Abstract

A novel technique for axial resolution improvement of Optical Coherence Tomography (OCT) systems is proposed. The technique is based on step-frequency encoding, using frequency shifting, of the OCT signal. A resolution improvement by a factor of ~7 is achieved without the need for a broader bandwidth light source. This method exploits a combination of two basic principles: the appearance of beating, when adding two signals of slightly different carrier frequencies, and the resolution improvement by deconvolution of the interferogram with an encoded autocorrelation function. In time domain OCT, step-frequency encoding can be implemented by performing two scans, with different carrier frequencies, and subsequently adding them to create the encoded signal. When the frequency steps are properly selected, deconvolution of the resulting interferogram, using appropriate kernels, results in a narrower resolution width.

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  1. J. G. Fujimoto, C. Pitris, S. A. Boppart, and M. E. Brezinski, “Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy,” Neoplasia 2(1-2), 9–25 (2000).
    [CrossRef] [PubMed]
  2. W. Drexler, U. Morgner, F. X. Kärtner, C. Pitris, S. A. Boppart, X. D. Li, E. P. Ippen, and J. G. Fujimoto, “In vivo ultrahigh-resolution optical coherence tomography,” Opt. Lett. 24(17), 1221–1223 (1999).
    [CrossRef]
  3. B. Povazay, K. Bizheva, A. Unterhuber, B. Hermann, H. Sattmann, A. F. Fercher, W. Drexler, A. Apolonski, W. J. Wadsworth, J. C. Knight, P. St. J. Russell, M. Vetterlein, and E. Scherzer, “Submicrometer axial resolution optical coherence tomography,” Opt. Lett. 27(20), 1800–1802 (2002).
    [CrossRef]
  4. W. Drexler, “Ultrahigh-resolution optical coherence tomography,” J. Biomed. Opt. 9(1), 47–74 (2004).
    [CrossRef] [PubMed]
  5. A. Dubois, G. Moneron, K. Grieve, and A. C. Boccara, “Three-dimensional cellular-level imaging using full-field optical coherence tomography,” Phys. Med. Biol. 49(7), 1227–1234 (2004).
    [CrossRef] [PubMed]
  6. A. Wax, C. H. Yang, and J. A. Izatt, “Fourier-domain low-coherence interferometry for light-scattering spectroscopy,” Opt. Lett. 28(14), 1230–1232 (2003).
    [CrossRef] [PubMed]
  7. A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
    [CrossRef] [PubMed]
  8. K. Bizheva, B. Povazay, B. Hermann, H. Sattmann, W. Drexler, M. Mei, R. Holzwarth, T. Hoelzenbein, V. Wacheck, and H. Pehamberger, “Compact, broad-bandwidth fiber laser for sub-2-microm axial resolution optical coherence tomography in the 1300-nm wavelength region,” Opt. Lett. 28(9), 707–709 (2003).
    [CrossRef] [PubMed]
  9. F. Spöler, S. Kray, P. Grychtol, B. Hermes, J. Bornemann, M. Först, and H. Kurz, “Simultaneous dual-band ultra-high resolution optical coherence tomography,” Opt. Express 15(17), 10832–10841 (2007).
    [CrossRef] [PubMed]
  10. M. B. Nasr, O. Minaeva, G. N. Goltsman, A. V. Sergienko, B. E. A. Saleh, and M. C. Teich, “Submicron axial resolution in an ultrabroadband two-photon interferometer using superconducting single-photon detectors,” Opt. Express 16(19), 15104–15108 (2008).
    [CrossRef] [PubMed]
  11. M. D. Kulkarni, C. W. Thomas, and J. A. Izatt, “Image enhancement in optical coherence tomography using deconvolution,” Electron. Lett. 33(16), 1365–1367 (1997).
    [CrossRef]
  12. Y. Takahashi, Y. Watanabe, and M. Sato, “Application of the maximum entropy method to spectral-domain optical coherence tomography for enhancing axial resolution,” Appl. Opt. 46(22), 5228–5236 (2007).
    [CrossRef] [PubMed]
  13. J. Gong, B. Liu, Y. L. Kim, Y. Liu, X. Li, and V. Backman, “Optimal spectral reshaping for resolution improvement in optical coherence tomography,” Opt. Express 14(13), 5909–5915 (2006).
    [CrossRef] [PubMed]
  14. S. Carrasco, J. P. Torres, L. Torner, A. Sergienko, B. E. Saleh, and M. C. Teich, “Enhancing the axial resolution of quantum optical coherence tomography by chirped quasi-phase matching,” Opt. Lett. 29(20), 2429–2431 (2004).
    [CrossRef] [PubMed]
  15. J. D. Taylor, Ultra wideband radar technology, (CRC press LLC, 2001), Chap. 11.
  16. T. Misaridis and J. A. Jensen, “Use of modulated excitation signals in medical ultrasound. Part I: Basic concepts and expected benefits,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 52(2), 177–191 (2005).
    [CrossRef] [PubMed]
  17. J. M. Schmitt, “Restoration of optical coherence images of living tissue using the CLEAN algorithm,” J. Biomed. Opt. 3(1), 66–75 (1998).
    [CrossRef]
  18. Y. Liu, Y. Liang, G. Mu, and X. Zhu, “Deconvolution methods for image deblurring in optical coherence tomography,” J. Opt. Soc. Am. A 26(1), 72–77 (2009).
    [CrossRef]
  19. L. B. Lucy, “An iterative technique for the rectification of observed distributions,” Astron. J. 79, 745–753 (1974).
    [CrossRef]
  20. A. Kartakoullis, E. Bousi, and C. Pitris, “Scatterer size-based analysis of optical coherence tomography images using spectral estimation techniques,” Opt. Express 18(9), 9181–9191 (2010).
    [CrossRef] [PubMed]

