Kang; Yu, Feihong

2013-01-01

68

Modified Dyson imaging spectrometer with an aspheric grating surface  

NASA Astrophysics Data System (ADS)

A broadband, aberration-corrected Dyson arrangement with an aspheric grating surface is proposed. An aspheric grating surface is used to correct spherical aberration resulted from the air gap between the focal plane and the rear surface of Dyson lens. The principle and the method of aberration correction are described in detail. We compare the performance of this modified Dyson arrangement with that of the Dyson arrangement using a spherical grating surface by using a practical Dyson imaging spectrometer example.

Xue, Qingsheng

2013-11-01

69

Imaging Spectrometer Designs Utilizing Immersed Gratings With Accessible Entrance Slit  

DOEpatents

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

70

Accurate wavelength calibration method for flat-field grating spectrometers.  

PubMed

A portable spectrometer prototype is built to study wavelength calibration for flat-field grating spectrometers. An accurate calibration method called parameter fitting is presented. Both optical and structural parameters of the spectrometer are included in the wavelength calibration model, which accurately describes the relationship between wavelength and pixel position. Along with higher calibration accuracy, the proposed calibration method can provide information about errors in the installation of the optical components, which will be helpful for spectrometer alignment. PMID:21929865

Du, Xuewei; Li, Chaoyang; Xu, Zhe; Wang, Qiuping

2011-09-01

71

Compact Refractive Imaging Spectrometer Designs Utilizing Immersed Gratings  

Microsoft Academic Search

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

Scott A. Lerner; Charles L. Bennett; Jay V. Bixler; Paul J. Kuzmenko; Isabella T. Lewis

2005-01-01

72

Compact Catadioptric Imaging Spectrometer Designs Utilizing Immersed Gratings  

Microsoft Academic Search

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.

Scott A

2006-01-01

73

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

74

Fabrication and performance of silicon immersion gratings for infrared spectroscopy  

Microsoft Academic Search

Silicon immersion gratings open up the possibility of compact infrared spectrometers with high throughput, high spectral resolution, and extensive instantaneous coverage. The performance of the diffraction gratings that we have been developing over the past 15 years has reached the level where it can exceed that of commercially available diffraction gratings. We have produced science-grade immersion grating echelles with coarsely

Jasmina P. Marsh; Douglas J. Mar; Daniel T. Jaffe

2006-01-01

75

Fabrication and Performance of Silicon Immersion Gratings for Infrared Spectroscopy  

Microsoft Academic Search

Silicon immersion gratings open up the possibility of compact infrared spectrometers with high throughput, high spectral resolution, and extensive instantaneous coverage. The performance of the diffraction gratings that we have been developing over the past 15 years has reached the level where it can exceed that of commercially available diffraction gratings. We have produced science-grade immersion grating echelles with coarsely

Jasmina P. Marsh; Douglas J. Mar; Daniel T. Jaffe

76

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

77

Design of a mid-IR immersion echelle grating spectrograph for remote sensing.  

National Technical Information Service (NTIS)

We describe the design of a silicon immersion grating spectrograph for the remote detection of chemicals in the atmosphere. The instrument is designed to operate in the two atmospheric windows from 2.3 to 2.5 and 2.8 and 4.2 microns at a resolution of 0.1...

N. L. Thomas I. T. Lewis C. G. Stevens

1995-01-01

78

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

79

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

80

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

81

Manufacturing of silicon immersion gratings for infrared spectrometers  

NASA Astrophysics Data System (ADS)

Silicon immersion gratings have been a promising future technology for high resolution infrared spectroscopy for over 15 years. We report here on our current immersion grating research, including extensive measurements of the performance of micromachined silicon devices. We are currently producing gratings for two high resolution spectrometers: iSHELL at the University of Hawaii and IGRINS at the University of Texas and the Korea Astronomy and Space Science Institute. The gratings are R3 devices with total lengths of ~95 mm. The use of a high index material like silicon permits the spectrometers to have high resolving powers (40,000-70,000) at decent slit sizes with very small (25mm) collimated beams. The lithographic production of coarse grooves allows for instrument designs with continuous wavelength coverage over broad spectral ranges. We discuss the science requirements for grating quality and efficiency and the measurements we have made to verify that the gratings meet these requirements. The measurements include optical interferometry and measurements of the monochromatic point spread function in reflection.

Wang, Weisong; Gully-Santiago, Michael; Deen, Casey; Mar, Douglas J.; Jaffe, Daniel T.

2010-07-01

82

Reflection Grating Spectrometer on Board XMM-Newton.  

National Technical Information Service (NTIS)

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 ...

J. W. denHerder, A. C. Brinkman, S. M. Kahn, G. Branduardi-Raymont, K. Thomsen, H. Aarts, M. Audard, J. V. Bixler, A. J. denBoggende

2000-01-01

83

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, Jörn; Falcone, Abraham; Brickhouse, Nancy S.; Ptak, Andrew; Foster, Adam; Bregman, Joel N.

2014-06-01

84

Fabrication update on critical-angle transmission gratings for soft x-ray grating spectrometers  

NASA Astrophysics Data System (ADS)

Diffraction grating-based, wavelength dispersive high-resolution soft x-ray spectroscopy of celestial sources promises to reveal crucial data for the study of the Warm-Hot Intergalactic Medium, the Interstellar Medium, warm absorption and outflows in Active Galactic Nuclei, coronal emission from stars, and other areas of interest to the astrophysics community. Our recently developed critical-angle transmission (CAT) gratings combine the advantages of the Chandra high and medium energy transmission gratings (low mass, high tolerance of misalignments and figure errors, polarization insensitivity) with those of blazed reflection gratings (high broad band diffraction efficiency, high resolution through use of higher diffraction orders) such as the ones on XMM-Newton. Extensive instrument and system configuration studies have shown that a CAT grating-based spectrometer is an outstanding instrument capable of delivering resolving power on the order of 5,000 and high effective area, even with a telescope point-spread function on the order of many arc-seconds. We have fabricated freestanding, ultra-high aspect-ratio CAT grating bars from silicon-on-insulator wafers using both wet and dry etch processes. The 200 nm-period grating bars are supported by an integrated Level 1 support mesh, and a coarser external Level 2 support mesh. The resulting grating membrane is mounted to a frame, resulting in a grating facet. Many such facets comprise a grating array that provides light-weight coverage of large-area telescope apertures. Here we present fabrication results on the integration of CAT gratings and the different high-throughput support mesh levels and on membrane-frame bonding. We also summarize recent x-ray data analysis of 3 and 6 micron deep wet-etched CAT grating prototypes.

Heilmann, Ralf K.; Bruccoleri, Alex; Mukherjee, Pran; Yam, Jonathan; Schattenburg, Mark L.

2011-09-01

85

"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

86

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

87

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 Å, 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. Güdel; 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

88

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

89

Development of an In-House Grating Spectrometer System for Validating Acousto-Optic Tunable Filter Spectrometer Results.  

National Technical Information Service (NTIS)

We describe the design of a grating spectrometer system. We obtained emission spectroscopy results of a lamp source from a visible to near infrared (vis-NIR) acousto-optic tunable filter (AOTF) spectrometer and from an IN-house developed Grating (ING) spe...

K. W. Bennett, N. Gupta, R. Dahmani

2001-01-01

90

Design of a hybrid-integrated MEMS scanning grating spectrometer  

NASA Astrophysics Data System (ADS)

Optical MEMS (micro electro mechanical systems) have been used to reduce size, weight and costs of any kind of optical systems very successfully starting in the last decades. Scientists at Fraunhofer IPMS invented a resonant drive for 1-d and 2-d MEMS scanning mirror devices. Besides mirrors also scanning gratings have been realized. Now, rapidly growing new applications demand for enhanced functions and further miniaturization. This task cannot be solved by simply putting more functionality into the MEMS chip, for example grating and slit structures, but by three dimensional hybrid integration of the complete optical system into a stack of several functional substrates. Here we present the optical system design and realization strategy for a scanning grating spectrometer for the near infrared (NIR) range. First samples will be mounted from single components by a bonder tool (Finetech Fineplacer Femto) but the option of wafer assembly will be kept open for future developments. Extremely miniaturized NIR spectrometer could serve a wide variety of applications for handheld devices from food quality analysis to medical services or materials identification.

Pügner, Tino; Knobbe, Jens; Grüger, Heinrich; Schenk, Harald

2011-09-01

91

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

92

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

93

Compact Imaging Spectrometer Utilizing Immersed Gratings (PAT-APPL-10-920 880).  

National Technical Information Service (NTIS)

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 grat...

C. L. Bennett M. P. Chrisp P. J. Kuzmenko S. A. Lerner

2004-01-01

94

Compact Imaging Spectrometer Utilizing Immersed Gratings (PAT-APPL-11-066-370).  

National Technical Information Service (NTIS)

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 g...

C. L. Bennett M. P. Chrisp P. J. Kuzmenko S. A. Lerner

2005-01-01

95

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

Microsoft Academic Search

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

Scott A

2006-01-01

96

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

97

Transmission grating based imaging spectrometers in the XUV and VUV for various plasmas  

NASA Astrophysics Data System (ADS)

This report describes the design of imaging survey spectrometers in the XUV and the VUV ranges respectively. These survey spectrometers provide space resolved spectra using free standing transmission gratings and CCD based direct photon detection. The spectrometers were tested on a table top reflex discharge. Spectra shown in this report highlight the space and spectral resolving capabilities of the spectrometers.

Kumar, D.; Parman, M.; Stutman, D.; Finkenthal, M.

2013-10-01

98

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

99

Design and fabrication of an active polynomial grating for soft-X-ray monochromators and spectrometers  

Microsoft Academic Search

An active polynomial grating has been designed for use in synchrotron radiation soft-X-ray monochromators and spectrometers. The grating can be dynamically adjusted to obtain the third-order-polynomial surface needed to eliminate the defocus and coma aberrations at any photon energy. Ray-tracing results confirm that a monochromator or spectrometer based on this active grating has nearly no aberration limit to the overall

S.-J. Chen; C. T. Chen; S. Y. Perng; C. K. Kuan; T. C. Tseng; D. J. Wang

2001-01-01

100

InGaAs/InP-based Echelle mirror multiplexer using dual Rowland circle gratings for DFB QCL arrays in the mid-long infrared range  

NASA Astrophysics Data System (ADS)

In this work we introduce the design, optimization, simulation and experimental characterization results of a 30-to-1 wavelength multiplexer for a Distributed Feedback Quantum Cascade Laser (DFB QCL) laser array operating in the 7- 8.5 ?m (mid-long) infrared (IR) range based on an Echelle mirror using a dual Rowland circle grating scheme. This design is proposed in order to achieve a continuous tuning range overcoming the limited tunability of individual QCLs. The design is based on a DFB-QCL array with wavelength spacing of 0.05 ?m, aiming to reducing coupling between the slab waveguides to a minimum. We discuss the design parameters such as the order of diffraction, the operation wavelength range in the slab waveguides and the position of both the input and output waveguides are optimized for obtaining higher output power in the overall wavelength range of the multiplexer device than in a single Rowland circle grating scheme, providing an improvement in channel transmission. Other design characteristics, such as the structure scalability and reduction in size for these devices are considered and studied, including the input/output waveguide optimization as a function of parameters such as waveguide width, etching depth and wavelength. A systematic process is presented for all steps in the design of these devices, comparing both simulated and experimental results, placing them as suitable options when compared to other IR multiplexer schemes in terms of size and transmission.

Orbe, L. J.; Gordon, C.; Carpintero, G.; Maisons, G.; Carras, M.

2014-02-01

101

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 1.5×10?3sr is achieved by utilizing the Wolter mirror as a

Takaki Hatsui; Hiroyuki Setoyama; Eiji Shigemasa; Nobuhiro Kosugi

2005-01-01

102

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

103

The Reflection Grating Spectrometer on Board XMM-Newton  

NASA Technical Reports Server (NTRS)

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 A or 2.1 to 0.3 keV) with a maximum effective area of about 140 sq cm at 15 A. 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 present paper gives a full description of the design of the RGS and its operational modes. We also review details of the calibrations and in-orbit performance including the line spread function, the wavelength calibration, the effective area, and the instrumental background.

denHerder, J. W.; Brinkman, A. C.; Kahn, S. M.; Branduardi-Raymont, G.; Thomsen, K.; Aarts, H.; Audard, M.; Bixler, J. V.; denBoggende, A. J.

2000-01-01

104

The Reflection Grating Spectrometer on board XMM-Newton  

NASA Astrophysics Data System (ADS)

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 Å, or 2.1 to 0.3 keV) with a maximum effective area of about 140 cm2 at 15 Å. 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 present paper gives a full description of the design of the RGS and its operational modes. We also review details of the calibrations and in-orbit performance including the line spread function, the wavelength calibration, the effective area, and the instrumental background.

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

2001-01-01

105

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

106

Analysis of a Hadamard transform near-infrared spectrometer based on grating light modulator  

NASA Astrophysics Data System (ADS)

This paper proposes a novel Hadamard Transform near-infrared spectrometer based on MOEMS(Optical micro-electro-mechanical system ) grating light modulator. A new method that grating light modulator combined with a single near -infrared detector to detect spectrum is applied. The programmability of the grating light modulator linear array is used to implement a Hadamard Transform encoding masks. Firstly, optics theory has been used to analyze the essential principle of the spectrometer and the optical principle of grating light modulator. Then, It is theoretically proved that the Hadamard Transform near-infrared spectrometer can reconstruct spectrum effectively and have a high signal noise ratio. Finally, a new structure of the grating light modulator is given. Results of the software simulation show that 5.5V maximum actuating voltage and 5 kHz response frequency are suitable for a miniature, portable, cost-efficient spectrometer.

Wei, Wei; Huang, Shanglian; Zhu, Yong; Wang, Ning; Zhang, Jie; Jin, Zhu

2008-12-01

107

[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

108

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

NASA Technical Reports Server (NTRS)

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.

Houck, J. R.; Ward, D.

1979-01-01

109

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

110

[Technology Development for X-Ray Reflection for the Constellation-X Reflection Grating Spectrometer (RGS)  

NASA Technical Reports Server (NTRS)

This Grant covers MIT support for the technology development of x-ray reflection gratings for the Constellation-X Reflection Grating Spectrometer (RGS). Since the start of the Grant MIT has extended its previously-developed patterning and super-smooth, blazed grating fabrication technology to ten-times smaller grating periods and ten-times larger blaze angles to demonstrate feasibility and performance in the off-plane grating geometry. In the past year we successfully developed several nanoimprint grating replication methods that achieved very high fidelity replication of master silicon gratings. Grating geometry on the nano and macro scales were faithfully replicated, demonstrating the viability of the process for manufacturing the thousands of gratings required for the RGS. We also successfully developed an improved metrology truss for holding test grating substrates during metrology. The flatness goal of grating substrates is under 500 nm. In the past, grating holders would cause non-repeatable distortion of >> 500 nm to the substrates due to friction and gravity sag. The new holder has a repeatability of under 50 nm which is adequate for the proposed RGS grating substrates.

Schattenburg, Mark L.

2003-01-01

111

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

112

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

113

Fabrication and testing of a silicon immersion grating for infrared spectroscopy  

Microsoft Academic Search

recent advances in silicon micromachining techniques allow the fabrication of very coarse infrared echelle gratings. When used in immersion mode the dispersion is increased proportionally to the refractive index. This permits a very significant reduction in the overall size of a spectrometer while maintaining the same resolution. We have fabricated a right triangular prism from silicon with a grating etched

Paul J. Kuzmenko; Dino R. Ciarlo; Charles G. Stevens

1994-01-01

114

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

115

Developments in Off-Plane X-ray Reflection Grating Spectrometers  

NASA Astrophysics Data System (ADS)

X-ray reflection gratings have significant flight heritage from suborbital rockets to XMM-Newton. The off-plane mount is a configuration capable of obtaining the high throughput, high spectral resolving power requirements necessary for achieving key science goals. We detail the current state of off-plane gratings and plans for their technology development. We present a notional spectrometer design and outline the major difficulties involved with grating development, and plans on dealing with these issues.

McEntaffer, Randall L.

2013-01-01

116

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

117

Development of immersed diffraction grating for the TROPOMI-SWIR spectrometer  

Microsoft Academic Search

We have developed a novel diffraction grating based on lithographical techniques and anisotropic etching in silicon. The grating is designed for the short-wave-infrared channel of the TROPOMI imaging spectrometer that will be launched on ESA's Sentinel 5 Precursor mission to monitor trace gases in the earth atmosphere. Stringent requirements on both the imaging properties and the quality of the spectra

A. H. van Amerongen; H. Visser; R. J. P. Vink; T. Coppens; R. W. M. Hoogeveen

2010-01-01

118

Design of compact integral field spectrometers for mid- to high-resolving powers using immersed gratings  

Microsoft Academic Search

We present designs for compact near-IR spectrometers with mid to high resolving powers. They use an innovative combination of integral-field units and immersed gratings, both with and without cross-dispersion. The advent of ELTs with scientific requirements for multi-channel instruments (e.g. EAGLE) with high resolving powers has led to designs for spectrometers which are made more compact by using immersed gratings

Martyn Wells; Christopher J. Evans; Peter R. Hastings

2008-01-01

119

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

120

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

121

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

122

The joint astrophysical plasmadynamic experiment (J-PEX) high-resolution EUV spectrometer: diffraction grating efficiency  

NASA Astrophysics Data System (ADS)

We have fabricated five new holographic ion-etched polymer-coated gratings for a reflight on a sounding rocket of the J-PEX high-resolution EUV spectrometer. The gratings are parabolic (nominal 2000-mm focal length), large (160 mm x 90 mm), and have a blazed groove profile of high density (3600 grooves/mm at the vertex). They have been coated with a high-reflectance multilayer of Mo/Si/C. Using an atomic force microscope, we examined grating topography before multilayer coating. The surface roughness is 2 angstrom rms and the blaze angle is near the target value of 2.4°. Using synchrotron radiation, we completed an efficiency calibration map of each multilayer-coated grating over the wavelength range 220-245 angstrom. At an angle of incidence of 5°, the average efficiency in the first inside order peaks near 234 angstrom. The average peak efficiency is 12.3 +/- 1.0% for Grating 1, 12.6 +/- 2.4% for Grating 2, 12.6 +/- 1.8% for Grating 3, 14.1 +/- 3.0% for Grating 4, and 13.0 +/- 1.0% for Grating 5. The derived groove efficiency averaged over all gratings is approximately 50%, which meets our goals. Refined models of the multilayer gratings are required to resolve remaining issues.

Kowalski, M. P.; Berendse, F. B.; Barbee, T. W., Jr.; Hunter, W. R.; Heidemann, K. F.; Lenke, R.; Seifert, A.; Cruddace, R. G.

2006-06-01

123

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

124

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

NASA Astrophysics Data System (ADS)

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; Song, Eun-Ji; Park, Young-Dong; Oh, Soo-Ghee; Ko, Won-Ha

2011-06-01

125

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

PubMed

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 Å (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. PMID:21721694

Lee, Hyungho; Song, Eun-ji; Park, Young-dong; Oh, Soo-ghee; Ko, Won-Ha

2011-06-01

126

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

127

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

128

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

129

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

130

Development of immersed diffraction grating for the TROPOMI-SWIR spectrometer  

NASA Astrophysics Data System (ADS)

We have developed a novel diffraction grating based on lithographical techniques and anisotropic etching in silicon. The grating is designed for the short-wave-infrared channel of the TROPOMI imaging spectrometer that will be launched on ESA's Sentinel 5 Precursor mission to monitor trace gases in the earth atmosphere. Stringent requirements on both the imaging properties and the quality of the spectra translate to a high-tech grating. In our design the dispersion and resolution is increased with a factor 3.4 with respect to conventional gratings by using the grating in immersion, such that diffraction takes place inside the silicon grating material. By lithographic patterning and anisotropic etching of the mono-crystalline silicon we precisely control line spacing and blaze angle. The grating has a line spacing of 2.5 ?m and is operated in sixth order. We show that an efficiency of 60% is reached on a 50 x 60 mm2 grating surface. We compare our test results with numerical calculations for grating efficiency for both polarizations and find good agreement.

van Amerongen, A. H.; Visser, H.; Vink, R. J. P.; Coppens, T.; Hoogeveen, R. W. M.

2010-10-01

131

Development, fabrication, and metrology of the electro-optical breadboard model for the reflection grating array of the XMM grating spectrometer  

SciTech Connect

A prototype array consisting of eight diffraction gratings has been fabricated for the XMM Reflection Grating Spectrometer. A component of the full spectrometer is an array of approximately 200 diffraction gratings. The diffraction gratings were produced using lightweight silicon carbide substrates and a replication technique. The prototype array was developed and assembled using the same tolerances as the flight arrays which have typical tolerances of 3 {mu}m in translation and sub-arc seconds in rotation. The metrology applied during inspection and assembly included precision linear measurements, full aperture figure measurements, and angular interferometry.

Decker, T.A.; Montesanti, R.C.; Bixler, J.V.; Hailey, C.J. [Lawrence Livermore National Lab., CA (United States); Kahn, S.M. [Lawrence Livermore National Lab., CA (United States)]|[California Univ., Berkeley, CA (United States). Dept. of Physics

1994-07-01

132

Imaging extreme ultraviolet spectrometer employing a single toroidal diffraction grating: the initial evaluation.  

PubMed

A high-efficiency extreme ultraviolet (EUV) imaging spectrometer has been 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 submaster grating which is 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 2-D pulse-counting detector system have verified the image quality of the toroidal grating at wavelengths near 600 A. The results of these initial tests are described in detail, and the basic designs of two instruments which could employ the imaging spectrometer for astrophysical investigations in space are briefly described, namely, a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona and an EUV spectroscopic telescope for studies of nonsolar objects. PMID:20539406

Huber, M C; Timothy, J G; Morgan, J S; Lemaitre, G; Tondello, G; Jannitti, E; Scarin, P

1988-08-15

133

A compact optical spectrometer based on a single-grating Fresnel diffractive optical element  

NASA Astrophysics Data System (ADS)

Recently, we have demonstrated a hybrid diffractive optical element that combines the dispersion function of a grating and the focusing function of a Fresnel lens (G-Fresnel) into a single device. The G-Fresnel promises a low f-number enabling miniaturization of a spectrometer system while maintaining high spectral resolution. A proof-of-concept G-Fresnel based spectrometer is demonstrated, yielding sub-nanometer resolution. Due to its compactness and low-cost fabrication technique, the G-Fresnel based spectrometer has the potential for use in mobile platforms such as lab-on-a-chip microfluidic devices and other mobile spectrometer applications.

Yang, Chuan; Edwards, Perry S.; Shi, Kebin; Liu, Zhiwen

2012-05-01

134

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

135

Single-shot analysis of hard x-ray laser radiation using a noninvasive grating spectrometer.  

PubMed

We present a spectrometer setup based on grating dispersion for hard x-ray free-electron lasers. This setup consists of a focusing spectrometer grating and a charge-integrating microstrip detector. Measurement results acquired at Linac Coherent Light Source are presented, demonstrating noninvasive monitoring of single-shot spectra with a resolution of 2.0×10(-4) ±0.3×10(-4) at photon energy of 6 keV with more than 95% transmission of the main beam. PMID:23258009

Karvinen, Petri; Rutishauser, Simon; Mozzanica, Aldo; Greiffenberg, Dominic; Jurani?, Pavle N; Menzel, Andreas; Lutman, Alberto; Krzywinski, Jacek; Fritz, David M; Lemke, Henrik T; Cammarata, Marco; David, Christian

2012-12-15

136

Design of compact integral field spectrometers for mid- to high-resolving powers using immersed gratings  

NASA Astrophysics Data System (ADS)

We present designs for compact near-IR spectrometers with mid to high resolving powers. They use an innovative combination of integral-field units and immersed gratings, both with and without cross-dispersion. The advent of ELTs with scientific requirements for multi-channel instruments (e.g. EAGLE) with high resolving powers has led to designs for spectrometers which are made more compact by using immersed gratings and are capable of high spectral resolving power by including cross dispersion and an arrangement of the IFU output that provides the requisite short slit.

