Abstract

We describe a method to reduce residual speckles in an adaptive optics system which add to the halo of the point spread function (PSF). The halo is particularly problematic in astronomical applications involving the detection of faint companions. Areas of the pupil are selected where the residual wavefront aberrations are large and these are masked using a spatial light modulator. The method is also suitable for smaller telescopes without adaptive optics as a relatively simple method to increase the resolution of the telescope. We describe the principle of the technique and show simulation results.

© 2009 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. G. D. Love, N. Andrews, P. Birch, D. F. Buscher, P. Doel, C. Dunlop, J. Major, R. Myers, A. Purvis, R. Sharples, A. Vick, A. Zadrozny, S. R. Restaino, and A. Glindemann, "Binary adaptive optics: atmospheric wave-front correction with a half-wave phase shifter," Appl. Opt. 34, 6058 - 6066 (1995).
    [PubMed]
  2. D. Fried, "Probability of getting a lucky short-exposure image through turbulence," J. Opt. Soc. Am. 68, 1651-1658 (1978).
  3. N. M. Law, C. D. Mackay, and J. E. Baldwin, "Lucky imaging: high angular resolution imaging in the visible from the ground," AAP 446, 739 - 745 (2006).
  4. N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).
  5. C. Morossi, M. Franchini, and S. Furlani, "Spatial Resolution Improvement for an 8 Meter Class Telescope via Adaptive Optics and On-Line Subaperture Selection," PASP 114, 187-197 (2002).
  6. R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).
  7. A. Sivaramakrishnan, J. P. Lloyd, P. E. Hodge, and B. A. Macintosh, "Speckle Decorrelation and Dynamic Range in Speckle Noise-limited Imaging," ApJL 581, 59-62 (2002).
  8. M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).
  9. C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).
  10. C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
    [PubMed]
  11. J. R. P. Angel, "Ground-based imaging of extrasolar planets using adaptive optics," Nature 368, 203-207 (1994).
  12. E. Masciadri, M. Feldt, and S. Hippler, "Scintillation Effects on a High-Contrast Imaging Instrument for Direct Extrasolar Planets’ Detection," ApJ 615, 850-854 (2004).
  13. A. Basden, T. Butterley, R. Myers, and R. Wilson, "The Durham ELT adaptive optics simulation platform," Appl. Opt. 46, 1089-1098 (2007).
    [PubMed]
  14. A. Zadrozny, M. P. J. L. Chang, D. F. Buscher, R. M. Myers, A. P. Doel, C. N. Dunlop, and R. M. Sharples, "First atmospheric compensation with a linearised high order adaptive mirror - ELECTRA," in Topical Meeting on Astronomy with Adaptive Optics, D. Bonaccini, ed., 56, pp. 459 - 468 (ESO Conf. Workshop Proc., 1999).
  15. D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).
  16. J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).
  17. P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).
  18. F. Roddier, "Optical propagation and image formation through the turbulent atmosphere," in Diffraction Limited Imaging with Very Large Telescopes, D. M. Alloin and J.-M. Mariotti, eds., pp. 33 - 52 (NATO ASI, 1988).
  19. D. L. Fried, "Statistics of a Geometric Representation ofWavefront Distortion," J. Opt. Soc. Am. 55, 1427-1431 (1965).
  20. P. D. Greenwood, "Mutual coherence functions of a wave front corrected by zonal adaptive optics," J. Opt. Soc. Am. 69, 549 - 554 (1978).
  21. "DLP Discovery 4000," Tech. rep., Texas Instruments (2009).

2008 (2)

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

2007 (1)

2006 (2)

N. M. Law, C. D. Mackay, and J. E. Baldwin, "Lucky imaging: high angular resolution imaging in the visible from the ground," AAP 446, 739 - 745 (2006).

C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).

2004 (2)

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

E. Masciadri, M. Feldt, and S. Hippler, "Scintillation Effects on a High-Contrast Imaging Instrument for Direct Extrasolar Planets’ Detection," ApJ 615, 850-854 (2004).

