Abstract

We present an optical testbed demonstration of the Fizeau Interferometric Cophasing of Segmented Mirrors (FICSM) algorithm. FICSM allows a segmented mirror to be phased with a science imaging detector and three filters (selected among the normal science complement). It requires no specialised, dedicated wavefront sensing hardware. Applying random piston and tip/tilt aberrations of more than 5 wavelengths to a small segmented mirror array produced an initial unphased point spread function with an estimated Strehl ratio of 9% that served as the starting point for our phasing algorithm. After using the FICSM algorithm to cophase the pupil, we estimated a Strehl ratio of 94% based on a comparison between our data and simulated encircled energy metrics. Our final image quality is limited by the accuracy of our segment actuation, which yields a root mean square (RMS) wavefront error of 25 nm. This is the first hardware demonstration of coarse and fine phasing an 18-segment pupil with the James Webb Space Telescope (JWST) geometry using a single algorithm. FICSM can be implemented on JWST using any of its scientic imaging cameras making it useful as a fall-back in the event that accepted phasing strategies encounter problems. We present an operational sequence that would co-phase such an 18-segment primary in 3 sequential iterations of the FICSM algorithm. Similar sequences can be readily devised for any segmented mirror.

© 2014 Optical Society of America

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References

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  1. J. E. Nelson, “The University of California 10-m telescope project,” J. Opt. Soc. Am., 69, 1436 (1979).
  2. J. E. Nelson, “Design concepts for the California extremely large telescope (CELT)”, Proc. SPIE, 4004, 282–289 (2000).
    [CrossRef]
  3. R. Gilmozzi, “Science and technology drivers for future giant telescopes”, Proc. SPIE, 5489, 1–10 (2000).
    [CrossRef]
  4. G. Chanan, M. Troy, F. Dekens, S. Michaels, J. Nelson, T. Mast, D. Kirkman, “Phasing the mirror segments of the Keck telescopes: the broadband phasing algorithm,” Appl. Opt. 37, 140–155 (1998).
    [CrossRef]
  5. G. Chanan, C. Ohara, M. Troy, “Phasing the mirror segments of the Keck telescopes II: the narrow-band phasing algorithm,” Appl. Opt. 39, 4706–4714 (2000).
    [CrossRef]
  6. D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
    [CrossRef]
  7. D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).
  8. J. R. Fienup, J. C. Marron, T. J. Schulz, J. H. Seldin, “Hubble Space Telescope characterized by using phase-retrieval algorithms”, Appl. Opt., 32, 1747–1767 (1993).
    [CrossRef] [PubMed]
  9. A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
    [CrossRef]
  10. J. E. Krist, C. J. Burrows, “Phase-retrieval analysis of pre-and post-repair Hubble Space Telescope images”, Appl. Opt., 34, 4951–4964 (1995).
    [CrossRef] [PubMed]
  11. A. Cheetham, Cophasing JWST’s segmented mirror using sparse aperture interferometry (University of Sydney Hons. Thesis, 2011).
  12. A. Cheetham, P. Tuthill, A. Sivaramakrishnan, J. Lloyd, “Fizeau interferometric cophasing of segmented mirrors,” Opt. Express 20, 29457–29471 (2012).
    [CrossRef]
  13. A. Wirth, “Dispersed Hartmann sensor and method for mirror segment alignment and phasing”, https://www.google.com/patents/US6649895 , US Patent 6, 649,895 (2003).
  14. F. Shi, C. M. Ohara, G. Chanan, M. Troy, D. C. Redding, “Experimental verification of dispersed fringe sensing as a segment-phasing technique using the Keck Telescope”, Proc. SPIE, 5489, 1061–1073 (2004).
    [CrossRef]
  15. J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
    [CrossRef]
  16. E. Sabatke, J. Burge, D. Sabatke, “Analytic diffraction analysis of a 32-m telescope with hexagonal segments for high-contrast imaging,” Appl. Opt. 44, 1360–1365 (2005).
    [CrossRef] [PubMed]
  17. M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
    [CrossRef]
  18. J. Daniel, T. Hull, J. B. Barentine, “JWST: Tinsley achievements on the largest beryllium polishing project”, Proc. SPIE, 8450, 845021 (2012).
    [CrossRef]
  19. C. Neyman, R. Flicker, S. Panteleev, “Effect of Keck segment figure errors on Keck AO performance”, Keck Adaptive Optics Note469 (2007).
  20. M. Helmbrecht, M. He, C. Kempf, M. Besse, “MEMS DM development at Iris AO, Inc.”, Proc. SPIE, 7931, 793108 (2011).
    [CrossRef]