2010 (1)

2009 (1)

2008 (1)

2007 (2)

2006 (1)

2005 (1)

T. Misaridis and J. A. Jensen, “Use of modulated excitation signals in medical ultrasound. Part I: Basic concepts and expected benefits,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 52(2), 177–191 (2005).
[CrossRef] [PubMed]

2004 (4)

S. Carrasco, J. P. Torres, L. Torner, A. Sergienko, B. E. Saleh, and M. C. Teich, “Enhancing the axial resolution of quantum optical coherence tomography by chirped quasi-phase matching,” Opt. Lett. 29(20), 2429–2431 (2004).
[CrossRef] [PubMed]

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

W. Drexler, “Ultrahigh-resolution optical coherence tomography,” J. Biomed. Opt. 9(1), 47–74 (2004).
[CrossRef] [PubMed]

A. Dubois, G. Moneron, K. Grieve, and A. C. Boccara, “Three-dimensional cellular-level imaging using full-field optical coherence tomography,” Phys. Med. Biol. 49(7), 1227–1234 (2004).
[CrossRef] [PubMed]

2003 (2)

2002 (1)

2000 (1)

J. G. Fujimoto, C. Pitris, S. A. Boppart, and M. E. Brezinski, “Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy,” Neoplasia 2(1-2), 9–25 (2000).
[CrossRef] [PubMed]

1999 (1)

1998 (1)

J. M. Schmitt, “Restoration of optical coherence images of living tissue using the CLEAN algorithm,” J. Biomed. Opt. 3(1), 66–75 (1998).
[CrossRef]

1997 (1)

M. D. Kulkarni, C. W. Thomas, and J. A. Izatt, “Image enhancement in optical coherence tomography using deconvolution,” Electron. Lett. 33(16), 1365–1367 (1997).
[CrossRef]

1974 (1)

L. B. Lucy, “An iterative technique for the rectification of observed distributions,” Astron. J. 79, 745–753 (1974).
[CrossRef]

Ahnelt, P. K.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Apolonski, A.

Backman, V.

Bizheva, K.

Boccara, A. C.

A. Dubois, G. Moneron, K. Grieve, and A. C. Boccara, “Three-dimensional cellular-level imaging using full-field optical coherence tomography,” Phys. Med. Biol. 49(7), 1227–1234 (2004).
[CrossRef] [PubMed]

Boppart, S. A.

J. G. Fujimoto, C. Pitris, S. A. Boppart, and M. E. Brezinski, “Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy,” Neoplasia 2(1-2), 9–25 (2000).
[CrossRef] [PubMed]

W. Drexler, U. Morgner, F. X. Kärtner, C. Pitris, S. A. Boppart, X. D. Li, E. P. Ippen, and J. G. Fujimoto, “In vivo ultrahigh-resolution optical coherence tomography,” Opt. Lett. 24(17), 1221–1223 (1999).
[CrossRef]

Bornemann, J.

