Abstract

A Fourier domain optical coherence tomography system with two spectrometers in balance detection is assembled using each an InGaAs linear camera. Conditions and adjustments of spectrometer parameters are presented to ensure anti-phase channeled spectrum modulation across the two cameras for a majority of wavelengths within the optical source spectrum. By blocking the signal to one of the spectrometers, the setup was used to compare the conditions of operation of a single camera with that of a balanced configuration. Using multiple layer samples, balanced detection technique is compared with techniques applied to conventional single camera setups, based on sequential deduction of averaged spectra collected with different on/off settings for the sample or reference beams. In terms of reducing the autocorrelation terms and fixed pattern noise, it is concluded that balance detection performs better than single camera techniques, is more tolerant to movement, exhibits longer term stability and can operate dynamically in real time. The cameras used exhibit larger saturation power than the power threshold where excess photon noise exceeds shot noise. Therefore, conditions to adjust the two cameras to reduce the noise when used in a balanced configuration are presented. It is shown that balance detection can reduce the noise in real time operation, in comparison with single camera configurations. However, simple deduction of an average spectrum in single camera configurations delivers less noise than the balance detection.

© 2012 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. J. F. de Boer, B. Cense, B. H. Park, M. C. Pierce, G. J. Tearney, and B. E. Bouma, “Improved signal-to-noise ratio in spectral-domain compared with time-domain optical coherence tomography,” Opt. Lett.28(21), 2067–2069 (2003).
    [CrossRef] [PubMed]
  2. R. Leitgeb, C. Hitzenberger, and A. Fercher, “Performance of Fourier domain vs. time domain optical coherence tomography,” Opt. Express11(8), 889–894 (2003).
    [CrossRef] [PubMed]
  3. M. Wojtkowski, R. Leitgeb, A. Kowalczyk, T. Bajraszewski, and A. F. Fercher, “In vivo human retinal imaging by Fourier domain optical coherence tomography,” J. Biomed. Opt.7(3), 457–463 (2002).
    [CrossRef] [PubMed]
  4. R. A. Leitgeb, C. K. Hitzenberger, A. F. Fercher, and T. Bajraszewski, “Phase-shifting algorithm to achieve high-speed long-depth-range probing by frequency-domain optical coherence tomography,” Opt. Lett.28(22), 2201–2203 (2003).
    [CrossRef] [PubMed]
  5. E. Götzinger, M. Pircher, R. Leitgeb, and C. Hitzenberger, “High speed full range complex spectral domain optical coherence tomography,” Opt. Express13(2), 583–594 (2005).
    [CrossRef] [PubMed]
  6. J. Ai and L. V. Wang, “Synchronous self-elimination of autocorrelation interference in Fourier-domain optical coherence tomography,” Opt. Lett.30(21), 2939–2941 (2005).
    [CrossRef] [PubMed]
  7. J. Ai and L. Wang, “Spectral domain optical coherence tomography: removal of autocorrelation using an optical switch,” Appl. Phys. Lett.88(11), 111115 (2006).
    [CrossRef]
  8. S. Moon, S. W. Lee, and Z. Chen, “Reference spectrum extraction and fixed-pattern noise removal in optical coherence tomography,” Opt. Express18(24), 24395–24404 (2010).
    [CrossRef] [PubMed]
  9. A. G. Podoleanu and D. A. Jackson, “Noise analysis of a combined optical coherence tomograph and a confocal scanning ophthalmoscope,” Appl. Opt.38(10), 2116–2127 (1999).
    [CrossRef] [PubMed]
  10. A. G. Podoleanu, “Unbalanced versus balanced operation in an optical coherence tomography system,” Appl. Opt.39(1), 173–182 (2000).
    [CrossRef] [PubMed]
  11. I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).
  12. C. C. Rosa and A. G. Podoleanu, “Limitation of the achievable signal-to-noise ratio in optical coherence tomography due to mismatch of the balanced receiver,” Appl. Opt.43(25), 4802–4815 (2004).
    [CrossRef] [PubMed]
  13. Y. Chen, D. M. de Bruin, C. Kerbage, and J. F. de Boer, “Spectrally balanced detection for optical frequency domain imaging,” Opt. Express15(25), 16390–16399 (2007).
    [CrossRef] [PubMed]
  14. D. Woods and A. Podoleanu, “Controlling the shape of Talbot bands’ visibility,” Opt. Express16(13), 9654–9670 (2008).
    [CrossRef] [PubMed]
  15. N. Nassif, B. Cense, B. Park, M. Pierce, S. Yun, B. Bouma, G. Tearney, T. Chen, and J. de Boer, “In vivo high-resolution video-rate spectral-domain optical coherence tomography of the human retina and optic nerve,” Opt. Express12(3), 367–376 (2004).
    [CrossRef] [PubMed]
  16. N. Nassif, B. Cense, B. Hyle Park, S. H. Yun, T. C. Chen, B. E. Bouma, G. J. Tearney, and J. F. de Boer, “In vivo human retinal imaging by ultrahigh-speed spectral domain optical coherence tomography,” Opt. Lett.29(5), 480–482 (2004).
    [CrossRef] [PubMed]