2012 (2)

A. Cheetham, P. Tuthill, A. Sivaramakrishnan, J. Lloyd, “Fizeau interferometric cophasing of segmented mirrors,” Opt. Express 20, 29457–29471 (2012).
[CrossRef]

J. Daniel, T. Hull, J. B. Barentine, “JWST: Tinsley achievements on the largest beryllium polishing project”, Proc. SPIE, 8450, 845021 (2012).
[CrossRef]

2011 (1)

M. Helmbrecht, M. He, C. Kempf, M. Besse, “MEMS DM development at Iris AO, Inc.”, Proc. SPIE, 7931, 793108 (2011).
[CrossRef]

2009 (1)

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

2008 (1)

A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
[CrossRef]

2007 (2)

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

C. Neyman, R. Flicker, S. Panteleev, “Effect of Keck segment figure errors on Keck AO performance”, Keck Adaptive Optics Note469 (2007).

2006 (2)

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
[CrossRef]

2005 (1)

2004 (1)

F. Shi, C. M. Ohara, G. Chanan, M. Troy, D. C. Redding, “Experimental verification of dispersed fringe sensing as a segment-phasing technique using the Keck Telescope”, Proc. SPIE, 5489, 1061–1073 (2004).
[CrossRef]

2000 (3)

J. E. Nelson, “Design concepts for the California extremely large telescope (CELT)”, Proc. SPIE, 4004, 282–289 (2000).
[CrossRef]

R. Gilmozzi, “Science and technology drivers for future giant telescopes”, Proc. SPIE, 5489, 1–10 (2000).
[CrossRef]

G. Chanan, C. Ohara, M. Troy, “Phasing the mirror segments of the Keck telescopes II: the narrow-band phasing algorithm,” Appl. Opt. 39, 4706–4714 (2000).
[CrossRef]

1998 (1)

1995 (1)

1993 (1)

1979 (1)

J. E. Nelson, “The University of California 10-m telescope project,” J. Opt. Soc. Am., 69, 1436 (1979).

Acton, D. S.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Barentine, J. B.

J. Daniel, T. Hull, J. B. Barentine, “JWST: Tinsley achievements on the largest beryllium polishing project”, Proc. SPIE, 8450, 845021 (2012).
[CrossRef]

Bauer, B.

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Besse, M.

M. Helmbrecht, M. He, C. Kempf, M. Besse, “MEMS DM development at Iris AO, Inc.”, Proc. SPIE, 7931, 793108 (2011).
[CrossRef]

Bruce, D.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

Burge, J.

Burrows, C. J.

Chanan, G.

Cheetham, A.

A. Cheetham, P. Tuthill, A. Sivaramakrishnan, J. Lloyd, “Fizeau interferometric cophasing of segmented mirrors,” Opt. Express 20, 29457–29471 (2012).
[CrossRef]

A. Cheetham, Cophasing JWST’s segmented mirror using sparse aperture interferometry (University of Sydney Hons. Thesis, 2011).

Cohen, R.

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

Contos, A. R.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Daniel, J.

J. Daniel, T. Hull, J. B. Barentine, “JWST: Tinsley achievements on the largest beryllium polishing project”, Proc. SPIE, 8450, 845021 (2012).
[CrossRef]

Dekens, F.

Doble, N.

M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
[CrossRef]

Fang, S.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

Fienup, J. R.

Flicker, R.

C. Neyman, R. Flicker, S. Panteleev, “Effect of Keck segment figure errors on Keck AO performance”, Keck Adaptive Optics Note469 (2007).

Gilmozzi, R.

R. Gilmozzi, “Science and technology drivers for future giant telescopes”, Proc. SPIE, 5489, 1–10 (2000).
[CrossRef]

Hansen, K.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Hart, M.

M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
[CrossRef]

He, M.

M. Helmbrecht, M. He, C. Kempf, M. Besse, “MEMS DM development at Iris AO, Inc.”, Proc. SPIE, 7931, 793108 (2011).
[CrossRef]

M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
[CrossRef]

Helmbrecht, M.

M. Helmbrecht, M. He, C. Kempf, M. Besse, “MEMS DM development at Iris AO, Inc.”, Proc. SPIE, 7931, 793108 (2011).
[CrossRef]

M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
[CrossRef]

Hull, T.