Bousi, E.

Brezinski, M. E.

J. G. Fujimoto, C. Pitris, S. A. Boppart, and M. E. Brezinski, “Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy,” Neoplasia 2(1-2), 9–25 (2000).
[CrossRef] [PubMed]

Budka, H.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Carrasco, S.

Cowey, A.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Drexler, W.

Dubois, A.

A. Dubois, G. Moneron, K. Grieve, and A. C. Boccara, “Three-dimensional cellular-level imaging using full-field optical coherence tomography,” Phys. Med. Biol. 49(7), 1227–1234 (2004).
[CrossRef] [PubMed]

Fercher, A. F.

Först, M.

Fujimoto, J. G.

J. G. Fujimoto, C. Pitris, S. A. Boppart, and M. E. Brezinski, “Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy,” Neoplasia 2(1-2), 9–25 (2000).
[CrossRef] [PubMed]

W. Drexler, U. Morgner, F. X. Kärtner, C. Pitris, S. A. Boppart, X. D. Li, E. P. Ippen, and J. G. Fujimoto, “In vivo ultrahigh-resolution optical coherence tomography,” Opt. Lett. 24(17), 1221–1223 (1999).
[CrossRef]

Goltsman, G. N.

Gong, J.

Grieve, K.

A. Dubois, G. Moneron, K. Grieve, and A. C. Boccara, “Three-dimensional cellular-level imaging using full-field optical coherence tomography,” Phys. Med. Biol. 49(7), 1227–1234 (2004).
[CrossRef] [PubMed]

Grychtol, P.

Hermann, B.

Hermes, B.

Hoelzenbein, T.

Holzwarth, R.

Ippen, E. P.

Izatt, J. A.

A. Wax, C. H. Yang, and J. A. Izatt, “Fourier-domain low-coherence interferometry for light-scattering spectroscopy,” Opt. Lett. 28(14), 1230–1232 (2003).
[CrossRef] [PubMed]

M. D. Kulkarni, C. W. Thomas, and J. A. Izatt, “Image enhancement in optical coherence tomography using deconvolution,” Electron. Lett. 33(16), 1365–1367 (1997).
[CrossRef]

Jensen, J. A.

T. Misaridis and J. A. Jensen, “Use of modulated excitation signals in medical ultrasound. Part I: Basic concepts and expected benefits,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 52(2), 177–191 (2005).
[CrossRef] [PubMed]

Kartakoullis, A.

Kärtner, F. X.

Kim, Y. L.

Knight, J. C.

Kray, S.

Kulkarni, M. D.

M. D. Kulkarni, C. W. Thomas, and J. A. Izatt, “Image enhancement in optical coherence tomography using deconvolution,” Electron. Lett. 33(16), 1365–1367 (1997).
[CrossRef]

Kurz, H.

Le, T.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Li, X.

Li, X. D.

Liang, Y.

Liu, B.

Liu, Y.

Lucy, L. B.

L. B. Lucy, “An iterative technique for the rectification of observed distributions,” Astron. J. 79, 745–753 (1974).
[CrossRef]

Mei, M.

Menzel, R.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Minaeva, O.

Misaridis, T.

T. Misaridis and J. A. Jensen, “Use of modulated excitation signals in medical ultrasound. Part I: Basic concepts and expected benefits,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 52(2), 177–191 (2005).
[CrossRef] [PubMed]

Moneron, G.

A. Dubois, G. Moneron, K. Grieve, and A. C. Boccara, “Three-dimensional cellular-level imaging using full-field optical coherence tomography,” Phys. Med. Biol. 49(7), 1227–1234 (2004).
[CrossRef] [PubMed]

Morgan, J. E.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Morgner, U.

Mu, G.

Nasr, M. B.

Pehamberger, H.

Pitris, C.

Povazay, B.

Preusser, M.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Reitsamer, H.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Russell, P. St. J.

Saleh, B. E.

Saleh, B. E. A.

Sato, M.

Sattmann, H.

Scherzer, E.

Schmitt, J. M.

J. M. Schmitt, “Restoration of optical coherence images of living tissue using the CLEAN algorithm,” J. Biomed. Opt. 3(1), 66–75 (1998).
[CrossRef]

Schubert, Ch.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Seefeld, M.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Sergienko, A.

Sergienko, A. V.

Spöler, F.

