Abstract

Under seeing limited conditions very high resolution spectroscopy becomes very difficult for extremely large telescopes (ELTs). Using adaptive optics (AO) the stellar image size decreases proportional with the telescope diameter. This makes the spectrograph optics and hence its resolution independent of the telescope diameter. However AO for use with ELTs at visible wavelengths require deformable mirrors with many elements. Those are not likely to be available for quite some time. We propose to use the pupil slicing technique to create a number of sub-pupils each of which having its own deformable mirror. The images from all sub-pupils are combined incoherently with a diameter corresponding to the diffraction limit of the sub-pupil. The technique is referred to as “Pupil Slicing Adaptive Optics” or PSAO.

© 2007 Optical Society of America

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  1. C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
    [CrossRef]
  2. T. Andersen, M. Owner-Petersen and A. Gontcharov, "The Swedish 50 m ELT," in Beyond conventional adaptive optics : a conference devoted to the development of adaptive optics for extremely large telescopes, E. Vernet, R. Ragazzoni, S. Esposito, and N. Hubin eds., ESO Conference and Workshop Proceedings 58, 7 (2001).
  3. T. Andersen, A. Ardeberg and M. Owner-Petersen, eds., Euro50 Design Study of a 50m Adaptive Optics Telescope, (2003).
  4. W. G. Fastie, J. Opt. Soc. Am. 51, 1472 (1961).
  5. F. H. Chaffee and D. W. Latham, "An image stacker for high-resolution spectroscopy on the multiple mirror telescope," Pub. Astron. Soc. Pac. 94, 386 (1982).
    [CrossRef]
  6. J. M. Beckers, "Adaptive optics for astronomy - Principles, performance, and applications," Annual Rev. Astron. Astrophys. 31, 13-62 (1993).
    [CrossRef]
  7. J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
    [CrossRef]
  8. J. R. P. Angel, R. L. Hilliard and R. J. Weymann, "The MMT and the Future of Ground-Based Astronomy," SAO Special Report, T. C. Weekes, ed., 385, 87 (1979).
  9. F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).
  10. T. G. Hawarden, E. Atad, C. R. Cunningham, D. M. Henry, C. J. Norrie, C. D. Dainty, N. Devaney, and A. S. Goncharov, "Atmospheric dispersion correction for ELT instruments," Final Report on Atmospheric Dispersion Correction for the EC Framework Programme 6 (2006), http://www.mpia-hd.mpg.de/ELT/Manuscripts/Atad.pdf.
  11. J. M. Beckers, "Increasing the Size of the Isoplanatic Patch with Multiconjugate Adaptive Optics," in Proceedings of a ESO Conference on Very Large Telescopes and their Instrumentation, M.H. Ulrich, ed., ESO Conference and Workshop Proceedings No. 30, 693-700 (1988).
  12. J. M. Beckers, "Detailed compensation of atmospheric seeing using multiconjugate adaptive optics," in Active Telescope Systems, Francois J. Roddier, ed., Proc. SPIE 1114, 215-221 (1989).
  13. A. Enmark, T. Andersen, M. Browne, and M. Owner-Petersen, "Status of the integrated model of the Euro50," in Modeling, Systems Engineering, and Project Management for Astronomy II, Martin J. Cullum and George Z. Angeli eds., Proc. SPIE 6271, in press (2006).
    [CrossRef]
  14. F. Rigaut and E. Gendron, "Laser guide star in adaptive optics - The tilt determination problem," Astron. Astroph. 261, 677-684 (1992).
  15. G. Avila, G. Rupprecht and J. M. Beckers, "Atmospheric dispersion correction for the FORS focal reducers at the ESO VLT," in Optical Telescopes of Today and Tomorrow, Arne L. Ardeberg, ed., Proc. SPIE 2871, 1135-1143 (1997).
    [CrossRef]
  16. R. O. Reynolds and M. Lloyd-Hart, "First science observations with the ACES echelle spectrograph," in Ground-based Instrumentation for Astronomy; Alan F. Moorwood and Masanori Iye, eds., Proc. SPIE 5492, 172-180 (2004).
    [CrossRef]
  17. J. M. Beckers and L. E. Goad, "Image reconstruction using adaptive optics," in Instrumentation for Ground-Based Optical Astronomy L. B. Robinson, ed.(Springer-Verlag, 1987), pp. 315-336.
  18. M. Puech and F. Sayède, "FALCON: extending adaptive optics corrections to cosmological fields," in Ground-based Instrumentation for Astronomy, Alan F.M. Moorwood and Masanori Iye, eds., Proc. SPIE 5492, 303-311 (2004)
    [CrossRef]
  19. J. M. Beckers, "Overcoming perspective elongation effects in laser guide star adaptive optics," Appl. Opt. 31, 6592-6594 (1992).
    [CrossRef] [PubMed]
  20. J. M. Beckers, M. Owner-Petersen, T. Andersen, "A rapid refocusing system for the Euro50 telescope aimed at removing the perspective elongation of sodium beacons," in Astronomical Adaptive Optics Systems and Applications, Robert K. Tyson and Michael Lloyd-Hart, eds., Proc. SPIE 5169, 123-136 (2004).
    [CrossRef]

