Abstract

We demonstrate a simple quasi-optical technique for spatiotemporal shaping of half-cycle terahertz-radiation pulses. We show, both experimentally and theoretically, that properly polarized half-cycle pulses can be modulated temporally by diffraction through a conductive aperture of finite thickness. We use the finite-difference time-domain method to solve Maxwell’s equations for such a geometry and show that it can explain all the experimentally observed features. In the case of thick aperture, a planar waveguide model can also be used to describe the propagation of the pulse through the aperture, with excellent agreement with the experimental results.

© 1998 Optical Society of America

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  1. A. Baltuska, Z. Wei, M. Pshenichnikov, and D. Wiersma, “Optical pulse compression to 5 fs at a 1-MHz repetition rate,” Opt. Lett. 22, 102 (1997).
    [CrossRef] [PubMed]
  2. R. L. Fork, C. H. Brito Cruz, P. C. Becker, and C. V. Shank, “Compression of optical pulses to six femtoseconds by using cubic phase compensation,” Opt. Lett. 12, 483 (1987).
    [CrossRef] [PubMed]
  3. D. H. Auston, K. P. Cheung, and P. R. Smith, “Picosecond photoconducting Hertzian dipoles,” Appl. Phys. Lett. 45, 284 (1984).
    [CrossRef]
  4. D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
    [CrossRef]
  5. J. T. Darrow, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Subpicosecond electromagnetic pulses from large-aperture photoconducting antennas,” Opt. Lett. 15, 323 (1990).
    [CrossRef] [PubMed]
  6. X.-C. Zhang, B. B. Hu, J. T. Darrow, and D. H. Auston, “Generation of femtosecond electromagnetic pulses from semiconductor surfaces,” Appl. Phys. Lett. 56, 1011 (1990).
    [CrossRef]
  7. L. Xu, X.-C. Zhang, D. H. Auston, and B. Jahali, “Terahertz radiation from large aperture Si p-i-n diodes,” Appl. Phys. Lett. 59, 3357 (1991).
    [CrossRef]
  8. X.-C. Zhang, B. B. Hu, S. Xin, and D. H. Auston, “Optically induced femtosecond electromagnetic pulses from GaSb/AlSb strained-layer superlattice,” Appl. Phys. Lett. 57, 753 (1990).
    [CrossRef]
  9. A. S. Weling, B. B. Hu, N. M. Froberg, and D. H. Auston, “Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas,” Appl. Phys. Lett. 64, 137 (1994).
    [CrossRef]
  10. S. R. Keiding, “THz spectroscopy in atomic, molecular and optical physics,” Comments At. Mol. Phys. 30, 37 (1994).
  11. B. B. Hu and M. C. Nuss, “Imaging with terahertz waves,” Opt. Lett. 20, 1716 (1995).
    [CrossRef] [PubMed]
  12. R. R. Jones, “Creating and probing electronic wave packets using half-cycle pulses,” Phys. Rev. Lett. 76, 3927 (1996).
    [CrossRef] [PubMed]
  13. R. Cheville, B. Nicholson, and D. Grischkowsky, “Compact time-domain terahertz ranging system,” in Conference on Lasers and Electro-Optics, Vol. 15 of 1995 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1995), p. 360.
  14. J. Wenbin, S. Diechi, and L. Fuming, “Distortion of femtosecond optical pulses with Gaussian spatial distribution propagating in free space,” Chin. Phys. 10, 168 (1990).
  15. D. You and P. H. Bucksbaum, “Propagation of half-cycle FIR pulses,” J. Opt. Soc. Am. B 14, 1651 (1997).
    [CrossRef]
  16. N. M. Froberg, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Terahertz radiation from a photoconducting antenna array,” IEEE J. Quantum Electron. 28, 2291 (1992).
    [CrossRef]
  17. J. O. White, C. Ludwig, and J. Kuhl, “Response of grating pairs to single-cycle electromagnetic pulses,” J. Opt. Soc. Am. B 12, 1687 (1995).
    [CrossRef]
  18. J. T. Darrow, D. H. Auston, and J. Morse, “Large-aperture photoconducting antennas excited by high optical fluences,” in Ultrafast Pulse Generation and Spectroscopy, T. R. Gosnell, A. J. Taylor, K. A. Nelson, and M. C. Downer, eds., Proc. SPIE 1861, 186 (1993).
    [CrossRef]
  19. A. Taflove, Computational Electrodynamics: The Finite-Difference Time-Domain Method (Artech, Norwood, Mass., 1995).
  20. A. Taflove and M. Brodwin, “Numerical solution of steady-state electromagnetic scattering problems using the time-dependent Maxwell’s equations,” IEEE Trans. Microwave Theory Tech. MTT-23, 623 (1975).
    [CrossRef]
  21. R. Collin, Foundations for Microwave Engineering (McGraw-Hill, New York, 1992).
  22. J. S. Asvestas and R. E. Kleinman, in Electromagnetic and Acoustic Scattering by Simple Shapes, J. J. Bowman, T. B. A. Senior, and P. L. E. Uslenghi, eds. (North-Holland, Amsterdam, 1969), Chap. 4, pp. 181–239.
  23. R. H. Garnham, in Millimetre and Submillimetre Waves, F. A. Benson, ed. (Iliffe, London, 1969), Chap. 21, pp. 403–450.

