cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/pow_mierkerwicz... · 2009. 2. 27. ·...
TRANSCRIPT
![Page 1: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/1.jpg)
An Overview ofSpatial Heterodyne Spectroscopy
Principle OII SHS participants:
Fred Roesler (University of Wisconsin)John Harlander (St. Cloud State University)Edwin Mierkiewicz (University of Wisconsin)Ronald J. Reynolds (University of Wisconsin)Kurt Jaehnig (University of Wisconsin)
![Page 2: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/2.jpg)
θ
θ
G
G
B.S.
A
incident wavefront
12 exiting wavefronts
Imaging Detector
input
B.S. θG
P1
P2
Input
Output
a) b)
θ
G
The Spatial Heterodyne SpectrometerTransmitting SHS Properties
SHS is basically a Michelsoninterferometer with the return mirrorsreplaced by fixed diffraction gratings G.
For each wavenumber in the wavefrontentering the interferometer, twowavefronts exit the system with awavenumber-dependent crossing anglebetween them.
This produces a superposition of Fizeaufringes with wavenumber-dependentspatial frequencies localized near thegratings.
A position sensitive detector records theFizeau fringe pattern produced by theinterferometer.
x
x
![Page 3: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/3.jpg)
The Spatial Heterodyne Spectrometer
The heterodyne concept is evoked by the factthat the dispersive elements may be tuned toplace zero spatial frequency at a selectedwavenumber σo, where σo is the Littrowwavenumber of the diffraction gratings(2σosinθ=m/d)
For a system tuned to σo, adjacent spectralelements σo+δσ, σo+2δσ,..σo+nδσ produce1,2,…n-cycle spatial frequencies across thedetector.
As each spectral element produces a uniquespatial frequency, the Fourier transform of therecorded spatial frequencies provides thespectrum within a limited spectral range(determined by the detector sampling) aboutthe heterodyne wavelength.
x
Zero spatial frequency at the Littrow wavenumber σo
![Page 4: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/4.jpg)
θ
θ
G
G
B.S.
A
incident wavefront
12 exiting wavefronts
Imaging Detector
input
B.S. θG
P1
P2
Input
Output
a) b)
θ
G
The Spatial Heterodyne SpectrometerTransmitting SHS Additional SHS Properties
No mechanical part is moved in thisprocess.
The resolving power is the diffraction-limited resolving power of the gratingcombination.
The throughput is that characteristic ofinterference spectrometers at the achievedresolving power.
SHS can be field-widened with fixedprisms in each arm, giving SHS anenormous throughput gain overconventional systems of similar size andresolving power.
x
x
![Page 5: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/5.jpg)
θ
θ
G
G
B.S.
A
incident wavefront
12 exiting wavefronts
Imaging Detector
input
B.S. θG
P1
P2
Input
Output
a) b)
θ
G
The Spatial Heterodyne SpectrometerTransmitting SHS
x
x
![Page 6: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/6.jpg)
The instrument described thus farproduces identical output for inputwavenumbers σo+δσ and σo-δσ. Thisambiguity can be avoided by adding aslight y-tilt to one of the gratings.
Wavenumbers σ > σo are rotatedclockwise, while σ < σo are rotatedcounter clockwise.
3726.062 A3728.81 A
![Page 7: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/7.jpg)
Diffuse [OII] 372.7nm from the Warm Ionized Medium
Science Motivation:• The warm ionized medium was surveyed with WHAM at 656.3nm• Strong evidence for previously unrecognized energy sources has
emerged• [OII] 372.7nm emission is expected to verify their existence
Why SHS?:• WHAM does not work at 372.7nm• Fabry-Perot efficiencies are low and tolerances high below 400nm• The field-widened SHS is highly efficient in the NUV• SHS is more tolerant of defects by >15 compared to a FP
Status:• Observations are underway with the OII system at PBO
![Page 8: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/8.jpg)
Pine Bluff, WI (89o 40’ W, 43o 04’ N)
![Page 9: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/9.jpg)
![Page 10: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/10.jpg)
![Page 11: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/11.jpg)
Ne 3727.105 APix 733
Ne 3719.8 APix 441
Ne 3713.08 APix 160
R~20,000
![Page 12: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/12.jpg)
![Page 13: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/13.jpg)
![Page 14: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/14.jpg)
![Page 15: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/15.jpg)
OII SHS on
OII SHS off
![Page 16: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/16.jpg)
Slanger, Keck order 96 (high res)
OII SHS on
![Page 17: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/17.jpg)
• Diffuse [OII] 372.7nm Emission from the Warm ISM
• SHIMMERSpatial Heterodyne Imager for Mesospheric RadicalsMeasuring mesospheric OH at 308.0nmSTS 112 and STPSat-1
• Diffuse CIV 155.0mn Emission from the Hot ISM
• Interplanetary Hydrogen 121.6nm
• Comet C/Neat (2001 Q4) OH and OI
• Daysky OI, R ~300,000
![Page 18: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/18.jpg)
the end
![Page 19: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/19.jpg)
![Page 20: cedarweb.vsp.ucar.educedarweb.vsp.ucar.edu/wiki/images/0/0a/POW_Mierkerwicz... · 2009. 2. 27. · Created Date: 9/24/2004 3:40:53 PM](https://reader033.vdocuments.pub/reader033/viewer/2022051603/5ff2bd0609303a43613c8bc0/html5/thumbnails/20.jpg)
Monoch
rom
atic
Sourc
e (Z
n)
Em
issi
on L
ine
Sourc
e (M
nN
e)Bro
ad B
and
Sourc
e (D
2)
(Harlander et al., 2004)
Single well isolated lineat 307.59 nm; fivefringe tilt perpendicularto the dispersion plane
Several emission featuresin the bandpass; provideswavelength calibrationand spectral resolution(~0.12 A)
Continuum source,spectral shape dominatedby the prefilter; allspectral informationlocalized near zero path