2006

A. Enmark, T. Andersen, M. Browne, and M. Owner-Petersen, "Status of the integrated model of the Euro50," in Modeling, Systems Engineering, and Project Management for Astronomy II, Martin J. Cullum and George Z. Angeli eds., Proc. SPIE 6271, in press (2006).
[CrossRef]

2002

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

1995

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

1993

J. M. Beckers, "Adaptive optics for astronomy - Principles, performance, and applications," Annual Rev. Astron. Astrophys. 31, 13-62 (1993).
[CrossRef]

1992

F. Rigaut and E. Gendron, "Laser guide star in adaptive optics - The tilt determination problem," Astron. Astroph. 261, 677-684 (1992).

J. M. Beckers, "Overcoming perspective elongation effects in laser guide star adaptive optics," Appl. Opt. 31, 6592-6594 (1992).
[CrossRef] [PubMed]

1982

F. H. Chaffee and D. W. Latham, "An image stacker for high-resolution spectroscopy on the multiple mirror telescope," Pub. Astron. Soc. Pac. 94, 386 (1982).
[CrossRef]

1961

W. G. Fastie, J. Opt. Soc. Am. 51, 1472 (1961).

Andersen, T.

A. Enmark, T. Andersen, M. Browne, and M. Owner-Petersen, "Status of the integrated model of the Euro50," in Modeling, Systems Engineering, and Project Management for Astronomy II, Martin J. Cullum and George Z. Angeli eds., Proc. SPIE 6271, in press (2006).
[CrossRef]

Angel, J. R. P.

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Angel, R.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

Barlow, M. J.

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Beckers, J. M.

J. M. Beckers, "Adaptive optics for astronomy - Principles, performance, and applications," Annual Rev. Astron. Astrophys. 31, 13-62 (1993).
[CrossRef]

J. M. Beckers, "Overcoming perspective elongation effects in laser guide star adaptive optics," Appl. Opt. 31, 6592-6594 (1992).
[CrossRef] [PubMed]

Black, J. H.

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Brooks, D.

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Browne, M.

A. Enmark, T. Andersen, M. Browne, and M. Owner-Petersen, "Status of the integrated model of the Euro50," in Modeling, Systems Engineering, and Project Management for Astronomy II, Martin J. Cullum and George Z. Angeli eds., Proc. SPIE 6271, in press (2006).
[CrossRef]

Chaffee, F. H.

F. H. Chaffee and D. W. Latham, "An image stacker for high-resolution spectroscopy on the multiple mirror telescope," Pub. Astron. Soc. Pac. 94, 386 (1982).
[CrossRef]

Crawford, I. A.

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Dekker, H.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

Diego, F.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Dryburgh, J. M.

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Enmark, A.

A. Enmark, T. Andersen, M. Browne, and M. Owner-Petersen, "Status of the integrated model of the Euro50," in Modeling, Systems Engineering, and Project Management for Astronomy II, Martin J. Cullum and George Z. Angeli eds., Proc. SPIE 6271, in press (2006).
[CrossRef]

Fastie, W. G.

W. G. Fastie, J. Opt. Soc. Am. 51, 1472 (1961).

Fish, A. C.

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Fugate, R. G.

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Ge, J.

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Gendron, E.

F. Rigaut and E. Gendron, "Laser guide star in adaptive optics - The tilt determination problem," Astron. Astroph. 261, 677-684 (1992).