1997 (2)

1996 (1)

R. R. Jones, “Creating and probing electronic wave packets using half-cycle pulses,” Phys. Rev. Lett. 76, 3927 (1996).
[CrossRef] [PubMed]

1995 (2)

1994 (2)

A. S. Weling, B. B. Hu, N. M. Froberg, and D. H. Auston, “Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas,” Appl. Phys. Lett. 64, 137 (1994).
[CrossRef]

S. R. Keiding, “THz spectroscopy in atomic, molecular and optical physics,” Comments At. Mol. Phys. 30, 37 (1994).

1993 (1)

J. T. Darrow, D. H. Auston, and J. Morse, “Large-aperture photoconducting antennas excited by high optical fluences,” in Ultrafast Pulse Generation and Spectroscopy, T. R. Gosnell, A. J. Taylor, K. A. Nelson, and M. C. Downer, eds., Proc. SPIE 1861, 186 (1993).
[CrossRef]

1992 (1)

N. M. Froberg, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Terahertz radiation from a photoconducting antenna array,” IEEE J. Quantum Electron. 28, 2291 (1992).
[CrossRef]

1991 (2)

L. Xu, X.-C. Zhang, D. H. Auston, and B. Jahali, “Terahertz radiation from large aperture Si p-i-n diodes,” Appl. Phys. Lett. 59, 3357 (1991).
[CrossRef]

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

1990 (4)

J. T. Darrow, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Subpicosecond electromagnetic pulses from large-aperture photoconducting antennas,” Opt. Lett. 15, 323 (1990).
[CrossRef] [PubMed]

X.-C. Zhang, B. B. Hu, J. T. Darrow, and D. H. Auston, “Generation of femtosecond electromagnetic pulses from semiconductor surfaces,” Appl. Phys. Lett. 56, 1011 (1990).
[CrossRef]

X.-C. Zhang, B. B. Hu, S. Xin, and D. H. Auston, “Optically induced femtosecond electromagnetic pulses from GaSb/AlSb strained-layer superlattice,” Appl. Phys. Lett. 57, 753 (1990).
[CrossRef]

J. Wenbin, S. Diechi, and L. Fuming, “Distortion of femtosecond optical pulses with Gaussian spatial distribution propagating in free space,” Chin. Phys. 10, 168 (1990).

1987 (1)

1984 (1)

D. H. Auston, K. P. Cheung, and P. R. Smith, “Picosecond photoconducting Hertzian dipoles,” Appl. Phys. Lett. 45, 284 (1984).
[CrossRef]

1975 (1)

A. Taflove and M. Brodwin, “Numerical solution of steady-state electromagnetic scattering problems using the time-dependent Maxwell’s equations,” IEEE Trans. Microwave Theory Tech. MTT-23, 623 (1975).
[CrossRef]

Auston, D. H.

A. S. Weling, B. B. Hu, N. M. Froberg, and D. H. Auston, “Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas,” Appl. Phys. Lett. 64, 137 (1994).
[CrossRef]

J. T. Darrow, D. H. Auston, and J. Morse, “Large-aperture photoconducting antennas excited by high optical fluences,” in Ultrafast Pulse Generation and Spectroscopy, T. R. Gosnell, A. J. Taylor, K. A. Nelson, and M. C. Downer, eds., Proc. SPIE 1861, 186 (1993).
[CrossRef]

N. M. Froberg, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Terahertz radiation from a photoconducting antenna array,” IEEE J. Quantum Electron. 28, 2291 (1992).
[CrossRef]

L. Xu, X.-C. Zhang, D. H. Auston, and B. Jahali, “Terahertz radiation from large aperture Si p-i-n diodes,” Appl. Phys. Lett. 59, 3357 (1991).
[CrossRef]