2003 (1)

M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).

2002 (2)

A. Sivaramakrishnan, J. P. Lloyd, P. E. Hodge, and B. A. Macintosh, "Speckle Decorrelation and Dynamic Range in Speckle Noise-limited Imaging," ApJL 581, 59-62 (2002).

C. Morossi, M. Franchini, and S. Furlani, "Spatial Resolution Improvement for an 8 Meter Class Telescope via Adaptive Optics and On-Line Subaperture Selection," PASP 114, 187-197 (2002).

2001 (1)

P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).

2000 (1)

D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).

1999 (1)

R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).

1995 (1)

1994 (1)

J. R. P. Angel, "Ground-based imaging of extrasolar planets using adaptive optics," Nature 368, 203-207 (1994).

1978 (2)

1965 (1)

Andrews, N.

Angel, J. R. P.

J. R. P. Angel, "Ground-based imaging of extrasolar planets using adaptive optics," Nature 368, 203-207 (1994).

Baldwin, J. E.

N. M. Law, C. D. Mackay, and J. E. Baldwin, "Lucky imaging: high angular resolution imaging in the visible from the ground," AAP 446, 739 - 745 (2006).

Barman, T.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

Basden, A.

Birch, P.

Boccaletti, A.

P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).

D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).

Britton, M. C.

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

Buscher, D. F.

Butterley, T.

Clenet, Y.

D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).

Dekany, R. G.

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

Doel, P.

Doyon, R.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).

R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).

Dunlop, C.

Feldt, M.

E. Masciadri, M. Feldt, and S. Hippler, "Scintillation Effects on a High-Contrast Imaging Instrument for Direct Extrasolar Planets’ Detection," ApJ 615, 850-854 (2004).

Franchini, M.

C. Morossi, M. Franchini, and S. Furlani, "Spatial Resolution Improvement for an 8 Meter Class Telescope via Adaptive Optics and On-Line Subaperture Selection," PASP 114, 187-197 (2002).

Fried, D.

Fried, D. L.

Furlani, S.

C. Morossi, M. Franchini, and S. Furlani, "Spatial Resolution Improvement for an 8 Meter Class Telescope via Adaptive Optics and On-Line Subaperture Selection," PASP 114, 187-197 (2002).

Gavel, D. T.

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

Glindemann, A.

Graham, J. R.

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).

Greenwood, P. D.

Hippler, S.

E. Masciadri, M. Feldt, and S. Hippler, "Scintillation Effects on a High-Contrast Imaging Instrument for Direct Extrasolar Planets’ Detection," ApJ 615, 850-854 (2004).

Hodge, P. E.

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

A. Sivaramakrishnan, J. P. Lloyd, P. E. Hodge, and B. A. Macintosh, "Speckle Decorrelation and Dynamic Range in Speckle Noise-limited Imaging," ApJL 581, 59-62 (2002).

Labeyrie, A.

P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).

D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).

Lafreni`ere, D.

C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).

Lafreniere, D.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

Law, N. M.

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

N. M. Law, C. D. Mackay, and J. E. Baldwin, "Lucky imaging: high angular resolution imaging in the visible from the ground," AAP 446, 739 - 745 (2006).

Lemarquis, F.

P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).

Lloyd, J. P.

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

A. Sivaramakrishnan, J. P. Lloyd, P. E. Hodge, and B. A. Macintosh, "Speckle Decorrelation and Dynamic Range in Speckle Noise-limited Imaging," ApJL 581, 59-62 (2002).

Love, G. D.

Macintosh, B.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

Macintosh, B. A.

C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).

A. Sivaramakrishnan, J. P. Lloyd, P. E. Hodge, and B. A. Macintosh, "Speckle Decorrelation and Dynamic Range in Speckle Noise-limited Imaging," ApJL 581, 59-62 (2002).

Mackay, C. D.

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

N. M. Law, C. D. Mackay, and J. E. Baldwin, "Lucky imaging: high angular resolution imaging in the visible from the ground," AAP 446, 739 - 745 (2006).