Wells, Martyn; Evans, Christopher J.; Hastings, Peter R.

2008-08-01

137

Combining rigorous diffraction calculation and GPU accelerated nonsequential raytracing for high precision simulation of a linear grating spectrometer  

Microsoft Academic Search

Simulation of grating spectrometers constitutes the problem of propagating a spectrally broad light field through a macroscopic optical system that contains a nanostructured grating surface. The interest of the simulation is to quantify and optimize the stray light behaviour, which is the limiting factor in modern high end spectrometers. In order to accomplish this we present a simulation scheme that

Florian Mauch; David Fleischle; Wolfram Lyda; Wolfgang Osten; Torsten Krug; Reto Häring

2011-01-01

138

[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

139

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

Microsoft Academic Search

We present a spectrometer design based on a novel nanofabricated blazed X-ray transmission grating which is modeled to have superior efficiency. Here we outline a full instrument design proposed for Constellation-X which is expected to give resolving powers ~2000 (HEW). The spectrometer advantages include lower mass budget and smaller diffractor area, as well as order-of-magnitude more relaxed alignment tolerances for

Kathryn Flanagan; Minseung Ahn; John Davis; Ralf Heilmann; David Huenemoerder; Alan Levine; Herman Marshall; Gregory Prigozhin; Andrew Rasmussen; George Ricker; Mark Schattenburg; Norbert Schulz; Yong Zhao

2007-01-01

140

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

141

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

142

Numerical design method for aberration-reduced concave grating spectrometers.  

PubMed

A general method is described for the design of single concave grating optical systems. Proper parameter and variable sets are defined, and a straightforward technique leads to a final set of optimized variable values which minimize a merit function based on spectroscopic performance. PMID:20490017

McKinney, W R; Palmer, C

1987-08-01

143

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

144

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 Å 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

145

First results from the online variable line spacing grating spectrometer at FLASH  

NASA Astrophysics Data System (ADS)

A high resolution online grating spectrometer has been set up at the free electron laser in Hamburg FLASH at DESY in Hamburg. This new photon diagnostic device allows to parasitically measure the spectral distribution of the FEL laser pulses on a single shot basis and therefore gives complementary spectral and temporal pulse information for user experiments and FEL operation. The spectrometer combines a plane mirror and two plane variable line spacing (VLS) gratings and is installed at the non-monochromized beamline branch at FLASH. In contrast to a standard grating the blaze angle is optimized for the zero-order radiation transferred to the experimental stations, leaving approximately 1-10% intensity for recording the wavelength in the spectrometer. The detector, an intensified CCD camera imaging the dispersed beam on a Ce:YAG crystal, can follow the focal plane of the gratings covering a wavelength ranging from 6 to 60 nm. The resolving power of the spectrometer is expected to range from 500 to 8000 depending on the FEL wavelength.

Brenner, G.; Kapitzki, S.; Kuhlmann, M.; Ploenjes, E.; Noll, T.; Siewert, F.; Treusch, R.; Tiedtke, K.; Reininger, R.; Roper, M. D.; Bowler, M. A.; Quinn, F. M.; Feldhaus, J.

2011-04-01

146

Design of highly reflective subwavelength diffraction gratings for use in a tunable spectrometer  

Microsoft Academic Search

The design of highly reflective subwavelength gratings (SWGs) for use in a micro-electromechanical system (MEMS) tunable spectrometer is presented. The SWGs are designed to be polarization independent at an incident wavelength of 1.5 ¿m with high reflectivity over a 200 nm bandwidth. Two designs are considered; Model 1: a silicon layer with periodic air holes and Model 2: a stacked

Maxwell Kerber; Brian Dick; Mark Fralick; Hugo Jazo; Richard Waters

2009-01-01

147

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

148

Miniaturized spectrometer employing planar waveguides and grating couplers for chemical analysis  

SciTech Connect

Polymeric and metal oxide planar waveguides were used to demonstrate the potential of a miniature spectrometer. Multiwavelength light was transmitted through the substrate and coupled into the waveguide through a diffraction grating located at the substrate/waveguide interface. A second diffraction grating spatially dispersed the light propagated through the waveguide into component wavelengths for rapid analysis with a photodiode array detector. These results suggest that planar waveguides can be used to perform attenuated total internal reflection measurements in the visible and near-IR regions for chemical analysis of weak vibrational overtones and combination modes with effective path lengths of several millimeters. Keywords: Planar waveguide, internal reflectance, spectrometer, grating, thin film, polystyrene, tantalum pentoxide, photodiode array.

Goldman, D.S.; White, P.L.; Anheier, N. (Battelle Pacific Northwest Laboratories, P.O. Box 999, Richland, Washington 99352 (US))

1990-11-01

149

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 mm×4 mm×3.7 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

150

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

NASA Astrophysics Data System (ADS)

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.

Marshall, Herman L.; Dewey, Daniel; Ishibashi, Kazunori

2004-02-01

151

High-Energy Transmission Grating Spectrometer for the Advanced X-ray Astrophysics Facility (AXAF)  

NASA Astrophysics Data System (ADS)

The High Energy Transmission Grating Spectrometer (HETGS) is one of the scientific instruments being developed for NASA's Advanced X-ray Astrophysics Facility (AXAF), scheduled for launch in 1998. The HETGS will be capable of measuring spectra with high resolution and sensitivity from a variety of compact and slightly extended cosmic X-ray sources. In this paper we describe the overall design of the HETGS and its expected scientific performance. The HETGS consists of two arrays of gold grating elements (High-Energy gratings [HEGs] and Medium-Energy Gratings [MEGs] which are optimized for the energy ranges 0.8-10 keV [HEG] and 0.4-5 keV [MEG]). The details of the grating elements and their fabrication methods are described in Schattenburg et al. (this conference). The gratings are mounted on a support plate which can be inserted immediately behind the AXAF telescope assembly. X-rays diffracted by the gratings are dispersed onto the focal plane detector strips which are components of either of the two AXAF imagers (the HRC or ACIS). The two kinds of gratings are oriented at a slight angle with respect to each other so that the dispersed spectra form a shallow 'X' on the readout device. The gratings and detectors are mounted on a Rowland torus to correct for most of the optical aberrations. The grating-detector combination achieves resolving powers (E/(Delta) E) as high as 1000 at some energies, and has significant effective area (10-200 square cm) for all energies 400 eV < E < 10 keV.

Markert, Thomas H.; Canizares, Claude R.; Dewey, Daniel; McGuirk, Michael; Pak, Chris S.; Schattenburg, Mark L.

1994-09-01

152

Design and fabrication of an active polynomial grating for soft-X-ray monochromators and spectrometers  

NASA Astrophysics Data System (ADS)

An active polynomial grating has been designed for use in synchrotron radiation soft-X-ray monochromators and spectrometers. The grating can be dynamically adjusted to obtain the third-order-polynomial surface needed to eliminate the defocus and coma aberrations at any photon energy. Ray-tracing results confirm that a monochromator or spectrometer based on this active grating has nearly no aberration limit to the overall spectral resolution in the entire soft-X-ray region. The grating substrate is made of a precisely milled 17-4 PH stainless steel parallel plate, which is joined to a flexure-hinge bender shaped by wire electrical discharge machining. The substrate is grounded into a concave cylindrical shape with a nominal radius and then polished to achieve a roughness of 0.45 nm and a slope error of 1.2 ?rad rms. The long trace profiler measurements show that the active grating can reach the desired third-order polynomial with a high degree of figure accuracy.

Chen, S.-J.; Chen, C. T.; Perng, S. Y.; Kuan, C. K.; Tseng, T. C.; Wang, D. J.

2001-07-01

153

Concave reflective SU-8 photoresist gratings for flat-field integrated spectrometers.  

PubMed

On-chip spectrometry will play a leading role in the development of micro-optofluidic systems for analytical chemistry. Integrated spectrometers fabricated using a polymer-on-silicon platform have been designed, fabricated, and characterized. Reflective grating designs have been implemented using a recursive algorithm to calculate the facet positions as described by McGreer [Appl. Opt. 35, 5904 (1996)]. It is shown that the free spectral range, the output focal plane geometry, and the linear dispersion can be selected with a high degree of control independently of the chosen grating order. The polymer-on-silicon platform facilitates integration with microfluidic circuits and cost-efficient batch fabrication. PMID:16926875

Zauner, Dan A; Jorgensen, Anders M; Anhoj, Thomas A; Hübner, Jörg

2006-08-10

154

Developments in Off-Plane X-ray Reflection Grating Spectrometers  

NASA Astrophysics Data System (ADS)

X-ray reflection gratings have significant flight heritage from suborbital rockets to XMM-Newton. The off-plane mount is a configuration capable of obtaining the high throughput, high spectral resolving power requirements necessary for achieving key science goals in future NASA Explorer missions and Observatories. We detail the current state of off-plane gratings and highlight recent results in performance testing. We discuss the major difficulties involved with spectrometer development and plans on dealing with these issues. Finally, we present our future plans and a roadmap for technology development.

McEntaffer, Randall L.; Off-Plane X-ray Grating Spectrometer (OP-XGS) Team

2013-04-01

155

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

156

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

157

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

158

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

159

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, Jörn; Willingale, Richard

2014-06-01

160

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

161

A Near-Infrared Spectrometer Based on Novel Grating Light Modulators  

PubMed Central

A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification.

Wei, Wei; Huang, Shanglian; Wang, Ning; Jin, Zhu; Zhang, Jie; Chen, Weimin

2009-01-01

162

Design and characterization of a hybrid-integrated MEMS scanning grating spectrometer  

NASA Astrophysics Data System (ADS)

Grating spectrometer, like the well-established Czerny-Turner, are based on an optical design consisting of several components. Typically at least two slits, two mirrors, the grating stage and a detector are required. There has been much work to reduce this effort, setups using only one mirror (Ebert - Fastie) or the replacement of the entrance slit through the use of thin optical fibers as well as integrated electronic detector arrays instead of a moving grating and an exit slit and single detector device have been applied. Reduced effort comes along with performance limitations: Either the optical resolution or throughput is affected or the use of the system is limited to the availability of detectors arrays with reasonable price. Components in micro opto electro mechanical systems (MOEMS-) technology and spectroscopic systems based thereon have been developed to improve this situation. Miniaturized scanning gratings fabricated on bonded silicon on insulator (BSOI-) wafers were used to design grating spectrometer for the near infrared requiring single detectors only. Discrete components offer flexibility but also need for adjustment of two mirrors, grating stage, fiber mount and the detector with its slit and optionally a second slit in the entrance area. Further development leads towards the integration of the slits into the MOEMS chip, thus less effort for adjustment. Flexibility might be reduced as adjustments of the optical design or grating spacing would require a new chip with own set of masks. Nevertheless if extreme miniaturization is desired this approach seems to be promising. Besides this, high volume production might be able for a comparable low price. A new chip was developed offering grating, two slits and a cavity for the detector chip. The optical design was adjusted to a planar arrangement of grating and slits. A detector buried in a chip cavity required a new mounting strategy. Other optical components were optimized and fabricated then the systems was assembled with electronics and software adjusted to the new design including some new features like integrated position sensors. A first test of systems to grant function of all components is presented. Further work will be aimed at improved performance like higher resolution and lower SNR.

Grüger, Heinrich; Knobbe, Jens; Pügner, Tino; Schenk, Harald

2013-03-01

163

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

164

All-fiber time-delay spectrometer based on an array of fiber Bragg gratings  

NASA Astrophysics Data System (ADS)

We have investigated the possibility to use a step-chirped fiber Bragg grating array for a time-delay-spectrometer. This concept allows a simultaneous spectral and temporal characterization of pulsed light in the nanosecond regime which can also be applied for the investigation of single pulses. A spectral resolution in the 100 picometer range has been achieved and used for the characterization of laser pulses in the nanosecond range.

Tiess, T.; Rothhardt, M.; Jäger, M.; Bartelt, H.

2013-09-01

165

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

Microsoft Academic Search

The dependence of Ångstrom's turbidity parameters on the wavelength has been analyzed in the wavelength interval 0.45–0.70 ?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

166

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

Microsoft Academic Search

A far-infrared computer-controlled Fabry-Pérot 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

167

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

168

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

169

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 0.1–1.2 keV spectral region. The deconvolution and calibration techniques

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

1996-01-01

170

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

Microsoft Academic Search

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

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

2012-01-01

171

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

172

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

NASA Astrophysics Data System (ADS)

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 cryostat that is of order 1 meter in size. For background-limited astronomical observations in the 1mm terrestrial window, Z-Spec uses 160 silicon nitride micro-mesh bolometers and the detectors and waveguide grating are cooled to ~0.1 K. Our first cryogenic measurements at 225 GHz show resolving power greater than 200, and the end-to-end throughput is estimated to be greater than 30%, possibly as high as 40%. Z-Spec represents the first systematic approach to cosmological redshift measurement that is not based on optical or near-IR identifications. With its good sensitivity and large bandwidth, Z-Spec provides a new capability for millimeter-wave astrophysics. The instrument will be capable of measureing rotational carbon monoxide line emission from bright dusty galaxies at redshifts of up to 4, and the broad bandwidth insures that at least two lines will be simultaneously detected, providing an unambiguous redshift determination. In addition to Z-Spec's observations over the next 1-3 years, the WaFIRS spectrometer architecture makes an excellent candidate for mid-IR to millimeter-wave spectrometers on future space-borned and suborbital platforms such as SPICA and SAFIR. The concept is dramatically more compact and lightweight than conventional free-space grating spectrometers, and no mirrors or lenses are used in the instrument. After the progress report on Z-Spec we highlight this capability.

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

2004-10-01

173

Design of a high-resolution extreme-ultraviolet imaging spectrometer with aberration-corrected concave gratings.  

PubMed

A high-resolution extreme-ultraviolet imaging spectrometer is designed for the Japanese solar mission Solar-B. A spherical varied-line-space (SVLS) grating and a toroidal uniform-line-space (TULS) grating are chosen as candidates for use in the spectrometer to yield high spectral and spatial resolution within the spectral range 25-29 nm. The spectral image-focusing properties and the mechanical tolerances for fabrication and alignment are compared for the two types of grating. The SVLS design is found to be superior to the TULS design for off-plane spectral images and in ease of fabrication and optical alignment. PMID:18301496

Harada, T; Sakuma, H; Takahashi, K; Watanabe, T; Hara, H; Kita, T

1998-10-01

174

Combining rigorous diffraction calculation and GPU accelerated nonsequential raytracing for high precision simulation of a linear grating spectrometer  

NASA Astrophysics Data System (ADS)

Simulation of grating spectrometers constitutes the problem of propagating a spectrally broad light field through a macroscopic optical system that contains a nanostructured grating surface. The interest of the simulation is to quantify and optimize the stray light behaviour, which is the limiting factor in modern high end spectrometers. In order to accomplish this we present a simulation scheme that combines a RCWA (rigorous coupled wave analysis) simulation of the grating surface with a selfmade GPU (graphics processor unit) accelerated nonsequential raytracer. Using this, we are able to represent the broad spectrum of the light field as a superposition of many monochromatic raysets and handle the huge raynumber in reasonable time.

Mauch, Florian; Fleischle, David; Lyda, Wolfram; Osten, Wolfgang; Krug, Torsten; Häring, Reto

2011-05-01

175

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

176

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 NASA’s 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 21Å 0.5 keV), with an overall bandpass from 8-52Å (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

177

Development of a Novel Breast Cancer Detector based on Improved Holography Concave Grating Imaging Spectrometer  

NASA Astrophysics Data System (ADS)

Breast cancer can be detected by B-mode ultrasonic imaging, X-mammography, CT imaging, and MRI. But some drawbacks existed in these methods, their applications was limited in some certain. So, a novel high resolution breast cancer detector (BCD) is developed in this paper. Meanwhile, an improved holography concave grating imaging spectrometer (HCGIS) is designed. In this HCGIS, the holography concave grating is used as the diffraction grating. Additionally, CCD with combined image acquisition (IAQ) card and the 3D scan platform are used as the spectral image acquisition component. This BCD consists of the light source unit, light-path unit, check cavity, splitting-light unit, spectrum acquisition and imaging unit, signal processing unit, computer and data analysis software unit, etc. Experimental results show that the spectral range of the novel BCD can reach 300-1000 nm, its wavelength resolution can reach 1nm, and this system uses the back-split-light technology and the splitting-light structure of holography concave grating. Compared with the other instruments of breast cancer detection, this BCD has many advantages, such as, compacter volume, simpler algorithm, faster processing speed, higher accuracy, cheaper cost and higher resolution, etc. Therefore, this BCD will have the potential values in the detection of breast disease.

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

2011-01-01

178

Performance and results of the reflection grating spectrometers onboard XMM-Newton  

NASA Astrophysics Data System (ADS)

XMM-Newton was launched in December 1999 and science operations started in March 2000. Following two years of very successful operations, a report on the instrument performance and a selection of exciting new results are presented. Behind two of the three telescopes of XMM-Newton Reflection Grating Spectrometers (RGS) are placed. Each spectrometer consists of an array of reflection gratings and a set of back illuminated CCDs. They cover the wavelength band between 6 and 38 Angstromwith a resolution varying between 100 and 600 (E/DE) and a maximum effective area of 140 cm2 for the two spectrometers combined. The selected wavelength band covers the K-shell transitions of C, N, O, Ne, Mg and Si as well as the L- and M-shell transitions of Fe. After a short introduction to the instrument design, the in-orbit performance is given. This includes the line spread function, the wavelength scale and the effective area including their stability during the more than 2 years of operations. Following this a number of key scientific results are briefly addressed, illustrating the power of the RGS instrument in combination with the other instruments on-board of XMM-Newton as well as the wealth of information which is obtained as the RGS instruments operate continuously.

den Herder, Jan-Willem W.; Brinkman, A. C.; Kahn, Steven M.; Branduardi-Raymont, Graziella; Audard, M.; Behar, E.; Blustin, A.; den Boggende, Antonius J. F.; Cottam, Jean; Erd, Christian; Gabriel, Carlos; Guedel, Manuel; van der Heyden, K.; Kaastra, Jelle S.; Kinkhabwala, A.; Leutenegger, Maurice A.; Mewe, Rolf; Paerels, Frits B. S.; Raassen, A. J. J.; Peterson, J. R.; Pollock, A.; Rasmussen, Andrew P.; Sako, M.; Santos-Lleo, M.; Steenbrugge, K.; Tamura, T.; de Vries, Cor P.

2003-03-01

179

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

180

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

181

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

182

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

183

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

184

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

185

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

186

Aberration-corrected concave grating for the mid-infrared spectrometer aboard the Infrared Telescope in Space.  

PubMed

A mechanically ruled aberration-corrected concave grating was developed for use in the low-resolution mid-infrared spectrometer aboard the cryogenically cooled Infrared Telescope in Space. The design and the performance testing of the grating are reported. The spectrometer requires a wide spectral range (4.5-11.7 µm) and a wide field of view (8 × 8 arcmin) with a low wavelength resolution (?? ? 0.3 µm). The aberration-corrected concave grating provides a flat focal plane with a small aberration in the spatial direction compared with those caused by the finite size of the entrance slit. It also permits a simple design for the spectrometer, which is advantageous for applications in space cryogenic instruments. The measurements of the wavelength resolution and the spatial resolution are shown to be in good agreement with the predicted performance. The diffraction efficiency of the grating is more than 80% at the blaze wavelength (6 µm) and fairly high (>30%) over the entire wavelength range in question. The grating produces polarization of less than 10% for ? < 6.4 µm and of 10-20% for 6.7 µm grating to the wide-field IR spectroscopic observations. PMID:20963166

Onaka, T

1995-02-01

187

Aberration-corrected concave grating for the mid-infrared spectrometer aboard the Infrared Telescope in Space  

NASA Astrophysics Data System (ADS)

A mechanically ruled aberration-corrected concave grating was developed for use in the low-resolution mid-infrared spectrometer aboard the cryogenically cooled Infrared Telescope in Space. The design and the performance testing of the grating are reported. The spectrometer requires a wide spectral range (4.5-11.7 mu m) and a wide field of view (8 \\times 8 arcmin) with a low wavelength resolution ( Delta lambda less than or equals 0.3 mu m). The aberration-corrected concave grating provides a flat focal plane with a small aberration in the spatial direction compared with those caused by the finite size of the entrance slit. It also permits a simple design for the spectrometer, which is advantageous for applications in space cryogenic instruments. The measurements of the wavelength resolution and the spatial resolution are shown to be in good agreement with the predicted performance. The diffraction efficiency of the grating is more than 80% at the blaze wavelength (6 mu m) and fairly high ( greater than 30%) over the entire wavelength range in question. The grating produces polarization of less than 10% for lambda less than 6.4 mu m and of 10-20% for 6.7 mu m less than lambda less than 9.7 mu m. These results indicate the potential applicability of this type of grating to the wide-field IR spectroscopic observations.

Onaka, Takashi

1995-02-01

188

Soft X-Ray Critical-Angle Transmission Grating Spectrometer for the International X-Ray Observatory  

NASA Astrophysics Data System (ADS)

We have developed a new type of soft x-ray diffraction grating. This critical-angle transmission (CAT) grating [1-4] combines the advantages of traditional transmission gratings (very low mass, extremely relaxed alignment and flatness tolerances) with those of x-ray reflection gratings (high efficiency due to blazing in the direction of grazing-incidence reflection). In addition, grating spectrometers based on CAT gratings are well-suited for co-existence with high-energy focal plane microcalorimeter detectors as planned for the International X-Ray Observatory, since most high-energy x rays are undeflected and arrive at the telescope focus. We have previously micro-fabricated 574 and 200 nm-period prototypes of the smooth, high-aspect ratio, and sub-micron period structures necessary for efficient CAT gratings through interference lithography, anisotropic etching of silicon crystals, and critical-point drying. X-ray test have demonstrated high-efficiency blazing in accordance with theoretical predictions. We will describe the CAT grating principle and design, fabrication, and x-ray efficiency measurements, and discuss various high-resolution (E/?E 5000), high-effective area (up to 10,000 cm2) implementations for a CAT grating spectrometer. This work was supported in part by NASA grants NNX07AG98G and NNX08AI62G. [1] R. K. Heilmann, M. Ahn, E. M. Gullikson, and M. L. Schattenburg Blazed High-Efficiency X-Ray Diffraction via Transmission through Arrays of Nanometer-Scale Mirrors Opt. Express 16, 8658 (2008). [2] R. K. Heilmann, M. Ahn, and M. L. Schattenburg Fabrication and Performance of Blazed Transmission Gratings for X-Ray Astronomy Proc. SPIE 7011, 701106 (2008). [3] K. Flanagan, et al. Spectrometer Concept and Design for X-Ray Astronomy Using a Blazed Transmission Grating Proc. SPIE 6688, 66880Y (2007). [4] M. Ahn, R. K. Heilmann, and M. L. Schattenburg Fabrication of Ultrahigh Aspect Ratio Freestanding Gratings on Silicon-on-Insulator Wafers J. Vac. Sci. Technol. B 25, 2593 (2007).