X.-C. Zhang, B. B. Hu, J. T. Darrow, and D. H. Auston, “Generation of femtosecond electromagnetic pulses from semiconductor surfaces,” Appl. Phys. Lett. 56, 1011 (1990).
[CrossRef]

J. T. Darrow, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Subpicosecond electromagnetic pulses from large-aperture photoconducting antennas,” Opt. Lett. 15, 323 (1990).
[CrossRef] [PubMed]

X.-C. Zhang, B. B. Hu, S. Xin, and D. H. Auston, “Optically induced femtosecond electromagnetic pulses from GaSb/AlSb strained-layer superlattice,” Appl. Phys. Lett. 57, 753 (1990).
[CrossRef]

D. H. Auston, K. P. Cheung, and P. R. Smith, “Picosecond photoconducting Hertzian dipoles,” Appl. Phys. Lett. 45, 284 (1984).
[CrossRef]

Baltuska, A.

Becker, P. C.

Brito Cruz, C. H.

Brodwin, M.

A. Taflove and M. Brodwin, “Numerical solution of steady-state electromagnetic scattering problems using the time-dependent Maxwell’s equations,” IEEE Trans. Microwave Theory Tech. MTT-23, 623 (1975).
[CrossRef]

Bucksbaum, P. H.

Cheung, K. P.

D. H. Auston, K. P. Cheung, and P. R. Smith, “Picosecond photoconducting Hertzian dipoles,” Appl. Phys. Lett. 45, 284 (1984).
[CrossRef]

Darrow, J. T.

J. T. Darrow, D. H. Auston, and J. Morse, “Large-aperture photoconducting antennas excited by high optical fluences,” in Ultrafast Pulse Generation and Spectroscopy, T. R. Gosnell, A. J. Taylor, K. A. Nelson, and M. C. Downer, eds., Proc. SPIE 1861, 186 (1993).
[CrossRef]

J. T. Darrow, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Subpicosecond electromagnetic pulses from large-aperture photoconducting antennas,” Opt. Lett. 15, 323 (1990).
[CrossRef] [PubMed]

X.-C. Zhang, B. B. Hu, J. T. Darrow, and D. H. Auston, “Generation of femtosecond electromagnetic pulses from semiconductor surfaces,” Appl. Phys. Lett. 56, 1011 (1990).
[CrossRef]

Diechi, S.

J. Wenbin, S. Diechi, and L. Fuming, “Distortion of femtosecond optical pulses with Gaussian spatial distribution propagating in free space,” Chin. Phys. 10, 168 (1990).

Dykaar, D. R.

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

Federici, J. F.

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

Fork, R. L.

Froberg, N. M.

A. S. Weling, B. B. Hu, N. M. Froberg, and D. H. Auston, “Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas,” Appl. Phys. Lett. 64, 137 (1994).
[CrossRef]

N. M. Froberg, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Terahertz radiation from a photoconducting antenna array,” IEEE J. Quantum Electron. 28, 2291 (1992).
[CrossRef]

Fuming, L.

J. Wenbin, S. Diechi, and L. Fuming, “Distortion of femtosecond optical pulses with Gaussian spatial distribution propagating in free space,” Chin. Phys. 10, 168 (1990).

Greene, B. I.

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

Hu, B. B.

B. B. Hu and M. C. Nuss, “Imaging with terahertz waves,” Opt. Lett. 20, 1716 (1995).
[CrossRef] [PubMed]

A. S. Weling, B. B. Hu, N. M. Froberg, and D. H. Auston, “Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas,” Appl. Phys. Lett. 64, 137 (1994).
[CrossRef]

N. M. Froberg, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Terahertz radiation from a photoconducting antenna array,” IEEE J. Quantum Electron. 28, 2291 (1992).
[CrossRef]

X.-C. Zhang, B. B. Hu, S. Xin, and D. H. Auston, “Optically induced femtosecond electromagnetic pulses from GaSb/AlSb strained-layer superlattice,” Appl. Phys. Lett. 57, 753 (1990).
[CrossRef]

X.-C. Zhang, B. B. Hu, J. T. Darrow, and D. H. Auston, “Generation of femtosecond electromagnetic pulses from semiconductor surfaces,” Appl. Phys. Lett. 56, 1011 (1990).
[CrossRef]

J. T. Darrow, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Subpicosecond electromagnetic pulses from large-aperture photoconducting antennas,” Opt. Lett. 15, 323 (1990).
[CrossRef] [PubMed]

Jahali, B.