Major, J.

Makidon, R. B.

M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).

Marois, C.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).

R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).

Masciadri, E.

E. Masciadri, M. Feldt, and S. Hippler, "Scintillation Effects on a High-Contrast Imaging Instrument for Direct Extrasolar Planets’ Detection," ApJ 615, 850-854 (2004).

Moore, A. M.

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

Morossi, C.

C. Morossi, M. Franchini, and S. Furlani, "Spatial Resolution Improvement for an 8 Meter Class Telescope via Adaptive Optics and On-Line Subaperture Selection," PASP 114, 187-197 (2002).

Myers, R.

Nadeau, D.

C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).

R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).

Oppenheimer, B. R.

M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).

Patience, J.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

Perrin, M. D.

M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).

Purvis, A.

Racine, R.

R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).

Restaino, S. R.

Riaud, P.

P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).

Riauld, P.

D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).

Rouan, D.

P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).

D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).

Sharples, R.

Sivaramakrishnan, A.

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).

A. Sivaramakrishnan, J. P. Lloyd, P. E. Hodge, and B. A. Macintosh, "Speckle Decorrelation and Dynamic Range in Speckle Noise-limited Imaging," ApJL 581, 59-62 (2002).

Song, I.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

Velur, V.

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

Vick, A.

Voit, G. M.

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

Walker, G. A. H.

R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).

Wilson, R.

Zadrozny, A.

Zuckerman, B.

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

AAP (1)

N. M. Law, C. D. Mackay, and J. E. Baldwin, "Lucky imaging: high angular resolution imaging in the visible from the ground," AAP 446, 739 - 745 (2006).

ApJ (3)

M. D. Perrin, A. Sivaramakrishnan, R. B. Makidon, B. R. Oppenheimer, and J. R. Graham, "The Structure of High Strehl Ratio Point-Spread Functions," ApJ 596, 702-712 (2003).

C. Marois, D. Lafreni`ere, R. Doyon, B. A. Macintosh, and D. Nadeau, "Angular Differential Imaging: A powerful high-contrast imaging technique," ApJ 641, 556-564 (2006).

E. Masciadri, M. Feldt, and S. Hippler, "Scintillation Effects on a High-Contrast Imaging Instrument for Direct Extrasolar Planets’ Detection," ApJ 615, 850-854 (2004).

ApJL (1)

A. Sivaramakrishnan, J. P. Lloyd, P. E. Hodge, and B. A. Macintosh, "Speckle Decorrelation and Dynamic Range in Speckle Noise-limited Imaging," ApJL 581, 59-62 (2002).

Appl. Opt. (2)

J. Opt. Soc. Am. (3)

Nature (1)

J. R. P. Angel, "Ground-based imaging of extrasolar planets using adaptive optics," Nature 368, 203-207 (1994).

PASP (4)

C. Morossi, M. Franchini, and S. Furlani, "Spatial Resolution Improvement for an 8 Meter Class Telescope via Adaptive Optics and On-Line Subaperture Selection," PASP 114, 187-197 (2002).

R. Racine, G. A. H. Walker, D. Nadeau, R. Doyon, and C. Marois, "Speckle Noise and the Detection of Faint Companions," PASP 111, 587-594 (1999).

D. Rouan, P. Riauld, A. Boccaletti, Y. Clenet, and A. Labeyrie, "The Four Quadrant Phase-Mask Coronagraph. I. Principle," PASP 112, 1479-1486 (2000).

P. Riaud, A. Boccaletti, D. Rouan, F. Lemarquis, and A. Labeyrie, "The Four-Quadrant Phase-Mask Coronagraph. II. Simulations," PASP 113, 1145-1154 (2001).

Science (1)

C. Marois, B. Macintosh, T. Barman, B. Zuckerman, I. Song, J. Patience, D. Lafreniere, and R. Doyon, "Direct Imaging of Multiple Planets Orbiting the Star HR 8799," Science 322, 1348-1352 (2008).
[PubMed]

SPIE (2)

N. M. Law, R. G. Dekany, C. D. Mackay, A. M. Moore, M. C. Britton, and V. Velur, "Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes," SPIE 7014, I152 (2008).

