Abstract

In this study, we propose a THz computed tomography (CT) method based on phase contrast, which retrieves the phase shift information at each data point through a phase modulation technique using a Mach-Zehnder interferometer with a continuous wave (CW) source. The THz CT is based on first-generation CT, which acquires a set of projections by translational and rotational scans using a thin beam. From the phase-shift projections, we reconstruct a spatial distribution of refractive indices in a cross section of interest. We constructed a preliminary system using a highly coherent CW THz source with a frequency of 0.54 THz to prove the concept and performed an imaging experiment using phantoms to investigate its imaging features such as artifact-immune imaging, quantitative measurement, and selective detection.

© 2013 Optical Society of America

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  1. B. B. Hu and M. C. Nuss, “Imaging with terahertz waves,” Opt. Lett.20(16), 1716–1718 (1995).
    [CrossRef] [PubMed]
  2. R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
    [CrossRef] [PubMed]
  3. R. Wilk, F. Breitfeld, M. Mikulics, and M. Koch, “Continuous wave terahertz spectrometer as a noncontact thickness measuring device,” Appl. Opt.47(16), 3023–3026 (2008).
    [CrossRef] [PubMed]
  4. T. Yasuda, T. Iwata, T. Araki, and T. Yasui, “Improvement of minimum paint film thickness for THz paint meters by multiple-regression analysis,” Appl. Opt.46(30), 7518–7526 (2007).
    [CrossRef] [PubMed]
  5. T. Kiwa, J. Kondo, S. Oka, I. Kawayama, H. Yamada, M. Tonouchi, and K. Tsukada, “Chemical sensing plate with a laser-terahertz monitoring system,” Appl. Opt.47(18), 3324–3327 (2008).
    [CrossRef] [PubMed]
  6. S. R. Murrill, E. L. Jacobs, S. K. Moyer, C. E. Halford, S. T. Griffin, F. C. De Lucia, D. T. Petkie, and C. C. Franck, “Terahertz imaging system performance model for concealed-weapon identification,” Appl. Opt.47(9), 1286–1297 (2008).
    [CrossRef] [PubMed]
  7. Y. Kawada, T. Yasuda, H. Takahashi, and S.-i. Aoshima, “Real-time measurement of temporal waveforms of a terahertz pulse using a probe pulse with a tilted pulse front,” Opt. Lett.33(2), 180–182 (2008).
    [CrossRef] [PubMed]
  8. Y. Kawada, T. Yasuda, H. Takahashi, and S. Aoshima, “Real-time measurement of temporal waveforms of a terahertz pulse using a probe pulse with a tilted pulse front,” Opt. Lett.33(2), 180–182 (2008).
    [CrossRef] [PubMed]
  9. C. Kak and M. Slanery, “Principles of Computerized Tomographic Imaging,” New York: IEEE Press (1987).
  10. D. M. Mittleman, S. Hunsche, L. Boivin, and M. C. Nuss, “T-ray tomography,” Opt. Lett.22(12), 904–906 (1997).
    [CrossRef] [PubMed]
  11. B. Ferguson, S. Wang, D. Gray, D. Abbot, and X. C. Zhang, “T-ray computed tomography,” Opt. Lett.27(15), 1312–1314 (2002).
    [CrossRef] [PubMed]
  12. S. Wang, B. Ferguson, and X.-C. Zhang, “Pulsed terahertz tomography,” J. Phys. D Appl. Phys.37(4), R1–R36 (2004).
    [CrossRef]
  13. E. Abraham, A. Younus, C. Aguerre, P. Desbarats, and P. Mounaix, “Refraction losses in terahertz computed tomography,” Opt. Commun.283(10), 2050–2055 (2010).
    [CrossRef]
  14. D. Porterfield, J. Hesler, T. Crowe, W. Bishop, and D. Woolard, “Integrated terahertz transmit / receive modules,” Proc. of 33rd European Microwave Conference, 1319–1322 (2003).
  15. A. Dobroiu, M. Yamashita, Y. N. Ohshima, Y. Morita, C. Otani, and K. Kawase, “Terahertz imaging system based on a backward-wave oscillator,” Appl. Opt.43(30), 5637–5646 (2004).
    [CrossRef] [PubMed]
  16. B. Recur, A. Younus, S. Salort, P. Mounaix, B. Chassagne, P. Desbarats, J.-P. Caumes, and E. Abraham, “Investigation on reconstruction methods applied to 3D terahertz computed tomography,” Opt. Express19(6), 5105–5117 (2011).
    [CrossRef] [PubMed]
  17. N. Sunaguchi, Y. Sasaki, N. Maikusa, M. Kawai, T. Yuasa, and C. Otani, “Depth-resolving THz imaging with tomosynthesis,” Opt. Express17(12), 9558–9570 (2009).
    [CrossRef] [PubMed]
  18. J. Hsieh, Computed Tomography Principles, Design, Artifacts, and Recent Advances, Second Edition (John Wiley & Sons, Inc. & SPIE, 2009).
  19. S. Feng and H. G. Winful, “Physical origin of the Gouy phase shift,” Opt. Lett.26(8), 485–487 (2001).
    [CrossRef] [PubMed]
  20. A. Rosenfeld and C. Kak, Digital Picture Processing, 2nd Ed., Vol. I (Academic Press, 1982).
  21. R. Cusack, J. M. Huntley, and H. T. Goldrein, “Improved noise-immune phase-unwrapping algorithm,” Appl. Opt.34(5), 781–789 (1995).
    [CrossRef] [PubMed]
  22. G. Zhao, M. Mors, T. Wenckebach, and P. C. M. Planken, “Terahertz dielectric properties of polystyrene foam,” J. Opt. Soc. Am. B19(6), 1476–1479 (2002).
    [CrossRef]