J. Daniel, T. Hull, J. B. Barentine, “JWST: Tinsley achievements on the largest beryllium polishing project”, Proc. SPIE, 8450, 845021 (2012).
[CrossRef]

Ireland, M.

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

Juneau, T.

M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
[CrossRef]

Kempf, C.

M. Helmbrecht, M. He, C. Kempf, M. Besse, “MEMS DM development at Iris AO, Inc.”, Proc. SPIE, 7931, 793108 (2011).
[CrossRef]

Kirkman, D.

Klingemann, L.

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Krist, J. E.

Lloyd, J.

Marron, J. C.

Mast, T.

Michaels, S.

Monnier, J.

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

Nelson, J.

Nelson, J. E.

J. E. Nelson, “Design concepts for the California extremely large telescope (CELT)”, Proc. SPIE, 4004, 282–289 (2000).
[CrossRef]

J. E. Nelson, “The University of California 10-m telescope project,” J. Opt. Soc. Am., 69, 1436 (1979).

Neyman, C.

C. Neyman, R. Flicker, S. Panteleev, “Effect of Keck segment figure errors on Keck AO performance”, Keck Adaptive Optics Note469 (2007).

Ohara, C.

Ohara, C. M.

F. Shi, C. M. Ohara, G. Chanan, M. Troy, D. C. Redding, “Experimental verification of dispersed fringe sensing as a segment-phasing technique using the Keck Telescope”, Proc. SPIE, 5489, 1061–1073 (2004).
[CrossRef]

Panteleev, S.

C. Neyman, R. Flicker, S. Panteleev, “Effect of Keck segment figure errors on Keck AO performance”, Keck Adaptive Optics Note469 (2007).

Perrin, M.

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

Pueyo, L.

A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
[CrossRef]

Redding, D. C.

F. Shi, C. M. Ohara, G. Chanan, M. Troy, D. C. Redding, “Experimental verification of dispersed fringe sensing as a segment-phasing technique using the Keck Telescope”, Proc. SPIE, 5489, 1061–1073 (2004).
[CrossRef]

Sabatke, D.

Sabatke, E.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

E. Sabatke, J. Burge, D. Sabatke, “Analytic diffraction analysis of a 32-m telescope with hexagonal segments for high-contrast imaging,” Appl. Opt. 44, 1360–1365 (2005).
[CrossRef] [PubMed]

Schulz, T. J.

Schwenker, J.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Seldin, J. H.

Shao, M.

A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
[CrossRef]

Shi, F.

F. Shi, C. M. Ohara, G. Chanan, M. Troy, D. C. Redding, “Experimental verification of dispersed fringe sensing as a segment-phasing technique using the Keck Telescope”, Proc. SPIE, 5489, 1061–1073 (2004).
[CrossRef]

Shields, D.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Sivaramakrishnan, A.

A. Cheetham, P. Tuthill, A. Sivaramakrishnan, J. Lloyd, “Fizeau interferometric cophasing of segmented mirrors,” Opt. Express 20, 29457–29471 (2012).
[CrossRef]

A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
[CrossRef]

Smith, S.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

Soummer, R.

A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
[CrossRef]

Swensen, J.

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Tannirkulam, A.

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

Towell, T.

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

Troy, M.

Tuthill, P.

A. Cheetham, P. Tuthill, A. Sivaramakrishnan, J. Lloyd, “Fizeau interferometric cophasing of segmented mirrors,” Opt. Express 20, 29457–29471 (2012).
[CrossRef]

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

Wallace, J. K.

A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
[CrossRef]

Appl. Opt. (5)

Astrophys. J. (2)

J. Monnier, P. Tuthill, M. Ireland, R. Cohen, A. Tannirkulam, M. Perrin, “Mid-infrared size survey of young stellar objects: description of Keck segment-tilting experiment and basic results,” Astrophys. J. 700, 491 (2009).
[CrossRef]

A. Sivaramakrishnan, R. Soummer, L. Pueyo, J. K. Wallace, M. Shao, “Sensing phase aberrations behind Lyot coronagraphs”, Astrophys. J., 688, 701–708 (2008).
[CrossRef]

J. Opt. Soc. Am. (1)

J. E. Nelson, “The University of California 10-m telescope project,” J. Opt. Soc. Am., 69, 1436 (1979).

Keck Adaptive Optics Note (1)

C. Neyman, R. Flicker, S. Panteleev, “Effect of Keck segment figure errors on Keck AO performance”, Keck Adaptive Optics Note469 (2007).