J. P. Lloyd, D. T. Gavel, J. R. Graham, P. E. Hodge, A. Sivaramakrishnan, and G. M. Voit, "Four Quadrant Phase Mask: Analytical Calculation and Pupil Geometry," SPIE 4860, 171-181 (2004).

Other (3)

A. Zadrozny, M. P. J. L. Chang, D. F. Buscher, R. M. Myers, A. P. Doel, C. N. Dunlop, and R. M. Sharples, "First atmospheric compensation with a linearised high order adaptive mirror - ELECTRA," in Topical Meeting on Astronomy with Adaptive Optics, D. Bonaccini, ed., 56, pp. 459 - 468 (ESO Conf. Workshop Proc., 1999).

F. Roddier, "Optical propagation and image formation through the turbulent atmosphere," in Diffraction Limited Imaging with Very Large Telescopes, D. M. Alloin and J.-M. Mariotti, eds., pp. 33 - 52 (NATO ASI, 1988).

"DLP Discovery 4000," Tech. rep., Texas Instruments (2009).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1.
Fig. 1.

Block diagram for the adaptive pupil mask system. The mask is positioned in the pupil plane of the telescope after the deformable mirror (DM) and after the wavefront sensor (WFS) pickoff.

Fig. 2.
Fig. 2.

Simulation results showing how the FWHM of the PSF is modified by the adaptive pupil mask. All areas of the pupil which have a phase error greater than the threshold (either positive or negative) are blocked. The plots show the FWHM for (a) a 1 m class telescope and (b) an 8 m telescope with AO. The solid horizontal black line at the top of the plot shows the FWHM without the adaptive pupil mask and the dashed line at the bottom shows the FWHM for a perfect system with no aberrations. For a large threshold only a small fraction of the pupil is blocked and there is little change of the PSF. As the threshold is reduced more of the pupil is blocked, the resulting wavefront is flatter and the FWHM is reduced. If the threshold is too low we block a large fraction of the pupil broadening the diffraction pattern due to the low fill factor of the pupil.

Fig. 3.
Fig. 3.

Simulation results showing how the peak intensity of the PSF is modified by the adaptive pupil mask. (a) shows the peak intensity for the 1 m telescope without AO and (b) for the 8 m telescope with AO. The solid black line indicates the peak intensity of the PSF with no blocking. For low threshold values large fractions of the pupil are blocked and so the total intensity is also reduced by a large amount. For high threshold values the effect is negligible, but there is an intermediate value where the peak intensity is increased. The intensity is normalised to the peak value without a pupil mask.

Fig. 4.
Fig. 4.

Example PSF from a 1 m telescope without AO with r0=0.15 m. On the top left is the original PSF from the telescope with no AO and on the top right is the PSF with no AO but using the adaptive pupil mask with a threshold value of ±1.8 radians. The bottom plot shows the radial intensity profiles of the two PSFs. The black dashed line is the original intensity pattern and the red line is the modified radial profile. The modified intensity is 40 % higher and the FWHM 4 times smaller than the original PSF.

Fig. 5.
Fig. 5.

Example PSF from an 8 m telescope equipped with a 16×16 AO system with r0=0.15 m. On the top left is the original PSF from the telescope and on the top right is the PSF with AO and the adaptive pupil mask and a threshold value of ±1.4 radians. The bottom plot shows the radial intensity profiles of the two PSFs. The black dashed line is the original intensity pattern and the red line is the modified radial profile. The modified intensity is 23 % higher and the FWHM is reduced from 0.022 ” to 0.018 ”. As the fraction of the light in the core has been increased the halo component is seen to be reduced.

Fig. 6.
Fig. 6.

SNR obtained as a function of threshold for observing a faint companion at 2λ/D and δm=7.7 with a D=1 m telescope (a) and δm=11.7 with a D=8 m telescope (b). The solid black line shows the SNR for the un-masked system.