Heilmann, Ralf K.; Ahn, M.; Flanagan, K. A.; Huenemoerder, D. P.; Schattenburg, M. L.

2009-01-01

189

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

SciTech Connect

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)

Yoshida, Hiroyuki [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)] [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

2013-10-15

190

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

191

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

NASA Astrophysics Data System (ADS)

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).

Yoshida, Hiroyuki

2013-10-01

192

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

193

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 Astrophysics Data System (ADS)

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.

2001-04-01

194

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

195

Extremely High Dispersion Silicon Immersion Grating for Hunting Life-bearing, Earth-like Planets around M Dwarfs in the Near-IR  

Microsoft Academic Search

Hunting Earth-like, life-bearing planets around M dwarfs requires a high resolution spectrometer with an R = 30,000 at large ground-based telescopes. This is an enormous challenge for traditional designs using commercial echelle gratings since the cryogenic instrument becomes too large. A newly developed silicon immersion grating at the University of Florida (UF) offers an emerging opportunity for building a high

D. McDavitt; J. Ge; B. Zhao; S. Miller

2005-01-01

196

[A technology of real-time image compression for convex grating imaging spectrometer].  

PubMed

The huge amount of convex grating imaging spectrometer image data brings much pressure to data transmission and storage, so the image must be compressed in real time. Firstly, the image characteristics were analyzed according to the imaging principle, and the compression approach to removing spatial correlation and spectral correlation was achieved; Secondly, the compression algorithms were analyzed and the 3-D compression scheme of one-order linear compression in spectral dimension and JPEG2000 compression in spatial dimension was proposed. Finally, a real-time compression system based on FPGA and ADV212 was designed, in which FPGA was used for logic control and implementation of prediction algorithm, and ADV212 was used for JPEG2000 compression. The analysis result shows that the system has the ability of lossless and lossy compression, enabling real-time image compression. PMID:22715801

Liu, Yang-chuan; Bayanheshig; Cui, Ji-cheng; Tang, Yu-guo

2012-04-01

197

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

198

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

199

Transmission-grating, multi-channel PCD soft-x-ray spectrometer*  

NASA Astrophysics Data System (ADS)

To measure the radiation temperature of hohlraums in ICF experiments, we are developing a transmission grating spectrometer with a diamond photo-conductive device (PCD) for 100-ps temporal resolution (John Porter, Sandia, 1994). Interdigitated electrodes on the PCD provide for fast time response and discrete energy channels. An x-ray CCD camera is used for wavelength and sensitivity calibration. First experiments on a single-channel device show the PCD sensitivity to keV radiation to exceed 10 mA/W. This was with a non-optimal electrode configuration. We plan also to use diamond created by chemical vapor deposition. The sensitivity thus can be expected to increase. A multi-channel instrument is being tested. Special design considerations and the latest results will be exhibited. *Work performed under the auspices of the U.S. Department of Energy.

Cobble, James A.; Han, Sung

1996-11-01

200

Alignment based on a no adjustment philosophy for the Immersion Grating Infrared Spectrometer (IGRINS)  

NASA Astrophysics Data System (ADS)

IGRINS, the Immersion GRating INfrared Spectrometer includes an immersion grating made of silicon and observes both H-band (1.49~1.80 ?m) and K-band (1.96~2.46 ?m), simultaneously. In order to align such an infrared optical system, the compensator in its optical components has been adjusted within tolerances at room temperature without vacuum environment. However, such a system will ultimately operate at low temperature and vacuum with no adjustment mechanism. Therefore a reasonable relationship between different environmental variations such as room and low temperature might provide useful knowledge to align the system properly. We are attempting to develop a new process to predict the Wave Front Error (WFE), and to produce correct mechanical control values when the optical system is perturbed by moving the lens at room temperature. The purpose is to provide adequate optical performance without making changes at operating temperature. In other words, WFE was measured at operating temperature without any modification but a compensator was altered correctly at room temperature to meet target performance. The `no adjustment' philosophy was achieved by deterministic mechanical adjustment at room temperature from a simulation that we developed. In this study, an achromatic doublet lens was used to substitute for the H and K band camera of IGRINS. This novel process exhibits accuracy predictability of about 0.002 ? rms WFE and can be applied to a cooled infrared optical systems.

Han, Jeong-Yeol; Yuk, In-Soo; Ko, Kyeongyeon; Oh, Heeyoung; Nah, Jakyoung; Oh, Jae Sok; Park, Chan; Lee, Sungho; Kim, Kang-Min; Chun, Moo-Young; Jaffe, Daniel T.; Pak, Soojong; Gully-Santiago, Michael

2012-12-01

201

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

202

A computer program for the collection, reduction and analysis of echelle spectra  

NASA Astrophysics Data System (ADS)

This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta Part B (SAB). The hardcopy text, comprising the main article and an appendix, is accompanied by a disk containing the compiled program, a manual, the source code and tutorial in ASCII format, and data files. The work presented is a result of the need to facilitate collection, calibration, and extraction of data from an echelle spectrometer employing charge coupled array detection (CCD). A computer program, written using Microsoft's BASIC Professional Development System version 7.1 under MS DOS, is explained and demonstrated. Wavelength calibration requires critical spectrometer dimensions, grating counter settings, and the identification of a single spectral line. Calibration accuracies are better than ± 1 pixel across a 576 × 384 pixel array. Extraction of intensity-normalized spectra for all detected orders requires less than 3 min on a 33 MHz 80386 personal computer with an 80387 math coprocessor.

Miller, Duane L.; Scheeline, Alexander

1993-07-01

203

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

204

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

205

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

206

Design for an aberration-corrected concave grating for a mid-infrared long-slit spectrometer.  

PubMed

A new design for an aberration-corrected concave grating for the spectral region near 10 microm is presented. It was designed for use in the ground-based astronomical medium-resolution (lambda/Dlambda approximately 100) Mid-Infrared Camera and Spectrometer (MICS). It provides a flat focal plane for a wide spectral range (7.5-13.5 microm) with small aberrations, permitting efficient long-slit observations in the mid-infrared region. It permits a simple design of the spectrometer without collimator and camera mirrors, which is quite advantageous for cryogenic instruments. The grating has variable spacing grooves to reduce aberrations. In addition, the grating surface figure is designed to be toroidal and in the direction perpendicular to the grooves, aspherical, to suppress the aberrations further over a wide spectral range. The angle of the grooves is also varied to yield better efficiency near the blaze angle. The grating was fabricated by high-quality ultraprecision machining, which made these features possible. Test observations confirmed that the designed spectral resolution was achieved. PMID:18345038

Onaka, T; Miyata, T; Kataza, H; Okamoto, Y

2000-04-01

207

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

208

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

209

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

210

X-ray spectroscopy with the Reflection Grating Spectrometer on-board of XMM.  

NASA Astrophysics Data System (ADS)

The X-ray Multi-Mirror (XMM) mission is the second of the four cornerstone projects of the ESA long-term programme for space science, Horizon 2000. The payload comprises three co-aligned high-throughput, imaging telescopes with a FOV of 30' and spatial resolution <20? Imaging CCD-detectors (EPIC) are placed in the focus of each telescope (with total effective area ?4000 cm2 at 1.5 keV). Behind two of the three telescopes, about half of the X-ray light is utilized by the Reflection Grating Spectrometer (RGS) (with maximum total effective area in first order of ?200 cm2 at 12 Å for both modules). The instruments are co-aligned and measure simultaneously with an optical monitor (1800-10000 Å, limiting magnitude 24m5, spatial resolution 1? FOV 8'). It is envisaged that the observatory is launched near the end of the 20th century in a deep eccentric orbit allowing for sensitive, long uninterrupted observations of a large variety of astrophysical sources. XMM offers the possibility to perform broadband (0.1-10 keV) imaging spectroscopy with a resolving power E/?E ? 5-60 with the EPIC, combined with high resolution (?? 0.04 Å, or E/? 150-800 in 1st order) spectroscopy between 5-35 Å with the RGS. Compared to the ASCA-SIS, the EPIC has the same spectral resolution, but more than 10 times larger effective area and spatial resolution, covering a wider energy range, while the RGS has comparable effective area, but at least 10 times more spectral resolution.

Brinkman, A. C.; Aarts, H. J. M.; den Boggende, A. J. F.; Dubbeldam, L.; den Herder, J. W.; Kaastra, J. S.; de Korte, P. A. J.; Mewe, R.; Hailey, C. J.; Kahn, S. M.; Paerels, F.; Branduardi-Raymont, G.; Bixler, J.; Thomsen, K.; Zehnder, A.

1996-02-01

211

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

212

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

213

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

214

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

215

The CESAR Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

CESAR (Compact Echelle Spectrograph for Aeronomic Research) is an NSF MRI-funded instrument being constructed in the Molecular Physics Laboratory at SRI International. This spectrograph is patterned after instruments in use at the Keck telescopes on Mauna Kea, which generate sky spectra that have proven to be of great aeronomical value. CESAR is designed to be re-locatable, with initial measurements planned for high latitudes, in contrast to the Keck equatorial site. CESAR is to be operated remotely, continuously collecting data in real time. Initial measurements have been carried out with a laboratory N2 discharge, generating an aurora-like spectrum. The N2 1PG system was recorded at a resolution close to the design figure of 20,000, and the spectrum has been accurately simulated. The work was supported by NSF grant ATM-0723232.

Grill, M.; Kendall, E. A.; Slanger, T. G.

2011-12-01

216

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; Tournié, E; Bogaerts, W; Baets, R; Roelkens, G

2013-03-11

217

Post-SM4 Sensitivity Calibration of the STIS Echelle Modes  

NASA Astrophysics Data System (ADS)

On-orbit sensitivity curves for all echelle modes were derived for post - servicing mis- sion 4 data using observations of the DA white dwarf G191-B2B. Additionally, new echelle ripple tables and grating dependent bad pixel tables were created for the FUV and NUV MAMA. We review the procedures used to derive the adopted throughputs and implement them in the pipeline as well as the motivation for the modification of the additional reference files and pipeline procedures.

Bostroem, K. Azalee; Aloisi, A.; Bohlin, R.; Hodge, P.; Proffitt, C.

2012-01-01

218

Colorado High-resolution Echelle Stellar Spectrograph (CHESS)  

NASA Astrophysics Data System (ADS)

We discuss the design of a new high-efficiency, high-resolution far ultraviolet echelle spectrograph. Our project concentrates on utilizing new technologies for gratings and detectors to reduce the impact of scattered light and maximize quantum efficiency over a large bandpass. This program will enable advances in a vast number of astrophysical subjects. Topics ranging from protoplanetary disks to the intergalactic medium can be addressed by incorporating such a spectrograph into a future, long-duration mission.

Beasley, Matthew; Burgh, Eric; France, Kevin

2010-07-01

219

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

PubMed

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 ? 50. It has been used at the LULI-2000 laser facility at E?cole Polytechnique (France) to measure the ?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. PMID:23126955

Reverdin, Charles; Thais, Frédéric; Loisel, Guillaume; Busquet, M; Bastiani-Ceccotti, S; Blenski, T; Caillaud, T; Ducret, J E; Foelsner, W; Gilles, D; Gilleron, F; Pain, J C; Poirier, M; Serres, F; Silvert, V; Soullie, G; Turck-Chieze, S; Villette, B

2012-10-01

220

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

221

Grating spectrometer installation for electron cyclotron emission measurements on the DIII-D tokamak using circular waveguide and synchronous detection  

SciTech Connect

The grating spectrometer installation on the DIII-D tokamak uses fundamental circular waveguide propagating the TE/sub 11/ lowest-order mode followed by oversized circular guide carrying the low-loss TE/sub 01/ mode. The short section of fundamental guide permits use of an electronic chopper operating at 100 kHz for both calibration and plasma operation. By using ac-coupled amplifiers tuned to the chopping frequency, the background signal generated in the indium antimonide detectors by neutrons and x rays is automatically subtracted and the system noise bandwidth is reduced. Compared with a quasi-optical system, the much smaller fundamental horn and front-end waveguide allow the waveguide system to be located outside a gate valve. With this configuration the entire waveguide run, including the actual horn and vacuum window used during plasma operations, can be included in the calibration setup.

Lohr, J.; Jahns, G.; Moeller, C.; Prater, R.

1986-08-01

222

Grating spectrometer installation for electron cyclotron emission measurements on the DIII-D tokamak using circular waveguide and synchronous detection  

SciTech Connect

The grating spectrometer installation on the DIII-D tokamak uses fundamental circular waveguide propagating the TE/sub 11/ lowest order mode followed by oversized circular guide carrying the low loss TE/sub 01/ mode. The short section of fundamental guide permits use of an electronic chopper operating at 100 kHz for both calibration and plasma operation. By using ac-coupled amplifiers tuned to the chopping frequency, the background signal generated in the indium antimonide detectors by neutrons and x-rays is automatically subtracted and the system noise bandwidth is reduced. Compared with a quasi-optical system, the much smaller fundamental horn and front end waveguide allow the waveguide system to be located outside a gate valve. With this configuration the entire waveguide run, including the actual horn and vacuum window used during plasma operations, can be included in the calibration set-up.

Lohr, J.; Jahns, G.; Moeller, C.; Prater, R.

1986-03-01

223

Comparison of different peak detection algorithms with regards to spectrometic fiber Bragg grating interrogation systems  

Microsoft Academic Search

The resolution of many optical measurement systems employing ID or 2D array sensors (e.g. CCD-cameras) is limited by the pixel-resolution of the detector. Subpixel algorithms allow to exceed this limit. This paper aims at fiber Bragg grating interrogators, which acquire the sensor signal spectrometrically. The accuracy of measurement of these systems is strongly depending on the used algorithms. Five different

Thomas Bodendorfer; Mathias S. Muller; Florian Hirth; Alexander W. Koch

2009-01-01

224

Echelles: scalar, electromagnetic, and real-groove properties  

NASA Astrophysics Data System (ADS)

For lack of alternatives, echelle-grating diffraction behavior has in the past been modeled on scalar theory, despite observations that indicate significant deviations. To resolve this difficulty a detailed experimental, theoretical, and numerical study is performed for several echelles that work at low (8-13), medium (35-55), high (84-140), and very-high (to 660) diffraction orders. Noticeable deviations from the scalar model were detected both experimentally and numerically, on the basis of electromagnetic position was shown to decrease with the wavelength-to-period ratio, and it tends to zero more rapidly than the decrease of the maximum width, so that the TE-and TM-plane responses tend to merge into each other; (2) cut-off effects (Rayleigh anomalies) were found to play a significant role for high groove angles, where passing-off orders are close to the blaze order. A possibility for evaluation of the blaze angle from angular, rather than from spectral, measurements is discussed.Several reasons for the differences between real and ideal echelles (material-index deviations, profile deformations, and groove-angle errors) are analyzed, and their effects on the performance of echelles is studied.

Loewen, E.; Maystre, D.; Popov, E.; Tsonev, L.

1995-04-01

225

Multi-Order Satellite IR Grating Spectrometer (Sirs B), Volume I.  

National Technical Information Service (NTIS)

The report describes the development and design effort accomplished during the period of March through October 1967, and is concerned with the Optical and Mechanical unit for the Satellite Infrared Spectrometer (SIRS-B). The report does not include the pr...

J. C. Reed

1967-01-01

226

NIR spectroscopy on moving solids using a scanning grating spectrometer—impact 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

227

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

228

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 events it is also 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

229

The Upgraded Fiber Optic Echelle Spectrograph  

Microsoft Academic Search

The Upgraded Fiber Optic Echelle (UFOE) is a fiber-fed, white pupil echelle spectrograph to be implemented at the Hobby-Eberly Telescope (HET) in the spring of 1997. It will serve as the commissioning spectrograph until HET facility instruments come on line in early 1998. This instrument is a quick, cost effective upgrade of the Fiber Optic Echelle, resident at KPNO for

J. J. B. Harlow; L. W. Ramsey; D. R. Andersen; J. D. Fleig; B. T. Rhoads; L. G. Engel

1996-01-01

230

An Etched Silicon Immersion Echelle for Use in the Near Infrared  

Microsoft Academic Search

We have fabricated an immersion echelle grating using silicon micromachining (chemical etching) techniques (Graf et al. 1993, Applied Optics, Vol. 33, No. 1, p. 96). The grating consists of a pattern of V-shaped grooves (25mu m spacing, 70 degree opening angle, blazed at 55 degrees) etched onto one facet of a mono-crystaline silicon prism. By diffracting an IR beam inside

L. D. Keller; Tom Benedict; D. T. Jaffe

1995-01-01

231

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

232

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

233

A multi-aperture spectrometer design for the Atmospheric Infrared Sounder (AIRS)  

NASA Technical Reports Server (NTRS)

The baseline multiaperture echelle spectrometer for the Atmospheric IR Sounder (AIRS) is described in terms of design and applications. The functional requirements for the optical design are set forth including the 1-K measurement goal, the 3.4-15.4 spectral bandpass, and the full global coverage twice daily. The multiaperture spectrometer is compared to the cross-dispersed spectrometer, and the multiaperture model is found to permit specific adjustments to the signal-to-noise ratio. The optical design of the spectrometer is described in terms of the focal-plane constraints, the multiaperture pupil-imaging relay, the spectrometer collimator, and the grating format and efficiency. The multiaperture design is found to have a good spectral-response function, and a 1.2 percent signal change is noted for a 95-percent unpolarized scene. The AIRS instrument is illustrated in its deployment configuration and is concluded to be capable of fulfilling the performance requirements.

Pagano, Robert; Hatch, Marcus

1990-01-01

234

High Resolution X-Ray Spectroscopy of zeta Puppis with the XMM-Newton Reflection Grating Spectrometer  

NASA Technical Reports Server (NTRS)

We present the first high resolution X-ray spectrum of the bright O4Ief supergiant star 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. 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 agree remarkably well with current theoretical models for this system.

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

2000-01-01

235

ECHOMOP: Echelle data reduction package  

NASA Astrophysics Data System (ADS)

ECHOMOP extracts spectra from 2-D data frames. These data can be single-order spectra or multi-order echelle spectra. A substantial degree of automation is provided, particularly in the traditionally manual functions for cosmic-ray detection and wavelength calibration; manual overrides are available. Features include robust and flexible order tracing, optimal extraction, support for variance arrays, and 2-D distortion fitting and extraction. ECHOMOP is distributed as part of the Starlink software collection (ascl:1110.012).

Mills, Dave; Webb, John; Clayton, Martin; Gray, Norman

2014-05-01

236

Silicon immersion gratings and their spectroscopic applications  

NASA Astrophysics Data System (ADS)

Silicon immersion gratings (SIGs) offer several advantages over the commercial echelle gratings for high resolution infrared (IR) spectroscopy: 3.4 times the gain in dispersion or ~10 times the reduction in the instrument volume, a multiplex gain for a large continuous wavelength coverage and low cost. We present results from lab characterization of a large format SIG of astronomical observation quality. This SIG, with a 54.74 degree blaze angle (R1.4), 16.1 l/mm groove density, and 50x86 mm2 grating area, was developed for high resolution IR spectroscopy (R~70,000) in the near IR (1.1-2.5 ?m). Its entrance surface was coated with a single layer of silicon nitride antireflection (AR) coating and its grating surface was coated with a thin layer of gold to increase its throughput at 1.1-2.5 ?m. The lab measurements have shown that the SIG delivered a spectral resolution of R=114,000 at 1.55 ?m with a lab testing spectrograph with a 20 mm diameter pupil. The measured peak grating efficiency is 72% at 1.55 ?m, which is consistent with the measurements in the optical wavelengths from the grating surface at the air side. This SIG is being implemented in a new generation cryogenic IR spectrograph, called the Florida IR Silicon immersion grating spectrometer (FIRST), to offer broad-band high resolution IR spectroscopy with R=72,000 at 1.4-1.8 um under a typical seeing condition in a single exposure with a 2kx2k H2RG IR array at the robotically controlled Tennessee State University 2-meter Automatic Spectroscopic Telescope (AST) at Fairborn Observatory in Arizona. FIRST is designed to provide high precision Doppler measurements (~4 m/s) for the identification and characterization of extrasolar planets, especially rocky planets in habitable zones, orbiting low mass M dwarf stars. It will also be used for other high resolution IR spectroscopic observations of such as young stars, brown dwarfs, magnetic fields, star formation and interstellar mediums. An optimally designed SIG of the similar size can be used in the Silicon Immersion Grating Spectrometer (SIGS) to fill the need for high resolution spectroscopy at mid IR to far IR (~25-300 ?m) for the NASA SOFIA airborne mission in the future.

Ge, Jian; Zhao, Bo; Powell, Scott; Fletcher, Adam; Wan, Xiaoke; Chang, Liang; Jakeman, Hali; Koukis, Dimitrios; Tanner, David B.; Ebbets, Dennis; Weinberg, Jonathan; Lipscy, Sarah; Nyquist, Rich; Bally, John

2012-09-01

237

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

238

Photoelectrochemical Fabrication of Spectroscopic Diffraction Gratings, Phase 2.  

National Technical Information Service (NTIS)

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 o...

R. D. Rauh M. M. Carrabba J. Li R. F. Cartland J. P. Hachey

1990-01-01

239

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

1998-01-01

240

Multiaperture Spectrometer  

NASA Technical Reports Server (NTRS)

Proposed multiaperture spectrometer containing single grating provides high spectral resolution over broad spectrum. Produces parallel line images, each of which highly spectrally resolved display of intensity vs. wavelength in wavelength band of one of orders of spectrum produced by grating. Advantages; convenient two-dimensional spectral image, fewer components, and greater efficiency.

Schindler, Rudolf A.; Pagano, Robert J.; O'Callaghan, Fred G.

1991-01-01

241

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

242

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

243

Fabrication and testing of a silicon immersion grating for infrared spectroscopy  

SciTech Connect

Recent advances in silicon micromachining techniques (e.g. anisotropic etching) allow the fabrication of very coarse infrared echelle gratings. When used in immersion mode, the dispersion is increased proportionally to the refractive index. This permits a very significant reduction in the overall size of a spectrometer while maintaining the same resolution. We have fabricated a right triangular prism (30{times}60{times}67 mm with a rectangular entrance face 30{times}38 mm) from silicon with a grating etched into the face of the hypotenuse. The grating covers an area of 32 mm by 64 mm and has a 97.5 PM periodicity with a blaze angle of 63.4{sup o}. The groove surfaces are very smooth with a roughness of a few manometers. Random defects in the silicon are the dominant source of grating scatter ({approx} 12% at 3.39 {mu}m). We measure a grating ghost intensity of 1.2%. The diffraction peak is quite narrow, slightly larger than the Airy disc diameter at F/12. However due to wavefront aberrations, perhaps 15--20% of the diffracted power is in the peak with the rest distributed in a diameter roughly five times the Airy disc.

Kuzmenko, P.J.; Ciarlo, D.R.; Stevens, C.G.