2011 (1)

2010 (1)

E. Abraham, A. Younus, C. Aguerre, P. Desbarats, and P. Mounaix, “Refraction losses in terahertz computed tomography,” Opt. Commun.283(10), 2050–2055 (2010).
[CrossRef]

2009 (1)

2008 (5)

2007 (1)

2004 (2)

2003 (1)

R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
[CrossRef] [PubMed]

2002 (2)

2001 (1)

1997 (1)

1995 (2)

Abbot, D.

Abraham, E.

Aguerre, C.

E. Abraham, A. Younus, C. Aguerre, P. Desbarats, and P. Mounaix, “Refraction losses in terahertz computed tomography,” Opt. Commun.283(10), 2050–2055 (2010).
[CrossRef]

Aoshima, S.

Aoshima, S.-i.

Araki, T.

Arnone, D. D.

R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
[CrossRef] [PubMed]

Bishop, W.

D. Porterfield, J. Hesler, T. Crowe, W. Bishop, and D. Woolard, “Integrated terahertz transmit / receive modules,” Proc. of 33rd European Microwave Conference, 1319–1322 (2003).

Boivin, L.

Breitfeld, F.

Caumes, J.-P.

Chassagne, B.

Crowe, T.

D. Porterfield, J. Hesler, T. Crowe, W. Bishop, and D. Woolard, “Integrated terahertz transmit / receive modules,” Proc. of 33rd European Microwave Conference, 1319–1322 (2003).

Cusack, R.

De Lucia, F. C.

Desbarats, P.

Dobroiu, A.

Feng, S.

Ferguson, B.

S. Wang, B. Ferguson, and X.-C. Zhang, “Pulsed terahertz tomography,” J. Phys. D Appl. Phys.37(4), R1–R36 (2004).
[CrossRef]

B. Ferguson, S. Wang, D. Gray, D. Abbot, and X. C. Zhang, “T-ray computed tomography,” Opt. Lett.27(15), 1312–1314 (2002).
[CrossRef] [PubMed]

Franck, C. C.

Goldrein, H. T.

Gray, D.

Griffin, S. T.

Halford, C. E.

Hesler, J.

D. Porterfield, J. Hesler, T. Crowe, W. Bishop, and D. Woolard, “Integrated terahertz transmit / receive modules,” Proc. of 33rd European Microwave Conference, 1319–1322 (2003).

Hu, B. B.

Hunsche, S.

Huntley, J. M.

Iwata, T.

Jacobs, E. L.

Kawada, Y.

Kawai, M.

Kawase, K.

Kawayama, I.

Kiwa, T.

Koch, M.

Kondo, J.

Linfield, E. H.