Fig. 7.
Fig. 7.

Theoretical plots to show the effect of an AO system on the wavefront structure function. (a) is the AO high pass filter function as defined by Greenwood [20]. Low spatial frequencies are removed by the AO system and high spatial frequencies propagate. (b) shows the uncorrected structure function (black line) and partially corrected structure function (red line). The partially corrected structure function saturates when r>d as large spatial scale deformations (low spatial frequencies) have been removed by the AO system as seen in (a).

Fig. 8.
Fig. 8.

The performance of the pupil mask is defined by the balance between reducing the residual wavefront variance and minimising the fraction of the pupil being blocked. The plot on the left shows the relationship between initial variance and residual variance for a number of thresholds. The lower the threshold the greater the reduction in variance. The plot on the right shows the relationship between the initial variance and the fraction of the pupil which is blocked for a given threshold. A low threshold will result in a decreased wavefront variance but it will also require blocking a large fraction of the pupil, reducing the total intensity in the image and changing the diffraction limited PSF.

Fig. 9.
Fig. 9.

The atmospheric modulation transfer function after AO correction depends on the wavefront variance, defined by the d/r0 ratio. The left plot shows the atmospheric modulation transfer function for a range of d/r0 values. A lower ratio means the AO system is capable of better correction and so will converge at a higher level. Equation (16) states that the MTF atmos converges to exp(-σ2) which using the Maréchal approximation indicates the fraction of energy within the diffraction limited core. The plot on the right shows how the MTF atmos is modified by the pupil mask for a single value of d/r 0=4. As the threshold is reduced the system rejects more subapertures and so the residual wavefront variance is reduced, increasing the fraction of energy in the PSF core.

Fig. 10.
Fig. 10.

The adaptive pupil mask will have an effect on the telescope transfer function. The magnitude of this effect will depend on the fraction of the pupil that is blocked. The black line in the plot is the telescope MTF for a circular aperture, the blue line shows the MTF for a telescope with a central obscuration 1/4 the diameter of the primary and the red lines show the extent of modication due to the pupil mask with 20 %, 40 % and 60 % of the pupil blocked.

Tables (1)

Tables Icon

Table 1. Simulation results for a combination of different telescope diameters and instruments to show the achievable SNR with each system. The target separation was chosen to be 2λ/D and the magnitude difference (δ Mag) of the binary system was selected so that the signal to noise ration (SNR) of the system without the mask (control) was 5. The adaptive pupil mask (APM) can then increase the SNR dramatically. For the 8 m telescope the SNR with a four quadrant phase mask coronagraph (FQPM) and the combination of the APM and FQPM is shown.

Equations (16)

Equations on this page are rendered with MathJax. Learn more.

P5.6 exp  [0.1557(Dr0)2]
PSF=([MTFatmos×MTFtel])×(IT'IT)
MTFatmos(r)=exp (0.5Dϕ(r)) ,
Dϕ(r)=ϕ(r)ϕ(r+r')2
Dϕ(rL0)=6.88 (rr0)53
Dϕ(r)=2 σ2
H(κd2)=1(2J1(κd2)κd2)216(2κd)2J22(κd2)
Dϕ,AO(r)=4 π 0[1J0(κr)]Fϕ(κ)H(κd2)κdκ,
Fϕ(κ)=0.489 r053 κ113 .
Dϕ,AO(x)=6.14 (dr0)53 0[1J0(ux)]H(u2)u83du
Dϕ,AO(x)=45.8 σ2 0[1J0(ux)]H(u2)u83du.
Dϕ,AO(r>d)=2 σ2 .
σT2T+T(ϕϕ¯)2P(ϕ)dϕ
Dϕ,AO+APM(rd)=45.8 T+T(ϕϕ¯)2P(ϕ)dϕ0[1J0(ux)]H(u2)u83du
Dϕ,APM(rD)=6.68 (rD)53 T+T(ϕϕ¯)2P(ϕ)dϕ.
MTFatmos(r)=exp (σ2) .

Metrics