1994-07-25

244

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

245

High-resolution spectrometer: solution to the axial resolution and ranging depth trade-off of SD-OCT  

NASA Astrophysics Data System (ADS)

We demonstrate a cross-dispersed spectrometer for Spectral Domain Optical Coherence Tomography (SD-OCT). The resolution of a conventional SD-OCT spectrometer is limited by the available sizes of the linear array detectors. The adverse consequences of this finite resolution is a trade-off between achieving practical field of view (i.e. ranging depth) and maintaining high axial resolution. Inspired by spectrometer designs for astronomy, we take advantage of very high pixel-density 2D CCD arrays to map a single-shot 2D spectrum to an OCT A-scan. The basic system can be implemented using a high-resolution Echelle grating crossed with a prism in a direction orthogonal to the dispersion axis. In this geometry, the interferometric light returning from the OCT system is dispersed in two dimensions; the resulting spectrum can achieve more pixels than a traditional OCT spectrometer (which increases the ranging depth) and maintains impressive axial resolution because of the broad bandwidth of the detected OCT light. To the best of our knowledge, we present the first demonstration of OCT data using an Echelle-based cross-dispersed spectrometer. Potential applications for such a system include high-resolution imaging of the retina or the anterior segment of the eye over extended imaging depths and small animal imaging.

Marvdashti, Tahereh; Lee, Hee Yoon; Ellerbee, Audrey K.

2013-03-01

246

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

247

Materials and Fabrication Issues for Large Machined Germanium Immersion Gratings.  

National Technical Information Service (NTIS)

LLNL has successfully fabricated small (1.5 cm2 area) germanium immersion gratings. We studied the feasibility of producing a large germanium immersion grating by means of single point diamond flycutting. Our baseline design is a 63.4(sup o) blaze echelle...

P. J. Kuzmenko P. J. Davis S. L. Little L. C. Hale

2006-01-01

248

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

249

Fabrication and testing of a silicon immersion grating for infrared spectroscopy.  

National Technical Information Service (NTIS)

Recent advances in silicon micromachining techniques (e.g. anisotropic etching) allow the fabrication of very coarse infrared echelle gratings. When used in immersion mode, the dispersion is increased proportionally to the refractive index. This permits a...

P. J. Kuzmenko D. R. Ciarlo C. G. Stevens

1994-01-01

250

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

251

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

252

Transmission grating streaked spectrometer for the diagnosis of soft x-ray emission from ultrahigh intensity laser heated targets  

SciTech Connect

A free-standing gold transmission grating with a period of 5000 A has been coupled to a soft x-ray sensitive streak camera with a limiting temporal resolution of 10 ps. The streak camera is equipped with a caesium iodide transmission photocathode and observations have been made in the 10-100 A regime. For a small source (200 {mu}m diameter) the spectral resolution is predicted to be around 2.5 A. This has been confirmed by examination of the Lyman-{alpha} line in hydrogen-like laser heated boron. A recorded linewidth of 2.44 A is demonstrated. The instrument has been used to diagnose the soft x-ray emission from a plastic (CH) foil target heated by an ultra-intense (2x10{sup 20} W cm{sup -2}) laser pulse.

Eagleton, R.T.; James, S.F. [AWE Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

2004-10-01

253

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; Wörhoff, K; Pollnau, M; de Ridder, R M

2012-07-30

254

Production of high-order micromachined silicon echelles on optically flat substrates  

Microsoft Academic Search

Infrared spectrometers using silicon immersion gratings and prisms can have substantial performance advantages over conventional instruments. The immersion gratings and grisms share a common geometry: prism-shaped pieces of silicon with blazed grooves along one side. The grooves can either be machined directly into substrates or the grooves can be machined into thin wafers which are then bonded to flat-surfaced prisms.

Oleg A. Ershov; Daniel T. Jaffe; Jasmina P. Marsh; Luke D. Keller

2001-01-01

255

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

256

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 Å is of unprecedented quality and shows numerous features attributed to transitions of the elements C, N,

A. C. Brinkman; E. Behar; M. Güdel; 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

257

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

258

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

259

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

260

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

261

Transmission grating spectroscopy and the Advanced X-ray Astrophysics Facility (AXAF)  

NASA Technical Reports Server (NTRS)

The use of transmission gratings with grazing-incidence telescopes in celestial X-ray astrononmy is reviewed. The basic properties of transmission grating spectrometers and the use of 'phased' gratings to enhance the diffraction efficiency are outlined. The fabrication of the gratings is examined, giving special attention to the AXAF High Energy Transmission Grating. The performance of finite-period thick gratings is briefly discussed, and the performance of the transmission grating spectrometers planned for SPECTROSAT and AXAF are examined.

Schattenburg, M. L.; Canizares, C. R.; Dewey, D.; Levine, A. M.; Markert, T. H.

1988-01-01

262

Scattered light in the STIS echelle modes  

NASA Technical Reports Server (NTRS)

The Space Telescope Imaging Spectrograph (STIS) echelle spectra obtained during the Early Release Observations have non-zero residuals in the cores of saturated interstellar lines, indicating the need for a scattered light correction. A rough measure of the magnitude of the needed correction shows the ratio of the interorder to the in-order flux in different echelle modes in both pre-launch calibration images of a continuum lamp source and in post-launch images of stellar continuum sources. The interorder and in-order fluxes are computed by averaging the central 200 pixels in the dispersion direction. The amount of scattered light in the interorder region rises toward shorter wavelengths for two reasons: (1) the order separation decreases toward shorter wavelengths; and (2) the amount of echelle scattering is expected to have an inverse dependence on wavelength. At the shortest wavelengths the fraction of light scattered into the interorder region can be 10% for the Near-ultraviolet-Multi-Anode Microchannel Array (NUV-MAMA) and 15% for the Far-ultraviolet-Multi-Anode Microchannel Array (FUV-MAMA).

Landsman, W.; Bowers, C.

1997-01-01

263

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

264

DYNAMICS OF X-RAY-EMITTING EJECTA IN THE OXYGEN-RICH SUPERNOVA REMNANT PUPPIS A REVEALED BY THE XMM-NEWTON REFLECTION GRATING SPECTROMETER  

SciTech Connect

Using the unprecedented spectral resolution of the reflection grating spectrometer (RGS) on board XMM-Newton, we reveal dynamics of X-ray-emitting ejecta in the oxygen-rich supernova remnant Puppis A. The RGS spectrum shows prominent K-shell lines, including O VII He{alpha} forbidden and resonance, O VIII Ly{alpha}, O VIII Ly{beta}, and Ne IX He{alpha} resonance, from an ejecta knot positionally coincident with an optical oxygen-rich filament (the so-called {Omega} filament) in the northeast of the remnant. We find that the line centroids are blueshifted by 1480 {+-} 140 {+-} 60 km s{sup -1} (the first and second term errors are measurement and calibration uncertainties, respectively), which is fully consistent with that of the optical {Omega} filament. Line broadening at 654 eV (corresponding to O VIII Ly{alpha}) is obtained to be {sigma} {approx}< 0.9 eV, indicating an oxygen temperature of {approx}< 30 keV. Analysis of XMM-Newton MOS spectra shows an electron temperature of {approx}0.8 keV and an ionization timescale of {approx}2 Multiplication-Sign 10{sup 10} cm{sup -3} s. We show that the oxygen and electron temperatures as well as the ionization timescale can be reconciled if the ejecta knot was heated by a collisionless shock whose velocity is {approx}600-1200 km s{sup -1} and was subsequently equilibrated due to Coulomb interactions. The RGS spectrum also shows relatively weak K-shell lines of another ejecta feature located near the northeastern edge of the remnant, from which we measure redward Doppler velocities of 650 {+-} 70 {+-} 60 km s{sup -1}.

Katsuda, Satoru; Tamagawa, Toru [RIKEN - Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Ohira, Yutaka [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe Sagamihara 252-5258 (Japan); Mori, Koji [Department of Applied Physics, Faculty of Engineering, University of Miyazaki, 1-1 Gakuen Kibana-dai Nishi, Miyazaki 889-2192 (Japan); Tsunemi, Hiroshi; Koyama, Katsuji [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 60-0043 (Japan); Uchida, Hiroyuki [Department of Physics, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo, Kyoto 606-8502 (Japan)

2013-05-10

265

The ORFEUS II Echelle spectrum of HD 93521: A reference for interstellar molecular hydrogen  

NASA Astrophysics Data System (ADS)

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. The spectrum of HD 93521 was obtained during this mission with a total integration time of 1740 s. This spectrum shows numerous sharp interstellar absorption lines. We identified 198 lines of molecular hydrogen including at least 7 lines with a high velocity component. Also most of the 67 identified interstellar metal lines are visible with a high velocity component. We present plots of the complete ORFEUS II Echelle spectrum together with tables of all identified interstellar absorption lines including all 14 detectable H I lines. In addition several identified stellar lines, partially with narrow absorption components, and stellar wind lines are given in a separate table.

Barnstedt, J.; Gringel, W.; Kappelmann, N.; Grewing, M.

2000-04-01

266

Post - SM4 Flux Calibration of the STIS Echelle Modes  

NASA Astrophysics Data System (ADS)

Like all STIS spectroscopic modes, STIS echelle modes show a wavelength dependent decline in detector sensitivity with time. The echelle sensitivity is further affected by a time-dependent shift in the blaze function. To better correct the effects of the echelle sensitivity loss and the blaze function changes, we derive new baselines for echelle sensitivities from post-HST Servicing Mission 4 observations of the standard star G191-B2B. We present how these baseline sensitivities compare to pre-failure trends.

Bostroem, Azalee; Aloisi, A.; Bohlin, R. C.; Proffitt, C. R.; Osten, R. A.; Lennon, D.

2010-07-01

267

Materials and fabrication issues for large machined germanium immersion gratings  

Microsoft Academic Search

LLNL has successfully fabricated small (1.5 cm2 area) germanium immersion gratings. We studied the feasibility of producing a large germanium immersion grating by means of single point diamond flycutting. Our baseline design is a 63.4° blaze echelle with a 6 cm beam diameter. Birefringence and refractive index inhomogeneity due to stresses produced by the crystal growth process are of concern.

Paul J. Kuzmenko; Pete J. Davis; Steve L. Little; Layton C. Hale

2006-01-01

268

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 Å.

Pakhomov, Yu. V.; Zhao, G.

2013-10-01

269

Production and evaluation of silicon immersion gratings for infrared astronomy.  

PubMed

Immersion gratings, diffraction gratings where the incident radiation strikes the grooves while immersed in a dielectric medium, offer significant compactness and performance advantages over front-surface gratings. These advantages become particularly large for high-resolution spectroscopy in the near-IR. The production and evaluation of immersion gratings produced by fabricating grooves in silicon substrates using photolithographic patterning and anisotropic etching is described. The gratings produced under this program accommodate beams up to 25 mm in diameter (grating areas to 55 mm x 75 mm). Several devices are complete with appropriate reflective and antireflection coatings. All gratings were tested as front-surface devices as well as immersed gratings. The results of the testing show that the echelles behave according to the predictions of the scalar efficiency model and that tests done on front surfaces are in good agreement with tests done in immersion. The relative efficiencies range from 59% to 75% at 632.8 nm. Tests of fully completed devices in immersion show that the gratings have reached the level where they compete with and, in some cases, exceed the performance of commercially available conventional diffraction gratings (relative efficiencies up to 71%). Several diffraction gratings on silicon substrates up to 75 mm in diameter having been produced, the current state of the silicon grating technology is evaluated. PMID:17514298

Marsh, J P; Mar, D J; Jaffe, D T

2007-06-10

270

The Colorado High-Resolution Echelle Stellar Spectrograph (CHESS) Design and Status  

NASA Astrophysics Data System (ADS)

I present a new far-ultraviolet echelle spectrograph, which will provide resolving power greater than any currently existing far-ultraviolet instrument. We are using new gratings, detectors, and coatings that allow substantial advances in performance. I will present the current status of the design, and discuss known challenges and our plans to resolve them. While the design purpose of this instrument is for observations of nearby hot stars, the technologies we incorporate will allow for advances relevant to observation subjects from protoplanetary disks to the intergalactic medium. Incorporating such a spectrograph into a future, long-duration mission will make new high-quality observations possible and enhance our understanding of astrophysical plasmas.

Beasley, Matthew

271

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.; Hänsch, T. W.; Schmidt, W.

2012-09-01

272

New On-Orbit Sensitivity Calibrationfor All STIS Echelle Modes  

NASA Astrophysics Data System (ADS)

On-orbit sensitivities for the 32 medium- and high-resolution STIS echelle secondarymodes were determined for the rst time using observations of the fundamental DAwhite dwarf standard star G191-B2B. Revised on-orbit sensitivities for the 12 mediumandhigh-resolution echelle prime modes based on observations of the same standardstar are also presented. We review the procedures and assumptions used to derive theadopted throughputs and implement them into the pipeline.

Aloisi, Alessandra; Bohlin, Ralph; Quijano, Jessica Kim

2007-01-01

273

HIRDES The High-Resolution Double-Echelle Spectrograph for the World Space Observatory Ultraviolet (WSO/UV)  

NASA Astrophysics Data System (ADS)

The World Space Observatory Ultraviolet (WSO/UV) is a multi-national project grown out of the needs of the astronomical community to have future access to the UV range. WSO/UV consists of a single UV telescope with a primary mirror of 1.7 m diameter feeding the UV spectrometer and UV imagers. The spectrometer comprises three different spectrographs, two high-resolution echelle spectrographs (the High-Resolution Double-Echelle Spectrograph, HIRDES) and a low-dispersion long-slit instrument. Within HIRDES the 102 310 nm spectral band is split to feed two echelle spectrographs covering the UV range 174 310 nm and the vacuum-UV range 102 176 nm with high spectral resolution (R > 50,000). The technical concept is based on the heritage of two previous ORFEUS SPAS missions. The phase-B1 development activities are described in this paper considering performance aspects, design drivers, related trade-offs (mechanical concepts, material selection etc.) and a critical functional and environmental test verification approach. The current state of other WSO/UV scientific instruments (imagers) is also described.

Werner, K.; Barnstedt, J.; Gringel, W.; Kappelmann, N.; Becker-Roß, H.; Florek, S.; Graue, R.; Kampf, D.; Reutlinger, A.; Neumann, C.; Shustov, B.; Moisheev, A.; Skripunov, E.

274

Method for the analysis of echelle spectra  

US Patent & Trademark Office Database

A method for the wavelength calibration of echelle spectra, in which the wavelengths are distributed across number of orders is characterised by the steps: recording of a line-rich reference spectrum with known wavelengths for a number of the lines, determination of the position of a number of peaks of the reference spectrum in the recorded spectrum, selection of at least two first lines of known order, position and wavelength, determination of a wavelength scale for the order in which the known lines lie, by means of a fit function .gamma..sub.m(x), determination of a provisional wavelength scale .gamma.?m 1(x) for at least one neighboring order m 1, by means of addition/subtraction of a wavelength difference .gamma..sub.FSR which corresponds to a free spectral region, according to .gamma.m 1 ?(x)=.gamma..sub.m(x).gamma..sub.FSR with .gamma..sub.FSR=.gamma..sub.m(x)/m, determination of the wavelengths of lines in said neighboring order m 1, by means of the provisional wavelength scale .gamma. 1(x), replacement of the provisional wavelength of at least two lines by the reference wavelength for said lines as obtained in step (a) and repeat of steps (d) to (g) for at least one further neighboring order.

2008-01-15

275

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

276

Imaging spectrometer wide field catadioptric design  

Microsoft Academic Search

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

Chrisp; Michael P

2008-01-01

277

High performance gratings for space applications  

NASA Astrophysics Data System (ADS)

Different earth-observation and scientific space missions have the need for special spectrometer gratings. As satellite instruments typically operate close to the technologically accessible limits also the realization of the respective gratings is extremely demanding. Critical parameters are the diffraction efficiency and its polarization dependency, the wavefront error introduced by the grating, stray-light performance, and usability in a space environment. We show that it is necessary to include technological considerations into the design and specification of the grating in order to achieve the optimal performance of the complete optical system. We demonstrate this approach by two examples. The first one is the design and fabrication of the grating for the Radial-Velocity-Spectrometer of the GAIA-mission of the ESA using a novel approach based on an effective medium sub-structure within one grating period. The second example is a high dispersion NIR-spectrometer grating for an earth observation mission. Such gratings are typically realized as immersed structures in order to maximize the dispersion. We show that the same optical performance can be achieved with gratings operating in the resonance domain which can be realized by electron-beam lithography as well.

Zeitner, U. D.; Michaelis, D.; Kley, E.-B.; Erdmann, M.

2010-04-01

278

Imaging Spectrometer for Geophysical Surveys  

NASA Technical Reports Server (NTRS)

Airborne spectrometer combines technologies of television imaging and spectroscopy to produce data for geophysical surveys, agricultural assessments, forest and land management, and exploration for oil and minerals. Designed for Small Size, infrared imaging spectrometer uses folded telescope and passes input and output of its monochromator through hole in monochromator grating. Instrument permits analysis of terrain at many infrared wavelengths.

Labaw, C. C.

1985-01-01

279

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

280

Study of the image quality and stray light in the critical design phase of the Compact Echelle Spectrograph for Aeronomical Research (CESAR))  

NASA Astrophysics Data System (ADS)

The success of the high resolution nightglow studies conducted with the Keck telescopes on Mauna Kea and the Very Large Telescopes in Chile led to the design of the Compact Echelle Spectrograph for Aeronomical Research (CESAR). This is an echelle spectrograph with grating post-dispersion that will be dedicated to nightglow studies at high spectral resolution (R ~ 20000) between 300-1000 nm, and that will be easily deployable at different sites. The development of CESAR is conducted by SRI International, and INO is involved in the optical design and integration of the spectrograph camera, whose all-spherical form is based on the camera of the HIRES spectrograph at the Keck I telescope. The detailed optical design is used to calculate the position of the spectral elements on the detector, predict their image quality, and estimate the level of stray light. This paper presents the methodology used in these analyses.

Lavigne, Jean-François; Doucet, Michel; Wang, Min; Lacoursière, Jean; Grill, Martin; Melchiorri, Riccardo; Slanger, Tom G.; Kendall, Elizabeth

2010-07-01

281

Planar waveguide spectrometer  

SciTech Connect

An integrated optic consisting of buried diffraction gratings and a planar waveguide was developed as an internal reflectance element for broad-band spectroscopic analysis of liquids. Polystyrene or tantalum pentoxide waveguides were deposited over a pair of diffraction gratings etched into the surface of a glass slide. Multiwavelength light was focused through the substrate onto the first grating. Component wavelengths were coupled into the waveguide and spatially dispersed by the second grating after propagating through the waveguide. A silicon photodiode array detector was used to collect the spectra data. Our goal is to produce a compact, rapid spectrometer having no moving parts that can take advantage of fiber optics and fast array detectors in the visible and near-infrared regions for industrial process control. The thin planar waveguide provides enhanced sensitivity to analyze weaker absorptions in the near-infrared. 10 refs., 5 figs.

Goldman, D.S.; White, P.L.; Anheier, N.C.

1990-07-01

282

Slanted fringe volume phase holographic gratings in astronomical instrumentation  

NASA Astrophysics Data System (ADS)

Many existing astronomical spectrographs have been retrofitted with volume phase holographic gratings (VPHGs), since at higher line density they are significantly more efficient than surface relief transmission gratings. Designing the spectrograph around the VPHG offers additional advantages. In this paper we describe slanted fringe VPHG that are considered as cross-disperser / beam expander in high-resolution echelle spectrographs for the Combined Incoherent Focus of the VLT and the E-ELT. We will present simulations of diffraction efficiency of slanted fringe VPHGs that explore the useful parameter space of these devices in terms of efficiency, line density and anamorphic beam expansion.

Arns, James A.; Dekker, Hans

2008-07-01

283

Astigmatism of a Concave Grating Spectroscope Studio Dell'Astigmatismo di Uno Spettroscopio a Reticolo Concavo.  

National Technical Information Service (NTIS)

The OSO J concave grating spectrometer astigmatism effects are presented. The principal equation for the concave grating in reflection mode is detailed, and the image height discussed in the NAMIOKA formalism. In the same formalism, the image curvature du...

L. Rossi

1972-01-01

284

Near-infrared metrology of high-performance silicon immersion gratings  

NASA Astrophysics Data System (ADS)

Silicon immersion gratings offer size and cost savings for high-resolution near-infrared spectrographs. The IGRINS instrument at McDonald Observatory will employ a high-performance silicon immersion echelle grating to achieve spectral resolution R = ?/??40,000 simultaneously over H and K near-infrared band atmospheric windows (1.5-2.5 ?m). We chronicle the metrology of an R3 silicon immersion echelle grating for IGRINS. The grating is 30x80 mm, etched into a monolithic silicon prism. Optical interferometry of the grating surface in reflection indicates high phase coherence (grating grooves. These periodic errors manifest as spectroscopic ghosts. High dynamic range monochromatic spectral purity measurements reveal ghost levels relative to the main diffraction peak at 1.6x10-3 at ? = 632 nm in reflection, consistent with the interferometric results Improved grating surfaces demonstrate reflection-measured ghosts at negligible levels of 10-4 of the main diffraction peak. Relative on-blaze efficiency is ~75%. We investigate the immersion grating blaze efficiency performance over the entire operational bandwidth 1500

Gully-Santiago, Michael; Wang, Weisong; Deen, Casey; Jaffe, Daniel

2012-09-01

285

Design of UV long-slit spectrometer  

NASA Astrophysics Data System (ADS)

General approaches to the solution are shown on the example of one of the alternative variants of UV long-slit spectrometer. It is suggested using concave aberration-corrected holographic diffraction grating in FUV spectral range (102 - 175 nm). In NUV spectral range (175 - 310 nm), where mirror coating reflecting factor is higher, it is suggested using a beam of zero order of this grating with subsequent spectral decomposition performed with additional grating. It is known that diffractive grating efficiency depends on the form of grooves profile, in the first approximation step profile echelett grating fits quite well for this task.

Bazhanov, Y.; Demura, E.; Zacharova, N.

2012-09-01

286

[Design method of convex master gratings for replicating flat-field concave gratings].  

PubMed

Flat-field concave diffraction grating is the key device of a portable grating spectrometer with the advantage of integrating dispersion, focusing and flat-field in a single device. It directly determines the quality of a spectrometer. The most important two performances determining the quality of the spectrometer are spectral image quality and diffraction efficiency. The diffraction efficiency of a grating depends mainly on its groove shape. But it has long been a problem to get a uniform predetermined groove shape across the whole concave grating area, because the incident angle of the ion beam is restricted by the curvature of the concave substrate, and this severely limits the diffraction efficiency and restricts the application of concave gratings. The authors present a two-step method for designing convex gratings, which are made holographically with two exposure point sources placed behind a plano-convex transparent glass substrate, to solve this problem. The convex gratings are intended to be used as the master gratings for making aberration-corrected flat-field concave gratings. To achieve high spectral image quality for the replicated concave gratings, the refraction effect at the planar back surface and the extra optical path lengths through the substrate thickness experienced by the two divergent recording beams are considered during optimization. This two-step method combines the optical-path-length function method and the ZEMAX software to complete the optimization with a high success rate and high efficiency. In the first step, the optical-path-length function method is used without considering the refraction effect to get an approximate optimization result. In the second step, the approximate result of the first step is used as the initial value for ZEMAX to complete the optimization including the refraction effect. An example of design problem was considered. The simulation results of ZEMAX proved that the spectral image quality of a replicated concave grating is comparable with that of a directly recorded concave grating. PMID:19839358

Zhou, Qian; Li, Li-Feng

2009-08-01

287

First light results from PARAS: the PRL Echelle Spectrograph  

Microsoft Academic Search

We present the first light commissioning results from the Physical Research Laboratory (PRL) optical fiber-fed high resolution cross-dispersed Echelle Spectrograph. It is capable of a single- shot spectral coverage of 3700A to 8600A at R ~ 63,000 and is under very stable conditions of temperature (0.04°C at 23°C). In the very near future pressure control will also be achieved by

Abhijit Chakraborty; Suvrath Mahadevan; Arpita Roy; Fazalahmed M. Pathan; Vishal Shah; Eric H. Richardson; Girish Ubale; Rajesh Shah

2010-01-01

288

Thermal sensitivity of DASH interferometers: the role of thermal effects during the calibration of an Echelle DASH interferometer.  