R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
[CrossRef] [PubMed]

Maikusa, N.

Mikulics, M.

Mittleman, D. M.

Morita, Y.

Mors, M.

Mounaix, P.

Moyer, S. K.

Murrill, S. R.

Nuss, M. C.

Ohshima, Y. N.

Oka, S.

Otani, C.

Pepper, M.

R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
[CrossRef] [PubMed]

Petkie, D. T.

Planken, P. C. M.

Porterfield, D.

D. Porterfield, J. Hesler, T. Crowe, W. Bishop, and D. Woolard, “Integrated terahertz transmit / receive modules,” Proc. of 33rd European Microwave Conference, 1319–1322 (2003).

Recur, B.

Salort, S.

Sasaki, Y.

Sunaguchi, N.

Takahashi, H.

Tonouchi, M.

Tsukada, K.

Wallace, V. P.

R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
[CrossRef] [PubMed]

Wang, S.

S. Wang, B. Ferguson, and X.-C. Zhang, “Pulsed terahertz tomography,” J. Phys. D Appl. Phys.37(4), R1–R36 (2004).
[CrossRef]

B. Ferguson, S. Wang, D. Gray, D. Abbot, and X. C. Zhang, “T-ray computed tomography,” Opt. Lett.27(15), 1312–1314 (2002).
[CrossRef] [PubMed]

Wenckebach, T.

Wilk, R.

Winful, H. G.

Woodward, R. M.

R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
[CrossRef] [PubMed]

Woolard, D.

D. Porterfield, J. Hesler, T. Crowe, W. Bishop, and D. Woolard, “Integrated terahertz transmit / receive modules,” Proc. of 33rd European Microwave Conference, 1319–1322 (2003).

Yamada, H.

Yamashita, M.

Yasuda, T.

Yasui, T.

Younus, A.

Yuasa, T.

Zhang, X. C.

Zhang, X.-C.

S. Wang, B. Ferguson, and X.-C. Zhang, “Pulsed terahertz tomography,” J. Phys. D Appl. Phys.37(4), R1–R36 (2004).
[CrossRef]

Zhao, G.

Appl. Opt. (6)

J. Biol. Phys. (1)

R. M. Woodward, V. P. Wallace, D. D. Arnone, E. H. Linfield, and M. Pepper, “Terahertz pulsed imaging of skin cancer in the time and frequency domain,” J. Biol. Phys.29(2/3), 257–259 (2003).
[CrossRef] [PubMed]

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

J. Phys. D Appl. Phys. (1)

S. Wang, B. Ferguson, and X.-C. Zhang, “Pulsed terahertz tomography,” J. Phys. D Appl. Phys.37(4), R1–R36 (2004).
[CrossRef]

Opt. Commun. (1)

E. Abraham, A. Younus, C. Aguerre, P. Desbarats, and P. Mounaix, “Refraction losses in terahertz computed tomography,” Opt. Commun.283(10), 2050–2055 (2010).
[CrossRef]

Opt. Express (2)

Opt. Lett. (6)

Other (4)

C. Kak and M. Slanery, “Principles of Computerized Tomographic Imaging,” New York: IEEE Press (1987).

A. Rosenfeld and C. Kak, Digital Picture Processing, 2nd Ed., Vol. I (Academic Press, 1982).

D. Porterfield, J. Hesler, T. Crowe, W. Bishop, and D. Woolard, “Integrated terahertz transmit / receive modules,” Proc. of 33rd European Microwave Conference, 1319–1322 (2003).

J. Hsieh, Computed Tomography Principles, Design, Artifacts, and Recent Advances, Second Edition (John Wiley & Sons, Inc. & SPIE, 2009).

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Figures (11)

Fig. 1
Fig. 1

Conceptual diagram of phase-contrast THz-CT system based on the Mach–Zehnder interferometer.

Fig. 2
Fig. 2

Schematic diagram of a preliminary phase-contrast THz-CT system.

Fig. 3
Fig. 3

(a) Beam profile and (b) relationship between the beam diameter and the position in the direction of beam propagation.

Fig. 4
Fig. 4

A photograph of polystyrene foam phantom (a) from bird-view, and (b) from top-view. (c) Schematic of cross section of the phantom at the level where the diameter is maximum.