2011 (1)

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

2010 (1)

2008 (1)

2007 (1)

2006 (1)

J. Ai and L. Wang, “Spectral domain optical coherence tomography: removal of autocorrelation using an optical switch,” Appl. Phys. Lett.88(11), 111115 (2006).
[CrossRef]

2005 (2)

2004 (3)

2003 (3)

2002 (1)

M. Wojtkowski, R. Leitgeb, A. Kowalczyk, T. Bajraszewski, and A. F. Fercher, “In vivo human retinal imaging by Fourier domain optical coherence tomography,” J. Biomed. Opt.7(3), 457–463 (2002).
[CrossRef] [PubMed]

2000 (1)

1999 (1)

Ai, J.

J. Ai and L. Wang, “Spectral domain optical coherence tomography: removal of autocorrelation using an optical switch,” Appl. Phys. Lett.88(11), 111115 (2006).
[CrossRef]

J. Ai and L. V. Wang, “Synchronous self-elimination of autocorrelation interference in Fourier-domain optical coherence tomography,” Opt. Lett.30(21), 2939–2941 (2005).
[CrossRef] [PubMed]

Bajraszewski, T.

R. A. Leitgeb, C. K. Hitzenberger, A. F. Fercher, and T. Bajraszewski, “Phase-shifting algorithm to achieve high-speed long-depth-range probing by frequency-domain optical coherence tomography,” Opt. Lett.28(22), 2201–2203 (2003).
[CrossRef] [PubMed]

M. Wojtkowski, R. Leitgeb, A. Kowalczyk, T. Bajraszewski, and A. F. Fercher, “In vivo human retinal imaging by Fourier domain optical coherence tomography,” J. Biomed. Opt.7(3), 457–463 (2002).
[CrossRef] [PubMed]

Berendt, R.

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

Bouma, B.

Bouma, B. E.

Caldas, P.

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

Cense, B.

Chen, T.

Chen, T. C.

Chen, Y.

Chen, Z.

de Boer, J.

de Boer, J. F.

de Bruin, D. M.

Fercher, A.

Fercher, A. F.

R. A. Leitgeb, C. K. Hitzenberger, A. F. Fercher, and T. Bajraszewski, “Phase-shifting algorithm to achieve high-speed long-depth-range probing by frequency-domain optical coherence tomography,” Opt. Lett.28(22), 2201–2203 (2003).
[CrossRef] [PubMed]

M. Wojtkowski, R. Leitgeb, A. Kowalczyk, T. Bajraszewski, and A. F. Fercher, “In vivo human retinal imaging by Fourier domain optical coherence tomography,” J. Biomed. Opt.7(3), 457–463 (2002).
[CrossRef] [PubMed]

Götzinger, E.

Hitzenberger, C.

Hitzenberger, C. K.

Hyle Park, B.

Jackson, D. A.

Kerbage, C.

Kowalczyk, A.

M. Wojtkowski, R. Leitgeb, A. Kowalczyk, T. Bajraszewski, and A. F. Fercher, “In vivo human retinal imaging by Fourier domain optical coherence tomography,” J. Biomed. Opt.7(3), 457–463 (2002).
[CrossRef] [PubMed]

Lee, S. W.

Leitgeb, R.

Leitgeb, R. A.

Moon, S.

Nassif, N.

Neagu, L.

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

Park, B.

Park, B. H.

Pierce, M.

Pierce, M. C.

Pircher, M.

Podoleanu, A.

Podoleanu, A. G.

Ribeiro, A.

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

Rosa, C. C.

Salcedo, J.

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

Tearney, G.

Tearney, G. J.

Trifanov, I.

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

Wang, L.

J. Ai and L. Wang, “Spectral domain optical coherence tomography: removal of autocorrelation using an optical switch,” Appl. Phys. Lett.88(11), 111115 (2006).
[CrossRef]

Wang, L. V.

Wojtkowski, M.

M. Wojtkowski, R. Leitgeb, A. Kowalczyk, T. Bajraszewski, and A. F. Fercher, “In vivo human retinal imaging by Fourier domain optical coherence tomography,” J. Biomed. Opt.7(3), 457–463 (2002).
[CrossRef] [PubMed]

Woods, D.

Yun, S.

Yun, S. H.

Appl. Opt. (3)

Appl. Phys. Lett. (1)

J. Ai and L. Wang, “Spectral domain optical coherence tomography: removal of autocorrelation using an optical switch,” Appl. Phys. Lett.88(11), 111115 (2006).
[CrossRef]

IEEE Photon. Technol. Lett. (1)

I. Trifanov, P. Caldas, L. Neagu, R. Berendt, J. Salcedo, A. G. Podoleanu, and A. Ribeiro, “Combined neodymium–ytterbium-doped ASE fiber-optic Source for optical coherence tomography applications,” IEEE Photon. Technol. Lett.23(1), 21–23 (2011).