PubMed

The use of a Doppler asymmetric spatial heterodyne (DASH) interferometer with an Echelle grating provides the ability to simultaneously image the 558 and 630 nm emission lines (e.g., at grating orders of n=8 and n=7, respectively) of atomic oxygen in the thermosphere. By measuring the Doppler shifts of these lines (expected relative change in wavelength on the order of 10??), we are able to determine the thermospheric winds. Because the expected wavelength changes due to the Doppler shift are so small, understanding, monitoring, and accounting for thermal effects is expected to be important. Previously, the thermal behavior of a temperature-compensated monolithic DASH interferometer was found to have a higher thermal sensitivity than predicted by a simple model [Opt. Express 18, 26430, 2010]. A follow-up study [Opt. Express 20, 9535, 2012] suggested that this is due to thermal distortion of the interferometer, which consists of materials with different coefficients of thermal expansion. In this work, we characterize the thermal drift of a nonmonolithic Echelle DASH interferometer and discuss the implications of these results on the use of only a single wavelength source during calibration. Furthermore, we perform a finite element analysis of the earlier monolithic interferometer in order to determine how distortion would affect the thermal sensitivity of that device. Incorporating that data into the model, we find good agreement between the modified model and the measured thermal sensitivities. These findings emphasize the fact that distortion needs to be considered for the design of thermally compensated, monolithic DASH interferometers. PMID:24513761

Marr, Kenneth D; Englert, Christoph R; Harlander, John M; Miller, Kenneth W

2013-11-20

289

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

290

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

291

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

292

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

293

Post-Servicing Mission 4 Flux Calibration of the STIS Echelle Modes  

NASA Astrophysics Data System (ADS)

STIS echelle modes show a wavelength-dependent decline in sensitivity with time. While this trend is observed in all STIS spectroscopic modes, the echelle sensitivity is further affected by a time-dependent shift in the blaze function. To improve the echelle flux calibration, new baselines for the echelle sensitivities are derived from post-Servicing Mission 4 (SM4) observations of the Hubble Space Telescope standard star G191-B2B. We present how these baseline sensitivities compare to pre-failure trends. Specifically, where the new results differ from expectations and discuss anomalous results found in E140H monitoring observations are highlighted.

Azalee Bostroem, K.; Aloisi, A.; Proffitt, C.; Osten, R.; Bohlin, R.

2011-01-01

294

Double reflection in the concave reflective blazed grating.  

PubMed

The miniature spectrometer has many applications in integrated optics and photonics. The blazed grating with the Rowland circle structure has the advantage of self-focusing and is chosen as the major component in the spectrometer chip. In the simulations for the blaze angle design in the visible spectrum, we discover the phenomenon of the double reflection diffraction. Its cause and parameter space are discussed. The spectrometer utilizing the phenomenon has similar performance to the standard blazed grating and is easier to manufacture in microelectromechanical systems (MEMS) technology. The discovery will greatly ease the design of the spectrometer chip. PMID:19547403

Ko, Cheng-Hao; Liu, Wei-Chih; Chen, Nien-Po; Shen, Ji-Lin; Lin, Jian-Shian

2007-08-20

295

The first high resolution silicon immersion grating spectrograph  

Microsoft Academic Search

We report the development of the first high resolution cross-dispersed silicon immersion grating spectrometer. This instrument is called the Florida IR Silicon immersion grating specTrometer (FIRST). FIRST can produce R = 50,000 under a 0.6 arcsec seeing and simultaneously cover 1.3-1.8 mum with a 1kx1k HgCdTe array at the Apache Point Observatory 3.5 meter telescope. FIRST has a 50 mm

Jian Ge; Daniel McDavitt; Bo Zhao; Suvrath Mahadevan; Curtis DeWitt; Sara Seager

2006-01-01

296

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

297

Slitless Intensified Readout Gated Spectrometer.  

National Technical Information Service (NTIS)

A spectrometer has been developed to meet the requirements of the x-ray laser effort at LLNL. The instrument takes advantage of the intrinsically small divergence and size of the lasing source by putting it, the grating and the detector on the Rowland cir...

M. Gerassimenko

1986-01-01

298

Applications of multichannel imaging spectrometer  

Microsoft Academic Search

The described system applies advanced Volume Phase Holographic (VPH) diffraction gratings to provide a high-performance, line imaging \\/ multichannel spectrometer. Specifically designed optics produces spectrally dispersed image of the input slit on a two dimensional array of photodetectors in such a way that the full width, half maximum (FWHM) of monochromatic image of each point of the slit is not

Olga Pawluczyk; Romuald Pawluczyk

2004-01-01

299

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

300

Ion beam deposited silicon carbide on glass optics and replica gratings  

NASA Technical Reports Server (NTRS)

The results of an attempt to coat optical flats and replace echelle gratings with ion-deposited SiC are reported. Deposition was performed by bombarding a SiC target with an ion beam angled 45 deg relative to the target. Half the target was covered with stainless steel to furnish a comparison opportunity. After precleaning SiC coatings of 300-2200 A thickness were deposited. The specimens had previously been coated with either Au or Al or were left blank. Reflectance and diffraction data were taken of the finished flats and gratings. The SiC-coated flats performed as well as uncoated flats while the echelles exhibited deteriorating performance with increasing coating thickness. Further studies are indicated on the effect of coating thickness on surface roughness.

Windt, D. L.; Bach, B.

1984-01-01

301

Preliminary optical design of ARIES-High Resolution Echelle Spectrograph  

NASA Astrophysics Data System (ADS)

For the upcoming 3.6m telescope a High Resolution Echelle Spectrograph is being envisaged as the key instrument to meet wide range science goals namely, asteroseismology, exoplanet search, doppler imaging of spotted stars, massive stars, colliding wind binaries and abundance studies etc. These objectives, in turn, result in a series of technical requirements e.g. spectral coverage of 300 nm to 900 nm, spectral resolution ˜60,000, radial velocity stability < 20 ms^{-1} etc. In addition, a temperature controlled environment and flexible but robust operation is also required. The preliminary optical design of the ARIES-High Resolution Echelle Spectrograph (ARIES-HIRES) is based on the white pupil concept. It is a fiber fed spectrograph, which converts F/9 beam from the telescope to F/3.6. An image slicer would be used to slice the image of the fiber exit to achieve high spectral resolution. The use of intermediate folding mirror makes the instrument more compact. Prisms have been used as cross dispersers to achieve more uniform inter order separation. Simultaneous wavelength spectrum would be used to correct the instrument drift. The spectrograph will be mounted on the vibration isolation table kept inside the telescope pier in an isolated environment. The acquisition and guiding unit, atmospheric dispersion corrector, and calibration unit will be part of the instrument.

Pant, Jayshreekar; Pandey, J. C.; Sagar, Ram

302

V1647 Orionis: Keck/NIRSPEC 2 ?m Echelle Observations  

NASA Astrophysics Data System (ADS)

We present new Keck II NIRSPEC high-spectral resolution 2 ?m echelle observations of the young eruptive variable star V1647 Orionis. This star went into outburst in late 2003 and faded to its pre-outburst brightness after approximately 26 months. V1647 Orionis is the illuminating star of McNeil's Nebula and is located near M 78 in the Lynds 1630 dark cloud. Our spectra have a resolving power of approximately 18,000 and allow us to study in detail the weak absorption features present on the strong near-IR veiled continuum. An analysis of the echelle orders containing Mg I (2.1066 ?m) and Al I (2.1099 ?m), Br? (2.1661 ?m), the Na I doublet (2.206 and 2.209 ?m), and the CO overtone bandhead (2.2935 ?m) gives us considerable information on the physical and geometric characteristics of the regions producing these spectral features. We find that, at high spectral resolution, V1647 Orionis in quiescence resembles a significant number of FU Orionis type eruptive variables and does not appear similar to the quiescent EX Lupi variables observed. This correspondence is discussed and implications for the evolutionary state of the star are considered.

Aspin, Colin; Greene, Thomas P.; Reipurth, Bo

2009-02-01

303

Development of a broadband submillimeter grating spectrometer  

Microsoft Academic Search

One of the central issues in astronomy is the formation and evolution of galaxies at large redshifts. Submillimeter observations are essential to understanding these processes. One of the best prospects for high redshift submillimeter observations is the study of the C(subscript II) 158 micrometer fine- structure line, which carries about 0.2% of the total luminosity of nearby starburst galaxies. However,

Dominic J. Benford; Eugene Serabyn; Thomas G. Phillips; S. H. Moseley

1998-01-01

304

Imaging Spectrometers Using Concave Holographic Gratings.  

National Technical Information Service (NTIS)

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 ...

J. Gradie S. Wang

1993-01-01

305

ORFEUS II Echelle spectra: molecular hydrogen at high velocities toward HD 93521  

NASA Astrophysics Data System (ADS)

Absorption lines of interstellar molecular hydrogen in the far ultraviolet (FUV) have been observed in the spectrum of the O9.5 halo star HD 93521, located some 1500 pc from the Galactic plane. During the second ORFEUS-SPAS mission a spectrum with the Echelle spectrometer has been recorded with a total integration time of 1740 s. The resolution achieved was about lambda /Delta lambda >= 10.000 with a signal-to-noise ratio of up to 25. For the first time two components of molecular hydrogen have been observed in absorption at velocities of =~ -12 km s-1 in the Galactic disk and at =~ -62 km s-1 located presumably in the Galactic halo. The column densities derived from a standard curve of growth analysis were found to be N(H2) = 1017.0 cm-2 for the disk component and N(H2) = 1014.6 cm-2 respectively for the component located in the Galactic halo.

Gringel, W.; Barnstedt, J.; de Boer, K. S.; Grewing, M.; Kappelmann, N.; Richter, P.

2000-06-01

306

Full image spectral analysis of elemental emissions from an echelle spectrograph  

SciTech Connect

A new algorithm compares the background corrected echelle emission image obtained from reference standards to images of unknowns for quantitative elemental analyses. Wavelength was not used in the calculations but instead pixel position and intensity. The data reduction solution was unique to the particular detector/spectrometer. The approach was found useful for several types of images including ICP, DCP and glow discharge images. The analysis scheme required that the emission pattern of standards and background be held in memory. A dual weighting scheme was used that decreased the importance of pixels in high background areas and enhanced the importance of signals from pixels where the standards had emissions. Threshold values were used to limit the calculations to signals in the linear range of the electronics. Logarithmic weighting, (by taking the square root), was found to work well for weighting pixels from the standards. This assured that minor emissions had some influence on the data fit. In the program the best-fit scalar was determined using simple iterative guess, change and test approaches. The test looked for the minimum least square residual value in the areas of the flagged pixels.

Spencer, W.A.

2000-01-27

307

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

308

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

309

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) [Moraga, CA

1999-01-01

310

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

311

Fabrication of low straylight holographic gratings for space applications  

NASA Astrophysics Data System (ADS)

The main challenges of fabricating diffraction gratings for use in earth monitoring spectrometers are given by the requirements for low stray light, high diffraction efficiency and a low polarization sensitivity. Furthermore the use in space also requires a high environmental stability of these gratings. We found that holography in combination with ion beam plasma etching provides a way to obtain monolithic, robust fused silica gratings which are able to meet the above mentioned requirements for space applications. Holography accompanied by plasma etching allows the fabrication of a wide range of different grating profiles to optimize the efficiency including the polarization behavior according to a wealth of applications. Typical profile shapes feasible are blazed gratings, sinusoidal profiles and binary profiles and this allows to tailor the efficiency and polarization requirements exactly to the spectral range of the special application. Holographic gratings can be fabricated on plane and also on curved substrates as core components of imaging spectrometers. In this paper we present our grating fabrication flow for the example of plane blazed gratings and we relate the efficiency and stray light measurement results to certain steps of the process. The holographic setup was optimized to minimize stray light and ghosting recorded by the photoresist during the exposure. Low wave front deviations require the use of highly accurate grating substrates and high precision optics in the holographic exposure.

Steiner, Reinhard; Pesch, Alexander; Erdmann, Lars H.; Burkhardt, Matthias; Gatto, Alexandre; Wipf, Robert; Diehl, Torsten; Vink, H. J. P.; van den Bosch, B. G.

2013-09-01

312

Critical-angle Transmission Grating Development for AXSIO  

NASA Astrophysics Data System (ADS)

Large area, high resolving power spectroscopy in the soft x-ray band can at present only be achieved with a state-of-the-art diffraction grating spectrometer. Recently developed critical-angle transmission (CAT) gratings combine the advantages of transmission gratings (low mass, relaxed figure and alignment tolerances) and blazed reflection gratings (high broad band diffraction efficiency, utilization of higher diffraction orders). Several new mission concepts containing CAT grating based spectrometers such as AXSIO promise to deliver unprecedented order-of-magnitude improvements in soft x-ray spectroscopy figures of merit. The CAT grating principle has previously been demonstrated with x rays using small wet-etched samples. We report the latest progress in the fabrication and testing of large (32x32 mm2) CAT grating prototypes with an integrated hierarchy of low-obstruction support structures. The gratings are fabricated from silicon-on-insulator wafers using advanced lithography and highly anisotropic dry and wet etching techniques. We present our latest grating fabrication results.

Bautz, Mark W.; Heilmann, R. K.; Schattenburg, M.; Marshall, H. L.; Huenemoerder, D.; Dewey, D.; Schulz, N. S.; Davis, J. E.

2013-04-01

313

Critical-Angle Transmission Grating Development for AXSIO  

NASA Astrophysics Data System (ADS)

Large area, high resolving power spectroscopy in the soft x-ray band can only be achieved with a state-of-the-art diffraction grating spectrometer. Recently developed critical-angle transmission (CAT) gratings combine the advantages of transmission gratings (low mass, relaxed figure and alignment tolerances) and blazed reflection gratings (high broad band diffraction efficiency, utilization of higher diffraction orders). Since the demise of IXO there are no soft x-ray spectroscopy missions in the pipeline, but several new mission concepts containing CAT grating based spectrometers such as AXSIO promise to deliver unprecedented order-of-magnitude improvements in soft x-ray spectroscopy figures of merit. The CAT grating principle has previously been demonstrated with x rays using small wet-etched samples. We report the latest progress in the fabrication and testing of large (32x32 mm^2) CAT grating prototypes with an integrated hierarchy of low-obstruction support structures. The gratings are fabricated from silicon-on-insulator wafers using advanced lithography and highly anisotropic dry and wet etching techniques. We present our latest grating fabrication results.

Heilmann, Ralf K.; Bruccoleri, A.; Mukherjee, P.; Schattenburg, M. L.; Bautz, M. W.; Huenemoerder, D.; Davis, J. E.; Dewey, D.; Marshall, H. L.; Schulz, N. S.

2013-01-01

314

Fiber grating spectra  

Microsoft Academic Search

In this paper, we describe the spectral characteristics that can be achieved in fiber reflection (Bragg) and transmission gratings. Both principles for understanding and tools for designing fiber gratings are emphasized. Examples are given to illustrate the wide variety of optical properties that are possible in fiber gratings. The types of gratings considered include uniform, apodized, chirped, discrete phase-shifted, and

T. Erdogan

1997-01-01

315

Materials and Fabrication Issues for Large Machined Germanium Immersion Gratings  

SciTech Connect

LLNL has successfully fabricated small (1.5 cm{sup 2} area) germanium immersion gratings. We studied the feasibility of producing a large germanium immersion grating by means of single point diamond flycutting. Our baseline design is a 63.4o blaze echelle with a 6 cm beam diameter. Birefringence and refractive index inhomogeneity due to stresses produced by the crystal growth process are of concern. Careful selection of the grating blank and possibly additional annealing to relieve stress will be required. The Large Optics Diamond Turning Machine (LODTM) at LLNL is a good choice for the fabrication. It can handle parts up to 1.5 meter in diameter and 0.5 meter in length and is capable of a surface figure accuracy of better than 28 nm rms. We will describe the machine modifications and the machining process for a large grating. A next generation machine, the Precision Optical Grinder and Lathe (POGAL), currently under development has tighter specifications and could produce large gratings with higher precision.

Kuzmenko, P J; Davis, P J; Little, S L; Hale, L C

2006-05-22

316

Multilayer coated gratings for phase-contrast computed tomography (CT)  

NASA Astrophysics Data System (ADS)

By using the principle of grating interferometry, X-ray phase contrast imaging can now be performed with incoherent radiation from standard X-ray tube. This approach is in stark contrast with imaging methods using coherent synchrotron X-ray sources or micro-focus sources to improve contrast. The gratings interferometer imaging technique is capable of measuring the phase shift of hard X-rays travelling through a sample, which greatly enhances the contrast of low absorbing specimen compared to conventional amplitude contrast images. The key components in this approach are the gratings which consists of alternating layers of high and low Z (atomic number) materials fabricated with high aspect ratios. Here we report on a novel method of fabricating the grating structures using the technique of electron-beam (ebeam) thin film deposition. Alternating layers of silicon (Z=14) and tungsten (Z=74) were deposited, each measuring 100 nm each, on a specially designed echelle substrate, which resulted in an aspect ratio of ~100:1. Fabrication parameters related to the thin film deposition such as geometry, directionality, film adhesion, stress and the resulting scanning electron micrographs will be discussed in detail. Using e-beam method large-area gratings with precise multilayer coating thicknesses can be fabricated economically circumventing the expensive lithography steps.

Marton, Zsolt; Bhandari, Harish B.; Wen, Harold H.; Nagarkar, Vivek V.

2014-03-01

317

[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

318

Optimum design of a holographic parallel flat-field grating  

NASA Astrophysics Data System (ADS)

To widen the working waveband, a new holographic parallel flat-field grating (HPFG) with two sub-gratings lying parallel on the same substrate is designed. Grating parameters of the two gratings, one for 2~5 nm and the other for 5~30 nm, are optimized based on the aberration theory of concave grating. The radius tolerances of curvature of the substrate are also analyzed. Ray-traced spectral images indicate that errors cased by ±1% deviation of radius can be offset by shifting the detector position within 2.5 mm. Finally, we analyze the spectral image-focusing properties. Theoretical spectral resolution of this new HPFG is pretty much the same as that of existing holographic flat-field grating. The simulation results demonstrate that our work probably can be used in the compact spectrometers with a broad spectral region and moderately high resolution.

Wang, Qing-bo; Liu, Zheng-kun; Chen, Huo-yao; Fu, Shao-jun

2013-08-01

319

Tests performed with the improved MEGA spectrometer  

NASA Astrophysics Data System (ADS)

This paper describes an improved version of the MEGA (for multiechelle grating arrangement) spectrometer of Engman and Lindblom (1984) and the results of testing the improved instrument. The original MEGA instrument was improved by incorporating new gratings, an improved temperature control, and an improved grating clamping system which eliminated the deformation effects caused by the use of the old grating-mounting system. The spectral resolution of the improved system, determined in tests using a He-Ne laser and standard electrodeless discharge lamps (EDLs) to obtain scans of Hg 5461 and Hg 4358 lines, was found to be limited by Doppler broadening in the EDL. The improved spectrometer was used for determining the velocity of a supersonic jet by measuring the Doppler shifts of spectral lines emitted by the beam atoms or molecules. Doppler shifts were found to be independent of the initial pressure within the measurement accuracy.

Gustafsson, Ove; Lindblom, Peter

1988-01-01

320

Development of Multiple-Element Flame Emission Spectrometer Using CCD Detection  

ERIC Educational Resources Information Center

The full wavelength coverage of charge coupled device (CCD) detector when coupled with an echelle spectrography, the system allows for simultaneously multiple element spectroscopy to be performed. The multiple-element flame spectrometer was built and characterized through the analysis of environmentally significant elements such as Ca, K, Na, Cu,…

Seney, Caryn S.; Sinclair, Karen V.; Bright, Robin M.; Momoh, Paul O.; Bozeman, Amelia D.

2005-01-01

321

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

322

A compact multichannel spectrometer for Thomson scattering  

NASA Astrophysics Data System (ADS)

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 Te < 100 eV are achieved by a 2971 l/mm VPH grating and measurements Te > 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.

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

2012-10-01

323

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

324

High-throughput accurate-wavelength lens-based visible spectrometer  

NASA Astrophysics Data System (ADS)

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.

Bell, Ronald E.; Scotti, Filippo

2010-10-01

325

Surface Plasmon Based Spectrometer  

NASA Astrophysics Data System (ADS)

A spectrometer that uses surface plasmon excitation in thin metal films to separate light into its component wavelengths is described. The use of surface plasmons as a dispersive medium sets this spectrometer apart from prism, grating, and interference based variants and allows for the miniaturization of this device. Theoretical and experimental results are presented for two different operation models. In the first case surface plasmon tunneling in the near field is used to provide transmission spectra of different broad band-pass, glass filters across the visible wavelength range with high stray-light rejection at low resolution as well as absorption spectra of chlorophyll extracted from a spinach leaf. The second model looks at the far field components of surface plasmon scattering.

Wig, Andrew; Passian, Ali; Boudreaux, Philip; Ferrell, Tom

2008-03-01

326

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. 2 figs.

Barbee, T.W. Jr.

1990-04-10

327

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

328

A static multiplex Fabry-Perot spectrometer  

NASA Astrophysics Data System (ADS)

We demonstrate a static multiplex spectrometer based on a Fabry-Perot interferometric filter for measuring the mean spectral content of diffuse sources. By replacing the slit of a low-dispersion grating spectrometer with a Fabry-Perot interferometric filter, we improve the resolving power of the instrument while simultaneously overcoming the free spectral range limitation of the Fabry Perot. The resulting instrument is smaller than conventional spectrometers having the same resolving power. We present experimental results from the spectrometer using neon lamp, He-Ne laser, and diode laser sources over a wavelength range from 620 nm to 660 nm.

Zheng, Nan; Hagen, Nathan; John, Renu; Brady, David J.

2009-02-01

329

The Offner imaging spectrometer in quadrature.  

PubMed

This is a proposal and description of a new configuration for an Offner imaging spectrometer based on the theory of aberrations of off-plane classical-ruled spherical diffraction gratings. This new spectrometer comprises a concave mirror used in double reflection and a convex reflection grating operating in quadrature, in a concentric layout. A very simple procedure obtains designs that are anastigmatic for a given point on the entrance slit and a given wavelength. Specific examples show that the performance of this type of system improves the performance of analogous conventional in-plane systems, when compactness and/or high spectral resolution is of fundamental importance. PMID:20588404

Prieto-Blanco, Xesús; Montero-Orille, Carlos; González-Nuñez, Héctor; Mouriz, María Dolores; Lago, Elena López; de la Fuente, Raúl

2010-06-01

330

A variable-dispersion micro-spectrometer  

NASA Astrophysics Data System (ADS)

A space-variant variable-dispersion micro-spectrometer has been designed, fabricated, and tested. This spectrometer allows the dispersion to be varied on a pixel-by-pixel basis across the one-dimensional entrance slit. Micro-electro-mechanical mirrors are located at the entrance slit and direct light to one of three different diffraction gratings. A standard grating spectrometer geometry is used to achieve diffraction-limited performance across the 500--1000 nm wavelength range. Spectral resolutions ranging from 5 to 20 nanometers are achieved. Micro-optics fabrication techniques are employed to fabricate the spectrometer. Grayscale optical lithography using a custom high-energy beam-sensitive (HEBS) photomask was used to fabricate the spectrometer mirrors in photoresist. High-frequency noise inherent to the HEBS process was smoothed with a reflow technique to obtain smooth surface profiles. Blazed gratings were written using direct-write electron-beam lithography in SU-8. It is shown that SU-8, which has traditionally been used as a very thick resist for micro-electro-mechanical systems (MEMS) applications, is suitable for fabricating both diffractive and refractive optical elements. The spectrometer was tested with a variety of optical sources. These include a variety of lasers and elemental discharge tubes. The optical performance of the fabricated spectrometer closely matches the design specifications.