Fig. 5
Fig. 5

Raw sinograms obtained at differences in path length between the signal and local oscillator arms of (a) 0, (b) λ/4, (c) λ/2, and (d) 3 λ/4.

Fig. 6
Fig. 6

(a) Wrapped sinogram estimated using Eq. (13) from Figs. 5, and (b) line profile of the first row of Fig. 6(a).

Fig. 7
Fig. 7

(a) Unwrapped sinogram estimated using Eq. (13) from Figs. 5, and (b) line profile of the first row of Fig. 7(a).

Fig. 8
Fig. 8

(a) THz-CT image based on phase-contrast, (b) THz-CT image based on attenuation-contrast, and (c) profiles along the red lines indicated in Figs. 8(a) and 8(b).

Fig. 9
Fig. 9

(a) Photograph of the sample consisting of 0.5-mm-diameter ceramic balls made of Zirconia, which are randomly arranged on a sheet of hard paper and which enable Mie scattering, and (b) schematic of the sample.

Fig. 10
Fig. 10

(a) Distribution of the signal beam without the sample, (b) profile along the red line indicated in Fig. 10 (a), (c) distribution of the signal beam with the sample, (d) profile along the red line indicated in Fig. 10 (c), (e) distribution of the local oscillator beam, (f) profile along the red line indicated in Fig. 10 (e), (g) distribution of the mixed beam with the sample, and (h) profile along the red line indicated in Fig. 10 (g)

Fig. 11
Fig. 11

Observation of mixed signals, which are measured at positions P1, P2, P3, P4, and P5, which are represented as red x-marks on the horizontal lines in Figs. 10(d), 10(f), and 10(h), while changing the difference in path length between signal and local arms.

Tables (1)

Tables Icon

Table 1 Quantitative evaluation of the center of oscillation and amplitude of mixed signal. The second and third columns intensities of local and signal beams obtained from Figs. 10(d) and 10(f), respectively. The fourth and fifth columns are respectively estimated values of the center of oscillation and amplitude using Eqs. (6) and (7). The sixth and seventh columns are respectively maximum and minimum values of sinusoidal signals obtained Fig. 11. The eighth and ninth columns are respectively estimated values of the center of oscillation and amplitude under an assumption that the signals are sinusoidal.

Equations (18)

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| E S + E L | 2 = A s 2 + A L 2 +2 A s A L cosk( z S z L ).
E S = A S exp{ ik( z S t ) }exp{ ik 0 t ( n+iκ )dz },
E S = A S exp( 0 t μ dz )exp{ ik( z S t+ 0 t n dz ) },
I( z S z L )= | E S + E L | 2 = A S 2 exp( 2 0 t μdz )+ A L 2 +2 A S A L exp( 0 t μdz )cos{ k( 0 t ndz t+ z S z L ) }.
I( z S z L )= I D + I A cos{ k( ϕ+ z S z L ) },
I D = A S 2 exp( 2 0 t μdz )+ A L 2 ,
I A =2 A S A L exp( 0 t μdz ), and
ϕ= 0 t ( n1 ) dz.
I( 0 )= I D + I A cos( kϕ ),
I( λ 4 )= I D + I A cos( kϕ+ π 2 )= I D I A sin( kϕ ),
I( λ 2 )= I D + I A cos( kϕ+π )= I D I A cos( kϕ ),  and
I( 3λ 4 )= I D + I A cos( kϕ+ 3π 2 )= I D + I A sin( kϕ ).
ϕ= 1 k tan 1 I( 3λ 4 )I( λ 4 ) I( 0 )I( λ 2 ) .
σ ϕ 2 = i=1 n ( f X i ) 0 2 σ i 2 ,
σ ϕ 2 = 1 k 2 ( m 3 m 4 ) 2 ( σ 1 2 + σ 2 2 )+ ( m 1 m 2 ) 2 ( σ 3 2 + σ 4 2 ) { ( m 1 m 2 ) 2 + ( m 3 m 4 ) 2 } 2 .
σ ϕ 2 = σ 1 2 + σ 2 2 + σ 3 2 + σ 4 2 2 k 2 Δ I 2 .
( n1 ) dz= 0 t ( n1 ) dz=ϕ.
μdz = 0 t μdz .

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