L. Xu, X.-C. Zhang, D. H. Auston, and B. Jahali, “Terahertz radiation from large aperture Si p-i-n diodes,” Appl. Phys. Lett. 59, 3357 (1991).
[CrossRef]

Jones, R. R.

R. R. Jones, “Creating and probing electronic wave packets using half-cycle pulses,” Phys. Rev. Lett. 76, 3927 (1996).
[CrossRef] [PubMed]

Keiding, S. R.

S. R. Keiding, “THz spectroscopy in atomic, molecular and optical physics,” Comments At. Mol. Phys. 30, 37 (1994).

Kopf, R. F.

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

Kuhl, J.

Levi, A. F. J.

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

Ludwig, C.

Morse, J.

J. T. Darrow, D. H. Auston, and J. Morse, “Large-aperture photoconducting antennas excited by high optical fluences,” in Ultrafast Pulse Generation and Spectroscopy, T. R. Gosnell, A. J. Taylor, K. A. Nelson, and M. C. Downer, eds., Proc. SPIE 1861, 186 (1993).
[CrossRef]

Nuss, M. C.

Pfeiffer, L. N.

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

Pshenichnikov, M.

Shank, C. V.

Smith, P. R.

D. H. Auston, K. P. Cheung, and P. R. Smith, “Picosecond photoconducting Hertzian dipoles,” Appl. Phys. Lett. 45, 284 (1984).
[CrossRef]

Taflove, A.

A. Taflove and M. Brodwin, “Numerical solution of steady-state electromagnetic scattering problems using the time-dependent Maxwell’s equations,” IEEE Trans. Microwave Theory Tech. MTT-23, 623 (1975).
[CrossRef]

Wei, Z.

Weling, A. S.

A. S. Weling, B. B. Hu, N. M. Froberg, and D. H. Auston, “Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas,” Appl. Phys. Lett. 64, 137 (1994).
[CrossRef]

Wenbin, J.

J. Wenbin, S. Diechi, and L. Fuming, “Distortion of femtosecond optical pulses with Gaussian spatial distribution propagating in free space,” Chin. Phys. 10, 168 (1990).

White, J. O.

Wiersma, D.

Xin, S.

X.-C. Zhang, B. B. Hu, S. Xin, and D. H. Auston, “Optically induced femtosecond electromagnetic pulses from GaSb/AlSb strained-layer superlattice,” Appl. Phys. Lett. 57, 753 (1990).
[CrossRef]

Xu, L.

L. Xu, X.-C. Zhang, D. H. Auston, and B. Jahali, “Terahertz radiation from large aperture Si p-i-n diodes,” Appl. Phys. Lett. 59, 3357 (1991).
[CrossRef]

You, D.

Zhang, X.-C.

N. M. Froberg, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Terahertz radiation from a photoconducting antenna array,” IEEE J. Quantum Electron. 28, 2291 (1992).
[CrossRef]

L. Xu, X.-C. Zhang, D. H. Auston, and B. Jahali, “Terahertz radiation from large aperture Si p-i-n diodes,” Appl. Phys. Lett. 59, 3357 (1991).
[CrossRef]

X.-C. Zhang, B. B. Hu, S. Xin, and D. H. Auston, “Optically induced femtosecond electromagnetic pulses from GaSb/AlSb strained-layer superlattice,” Appl. Phys. Lett. 57, 753 (1990).
[CrossRef]

X.-C. Zhang, B. B. Hu, J. T. Darrow, and D. H. Auston, “Generation of femtosecond electromagnetic pulses from semiconductor surfaces,” Appl. Phys. Lett. 56, 1011 (1990).
[CrossRef]

J. T. Darrow, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Subpicosecond electromagnetic pulses from large-aperture photoconducting antennas,” Opt. Lett. 15, 323 (1990).
[CrossRef] [PubMed]

Appl. Phys. Lett. (6)

X.-C. Zhang, B. B. Hu, J. T. Darrow, and D. H. Auston, “Generation of femtosecond electromagnetic pulses from semiconductor surfaces,” Appl. Phys. Lett. 56, 1011 (1990).
[CrossRef]

L. Xu, X.-C. Zhang, D. H. Auston, and B. Jahali, “Terahertz radiation from large aperture Si p-i-n diodes,” Appl. Phys. Lett. 59, 3357 (1991).
[CrossRef]