Shields, Eric Arden

331

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

332

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

333

The Off-plane Grating Rocket Experiment (OGRE)  

NASA Astrophysics Data System (ADS)

Developments in grating spectroscopy are paramount for meeting the soft X-ray science goals of future NASA X-ray Observatories. While developments in the laboratory setting have verified the technical feasibility of using off-plane reflection gratings to reach this goal, flight heritage is a key step in the development process toward large missions. To this end we have developed a design for a suborbital rocket payload employing an Off-Plane X-ray Grating Spectrometer. This spectrometer utilizes slumped glass Wolter-1 optics, an array of gratings, and a CCD camera. We discuss the unique capabilities of this design, the expected performance, the science return, and the perceived impact to future missions.

McEntaffer, Randall L.; DeRoo, Casey; Tutt, James; Schultz, Ted; Zhang, William; McClelland, Ryan; Murray, Neil; Holland, Andrew

2014-08-01

334

Off-axis pivot mounting for aberration-corrected concave gratings at normal incidence.  

PubMed

The off-axis pivot-point mounting for toroidal uniform line-space (TULS) gratings and spherical varied line-space (SVLS) is presented: One scans the spectrum by rotating the grating about the pivot point. The best choice for the location of the point is discussed: For a monochromator the location is chosen such that the grating is moved approximately along the bisector of the subtended angle; for a spectrometer, it is chosen such that the grating is moved approximately along the direction of the incident ray. Minimizing the spectral defocusing caused by the rotation of the grating determines the optimum length of the pivot arm. The pivot points for TULS and SVLS gratings are found to be located on opposite sides with respect to the normal to the grating. In a comparison of the optical performance, the spectral focusing is similar, but the spatial aberrations can be fewer for a SVLS grating. PMID:18337988

Poletto, L

2000-03-01

335

Improved Performance (Transmission) Gratings.  

National Technical Information Service (NTIS)

Results of the study produced the following conclusions: higher line density gratings could be produced immediately by superimposing existing gratings (after reducing wire widths); unwanted higher orders could be reduced by chemical treatment of existing ...

P. L. Csonka

1978-01-01

336

Concave Diffraction Gratings.  

National Technical Information Service (NTIS)

The report summarizes the need for concave diffraction gratings in ultraviolet, visible, and near infra-red spectroscopy, and provides a brief resume of the relative merits of ruled gratings and those generated using interference or 'holographic' techniqu...

M. C. Hutley

1985-01-01

337

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

338

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

339

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

340

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.

2010-12-01

341

Analytical alignment tolerances for off-plane reflection grating spectroscopy  

NASA Astrophysics Data System (ADS)

Future NASA X-ray Observatories will shed light on a variety of high-energy astrophysical phenomena. Off-plane reflection gratings can be used to provide high throughput and spectral resolution in the 0.3-1.5 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. In this paper we present an analytical formulation of alignment tolerances that define grating orientations in all six degrees of freedom. We verify our analytical results with raytrace simulations to fully explore the alignment parameter space. We also investigate the effect of misalignments on diffraction efficiency.

Allured, Ryan; McEntaffer, Randall T.

2013-12-01

342

Novel immersion grating, VPH grating, and quasi-Bragg grating  

Microsoft Academic Search

We have successfully fabricated germanium immersion gratings with resolving power of 45,000 at 10 mum by using a nano precision 3D grinding machine and ELID (ELectrolytic In-process Dressing) method. However the method spends large amount of machine times. We propose grooves shape with a new principle for a solid grating, which achieves high performance and lower cost. We have developed

Noboru Ebizuka; Keiko Oka; Akiko Yamada; Masako Kashiwagi; Kashiko Kodate; Koji S. Kawabata; Mariko Uehara; Chie Nagashima; Kotaro Ichiyama; Takashi Ichikawa; Tomoyuki Shimizu; Shinya Morita; Yutaka Yamagata; Hitoshi Omori; Hitoshi Tokoro; Yasuhiro Hirahara; Shuji Sato; Masanori Iye

2006-01-01

343

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

344

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

345

[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

346

Frequency comb based spectrometer for in situ and real time measurements of IO, BrO, NO?, and H?CO at pptv and ppqv levels.  

PubMed

We report an instrument designed for trace gas measurement of highly reactive halogenated radicals, such as bromine oxide and iodine oxide, as well as for nitrogen dioxide and formaldehyde. This compact and robust spectrometer relies on an alternated injection of a frequency-doubled femtosecond radiation at 338 and 436 nm into two parallel high-finesse cavities, for measuring BrO + H(2)CO, and IO + NO(2), respectively. The transmission of the broadband radiation through the cavity is analyzed with a high resolution, compact spectrograph consisting of an echelle grating and a high sensitivity CCD camera. The transportable instrument fits on a breadboard 120 × 60 cm size and is suitable for in situ and real time measurements of these species. A field campaign at the Marine Boundary Layer in Roscoff (in the northwest of France, 48.7°N, 4.0°W) during June 2011 illustrates the outstanding performance of the instrument, which reaches a bandwidth normalized minimum absorption coefficient of 1.3 × 10(-11) cm(-1) Hz(-1/2) per spectral element, and provides detection levels as low as 20 parts per quadrillion of IO in 5 min of acquisition. PMID:22889080

Grilli, Roberto; Méjean, Guillaume; Kassi, Samir; Ventrillard, Irène; Abd-Alrahman, Chadi; Romanini, Daniele

2012-10-01

347

Concave diffraction gratings fabricated with planar lithography  

NASA Astrophysics Data System (ADS)

This paper reports on the development and validation of a new technology for the fabrication of variable line-spacing non-planar diffraction gratings to be used in compact spectrometers. The technique is based on the standard lithographic process commonly used for pattern transfer onto a flat substrate. The essence of the technology presented here is the lithographic fabrication of a planar grating structure on top of a flexible membrane on a glass or silicon wafer and the subsequent deformation of the membrane using a master shape. For the validation of the proposed technology we fabricated several reflection concave diffraction gratings with the f-numbers varying from 2 to 3.8 and a diameter in the 4 - 7 mm range. A glass wafer with circular holes was laminated by dry-film resist to form the membranes. Subsequently, standard planar lithography was applied to the top part of the membranes for realizing grating structures. Finally the membranes were deformed using plano-convex lenses in such a way that precise lens alignment is not required. A permanent non-planar structure remains after curing. The imaging properties of the fabricated gratings were tested in a three-component spectrograph setup in which the cleaved tip of an optical fiber served as an input slit and a CCD camera was used as a detector. This simple spectrograph demonstrated subnanometer spectral resolution in the 580 - 720 nm range.

Grabarnik, S.; Emadi, A.; Wu, H.; De Graaf, G.; Wolffenbuttel, R. F.

2008-05-01

348

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

2010-04-13

349

High-efficiency silicon immersion grating by electron-beam lithography  

Microsoft Academic Search

Silicon immersion grating have opened the new possibilities of building compact high-resolution cryogenic spectrometers for the near-infrared (NIR) region from 1.4 to 5.5mum. We are developing a silicon immersion grating for a next-generation NIR high-resolution spectrometer attached to the Subaru 8.2 m telescope. Since a long time, the anisotropic wet etching technique using photolithography has used for the fabrication of

Yuji Ikeda; Naoto Kobayashi; Hiroshi Terada; Akinori Shibayama; Akira Ozawa; Chikako Yasui; Sohei Kondo; Tae-Soo Pyo; Hideyo Kawakita

2008-01-01

350

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

351

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

352

Micro spectrometer for parallel light and method of use  

NASA Technical Reports Server (NTRS)

A spectrometer system includes an optical assembly for collimating light, a micro-ring grating assembly having a plurality of coaxially-aligned ring gratings, an aperture device defining an aperture circumscribing a target focal point, and a photon detector. An electro-optical layer of the grating assembly may be electrically connected to an energy supply to change the refractive index of the electro-optical layer. Alternately, the gratings may be electrically connected to the energy supply and energized, e.g., with alternating voltages, to change the refractive index. A data recorder may record the predetermined spectral characteristic. A method of detecting a spectral characteristic of a predetermined wavelength of source light includes generating collimated light using an optical assembly, directing the collimated light onto the micro-ring grating assembly, and selectively energizing the micro-ring grating assembly to diffract the predetermined wavelength onto the target focal point, and detecting the spectral characteristic using a photon detector.

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

2011-01-01

353

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

354

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

355

Polarimetry of transmission gratings  

NASA Astrophysics Data System (ADS)

We have investigated the polarizing properties of gold wire gratings in the resonance domain. The partial polarizing properties of 1- mu m period gratings in the near IR are then used to orient the wire structure of transmission grating facets parallel to each other by means of an alignment polarimeter technique. The absolute alignment accuracy for these gratings is limited by the influence of the support structure on the orientation of the polarization ellipse. If the polarizing properties of this perturbative component are known, the accuracy can be enhanced by treating the polarization by means of the Mueller calculus.

Lochbihler, Hans; Polnau, Ernst; Predehl, Peter

1995-09-01

356

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

357

STIS Grating Scatter in the First Order Modes  

NASA Astrophysics Data System (ADS)

The Space Telescope Imaging Spectrograph (STIS), installed in February 1997, is currently the only spectrograph in operation on the Hubble Space Telescope. STIS is designed to fulfill numerous scientific objectives using a cesium iodide photocathode Multi-anode Microchannel Array (MAMA) for 115 to 170 nm, a cesium telleride MAMA for 160 to 310 nm, and a Scientific Image Technologies CCD for 170 to 1000 nm, each with a format of 1024 x 1024 pixels. Its capabilities include spatially resolved spectroscopy at low to medium spectral resolution, echelle spectroscopy and solar blind imaging in the ultraviolet, time tagging of photons for high time resolution in the ultraviolet, and direct imaging in the optical. Data taken with STIS is processed using a program called CALSTIS, which was developed at the Space Telescope Science Institute in Baltimore. However, with so many optical modes there are bound to be a few problems, which are not addressed by the CALSTIS calibration. We devote this presentation to the problem of grating scatter in the primary first order modes. Light scattered from the grating structure, entrance apertures, and micro roughness of the ruled surface causes a diffused component in the first order modes. The grating scatter is evident as excess photons that contaminate about 30 nm of the shortest wavelengths in the ultraviolet spectrum. Specifically this occurs for data taken with the G230L (NUV-MAMA) grating that covers 157 to 318 nm, and the G230LB (CCD) grating that covers 168 to 306 nm. The scatter is worse for the CCD mode since the NUV-MAMA is less sensitive to red light. We also discuss a simple scatter correction for solar system objects and solar analog stars, as well as correction strategies for general targets, observed with the affected modes. The support for this research was provided by the Spectrographs Group, Space Telescope Science Institute, operated for NASA by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Dashevsky, I.; Caldwell, J.

2000-05-01

358

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

359

Digital spatial wavelength domain multiplexing (DSWDM) using a prism-grating-prism (PGP) and a CMOS imager: implementation and initial testing  

Microsoft Academic Search

A CMOS imager-based spectrometer is used to interrogate a network containing a large number of Bragg grating sensors on multiple fibers as part of a proprietary structural health monitoring system. The spectrometer uses a Prism-Grating-Prism (PGP) to spectrally separate serially multiplexed Bragg reflections on a single fiber. As a result, each Bragg grating produces a discrete spot on the CMOS

Martin B. Christiansen; Shiping Chen; Christopher S. Baldwin; John B. Niemczuk; Jason S. Kiddy; Peter C. Chen; Harri K. Kopola; Mauri Aikio; Pekka Suopajaervi; Steven G. Buckley

2001-01-01

360

Performance of multilayer coated concave gratings in the extreme ultraviolet  

SciTech Connect

Recent advances in multilayer structures for the Extreme Ultraviolet now make it possible to construct diffraction gratings in the wavelength range below 250 /angstrom/ which can be used for precision measurements using normal incidence spectrometers. We report results from two such gratings, one conventionally ruled and other holographically ruled. Both are one meter radius, 1200 lines per millimeter gratings coated with a molybdenum-silicon multilayer for use in the 150 /angstrom/ wavelength region. A McPherson 225 one meter normal incidence spectrometer with a Garton flash tube source and a film detector was used to test the resolution. Semiquantitative efficiency measurements were made by comparing the spectra with that produced by an osmium coated gratings. Oxygen lines in the wavelength region of interest (characteristic of the source) are easily detected and well resolved with both multilayer coated gratings. The same lines are faint or undetected with the osmium coated grating. Quantitative efficiency measurement were performed using a Penning source and a photon counting detector. 9 refs., 4 figs., 1 tab.

Bixler, J.V.; Barbee, T.W. Jr.; Dietrich, D.D.

1989-06-13

361

ISO observations of Titan with SWS/grating  

NASA Technical Reports Server (NTRS)

The observations of Titan performed by the Infrared Space Observatory (ISO) short wavelength spectrometer (SWS), in the 2 micrometer to 45 micrometer region using the grating mode, are reported on. Special attention is given to data from Titan concerning 7 micrometer to 45 micrometer spectral resolution. Future work for improving Titan's spectra investigation is suggested.

Coustenis, A.; Encrenaz, T.; Salama, A.; Lellouch, E.; Gautier, D.; Kessler, M. F.; deGraauw, T.; Samuelson, R. E.; Bjoraker, G.; Orton, G.

1997-01-01

362

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

363

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

364

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

365

An elastomeric grating coupler  

Microsoft Academic Search

We report on a novel nondestructive and reversible method for coupling free space light to planar optical waveguides. In this method, an elastomeric grating is used to produce an effective refractive index modulation on the surface of the optical waveguide. The external elastomeric grating binds to the surface of the waveguide with van der Waals forces and makes conformal contact

Askin Kocabas; Feridun Ay; Aykutlu Dâna; Atilla Aydinli

2006-01-01

366

Diffraction grating lens array  

NASA Astrophysics Data System (ADS)

We have proposed a new type of camera module with a thin structure and distance-detection capability. This camera module has a four-lens-array with diffraction gratings (one for blue, one for red, and two for green). The diffraction gratings on the mold are formed mechanically, and the plastic lens array is fabricated by injection molding. The two green images are compared to detect parallax, and parallax-corrected blue, red and green images are then composed to generate a color image. We have developed new design software and molding technologies for the grating lenses. The depth and period of blazed gratings and the shapes of aspheric lenses are optimized; and blue, red and two green aspheric lenses with gratings are molded as a single four-lens-array. The diffraction gratings on both surfaces of each lens act to improve field curvature and realize wide-angle imaging. However, blazed gratings sometimes cause unnecessary diffraction lights that impede the formation ofhigh-resolution images. We have developed a new method to measure necessary first-order diffraction lights and unnecessary diffraction lights separately. Use of this method allows the relationship between molding conditions and necessary/unnecessary diffraction lights to be shown. Unnecessary diffraction lights can be diminished by employing the optimal molding processes, allowing our grating lenses to be used for image capture.

Korenaga, Tsuguhiro; Ando, Takamasa; Moriguchi, Seiji; Takami, Fuminori; Takasu, Yoshifumi; Nishiwaki, Seiji; Suzuki, Masa-aki; Nagashima, Michiyoshi

2007-03-01

367

Efficiency measurements of the VIRTIS-M grating  

NASA Astrophysics Data System (ADS)

VIRTIS is an acronym for Visible and Infrared Thermal Imaging Spectrometer. It is an imaging spectrometer for the Rosetta mission, a mission to the comet 46P/Wirtanen. It is made of two channels: a high resolution one, named VIRTIS-H (resolving power up to 2000, spectral range 1-5 ?m) and the classical imaging spectrometer VIRTIS-M. The M in particular stands for "mapping" and is devoted to medium spectral resolution imaging. The spectral range of VIRTIS-M between 0.25 and 5 ?m is divided into two channels with a boundary at 1 ?m and a spectral resolution better than 3 nm. The peculiarity of the VIRTIS-M design is a custom grating produced by ZEISS, which consists of two different regions of groove spacing and shape to cover visible and infrared spectral regions with a single device. The grating efficiency has been designed in such a way to make the overall response of the spectrometer-target characteristic flat. The complex geometry of the grating makes the testing of the device alone, difficult. Another difficulty is that measurements should be performed at a low temperature (135 K). Therefore, we decided to use the development model of VIRTIS-M to perform the measurement of the grating efficiency first at ambient temperature. The measurement is done by comparing the light power of the order of interest of the grating to the light power of the zero-order when the grating is replaced by a mirror of the same geometry (no grooves). In this way we obtain a "relative" value. The efficiency is then compared to that of the mathematical model provided by ZEISS. The measurements compare well with the theoretical calculations.

Piccioni, G.; Amici, S.; Fonti, S.; Coradini, A.; Capaccioni, F.; Dami, M.

2000-04-01

368

Dual waveband compact catadioptric imaging spectrometer  

DOEpatents

A catadioptric dual waveband imaging spectrometer that covers the visible through short-wave infrared, and the midwave infrared spectral regions, dispersing the visible through shortwave infrared with a zinc selenide grating and midwave infrared with a sapphire prism. The grating and prism are at the cold stop position, enabling the pupil to be split between them. The spectra for both wavebands are focused onto the relevant sections of a single dual waveband detector. Spatial keystone distortion is controlled to less than one tenth of a pixel over the full wavelength range, facilitating the matching of the spectra in the midwave infrared with the shorter wavelength region.

Chrisp, Michael P.

2012-12-25

369

Performance of volume phase holographic transmission grating recorded in DCG for PGP  

NASA Astrophysics Data System (ADS)

The volume phase holographic (VPH) transmission grating recorded in dichromate gelatin (DCG) with a specific spectral coverage from 420 nm to 760 nm is designed for a novel prism-grating-prism imaging spectrometer. Based on the Rigorous Coupled-Wave Analysis, its performances are predicted and analyzed. The grating is manufactured and its properties are measured experimentally. The diffraction efficiency over the spectral range, the bandwidth, and the angular selectivity of the grating is measured, analyzed and compared with that of the theoretical ones. The results show that by adjusting and controlling the preparation conditions of DCG plates, the exposure time and the post-processing technique of the grating, the VPH transmission grating with high diffraction efficiency approximate to the design requirement can be obtained. The measured peak diffraction efficiency reaches nearly 85% at central wavelength of 590 nm while the average diffraction efficiency is larger than 75% over the required spectral range from 420 nm to 760 nm.

Li, Ming; Tang, Minxue; Xia, Haohan; Fang, Chunhuan; Wu, Jianhong; Zhao, Xunjie

2010-11-01

370

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

371

Optical system for high resolution spectrometer/monochromator  

SciTech Connect

This patent describes a spectrometer optical system employed in combination with a source of electromagnetic radiation and reception means. It comprises: a first concave mirror receiving electromagnetic radiation from the source and reflecting the electromagnetic radiation within a first plane; a second concave mirror receiving the electromagnetic radiation reflected from the source and reflecting the electromagnetic radiation to converge in a second plane. The first and second planes being substantially orthogonal relative to each other; a diffraction grating receiving the converging electromagnetic radiation from the source and producing a spectrum for capture by the reception means; and means for rotating the diffraction grating about an axis relative to the diffraction grating.

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

1988-10-11

372

An imaging extreme ultraviolet spectrometer for astrophysical investigations in space  

NASA Technical Reports Server (NTRS)

A high-efficiency, extreme ultraviolet (EUV) imaging spectrometer has been 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 submaster grating which is 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 have verified the image quality of the toroidal grating at wavelengths near 600 A. The basic designs of two instruments employing the spectrometer for astrophysical investigations in space are described, namely, a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona; and an EUV spectroscopic telescope for studies of nonsolar objects.

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

1986-01-01

373

Planar Rowland spectrometer for fiber-optic wavelength demultiplexing.  

PubMed

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 grating attached to one of the end faces. Semiconductor lasers with wavelengths between 0.825 and 0.845 microm were used for the measurements. Cross-talk isolation between two adjacent fibers with center-to-center separation of 175 microm (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. PMID:19710799

Yen, H W; Friedrich, H R; Morrison, R J; Tangonan, G L

1981-12-01

374

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

375

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

376

Dynamic-grating lasers  

NASA Astrophysics Data System (ADS)

The performance characteristics of dynamic-grating lasers, or degenerate four-wave mixing (FWM) lasers, are examined. In particular, attention is given to the general designs of FWM lasers, new efficient nonlinear lasing media (e.g., Ba2NaNb5O15 crystals), and lasers based on anisotropic diffraction gratings in crystals with photogalvanic nonlinearity (e.g., LiNbO3:Cu). Lasers based on media with local nonlinear response are also discussed.

Odulov, S. G.; Soskin, M. S.; Khizhniak, A. I.

1988-02-01

377

Blazed phononic crystal grating  

NASA Astrophysics Data System (ADS)

It is well known that blazed optical diffraction gratings can significantly increase the diffraction efficiency of plane waves for a selected angle of incidence. We show that by combining blazing with a phononic band gap, diffraction efficiency approaching 100% can be achieved for acoustic waves. We obtain experimentally 98% diffraction efficiency with a two-dimensional phononic crystal of rotated steel rods of square cross-section immersed in water. This result opens the way toward the design of efficient phononic crystal gratings.

Moiseyenko, Rayisa P.; Liu, Jingfei; Declercq, Nico F.; Laude, Vincent

2013-01-01

378

Diffraction grating lens array  

Microsoft Academic Search

We have proposed a new type of camera module with a thin structure and distance-detection capability. This camera module has a four-lens-array with diffraction gratings (one for blue, one for red, and two for green). The diffraction gratings on the mold are formed mechanically, and the plastic lens array is fabricated by injection molding. The two green images are compared

Tsuguhiro Korenaga; Takamasa Ando; Seiji Moriguchi; Fuminori Takami; Yoshifumi Takasu; Seiji Nishiwaki; Masa-aki Suzuki; Michiyoshi Nagashima

2007-01-01

379

Diffraction Gratings WDM Components  

Microsoft Academic Search

Diffraction grating WDM components have tremendous capability in number of channels (160 channel components and more with\\u000a bi-directionality are commercially available and components with two times more channels have been demonstrated experimentally).\\u000a They have a high free spectral range (typically 775 nm with gratings working in the first order). Small spacing such as 25\\u000a GHz is commercially available and 5

Jean-Pierre Laude

380

Reduction of echelle and long-slit Zeeman spectra in MIDAS  

NASA Astrophysics Data System (ADS)

The use of CCD detectors generates a need for elaboration of programmes for reduction of astronomical digital images. Zeeman spectra observed with echelle and long-slit spectrographs are a special sort of such images. The reduction of Zeeman spectra has a number of specific peculiarities which are not provided in standard spectral data reduction programmes. In this article we describe a set of programmes for the reduction of Zeeman spectra. The programmes have been designed as an ESO MIDAS context. The context allows the standard reduction of both echelle and long-slit Zeeman spectra to be made. Moreover the context contains programmes allowing automation of positional measurements for calculation of the effective magnetic field and measurement of radial velocities. An ability to reduce normal, not Zeeman, spectra has been provided.