Stingl, A.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Takahashi, Y.

Teich, M. C.

Thomas, C. W.

M. D. Kulkarni, C. W. Thomas, and J. A. Izatt, “Image enhancement in optical coherence tomography using deconvolution,” Electron. Lett. 33(16), 1365–1367 (1997).
[CrossRef]

Torner, L.

Torres, J. P.

Unterhuber, A.

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

B. Povazay, K. Bizheva, A. Unterhuber, B. Hermann, H. Sattmann, A. F. Fercher, W. Drexler, A. Apolonski, W. J. Wadsworth, J. C. Knight, P. St. J. Russell, M. Vetterlein, and E. Scherzer, “Submicrometer axial resolution optical coherence tomography,” Opt. Lett. 27(20), 1800–1802 (2002).
[CrossRef]

Vetterlein, M.

Wacheck, V.

Wadsworth, W. J.

Watanabe, Y.

Wax, A.

Yang, C. H.

Zhu, X.

Appl. Opt. (1)

Astron. J. (1)

L. B. Lucy, “An iterative technique for the rectification of observed distributions,” Astron. J. 79, 745–753 (1974).
[CrossRef]

Electron. Lett. (1)

M. D. Kulkarni, C. W. Thomas, and J. A. Izatt, “Image enhancement in optical coherence tomography using deconvolution,” Electron. Lett. 33(16), 1365–1367 (1997).
[CrossRef]

IEEE Trans. Ultrason. Ferroelectr. Freq. Control (1)

T. Misaridis and J. A. Jensen, “Use of modulated excitation signals in medical ultrasound. Part I: Basic concepts and expected benefits,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 52(2), 177–191 (2005).
[CrossRef] [PubMed]

J. Biomed. Opt. (2)

J. M. Schmitt, “Restoration of optical coherence images of living tissue using the CLEAN algorithm,” J. Biomed. Opt. 3(1), 66–75 (1998).
[CrossRef]

W. Drexler, “Ultrahigh-resolution optical coherence tomography,” J. Biomed. Opt. 9(1), 47–74 (2004).
[CrossRef] [PubMed]

J. Opt. Soc. Am. A (1)

Neoplasia (1)

J. G. Fujimoto, C. Pitris, S. A. Boppart, and M. E. Brezinski, “Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy,” Neoplasia 2(1-2), 9–25 (2000).
[CrossRef] [PubMed]

Opt. Express (4)

Opt. Lett. (5)

Phys. Med. Biol. (2)

A. Dubois, G. Moneron, K. Grieve, and A. C. Boccara, “Three-dimensional cellular-level imaging using full-field optical coherence tomography,” Phys. Med. Biol. 49(7), 1227–1234 (2004).
[CrossRef] [PubMed]

A. Unterhuber, B. Povazay, K. Bizheva, B. Hermann, H. Sattmann, A. Stingl, T. Le, M. Seefeld, R. Menzel, M. Preusser, H. Budka, Ch. Schubert, H. Reitsamer, P. K. Ahnelt, J. E. Morgan, A. Cowey, and W. Drexler, “Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography,” Phys. Med. Biol. 49(7), 1235–1246 (2004).
[CrossRef] [PubMed]

Other (1)

J. D. Taylor, Ultra wideband radar technology, (CRC press LLC, 2001), Chap. 11.

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Figures (11)

Fig. 1
Fig. 1

Beating of the interferogram of a single peak.

Fig. 2
Fig. 2

Dependence of sidelobes from frequency steps. (a) 3kHz frequency difference between steps. (b) 6kHz frequency difference between steps. Intensity scales are linear.

Fig. 3
Fig. 3

Different beating patterns as a result of different phases of interferograms.(a) zero distance shift corresponding to zero phase shift of the main lobe from the real position. (b), maximum distance shift corresponding to π/2 phase shift of the main lobe from the real position. Intensity scales are linear.

Fig. 4
Fig. 4

Configuration of the experimental Time Domain (TD) OCT system

Fig. 5
Fig. 5

Sample, consisting of 3 microscope cover slips (~170 μm thickness, spaced at ~170 μm apart), used to collect the interferograms of 6 individual peaks from each A-Scan. They were subsequently used as kernels for the deconvolution.