J. Biomed. Opt. (1)

M. Wojtkowski, R. Leitgeb, A. Kowalczyk, T. Bajraszewski, and A. F. Fercher, “In vivo human retinal imaging by Fourier domain optical coherence tomography,” J. Biomed. Opt.7(3), 457–463 (2002).
[CrossRef] [PubMed]

Opt. Express (6)

Opt. Lett. (4)

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 (13)

Fig. 1
Fig. 1

Schematic diagram of the balanced FD-CT setup. BBS: broadband source; MO1,2, MS1–3, MR1,2: microscope objectives; L1,2: spectrometer collimators; BS: bulk beam-splitter; DG1,2: diffraction gratings; DC1,2: directional coupler.

Fig. 2
Fig. 2

(a) Typical spectra recorded by the two line cameras. (b) FFT of the interferometric signal measured by a single camera before and after correction (subtraction of an average of consecutive spectra) (c) FFT of the balanced signal before and after correction with a factor C(λ) depending on the ratio of the two spectra (the spectra used to calculate the correction factor were obtained by averaging consecutive spectra).

Fig. 3
Fig. 3

(a) Interferograms recorded by the two cameras. The two signals are in anti-phase. (b) The FFT of the interferograms shown in (a) produced by each camera together with the FFT of the balanced case. (c) Sensitivity falloff across the measurement range for each of the single camera configuration and for the balance detection configuration.

Fig. 4
Fig. 4

Illustration of the autocorrelation terms removal.

Fig. 5
Fig. 5

B-scan images of an IR detection card demonstrating the removal of the autocorrelation image. 1st row, B-scan images collected with the reference arm blocked: 2nd row: reference arm unblocked, each frame displays at the top the autocorrelation image and underneath the image due to interference between the sample and reference beams, axially displaced to avoid their overlap; 3rd row: the autocorrelation and real image are nearly in perfect overlap; (a) column: B-scans recorded by camera 1; (b) column: B-scans recorded by camera 2; (c) column: B-scans delivered by camera 1 only, obtained by deducting an image recorded prior to measurement with the reference beam off; (d) column: B-scans delivered by the balance detection.

Fig. 6
Fig. 6

Averaged A-scans inferred from the B-scan images in Figs. 5(a1), 5(b1), 5(d1). The zoomed plot demonstrates the self-elimination of the auto-correlation terms.

Fig. 7
Fig. 7

(a) Averaged A-scans inferred from the B-scan images in Figs. 5(a2), 5(b2), 5(d2). (b) Averaged A-scans inferred from the B-scan images in Figs. 5(a3), 5(b3), 5(d3).

Fig. 8
Fig. 8

Averaged A-scans over B-scan images shown in Figs. 5(a1), 5(b1), 5(d1) obtained when data acquisition by the two cameras was perfectly synchronized (a) and free running (b).

Fig. 9
Fig. 9

B-scan images of a bovine tooth. Top row: raw images recorded (a1), (b1) by individual cameras and (c1) by the balanced scheme. Middle row (sample in place): elimination of the fixed pattern noise in images recorded by (a2), (b2) individual cameras by deducting the ACS from the spectra and (c2) in the balance case by correcting for the non-identicalness of the spectra. Bottom row, the same as middle row but with the sample arm blocked.

Fig. 10
Fig. 10

B-scan images of a tooth. (a1) and (a2) images are recorded using individual cameras, (b1) and (b2) images are produced by the balance detection scheme. For the bottom row images, the optical power reaching the cameras was increased in comparison to the power used to produce the top row images, by reducing the attenuation of reference power by 10%.

Fig. 11
Fig. 11

Noise variance at each camera pixel for 1024 consecutive spectra. The dark and readout noise were measured with no optical power on the detector.

Fig. 12
Fig. 12

RMS2 vs. optical power measured at the input of one of the spectrometers. Red curve: single camera configuration; Blue curve: single camera configuration, ACS removed; Green curve: balance detection scheme.

Fig. 13
Fig. 13

Average of 512 A-scans from a flat mirror for two values of the reference power reaching each camera. Top row: reference power ~1 μW; Bottom row: reference power ~10 μW. In the right column, the graphs for the single camera configuration are obtained after ACS removal whilst the graphs for the balanced configuration after correction for the spectrum shape seen by each camera using the correction coefficient C(λ) (see text).

Equations (3)

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

Shot noise:  σ SN 2 = η e 2 P τ i E
Excess photon noise:  σ EPN 2 = ( ηeP E ) 2 τ i τ coh
P sat = FWC η E τ i

Metrics