Kudryavtsev, D. O.

381

Gratings in polymeric waveguides  

NASA Astrophysics Data System (ADS)

Laser-induced formation of polymer Bragg grating filters for Dense Wavelength Division Multiplexing (DWDM) applications is discussed. Acrylate monomers halogenated with both fluorine and chlorine, which possess absorption losses less than 0.25 dB/cm and wide choice of refractive indices (from 1.3 to 1.5) in the 1.5 ?m telecom wavelength region were used. The monomers are highly intermixable thus permitting to adjust the refractive index of the composition within +/-0.0001. Moreover they are photocurable under UV exposure and exhibit high contrast in polymerization. These properties make halogenated acrylates very promising for fabricating polymeric waveguides and photonic circuits. Single-mode polymer waveguides were fabricated on silicon wafers using resistless contact lithography. Submicron index gratings have been written in polymer waveguides using holographic exposure with He-Cd laser beam (325 nm) through a phase mask. Both uniform and apodized gratings have been fabricated. The gratings are stable and are not erased by uniform UV exposure. The waveguide gratings possess narrowband reflection spectra in the 1.5 ?m wavelength region of 0.4 nm width, nearly rectangular shape of the stopband and reflectivity R > 99%. The fabricated Bragg grating filters can be used for multiplexing/demultiplexing optical signals in high-speed DWDM optical fiber networks.

Mishakov, G.; Sokolov, V.; Kocabas, A.; Aydinli, A.

2007-04-01

382

CaII H&K to CaII IRT echelle spectra (Montes+, 2000)  

Microsoft Academic Search

This is the third paper of a series aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features. High resolution echelle spectra including all the optical chromospheric activity indicators from the CaII H&K to CaII IRT lines are analysed here for 16 systems. The chromospheric contribution in these lines has been determined

D. Montes; M. J. Fernandez-Figueroa; E. de Castro; M. Cornide; A. Latorre; J. Sanz-Forcada

2000-01-01

383

[Development of X-ray Reflection Grating Technology for the Constellation-X Mission  

NASA Technical Reports Server (NTRS)

This Grant supports MIT technology development of x-ray reflection gratings for the Constellation-X Reflection Grating Spectrometer (RGS). Since the start of the Grant MIT has extended its previously-developed patterning and super-smooth, blazed grating fabrication technology to ten-times smaller grating periods and ten-times larger blaze angles to demonstrate feasibility and performance in the off-plane grating geometry. In the past year we have focused our efforts on extending our Nanoruler grating fabrication tool to enable it to perform variable-period scanning-beam interference lithography (VP-SBIL). This new capability required extensive optical and mechanical improvements to the system. The design phase of this work is largely completed and key components are now on order and assembly has begun. Over the next several months the new VP-SBIL Nanoruler system will be completed and testing begun. We have also demonstrated a new technique for patterning gratings using the Nanoruler called Doppler mode, which will be important for patterning the radial groove gratings for the RGS using the new VP-SBIL system. Flat and thin grating substrates will be critical for the RGS. In the last year we demonstrated a new technique for flattening thin substrates using magneto-rheologic fluid polishing (MRF) and achieved 2 arcsecond flatness with a 0.5 mm-thick substrate-a world's record. This meets the Con X requirement for grating substrate flatness.

Schattenburg, Mark L.

2005-01-01

384

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

385

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

386

Applications of multichannel imaging spectrometer  

NASA Astrophysics Data System (ADS)

The described system applies advanced Volume Phase Holographic (VPH) diffraction gratings to provide a high-performance, line imaging / multichannel spectrometer. Specifically designed optics produces spectrally dispersed image of the input slit on a two dimensional array of photodetectors in such a way that the full width, half maximum (FWHM) of monochromatic image of each point of the slit is not larger than a single pixel at the detector end. Correcting for aberrations typical to most other multichannel spectrometers allows for the creation of an instrument with very high spatial and spectral resolutions. Appropriate selection of collection fibers arranged along an entrance slit of the spectrometer renders the system into a multichannel spectrometer, where the number of channels is determined by the number of fibers within an 8mm long slit and their separation. The superior performance of the instrument opens the door to numerous applications in technical and biomedical research, process control, homeland security and other application where high performance and/or simultaneous spectral measurement of UV/VIS/NIR radiation produced at multiple sites is required.

Pawluczyk, Olga; Pawluczyk, Romuald

2004-10-01

387

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

González-Núñez, Héctor; Prieto-Blanco, Xesús; de la Fuente, Raúl

2012-04-01

388

Analysis and design of a concave diffraction grating with total-internal-reflection facets by a hybrid diffraction method.  

PubMed

A novel hybrid diffraction method is introduced to simulate the diffraction and imaging of a planar-integrated concave grating that has total internal reflection (TIR) facets. The Kirchhoff-Huygens diffraction formula is adopted to simulate the propagation of the lightwave field in the free-propagation region, and a rigorous coupled-wave analysis is used to calculate the polarization-dependent diffraction by the grating. The hybrid diffraction method can be used to analyze accurately the imaging properties as well as the polarization-dependent diffraction characteristics of a concave grating. The dependence of several merit parameters of a concave grating with TIR facets on its basic geometric parameters is studied. Compared with one with metallic echelle facets, a concave grating with TIR facets shows a much lower polarization-dependent loss. Since more performance specifications can be considered in the design of a concave grating than with the conventional scalar method, design error can be reduced greatly with the present hybrid diffraction method. PMID:15260252

Shi, Zhimin; He, Jian-Jun; He, Sailing

2004-07-01

389

Spectrometer system for diffuse extreme ultraviolet radiation  

Microsoft Academic Search

A unique grazing incidence spectrometer system has been designed to study diffuse line emission between 80 and 650 A with 10-30 A resolution. The minimum detectable emission line strength during a 5-min observation ranges from 100-2000 ph\\/sq cm sec str. The instrument uses mechanically ruled reflection gratings placed in front of a linear array of mirrors. These mirrors focus the

Simon E. Labov

1989-01-01

390

Immersion grating mount design for IGRINS and GMTNIRS  

NASA Astrophysics Data System (ADS)

The IGRINS (Immersion GRating INfrared Spectrometer) is a high resolution wide-band infrared spectrograph developed by the Korea Astronomy and Space Science Institute (KASI) and the University of Texas at Austin (UT). Immersion grating is a key component of IGRINS, which disperses the input ray by using a silicon material with a lithography technology. Optomechanical mount for the immersion grating is important to keep the high spectral resolution and the optical alignment in a cold temperature of 130+/-0.06K. The optical performance of immersion grating can maintain within the de-center tolerance of +/-0.05mm and the tip-tilt tolerance of +/-1.5arcmin. The mount mechanism utilizes the flexure and the semikinematic support design to satisfy the requirement and the operation condition. When the IGRINS system is cooled down to a cold temperature, three flexures compensate for the thermal contraction stress due to the different material between the immersion grating and the mounting part (aluminum 6061). They also support the immersion grating by an appropriate preload. Thermal stability is controlled by a copper strap with proper dimensions and a heater. Typically, structural and thermal analysis was performed to confirm the mount mechanism. This mechanism will be also applied to the GMTNIRS (Giant Magellan Telescope Near InfraRed Spectrograph) instrument, which is a first-generation candidate of the GMT telescope.

Moon, Bongkon; Wang, Weisong; Park, Chan; Yuk, In-soo; Chun, Moo-Young; Jaffe, Daniel T.

2012-09-01

391

Preliminary design of IGRINS (Immersion GRating INfrared Spectrograph)  

NASA Astrophysics Data System (ADS)

The Korea Astronomy and Space Science Institute (KASI) and the Department of Astronomy at the University of Texas at Austin (UT) are developing a near infrared wide-band high resolution spectrograph, IGRINS. IGRINS can observe all of the H- and K-band atmospheric windows with a resolving power of 40,000 in a single exposure. The spectrograph uses a white pupil cross-dispersed layout and includes a dichroic to divide the light between separate H and K cameras, each provided with a 2kx2k HgCdTe detector. A silicon immersion grating serves as the primary disperser and a pair of volume phased holographic gratings serve as cross dispersers, allowing the high resolution echelle spectrograph to be very compact. IGRINS is designed to be compatible with telescopes ranging in diameter from 2.7m (the Harlan J. Smith telescope; HJST) to 4 - 8 m telescopes. Commissioning and initial operation will be on the 2.7m telescope at McDonald Observatory from 2013.

Yuk, In-Soo; Jaffe, Daniel T.; Barnes, Stuart; Chun, Moo-Young; Park, Chan; Lee, Sungho; Lee, Hanshin; Wang, Weisong; Park, Kwi-Jong; Pak, Soojong; Strubhar, Joseph; Deen, Casey; Oh, Heeyoung; Seo, Haingja; Pyo, Tae-Soo; Park, Won-Kee; Lacy, John; Goertz, John; Rand, Jared; Gully-Santiago, Michael

2010-07-01

392

Immersion grating and etched gratings for infrared astronomy  

Microsoft Academic Search

An immersion grating with a high refractive index, n, increases the spectral resolution by a factor n over that of a reflective surface grating of equal length. A silicon immersion grating has been developed and tested; initial results are reported here.

Guenter R. Wiedemann; Hemant H. Dave; Donald E. Jennings

1993-01-01

393

Nanofabrication advances for high efficiency critical-angle transmission gratings  

NASA Astrophysics Data System (ADS)

We report several break-through nanofabrication developments enabling high efficiency and high resolving power spectrometers in the soft x-ray band. The device is the critical-angle transmission (CAT) grating, which combines the low mass and relaxed alignment tolerances of a transmission grating with the high broad-band efficiency and high diffraction orders of a blazed reflection grating. Past work successfully demonstrated the CAT grating concept; however, the open-area fraction was often less than 20% whilst more than 50% is desired. This presents numerous nanofabrication challenges including a requirement for a freestanding silicon membrane of ultra high-aspect ratio bars at a period of 200 nanometers with minimal cross support blockage. Furthermore, the sidewalls must be smooth to a few nanometers to efficiently reflect soft x-rays. We have developed a complete nanofabrication process for creating freestanding CAT gratings via plasma-etching silicon wafers with a buried layer of SiO2. This removable buried layer enables combining a record-performance plasma etch for the CAT grating with a millimeter-scale honeycomb structural support to create a large-area freestanding membrane. We have also developed a process for polishing sidewalls of plasma-etched ultra-high aspect ratio nanoscale silicon structures via potassium hydroxide (KOH). This process utilizes the anisotropic etch nature of single crystal silicon in KOH. We developed a novel alignment technique to align the CAT grating bars to the {111} planes of silicon within 0.2 degrees, which enables KOH to etch away sidewall roughness without destroying the structure, since the {111} planes etch approximately 100 times slower than the non-{111} planes. Preliminary results of a combined freestanding grating with polishing are presented to enable efficient diffraction of soft x-rays.

Bruccoleri, Alexander R.; Guan, Dong; Heilmann, Ralf K.; Vargo, Steve; DiPiazza, Frank; Schattenburg, Mark L.

2013-09-01

394

Multiplexing fiber bragg grating sensors  

Microsoft Academic Search

Bragg reflection gratings and out-coupling taps for sensors can be written holographically within the core of many commercial fibers available today. The gratings appear to be permanent and have been tested to temperatures in excess of 500°C. Quasi-distributed temperature, strain, pressure, chemical, and interferometric sensors can be made with the wavelength selective, reflection gratings, and taps. The fiber gratings, and

W. W. Morey; J. R. Dunphy; G. Meltz

1991-01-01

395

Designing an acousto-optical spectrometer for Guillermo Haro Astrophysical Observatory  

NASA Astrophysics Data System (ADS)

The Guillermo Haro astrophysical observatory (Mexico) realizes investigations in the visible and near-infrared range . Actually, the classical grating spectrometer with mechanically removable optical filters and diffraction gratings is exploited there. Unfortunately, the regular process of changing the diffraction gratings with different resolutions and recalibrating the spectrometer is inconvenient and wastes expensive time for observations. This is why exploiting an acousto-optical cell as a dynamic dispersive element is practically desirable, because potentially it realizes tuning the spectral resolution and the range of observation electronically and excludes filters. Some aspects of inserting just one dynamic acousto-optical diffraction grating instead of a set of the traditional static diffraction gratings are preliminarily considered.

Shcherbakov, Alexandre S.; Arellanes Bernabe, Adan Omar; Chavushyan, Vahram

2013-09-01

396

Straylight measurements of immersed gratings for high-resolution spectroscopy in the near infrared  

Microsoft Academic Search

New immersed grating technology is needed particularly for use in imaging spectrometers that will be used in sensing the atmosphere O2A spectral band (750nm - 775 nm) at spectral resolution in the order of 0.1 nm whilst keeping a high efficiency and low stray light. In this work, an Ion-beam etched grating in a fused-silica substrate of 100 mm 100mm

J. Fernandez-Saldivar; I. Bhatti; D. Lobb; B. Touzet; B. Guldimann

2011-01-01

397

Sectioned thin-film grating  

Microsoft Academic Search

The resolving power of metallic linear gratings deposited on a dielectric thin-film waveguide can be increased by separating sections of the grating by blank spaces. Because of the high coupling efficiencies of gratings deposited directly on the waveguide, the effects of the blank spaces cannot be observed for such guides. If a dielectric film with an index of refraction less

W. D. Westwood; J. W. Y. Lit

1974-01-01

398

An elastomeric grating coupler  

NASA Astrophysics Data System (ADS)

We report on a novel nondestructive and reversible method for coupling free space light to planar optical waveguides. In this method, an elastomeric grating is used to produce an effective refractive index modulation on the surface of the optical waveguide. The external elastomeric grating binds to the surface of the waveguide with van der Waals forces and makes conformal contact without any applied pressure. As a demonstration of the feasibility of the approach, we use it to measure the refractive index of a silicon oxynitride film. This technique is nondestructive, reversible, low cost and can easily be applied to the characterization of optical materials for integrated optics.

Kocabas, Askin; Ay, Feridun; Dâna, Aykutlu; Aydinli, Atilla

2006-01-01

399

Subwavelength grating filtering devices.  

PubMed

We propose and simulate the characteristics of optical filters based on subwavelength gratings. In particular, we demonstrate through numerical simulations the feasibility of implementing SWG Bragg gratings in silicon-on-insulator (SOI). We also propose SWG ring resonators in SOI and verify their operation using numerical simulations and experiments. The fabricated devices exhibit an extinction ratio as large as 30 dB and a Q-factor as high as ~20,000. These fundamental SWG filters can serve as building blocks for more complex devices. PMID:24977793

Wang, Junjia; Glesk, Ivan; Chen, Lawrence R

2014-06-30

400

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

401

Monolithic micro-spectrometer for low-cost sensing in materials processing  

Microsoft Academic Search

We have developed a monolithic micro-spectrometer suitable for a variety of sensing applications including industrial process monitoring. The device consists of a solid structure with a volume less than 6 cubic centimeters. All optical components of the spectrometer including two aspheric mirrors, a diffraction grating, and entrance and exit surfaces are fabricated onto the surface of the structure. All light

C. M. Egert; S. Rajic

1997-01-01

402

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

403

Z-Spec: A Dispersive Millimeter-Wave Spectrometer  

NASA Astrophysics Data System (ADS)

Z-Spec is a broad-band, moderate-resolution spectrometer employing a WaFIRS waveguide-coupled diffraction grating to an array of bolometers. We briefly describe the science case for the instrument, summarize its design, and present recent results from laboratory measurements and initial astronomical observations.

Glenn, J.; Aikin, R.; Aguirre, J.; Earle, L.; Maloney, P.; Bock, J. J.; Bradford, C. M.; Dragovan, M.; Nguyen, H.; Naylor, B.; Zmuidzinas, J.; Duband, L.; Matsuhara, H.; Ade, P. A. R.

2007-10-01

404

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

405

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

406

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

407

Optical properties of light emitting diodes with a cascading plasmonic grating.  

PubMed

In this paper, the polarization dependent optical properties of InGaN/GaN multi-quantum wells (MQWs) LED with cascading plasmonic gratings are investigated using an angle-resolved photoluminescence (ARPL) spectrometer. The plasmonic gratings consist of two Ag gratings with a half-pitch displacement. The ARPL spectra of the TE-TM state present a broadband emission with resonance dips occasioned by the SP resonance while the TM-TE state presents resonance peaks with low sideband emission. The resonance properties can be tuned by modifying the geometric parameters of the plasmonic grating. The ARPL spectrum of the LED sample with pure GaN 1D grating is also measured and discussed. The investigated plasmonics LED represents resonance optical properties different from the conventional surface relief LED, which can be used in special applications. PMID:21164906

Wang, Chih-Ming; Tsai, Yao-Lin; Tu, Sheng-Han; Lee, Chien-Chieh; Kuo, Cheng-Huang; Chang, Jenq-Yang

2010-12-01

408

Raman spectroscopy with an integrated arrayed-waveguide grating.  

PubMed

An integrated arrayed-waveguide grating fabricated in silicon-oxynitride technology is applied to Raman spectroscopy. After its validation by reproducing the well-known spectrum of cyclohexane, polarized Raman spectra are measured of extracted human teeth containing localized initial carious lesions. Excellent agreement is obtained between the spectra of healthy and carious tooth enamel measured with our integrated device and spectra recorded using a conventional Raman spectrometer. Our results represent a step toward the realization of compact, hand-held, integrated spectrometers, e.g. for the detection of dental caries at an early stage. PMID:22139265

Ismail, N; Choo-Smith, L-P; Wörhoff, K; Driessen, A; Baclig, A C; Caspers, P J; Puppels, G J; de Ridder, R M; Pollnau, M

2011-12-01

409

Groove profile modification of convex blazed gratings by dip (spin) coating with photoresist  

NASA Astrophysics Data System (ADS)

The Offner-like spectrometer, one most widely used hyperspectral imaging spectrometers, offers some advantages over other spectrometers used in pushbroom imaging spectrometry: low chromatic aberrations, a compact size with low optical distortion, and large numerical aperture. The standard Offner spectrometer is made of three spherical concentric elements-- two concave mirrors and one convex grating. Convex grating is the core part of Offner type hyper-spectral imager. Considering the difficulties in fabrication of small angles convex gratings by traditional ways, we propose a new method. The ion-beam-etching holographic grating is adopted to obtain the convex blazed gratings with blazed angle of 4°--5°, whose angle can be further reduced by dipping or spinning coating with hardenable liquids. A highly reproducible blaze angle reduction to as high as a factor of 3 is achieved by controlling the spinning speed and viscosity of solution. The precise control of the blaze angles and groove profiles will be further studied focusing on the designing of rotate dip equipment and optimization of pulling speed and viscosity of solution.

Cheng, Yu; Liu, Quan; Wu, Jianhong

2013-12-01

410

High-resolution Fourier transform spectrograph for characterization of echelle spectrograph wavelength calibrators  

NASA Astrophysics Data System (ADS)

Wavelength calibrators are a critical component of high precision and accuracy radial velocity measurements. An order of magnitude improvement of the state-of-the-art of calibration of echelle spectrographs is amongst the requirements needed to achieve detection of earth-mass planets around sun-like stars in the habitable zone. We present studies of calibrators using a custom Fourier Transform Spectrograph (FTS) optimized for characterizing broadband, high repetition-rate laser frequency combs ("astro-combs") as well as other calibration sources including Th:Ar lamps and white-light etalons.

Glenday, Alexander G.; Phillips, David F.; Webber, Matthew; Li, Chih-Hao; Furesz, Gabor; Chang, Guoqing; Chen, Li-Jin; Kärtner, Franz X.; Sasselov, Dimitar D.; Szentgyorgyi, Andrew H.; Walsworth, Ronald L.

2012-09-01

411

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

NASA Astrophysics Data System (ADS)

Large area, high resolving power spectroscopy in the soft x-ray band can only be achieved with a state-of-the-art diffraction grating spectrometer, comprised of large collecting-area focusing optics with a narrow point spread function, large-area high-resolving power diffraction gratings, and small pixel, order sorting x-ray detectors. Recently developed critical-angle transmission (CAT) gratings combine the advantages of transmission gratings (low mass, relaxed figure and alignment tolerances) and blazed reflection gratings (high broad band diffraction efficiency, utilization of higher diffraction orders). Several new mission concepts containing CAT grating based spectrometers (AEGIS, AXSIO, SMART-X) promise to deliver unprecedented order-of-magnitude improvements in soft x-ray spectroscopy figures of merit related to the detection and characterization of emission and absorption lines, thereby addressing high-priority questions identified in the Astro2010 Decadal Survey "New Worlds New Horizons". We review the current status of CAT grating fabrication, present recent fabrication results, and describe our plans and technology development roadmap for the coming year and beyond.

Heilmann, Ralf K.; Bruccoleri, Alex R.; Guan, Dong; Schattenburg, Mark L.

2013-09-01

412

Binary gratings with random heights  

SciTech Connect

We analyze the far-field intensity distribution of binary phase gratings whose strips present certain randomness in their height. A statistical analysis based on the mutual coherence function is done in the plane just after the grating. Then, the mutual coherence function is propagated to the far field and the intensity distribution is obtained. Generally, the intensity of the diffraction orders decreases in comparison to that of the ideal perfect grating. Several important limit cases, such as low- and high-randomness perturbed gratings, are analyzed. In the high-randomness limit, the phase grating is equivalent to an amplitude grating plus a ''halo.'' Although these structures are not purely periodic, they behave approximately as a diffraction grating.

Rico-Garcia, Jose Maria; Sanchez-Brea, Luis Miguel

2009-06-01

413

Degradation-Free Spectrometers for Solar EUV Measurements: A Progress Report  

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 2010. 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 is designed to provide solar irradiance at Lyman-alpha and He II to overlap EUV observations from SOHO/SEM and SDO/EVE. Electronic and mechanical designs for the flight prototype instruments and results of tests performed with the instruments in the laboratory are reported. 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.; Judge, D. L.; Didkovsky, L. V.

2009-12-01

414

Far-Ultraviolet Space Telescope Imaging Spectrometer Spectra of the White Dwarf REJ 1032+532. I. Interstellar Line of Sight  

NASA Astrophysics Data System (ADS)

An 1150-1725 Å echelle spectrum of the hot DA white dwarf REJ 1032+532, recently obtained with the Space Telescope Imaging Spectrometer E140M grating, reveals numerous stellar and interstellar lines. The interstellar column densities and abundances of C, N, O, Si, and S relative to the directly measured H column are determined for this particular line of sight through the local interstellar medium (ISM). An estimate of the electron density, ne=0.11+0.07-0.06, is obtained from the population ratio of the excited to ground state fine-structure levels in C II. This electron volume density is compared with an independent Extreme Ultraviolet Explorer measurement of the total line-of-sight electron column density derived from the ionization state of H and He. A path length of ~10 pc is estimated for the region responsible for the bulk of the ISM absorption. From the observed ISM velocity components, we identify this absorbing component as the local interstellar cloud (LIC) surrounding the solar system. For the LIC we find the abundances of nitrogen, oxygen, and silicon relative to hydrogen to be significantly less than those characteristic of much longer lines of sight through the local ISM. The LIC abundances of these elements are very consistent with the recent determinations of Vidal-Madjar and coworkers for the LIC. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Holberg, , J. B.; Bruhweiler, , F. C.; Barstow, M. A.; Dobbie, P. D.