Fig. 6
Fig. 6

(a) Single peaks from demodulated standard OCT interferogram used as kernels for deconvolution. (b) Single peaks from demodulated encoded OCT interferogram used as kernels for deconvolution. (c) A-Scan from standard OCT (blue line), and deconvolution of demodulated A-Scans from standard (red line) and encoded OCT(black line) in one plot for comparison reasons. (d) Center peak of Fig. 6(c). (e) First peak of Fig. 6(c). y axis normalized, (a) and (b) normalized to 1, (d) and (e) normalized to the highest peak of (c). Intensity scales are linear.

Fig. 7
Fig. 7

(a) Onion imaged with standard OCT, (b) after deconvolution of the standard OCT image, (c) onion imaged with encoded OCT after deconvolution, and (d) onion image with encoded OCT after deconvolution and motion correction. (Image size: 1.5mm x 0.5 mm). The area in the red rectangle appears in Fig. 8.

Fig. 8
Fig. 8

(a) Onion imaged with standard OCT, (b) after deconvolution of the standard OCT image, (c) onion imaged with encoded OCT after deconvolution., (d) onion image with encoded OCT after deconvolution and motion correction and (e) Light microscopy image of onion cells. (Image size: 0,5mm x 0,2 mm).

Fig. 10
Fig. 10

Speckle images from (a) standard OCT, (b) deconvolution of standard OCT, and (c) step-frequency encoded and deconvoluted OCT. The images are displayed using the same contrast and brightness scale for comparison purposes. Each image is 1.5x0.8 mm.

Fig. 11
Fig. 11

Single OCT A-Scans from the images of Fig. 9: standard OCT (blue), deconvoluted standard OCT (red), and encoded and deconvoluted OCT (green) signals. Specular reflections appear at the surface of the sample (at 0.2 mm).

Fig. 9
Fig. 9

(a) Rabbit lung parenchyma imaged ex vivo with standard OCT, (b) after deconvolution of the standard OCT image, and (c) imaged with encoded OCT after deconvolution. (Image size: 0,5mm x 0,5 mm). (d – f) Details of images a-c, where small alveoli are indicated by the arrow. (e) Light microscopy image of a section of lung parenchyma from an unrelated site included for reference purposes.

Equations (38)