Opt. Express (1)

Proc. SPIE (8)

F. Shi, C. M. Ohara, G. Chanan, M. Troy, D. C. Redding, “Experimental verification of dispersed fringe sensing as a segment-phasing technique using the Keck Telescope”, Proc. SPIE, 5489, 1061–1073 (2004).
[CrossRef]

M. Helmbrecht, M. He, T. Juneau, M. Hart, N. Doble, “Segmented MEMS deformable-mirror for wavefront correction”, Proc. SPIE, 6376, 63760D (2006).
[CrossRef]

J. Daniel, T. Hull, J. B. Barentine, “JWST: Tinsley achievements on the largest beryllium polishing project”, Proc. SPIE, 8450, 845021 (2012).
[CrossRef]

J. E. Nelson, “Design concepts for the California extremely large telescope (CELT)”, Proc. SPIE, 4004, 282–289 (2000).
[CrossRef]

R. Gilmozzi, “Science and technology drivers for future giant telescopes”, Proc. SPIE, 5489, 1–10 (2000).
[CrossRef]

D. S. Acton, T. Towell, J. Schwenker, J. Swensen, D. Shields, E. Sabatke, L. Klingemann, A. R. Contos, B. Bauer, K. Hansen, “Demonstration of the James Webb Space Telescope commissioning on the JWST testbed telescope”, Proc. SPIE, 6265, 62650R (2006).
[CrossRef]

D. S. Acton, T. Towell, J. Schwenker, D. Shields, E. Sabatke, A. R. Contos, K. Hansen, S. Fang, D. Bruce, S. Smith, “End-to-end commissioning demonstration of the James Webb Space Telescope”, Proc. SPIE, 6687, 6687E (2007).

M. Helmbrecht, M. He, C. Kempf, M. Besse, “MEMS DM development at Iris AO, Inc.”, Proc. SPIE, 7931, 793108 (2011).
[CrossRef]

Other (2)

A. Wirth, “Dispersed Hartmann sensor and method for mirror segment alignment and phasing”, https://www.google.com/patents/US6649895 , US Patent 6, 649,895 (2003).

A. Cheetham, Cophasing JWST’s segmented mirror using sparse aperture interferometry (University of Sydney Hons. Thesis, 2011).

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Figures (4)

Fig. 1:
Fig. 1:

The segment groups used for this demonstration. Each image shows several segment groups that are phased simultaneously. At each step, each group is shown in a different colour. Red segments are phased but unused in that step and could be used for telescope guiding (to ensure the PSF remains stationary), while black segments are unphased and unused in that step. Each group produces an interference pattern with acceptable levels of redundancy at bandwidths of up to 25% of the peak wavelength. If multiple pointings are possible this allows the entire mirror to be phased in the three steps shown. If this is not possible, the first blue group is unnecessary and the procedure is accomplished in 7 steps. The segment numbering scheme is also shown superimposed on the segments in the first step.

Fig. 2:
Fig. 2:

A schematic overview of the experimental setup. For the broadband images, light from a halogen lamp was passed through a filter into a multimode fibre, then coupled into a single mode fibre connected to a fibre collimator. For the narrow band images, a HeNe laser was connected to the fibre collimator using a single mode fibre only. Collimated light was then reflected off the MEMS mirror array and through an achromatic doublet lens onto a detector. MEMS inset image from Helmbrecht et al. (2011) [20].

Fig. 3:
Fig. 3:

Images showing the PSF before (left) and after (middle) phasing, with a log stretch. A simulated perfectly phased image (right) is also shown for comparison. Before phasing, power is spread over a large area. After applying FICSM, the PSF conforms well to the theoretical PSF in the absence of aberrations.

Fig. 4:
Fig. 4:

The encircled energy as a function of radius of several real and numerical images. The black curve shows the result for a numerically generated image in the absence of noise and free of wavefront error. A typical example of a theoretically generated image with pistons and tilts consistent with the noise limit of the segments is shown in yellow. The blue and green curves show the results for real images taken before and after phasing. These results suggest that FICSM has successfully phased the mirror from an extremely degraded state to a level consistent with the expected noise.

Tables (1)

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Table 1: Initial and final positions of each segment, measured at the wavefront.

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