Hinkle, K.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

Howarth, I. D.

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Jacobsen, B.

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Latham, D. W.

F. H. Chaffee and D. W. Latham, "An image stacker for high-resolution spectroscopy on the multiple mirror telescope," Pub. Astron. Soc. Pac. 94, 386 (1982).
[CrossRef]

Lloyd-Hart, M.

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Owner-Petersen, M.

A. Enmark, T. Andersen, M. Browne, and M. Owner-Petersen, "Status of the integrated model of the Euro50," in Modeling, Systems Engineering, and Project Management for Astronomy II, Martin J. Cullum and George Z. Angeli eds., Proc. SPIE 6271, in press (2006).
[CrossRef]

Pilachowski, C.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

Rigaut, F.

F. Rigaut and E. Gendron, "Laser guide star in adaptive optics - The tilt determination problem," Astron. Astroph. 261, 677-684 (1992).

Spyromilio, J.

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Tull, R.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

Vogt, S.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

Walker, D. D.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Woolf, N.

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Annual Rev. Astron. Astrophys.

J. M. Beckers, "Adaptive optics for astronomy - Principles, performance, and applications," Annual Rev. Astron. Astrophys. 31, 13-62 (1993).
[CrossRef]

Appl. Opt.

Astron. Astroph.

F. Rigaut and E. Gendron, "Laser guide star in adaptive optics - The tilt determination problem," Astron. Astroph. 261, 677-684 (1992).

J. Opt. Soc. Am.

W. G. Fastie, J. Opt. Soc. Am. 51, 1472 (1961).

Monthly Notices RAS

F. Diego, A.C. Fish, M. J. Barlow, I. A. Crawford, J. Spyromilio, J. M. Dryburgh, D. Brooks, I. D. Howarth and D. D. Walker, "The Ultra-High-Resolution Facility at the Anglo-Australian Telescope," Monthly Notices RAS 272, 323-332 (1995).

Proc. SPIE

A. Enmark, T. Andersen, M. Browne, and M. Owner-Petersen, "Status of the integrated model of the Euro50," in Modeling, Systems Engineering, and Project Management for Astronomy II, Martin J. Cullum and George Z. Angeli eds., Proc. SPIE 6271, in press (2006).
[CrossRef]

Pub. Astron. Soc. Pac.

F. H. Chaffee and D. W. Latham, "An image stacker for high-resolution spectroscopy on the multiple mirror telescope," Pub. Astron. Soc. Pac. 94, 386 (1982).
[CrossRef]

Publ. Astron. Soc. Pac.

C. Pilachowski, H. Dekker, K. Hinkle, R. Tull, S. Vogt, D. D. Walker, F. Diego, and R. Angel, "High-Resolution Spectrographs for Large Telescopes," Publ. Astron. Soc. Pac. 107, 983-989 (1995).
[CrossRef]

J. Ge, J. R. P. Angel, B. Jacobsen, N. Woolf, R. G. Fugate, J. H. Black, and M. Lloyd-Hart, "An Optical Ultrahigh-Resolution Cross-dispersed Echelle Spectrograph with Adaptive Optics," Publ. Astron. Soc. Pac. 114, 879-891 (2002).
[CrossRef]

Other

J. R. P. Angel, R. L. Hilliard and R. J. Weymann, "The MMT and the Future of Ground-Based Astronomy," SAO Special Report, T. C. Weekes, ed., 385, 87 (1979).

G. Avila, G. Rupprecht and J. M. Beckers, "Atmospheric dispersion correction for the FORS focal reducers at the ESO VLT," in Optical Telescopes of Today and Tomorrow, Arne L. Ardeberg, ed., Proc. SPIE 2871, 1135-1143 (1997).
[CrossRef]

R. O. Reynolds and M. Lloyd-Hart, "First science observations with the ACES echelle spectrograph," in Ground-based Instrumentation for Astronomy; Alan F. Moorwood and Masanori Iye, eds., Proc. SPIE 5492, 172-180 (2004).
[CrossRef]

J. M. Beckers and L. E. Goad, "Image reconstruction using adaptive optics," in Instrumentation for Ground-Based Optical Astronomy L. B. Robinson, ed.(Springer-Verlag, 1987), pp. 315-336.