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

Ι = k 1 R R Ι 0 + k 2 R S I 0 + 2 [ k 1 R R Ι 0 ] × [ k 2 R S I 0 ] Re [ γ ( τ ) ] ,
γ ( τ ) = exp [ ( π Δ f τ 2 ln 2 ) 2 ] exp ( j 2 π f d τ ) ,
f d = 2 v s c a n n e r λ 0 ,
I interf = R R R S I 0 exp [ ( π Δ f τ 2 ln 2 ) 2 ] cos ( 2 π f d τ ) .
S 0 ( t ) = I 0 exp [ ( π Δ f τ 2 ln 2 ) 2 ] ,
I interf = R R R S S 0 (t)cos(2 π f d t ) .
A i 1 ( t ) = R R R S S 0 ( t ) cos ( 2 π f 1 t + φ i 1 )
A i 2 ( t ) = R R R S S 0 ( t ) cos ( 2 π f 2 t + φ i 2 )
A i ( t ) = A i 1 ( t ) + A i 2 ( t ) = R R R S 2 S 0 ( t ) cos [ 2 π ( f 1 + f 2 ) t + ( φ i 1 + φ i 2 ) 2 ] cos [ 2 π ( f 1 f 2 ) t + ( φ i 1 φ i 2 ) 2 ] .
A i ( t ) = R R R S 2 S 0 ( t ) cos [ 2 π ( f 1 f 2 ) t + ( φ i 1 φ i 2 ) 2 ] .
A i 1 ( t ) = k = 1 N R s k h ( t t k ) S 0 ( t ) cos ( 2 π f 1 t + φ 1 ( φ i 1 , t k ) ) ,
A i 2 ( t ) = k = 1 N R s k h ( t t k ) S 0 ( t ) cos ( 2 π f 2 t + φ 2 ( φ i 2 , t k ) ) ,
ϕ 1 ( ϕ i 1 , t k ) = ϕ i 1 + 2 π f 1 t k ,
ϕ 2 ( ϕ i 2 , t k ) = ϕ i 2 + 2 π f 2 t k .
Α i ( t ) = A i 1 ( t ) + A i 2 ( t ) = k = 1 N R s k h ( t t k ) 2 S 0 ( t ) cos [ 2 π ( f 1 + f 2 ) t + ( φ 1 ( φ i 1 , t k ) + φ 2 ( φ i 2 , t k ) ) 2 ] cos [ 2 π ( f 1 f 2 ) t + ( φ 1 ( φ i 1 , t k ) φ 2 ( φ i 2 , t k ) ) 2 ] .
A i ( t ) = k = 1 N R s k h ( t t k ) 2 S 0 ( t ) cos [ 2 π ( f 1 f 2 ) t + ( φ 1 ( φ i 1 , t k ) φ 2 ( φ i 2 , t k ) ) 2 ] .
( A i ( t ) ) = k = 1 N ( R s k h ( t t k ) ) × ( 2 S 0 ( t ) cos ( [ 2 π ( f 1 f 2 ) t + ( φ 1 ( φ i 1 , t k ) φ 2 ( φ i 2 , t k ) ) 2 ] ) ,
( R s k h ( t t k ) ) = R s k H ( ω ) e j ω t k .
cos ( ω 0 t ) = π ( δ ( ω ω 0 ) + δ ( ω + ω 0 ) ) ,
cos ( ω 0 ( t t 0 ) ) = e j ω t 0 π ( δ ( ω ω 0 ) + δ ( ω + ω 0 ) ) ,
( 2 S 0 ( t ) cos 2 π ( f 1 f 2 ) t + ( φ 1 ( φ i 1 , t k ) φ 2 ( φ i 2 , t k ) ) 2 ) = ( 2 S 0 ( t ) cos [ ω 0 ( t + Δ φ k ω 0 ] ) = 2 S 0 ( ω ) [ π e j ω Δ ϕ k ω 0 ( δ ( ω ω 0 ) + δ ( ω + ω 0 ) ) ] = 2 π e j ω Δ ϕ k ω 0 [ S 0 ( ω ω 0 ) + S 0 ( ω + ω 0 ) ] ,
( A i ( t ) ) = k = 1 N R s k H ( ω ) e j ω t k 2 π e j ω Δ ϕ k ω 0 [ S 0 ( ω ω 0 ) + S 0 ( ω + ω 0 ) ] .
A m ( ω ) = 2 π e j ω Δ ϕ m ω 0 * [ S 0 ( ω ω 0 ) + S 0 ( ω + ω 0 ) ]
R s k H ^ ( ω ) = ( A ( t ) ) A m ( ω ) = k = 1 N H ( ω ) e j ω t k e j ω ( Δ φ k Δ φ m ω 0 ) ,
R s k h ( t ) = h ( t ) = k = 1 N h ( t t k Δ φ k Δ φ m ω 0 ) .
f m + 1 ( x , y ) = f m ( x , y ) [ h ( x , y ) g ( x , y ) h ( x , y ) f m ( x , y ) ] ,
sin ( 2 π ( f 1 f 2 2 ) ( t + τ ) ) = 0.5 2 π ( f 1 f 2 ) ( t + τ ) = 10 π 6 ,
sin ( 2 π ( f 1 f 2 2 ) t ) = 0.5 2 π ( f 1 f 2 ) t = 2 π 6 .
2 π ( f 1 f 2 ) τ = 8 π 6 τ = 2 3 ( f 1 f 2 ) .
τ = 1 3 ( f 1 f 2 ) .
d x = v 3 ( f 1 f 2 ) .
A ( t ) = A c e ( π Δ f t 2 ln 2 ) 2 ,
A s = A c e ( π Δ f 4 ( f 1 f 2 ) ln 2 ) ) 2 .
Δ φ ( t k ) = φ 1 ( t k ) φ 2 ( t k ) = φ i 1 + 2 π f 1 t k ( φ i 2 + 2 π f 2 t k ) = Δ φ i + 2 π t k ( f 1 f 2 ) ,
Δ φ ( t k ) Δ φ ( t m ) = Δ φ i Δ φ k + 2 π t i ( f 1 f 2 ) + 2 π t k ( f 1 f 2 ) = Δ φ i Δ φ k + 2 π Δ f ( t i t k ) ,
Δ t = π 2 2 π ( f 1 f 2 ) 2 = 1 2 ( f 1 f 2 ) .
Δ x = v 2 ( f 1 f 2 ) ,
x = v τ =  v 1 3 ( f 1 f 2 ) = 1.94 μ m .

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