1999-06-01

415

High efficiency extreme ultraviolet overview spectrometer: Construction and laboratory testing  

SciTech Connect

The new high efficiency extreme ultraviolet overview spectrometer system (HEXOS) has been developed to study impurity concentrations and impurity transport properties in the plasma of the stellarator W7-X. The HEXOS system consists of four different grating based spectrometers, which provide large etendue and good spectral resolution over a broad wavelength range (2.5-160 nm, divided into four subsections with some overlapping). The mechanical arrangement as two double spectrometers allows for a compact installation geometry on W7-X. Laboratory testing and wavelength and intensity calibrations have been performed using a dc hollow cathode discharge (24-150 nm) and a pinch discharge (2.5-30 nm)

Biel, W.; Greiche, A.; Burhenn, R.; Jourdain, E.; Lepere, D. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, EURATOM Association, Trilateral Euregio Cluster, D-52425 Juelich (Germany); Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Jobin-Yvon SAS, F-91165 Longjumeau (France)

2006-10-15

416

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

417

Miniaturized UV/VIS spectrometer made by MOEMS technology  

NASA Astrophysics Data System (ADS)

In recent years, many compact spectrometers for purposes such as environmental monitoring and process quality control in industrial production have been realized. However, most of them still employ spectrometer mounts with focal lengths in the range of several cm. Therefore, their size is about that of a palm which is too large for OEM-use in handily sized optical sensor equipment. Accordingly, we have developed a thumb-sized, truly miniaturized spectrometer for the spectral range 340nm to 750nm, which is particularly suited for use inside hand-held or portable color management sensor equipment. The spectrometer is using a self-imaging, aberration-corrected concave grating with very short focal length and a blazed grating profile for high diffraction efficiency. The grating is replicated onto the top of a convex glass lens using nano-imprint technology. Opposite to the concave grating, a dedicated C-MOS image sensor with an in-built on-chip slit is placed. The slit with a width of 75?m is formed into the silicon chip using MEMS technology. Due to this advanced technology, the distance between the sensor area and the slit is as small as 1mm. Based on this high level of integration, the number of optical components could be kept to a minimum and the distance between the concave grating and C-MOS image sensor is about 8.5mm only. In summary, we have realized a well-performing miniaturized spectrometer with an extremely small package size of 28mm - 17mm - 13mm and a weight of only about 9g, which is highly suited for integration into optical sensing equipment.

Shibayama, Katsumi; Yokino, Takafumi; Hikita, Katsuro; Iwasaki, Norihiro; Teichmann, Helmut; Staerker, Ulrich; Diprima, Flavio; Yamamoto, Koei

2009-02-01

418

Distributed grating sensors: an alternative to multiplexed grating arrays?  

NASA Astrophysics Data System (ADS)

Fiber Bragg gratings have been widely used for smart structures sensing applications. Until recently all sensor systems using gratings have only measured the average value of a physical field. The field has been averaged either over the length of a grating or over a length of fiber between gratings. To obtain a spatial image of the physical field, these sensors have been multiplexed to form a sensor array. Recently, fully distributed images of physical fields have been measured along the entire length of a grating. Distributed sensors show great promise for the detection and location of small physical features within structures, such as cracks and hot spots. As the fabrication length of gratings continues to increase, there appears great potential for distributed grating sensors. Distributed grating sensors may be classified as either narrowband or broadband, according to the spectral width of the interrogation source. Both types of sensor are discussed and briefly compared. The various forms of averaging grating sensors are also discussed and their performance is compared with that of distributed grating sensors using two specific smart structures applications. The latest results of our broadband distributed sensor are presented. This distributed sensor may be viewed as an adaptive averaging sensor since the number of interrogation regions, their size, location and the spatial resolution may all be viewed in response to the sensing information. Finally, a sensing network combining the advantages of both multiplexed and distributed sensors is demonstrated and discussed.

Volanthen, Mark; Geiger, Harald; Dakin, John P.

1997-06-01

419

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

420

Progress in the development of critical-angle transmission gratings  

NASA Astrophysics Data System (ADS)

Recently developed Critical-Angle Transmission (CAT) grating technology - in combination with x-ray CCD cameras and large collecting-area focusing optics - will enable a new generation of soft x-ray spectrometers with unprecedented resolving power and effective area and with at least an order of magnitude improvement in figures-of-merit for emission and absorption line detection. This technology will be essential to address a number of high-priority questions identified in the Astro2010 Decadal Survey “New Worlds New Horizons” and open the door to a new discovery space. CAT gratings combine the advantages of soft x-ray transmission gratings (low mass, relaxed figure and alignment tolerances, transparent at high energies) and blazed reflection gratings (high broad band diffraction efficiency, utilization of higher diffraction orders to increase resolving power). We report on progress in the fabrication of large-area (31× 31 mm2) free-standing gratings with two levels of low-blockage support structures using highly anisotropic deep reactive-ion etching.

Heilmann, Ralf K.; Bruccoleri, Alex R.; Mukherjee, Pran; Schattenburg, Mark L.

2012-09-01

421

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

422

Spectrometer Technology Development for Far-Infrared Line Surveys  

NASA Technical Reports Server (NTRS)

The objective of this proposal was to build and demonstrate a new direct-detection diffraction grating concept and couple it to an array of bolometers. The spectrometer was to be built around a parallel-plate waveguide diffraction grating, WaFIRS: Waveguide Far-InfraRed Spectrometer. The grating is two dimensional in nature, which provides a compact configuration to suit NASA s needs for cryogenic spectrometers for future opportunities, such as infrared/submillimeter spectrometers for a suborbital balloon platform, for SOFIA, for SPICA (a Japanese satellite), and for SAFIR. Our goal was to build a spectrometer (Z-Spec) for 1.0 - 1.5 mm and demonstrate spectral resolution, throughput, and background-limited performance. This grant would partially cover the expenses and we were subsequently awarded a second grant, NAGS-12788, to complete the project. We have one-year received a no-cost extension on NAG.5-12788, to be completed in 3/31/06.

Glenn, Jason

2005-01-01

423

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

424

ECHARPE: a fiber-fed echelle spectrograph for the Pico dos Dias Observatory  

NASA Astrophysics Data System (ADS)

At least during the last ten years, the Brazilian astronomical community has been asking for an echelle spectrograph for the 1.6 m telescope installed at Pico dos Dias Observatory (Brazópolis, MG, Brazil, OPD/MCTI/LNA). Among the scientific cases are topics related to the chemical evolution of the Galaxy, asteroseismology, chemical composition and chromospheric activities of solar type stars and the relations between solar analogues and terrestrial planets. During 2009 the project finally got started. The called ECHARPE spectrograph (Espectrógrafo ECHelle de Alta Resolução para o telescópio Perkin-Elmer) is being projected to offer a spectral resolution of R ~ 50000, in the range 390-900 nm and with a single exposition. It will be a bench spectrograph with two channels: blue and red, fed by two optical fibers (object, sky or calibration) with aperture of 1.5 or 2.0 arcseconds. The instrument will be placed in one of the telescope pillar ramification, in the originals installations of a Coudé spectrograph and in a specially created environment controlled room. In this work we will present the scientific motivations, the conceptual optical design, the expected performance of the spectrograph, and the status of its development. ECHARPE is expected to be delivered to the astronomical community in 2014, fully prepared and optimized for remote operations.

Dominici, Tania P.; Castilho, Bruno; Gneiding, Clemens D.; Delabre, Bernard A.; Macanhan, Vanessa B. P.; de Arruda, Marcio V.; de Oliveira, Antonio C.; Melendez, Jorge; Vaz, Luiz P. R.; Corradi, Wagner J. B.; Franco, Gabriel A. P.; do Nascimento, Jose D.; Quast, Germano R.; Porto de Mello, Gustavo F.

2012-09-01

425

Three infrared spectrometers, an atmospheric chemistry suite for the ExoMars 2016 trace gas orbiter  

NASA Astrophysics Data System (ADS)

The atmospheric chemistry suite (ACS) package is a part of the Russian contribution to the ExoMars ESA-Roscosmos mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. The near-infrared (NIR) channel is a versatile spectrometer for the spectral range of 0.7-1.6 ?m with a resolving power of ˜20,000. The instrument employs the principle of an echelle spectrometer with an acousto-optical tunable filter (AOTF) as a preselector. NIR will be operated in nadir, in solar occultations, and possibly on the limb. Scientific targets of NIR are the measurements of water vapor, aerosols, and dayside or nightside airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the range of 2.2-4.4 ?m targeting the resolving power of 50,000. MIR is dedicated to sensitive measurements of trace gases. The thermal infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer for the spectral range of 1.7-17 ?m with apodized resolution varying from 0.2 to 1.6 cm-1. TIRVIM is primarily dedicated to the monitoring of atmospheric temperatures and aerosol states in nadir. The present paper describes the concept of the instrument, and in more detail, the optical design and the expected parameters of its three parts channel by channel.

Korablev, Oleg; Trokhimovsky, Alexander; Grigoriev, Alexei V.; Shakun, Alexei; Ivanov, Yuriy S.; Moshkin, Boris; Anufreychik, Konstantin; Timonin, Denis; Dziuban, Ilia; Kalinnikov, Yurii K.; Montmessin, Franck

2014-01-01

426

Space-Resolved VUV and EUV Spectrometers in HL-2A  

NASA Astrophysics Data System (ADS)

A normal incidence vacuum ultraviolet (VUV) and a grazing incidence extreme ultraviolet (EUV) spectrometers have been developed for the edge and core impurity measurements in HL-2A tokamak. The VUV and the EUV spectrometers cover wavelength ranges of 300~3200 Å and 50~500 Å, respectively. A spatial resolution of 2 mm has been achieved for the VUV spectrometer when a space-resolved slit 50 ?m in width is used. The space-resolved slit is placed between the entrance slit and the grating of the spectrometer. The spectral resolutions of 0.15 Å for the VUV spectrometer in the wavelength coverage of the concave 1200 grooves/mm grating and of 0.22 Å for the EUV spectrometer at ?=200 Å with a flat-field laminar-type holographic grating are obtained. The sensitivity of the VUV spectrometer was calibrated in situ with the plasma bremsstrahlung radiation. The experimental results from both spectrometers are presented, especially the line intensity radial profiles measured by the VUV spectrometer.

Cui, Zhengying; Zhou, Hangyu; Morita, S.; Fu, Bingzhong; Sun, Ping; Gao, Yadong; Goto, M.; Xu, Yuan; Dong, Chunfeng; Yang, Qingwei

2013-02-01

427

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

428

Asymmetric acoustic gratings  

NASA Astrophysics Data System (ADS)

The unidirectional transmission of acoustic waves is realized by a simple geometrically asymmetric steel grating structure. This exotic phenomenon stems from the one-way diffraction effect induced by the different periods of the slits on the both surfaces of the sample. And the frequency range of unidirectional transmission is simply determined by the structure periods. The experimental results agree well with the theoretical simulation. This remarkable effect is expected potential applications in ultrasonic devices, such as acoustic rectifiers and acoustic diodes.

He, Zhaojian; Peng, Shasha; Ye, Yangtao; Dai, Zhongwei; Qiu, Chunyin; Ke, Manzhu; Liu, Zhengyou

2011-02-01

429

Grating-structured metallic microsprings.  

PubMed

We fabricate grating-structured metallic microsprings with well-defined helical angles and diameters, which are self-rolled from strained nanomembranes patterned with gratings. The grating structures on the metal membrane, replicated from the imprinted polymer layer beneath, give rise to the controlled rolling direction after selective etching of the underlying sacrificial layer. The rolling direction of the grating-structured thin metal film is always perpendicular to the long side edge of gratings, offering a good way to roll up strained strips into well controlled three-dimensional (3D) microsprings simply by altering the dimension and orientation of the structured strips. The mechanical elasticity of these grating-structured metallic microsprings is verified for the potential application as a flow rate sensor. Our work may stimulate rigorous synthesis of highly functional and complex 3D helical micro and nanostructures, and hint a broad range of applications such as environmental sensors, micro-/nanoscale robots, metamaterials, etc. PMID:24728100

Huang, Tao; Liu, Zhaoqian; Huang, Gaoshan; Liu, Ran; Mei, Yongfeng

2014-07-24

430

Nanohole induced microfiber Bragg gratings.  

PubMed

We demonstrate the fabrication of high-index-contrast microfiber Bragg gratings (MFBGs) using phase-mask technique under seconds' femtosecond laser ablation to drill periodic nanoholes in microfibers and study the aging properties of the gratings at room temperature. These sub-micrometer-diameter holes, benefited from the resolution of femtosecond laser micromachining beyond-diffraction limit, results in an effective negative refractive index change ?n ~-10(-3). Transmission dips over -23 dB are achieved for the gratings with excellent Gaussian apodization and 3-dB reflection bandwidths up to 1.14 nm. Moreover, the grating reflectivity increased by 3 dB, the resonant wavelength blue-shifted 1.35 nm after two weeks' placement of grating at room temperature and these gratings exhibit excellent stability in the following time. This makes them attractive elements in sensing, nanophotonics and nonlinear optics. PMID:23263100

Zhao, Ping; Li, Yuhua; Zhang, Jihua; Shi, Lei; Zhang, Xinliang

2012-12-17

431

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

432

The joint astrophysical plasmadynamic experiment extreme ultraviolet spectrometer: resolving power  

NASA Astrophysics Data System (ADS)

The Joint astrophysical Plasmadynamic EXperiment (J-PEX) is a high-resolution extreme ultraviolet (EUV) spectrometer (220-245 Å) used for the study of white dwarf atmospheres. Significant improvements have been achieved in both the normal-incidence gratings and the focal-plane detector since its first successful sounding rocket flight in 2001. The spherical laminar gratings have been replaced by paraboloidal gratings. The substrates of the new gratings have measured slope errors less than 0.35 arcsec. The gratings were recorded holographically and the rulings transferred into the silica substrates by ion etching. This procedure was followed by polymer overcoat to reduce the blaze angle of the groove profile. The detector uses microchannel plates with 6 ?m pores and a cross-strip anode, providing 17.9 ?m resolution in the dispersion direction. The detector employs a KBr photocathode with a projected efficiency of 0.24 at 256 Å. Using ray tracing simulations, we predict the resolving power expected from the spectrometer during upcoming EUV calibrations with a He II discharge source.

Berendse, F. B.; Cruddace, R. G.; Kowalski, M. P.; Yentis, D. J.; Hunter, W. R.; Fritz, G. G.; Siegmund, O.; Heidemann, K.; Lenke, R.; Seifert, A.; Barbee, T. W., Jr.

2006-06-01

433

[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

434

Holographic grating formation in photopolymers  

NASA Astrophysics Data System (ADS)

We introduce a model describing real-time grating formation in holographic photopolymers, assuming that the diffusion of free monomers is much faster than the grating formation. This model, which combines polymerization kinetics with results from coupled-wave theory, indicates that the grating formation time depends sublinearly on the average holographic recording intensity and the beam intensity ratio controls the grating index modulation at saturation. We validate the model by comparing its predictions with the results of experiments in which DuPont HRF-150X001 photopolymer was used.

Piazzolla, Sabino; Jenkins, B. Keith

1996-07-01

435

Fiber Bragg grating laser sensor  

NASA Astrophysics Data System (ADS)

An erbium-doped fiber laser utilizing a broadband mirror as the end reflector and an intracore Bragg grating as the output coupler is designed and developed. This arrangement is used as a laser sensor to improve interrogation efficiency of intracore Bragg gratings over broadband sensor interrogation methods. Wavelength tuning of the fiber laser has been achieved by varying the temperature and strain on the Bragg grating, demonstrating an improved SNR with respect to the previous techniques that use broadband interrogation of the Bragg grating sensor.

Othonos, Andreas; Alavie, A. Tino; Melle, Serge M.; Karr, Shawn E.; Measures, Raymond M.

1993-11-01

436

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

437

The Coude spectrograph and echelle scanner of the 2.7 m telescope at McDonald observatory  

NASA Technical Reports Server (NTRS)

The design of the Coude spectrograph of the 2.7 m McDonald telescope is discussed. A description is given of the Coude scanner which uses the spectrograph optics, the configuration of the large echelle and the computer scanner control and data systems.

Tull, R. G.

1972-01-01

438

Variation of blaze of concave diffraction gratings.  

PubMed

The change in blaze wavelength as a function of position on a blazed concave diffraction grating surface is discussed. An experimental study of ruled and interferometric blazed concave gratings showed that the change in blaze across the grating surface is much less for an interferometric grating than for a ruled grating. Thus interferometric gratings can be expected to have a more uniform distribution of efficiency across their surfaces. PMID:20309098

Hutley, M C; Hunter, W R

1981-01-15

439

High dispersion spectroscopy trials using an echelle spectrograph with CCD camera  

NASA Astrophysics Data System (ADS)

The performance of the Queen's University Belfast echelle spectrograph (McKeith et al., 1978) and a Royal Greenwich Observatory (RGO) CCD camera on the 90-cm Yapp telescope at RGO is evaluated experimentally in high-dispersion observations of the 589.0-nm and 589.6-nm D lines of Na in the bright stars Alpha Cyg and Alpha Boo during June-July 1984. The results are presented graphically, and the system is found to have dispersion about 1.0 A/mm, signal/noise about 80 for a 15-min exposure of Alpha Cyg and about 100 for a 5-min exposure of Alpha Boo, and resolving power about 100,000.

Bates, B.; McKeith, C. D.; Jorden, P. R.; van Breda, I. G.

1985-05-01

440

Progress Report on 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 SOFIA. It provides high, medium, and low spectral resolution in the wavelength region 4.5 to 28.3 microns using a 1024x1024 detector array. With the improved atmospheric transmission afforded by SOFIA, EXES will acquire truly unique data with its high spectral reosolution; data that cannot be replicated by any other ground or space-based mission currently available or planned. EXES has recently moved to NASA Ames Research Center where it will be completed by a team mostly from UC Davis and NASA Ames. We are currently involved with system testing. Our schedule includes two ground-based telescope runs to thoroughly debug the system before our first flights on SOFIA in 2013.

Richter, Matthew; Seifahrt, A.; McKelvey, M.; Ennico-Smith, K.; Lacy, J.

2010-01-01

441

PUCHEROS: a low-cost fiber-fed Echelle Spectrograph for the visible spectral range  

NASA Astrophysics Data System (ADS)

PUCHEROS is a high resolution optical Echelle spectrograph designed for the 50 cm telescope located at the Pontificia Universidad Cat´olica de Chile (PUC) observatory of Santa Martina. With a resolution about 20,000, PUCHEROS is an ideal instrument to study bright and variable objects, our driving science case is the study of bright early type stars. Using a fiber optic to bring the light from the telescope to the instrument, it can be located in a gravity invariant, temperature stabilized location, allowing precise long-term stability. PUCHEROS will be a valuable tool both for research and didactics at the graduate and undergraduate level. In this work we present the optical and mechanical design of the spectrograph as well as the first laboratory tests.

Vanzi, Leonardo; Chacon, Juan A.; Baffico, Maurizio; Avila, Gerardo; Guirao, Carlos; Rivinius, Thomas; Stefl, Stan; Baade, Dietrich

2010-07-01

442

Flat field concave holographic grating with broad spectral region and moderately high resolution.  

PubMed

In order to deal with the conflicts between broad spectral region and high resolution in compact spectrometers based on a flat field concave holographic grating and line array CCD, we present a simple and practical method to design a flat field concave holographic grating that is capable of imaging a broad spectral region at a moderately high resolution. First, we discuss the principle of realizing a broad spectral region and moderately high resolution. Second, we provide the practical method to realize our ideas, in which Namioka grating theory, a genetic algorithm, and ZEMAX are used to reach this purpose. Finally, a near-normal-incidence example modeled in ZEMAX is shown to verify our ideas. The results show that our work probably has a general applicability in compact spectrometers with a broad spectral region and moderately high resolution. PMID:22307123

Wu, Jian Fen; Chen, Yong Yan; Wang, Tai Sheng

2012-02-01

443

Immersed gratings and associated phenomena  

Microsoft Academic Search

The spectral resolution of an immersed diffraction grating is discussed. The main focus of the study is for astronomical spectroscopy, in which a substantial angular separation is generally required between the incident and diffracted collimated beams to accommodate a collimator and camera with different relative apertures. It is shown that when a grating immersed on one face of an entry

C. G. Lynne

1989-01-01

444

Decontamination of CPA diffraction gratings  

Microsoft Academic Search

Summary form only given. The diffraction gratings are mounted in a vacuum chamber of the compressor. In these conditions the diffraction gratings and other gold coated mirrors illuminated by the laser beam are subjected to carbon contamination, especially on the place of the output beam. This reduces diffraction efficiency of the compressor. The cleaning method used at our 100 TW

E. Gubbini; U. Eichmann; V. Karpov; H. Schonnagel; M. P. Kalachnikov; F. Eggenstein; G. Reichardt

2002-01-01

445

Straylight measurements of immersed gratings for high-resolution spectroscopy in the near infrared  

NASA Astrophysics Data System (ADS)

New immersed grating technology is needed particularly for use in imaging spectrometers that will be used in sensing the atmosphere O2A spectral band (750nm - 775 nm) at spectral resolution in the order of 0.1 nm whilst keeping a high efficiency and low stray light. In this work, an Ion-beam etched grating in a fused-silica substrate of 100 mm 100mm immersed on a prism of the same material is designed to obtain dispersions > 0.30°/nm-1 and 70% efficiency. The optical performance of the immersed grating is modelled and methods to measure its efficiency and scattered radiance are described. The optical setup allows the measurement of an 80mm beam diameter to derive the bidirectional scatter density function (BSDF) from the immersed grating from a minimum angle of 0.1° from the diffracted beam with angular resolution of 0.05°.

Fernandez-Saldivar, J.; Bhatti, I.; Lobb, D.; Touzet, B.; Guldimann, B.

2011-09-01

446

High-efficiency silicon immersion grating by electron-beam lithography  

NASA Astrophysics Data System (ADS)

Silicon immersion grating have opened the new possibilities of building compact high-resolution cryogenic spectrometers for the near-infrared (NIR) region from 1.4 to 5.5?m. We are developing a silicon immersion grating for a next-generation NIR high-resolution spectrometer attached to the Subaru 8.2 m telescope. Since a long time, the anisotropic wet etching technique using photolithography has used for the fabrication of silicon immersion gratings (e.g., Wiedemann & Jennings1 and Keller et al.2). Here, we present an alternative technique using electron-beam (EB) lithography, which does not employ either any photolithography masks or UV light source. This technique uses "direct" EBs to expose the resist. The EBs are precisely controlled by using a closed-looped system comprising a laser interferometer. As compared to photolithographic technique, this technique results in more accurate groove pitches and lower surface roughness near the edge of the mask. We fabricate a sample grating with a groove pitch of 30 µm and a blaze angle of 69° on a 10mm × 20mm × 2mm flat substrate by EB lithography. Our detailed optical testing of the grating using visible laser shows good optical performances: extremely low scattered light (< 0.9%), less production of ghost light (< 0.01%), and high relative diffraction efficiency (~ 88%). We plan to fabricate the final immersion grating by fixing the etched grating substrate to a silicon prism using the optical-contact method. We are in the middle of R&D of this process and found that much tighter optical-contact than usual seems to be required because of the high incidence angle to the contact surface. Our first sample immersion grating shows a significant reflection loss at the contact surface when it is used in an immersion mode with a NIR laser beam. We are trying to improve the polishing process of the thin silicon substrate for better contact.

Ikeda, Yuji; Kobayashi, Naoto; Terada, Hiroshi; Shibayama, Akinori; Ozawa, Akira; Yasui, Chikako; Kondo, Sohei; Pyo, Tae-Soo; Kawakita, Hideyo

2008-08-01

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