M. Puech and F. Sayède, "FALCON: extending adaptive optics corrections to cosmological fields," in Ground-based Instrumentation for Astronomy, Alan F.M. Moorwood and Masanori Iye, eds., Proc. SPIE 5492, 303-311 (2004)
[CrossRef]

J. M. Beckers, M. Owner-Petersen, T. Andersen, "A rapid refocusing system for the Euro50 telescope aimed at removing the perspective elongation of sodium beacons," in Astronomical Adaptive Optics Systems and Applications, Robert K. Tyson and Michael Lloyd-Hart, eds., Proc. SPIE 5169, 123-136 (2004).
[CrossRef]

T. Andersen, M. Owner-Petersen and A. Gontcharov, "The Swedish 50 m ELT," in Beyond conventional adaptive optics : a conference devoted to the development of adaptive optics for extremely large telescopes, E. Vernet, R. Ragazzoni, S. Esposito, and N. Hubin eds., ESO Conference and Workshop Proceedings 58, 7 (2001).

T. Andersen, A. Ardeberg and M. Owner-Petersen, eds., Euro50 Design Study of a 50m Adaptive Optics Telescope, (2003).

T. G. Hawarden, E. Atad, C. R. Cunningham, D. M. Henry, C. J. Norrie, C. D. Dainty, N. Devaney, and A. S. Goncharov, "Atmospheric dispersion correction for ELT instruments," Final Report on Atmospheric Dispersion Correction for the EC Framework Programme 6 (2006), http://www.mpia-hd.mpg.de/ELT/Manuscripts/Atad.pdf.

J. M. Beckers, "Increasing the Size of the Isoplanatic Patch with Multiconjugate Adaptive Optics," in Proceedings of a ESO Conference on Very Large Telescopes and their Instrumentation, M.H. Ulrich, ed., ESO Conference and Workshop Proceedings No. 30, 693-700 (1988).

J. M. Beckers, "Detailed compensation of atmospheric seeing using multiconjugate adaptive optics," in Active Telescope Systems, Francois J. Roddier, ed., Proc. SPIE 1114, 215-221 (1989).

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Figures (5)

Fig. 1.
Fig. 1.

Pupil slicing arrangement for the 6-mirror MMT A through F represents the 6 1.8-m mirrors. The column of 6 squares in the center represents the wedgelet array at the spectrograph slit. (Courtesy Chaffee and Latham).

Fig. 2.
Fig. 2.

Slicing the 618 element Euro50 primary mirror. The 18 (+ vignetted central) hexagons shown are the hexagonal sub-pupils segments each containing 32 to 33 primary mirror hexagonal elements. The large dashed hexagon represents the primary mirror outline.

Fig. 3.
Fig. 3.

Schematic of the proposed Euro50 pupil slicer. The collimator mirror images the pupil on a mirror consisting of an array of flat hexagonal segments (see Fig. 2 for the 18/19 segment array). The individual segments are slightly tilted to give the (seeing limited) stellar image pattern wanted on the spectrograph slit/wedgelet combination. In the Pupil Slicing Adaptive Optics configuration (section 5) the flat hexagonal segments are replaced by adaptive mirrors, which also allow for tip-tilt control of the wavefront error. In the PSAO mode the (diffraction limited) images are recombined incoherently on the spectrograph entrance.

Fig. 4.
Fig. 4.

Control diagram for PSAO wavefront control system.

Fig. 5.
Fig. 5.

Schematic of the Euro50 High Resolution Optical Echelle Spectrograph using an 18 element PSAO configuration. Preceding the spectrograph entrance fiber is a focal reducer and an atmospheric dispersion compensator consisting of a pair of 3-element Risley prisms. The spectrograph is a cross-dispersed Echelle spectrograph similar to the ESO HARPS. The MEMS-DM tilts in the PSAO unit are all adjusted to combine the 18 images on the fiber entrance. Not shown is the cross-disperser.

Tables (2)

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Table 1. Modern High-Resolution Spectrographs a

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Table 2. Some science targets requiring ELTs with high resolution spectrographs

Equations (3)

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R = 2 tan β∙D gr ∙FR coll / SW
R = 2 tan β∙D gr / ( φ∙D )
R = 2 tan β∙D gr / λ ,

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