X.-C. Zhang, B. B. Hu, S. Xin, and D. H. Auston, “Optically induced femtosecond electromagnetic pulses from GaSb/AlSb strained-layer superlattice,” Appl. Phys. Lett. 57, 753 (1990).
[CrossRef]

A. S. Weling, B. B. Hu, N. M. Froberg, and D. H. Auston, “Generation of tunable narrow-band THz radiation from large aperture photoconducting antennas,” Appl. Phys. Lett. 64, 137 (1994).
[CrossRef]

D. H. Auston, K. P. Cheung, and P. R. Smith, “Picosecond photoconducting Hertzian dipoles,” Appl. Phys. Lett. 45, 284 (1984).
[CrossRef]

D. R. Dykaar, B. I. Greene, J. F. Federici, A. F. J. Levi, L. N. Pfeiffer, and R. F. Kopf, “Log-periodic antennas for pulsed terahertz radiation,” Appl. Phys. Lett. 59, 262 (1991).
[CrossRef]

Chin. Phys. (1)

J. Wenbin, S. Diechi, and L. Fuming, “Distortion of femtosecond optical pulses with Gaussian spatial distribution propagating in free space,” Chin. Phys. 10, 168 (1990).

Comments At. Mol. Phys. (1)

S. R. Keiding, “THz spectroscopy in atomic, molecular and optical physics,” Comments At. Mol. Phys. 30, 37 (1994).

IEEE J. Quantum Electron. (1)

N. M. Froberg, B. B. Hu, X.-C. Zhang, and D. H. Auston, “Terahertz radiation from a photoconducting antenna array,” IEEE J. Quantum Electron. 28, 2291 (1992).
[CrossRef]

IEEE Trans. Microwave Theory Tech. (1)

A. Taflove and M. Brodwin, “Numerical solution of steady-state electromagnetic scattering problems using the time-dependent Maxwell’s equations,” IEEE Trans. Microwave Theory Tech. MTT-23, 623 (1975).
[CrossRef]

J. Opt. Soc. Am. B (2)

Opt. Lett. (4)

Phys. Rev. Lett. (1)

R. R. Jones, “Creating and probing electronic wave packets using half-cycle pulses,” Phys. Rev. Lett. 76, 3927 (1996).
[CrossRef] [PubMed]

Proc. SPIE (1)

J. T. Darrow, D. H. Auston, and J. Morse, “Large-aperture photoconducting antennas excited by high optical fluences,” in Ultrafast Pulse Generation and Spectroscopy, T. R. Gosnell, A. J. Taylor, K. A. Nelson, and M. C. Downer, eds., Proc. SPIE 1861, 186 (1993).
[CrossRef]

Other (5)

A. Taflove, Computational Electrodynamics: The Finite-Difference Time-Domain Method (Artech, Norwood, Mass., 1995).

R. Cheville, B. Nicholson, and D. Grischkowsky, “Compact time-domain terahertz ranging system,” in Conference on Lasers and Electro-Optics, Vol. 15 of 1995 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1995), p. 360.

R. Collin, Foundations for Microwave Engineering (McGraw-Hill, New York, 1992).

J. S. Asvestas and R. E. Kleinman, in Electromagnetic and Acoustic Scattering by Simple Shapes, J. J. Bowman, T. B. A. Senior, and P. L. E. Uslenghi, eds. (North-Holland, Amsterdam, 1969), Chap. 4, pp. 181–239.

R. H. Garnham, in Millimetre and Submillimetre Waves, F. A. Benson, ed. (Iliffe, London, 1969), Chap. 21, pp. 403–450.

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Figures (9)

Fig. 1
Fig. 1

(a) Experimental setup and (b) measured THz pulse incident upon the conducting aperture.

Fig. 2
Fig. 2

Measured (solid curves) and FDTD calculated THz pulse shapes for thin (left) and thick (right) apertures: (a) 300-μm, (b) 500-μm, (c) 700-μm widths.

Fig. 3
Fig. 3

Diffraction from a conductive slit: FDTD (dashed curves) versus measured (solid curves) field. The scattering geometry (inset) is defined by d=0.5 mm, D=3 mm, s=7 mm, and l=1.7 mm. The incident pulse shape (measured) is used in all subsequent FDTD simulations.

Fig. 4
Fig. 4

TE (left) versus TM diffraction: Pulse propagation is tracked as it penetrates the aperture in time increments of 1.5 ps. The solid curves are the on-axis pulse profiles.

Fig. 5
Fig. 5

Measured slit transfer function (d=0.5 mm). Dashed curve, phase as predicted by the waveguide model.

Fig. 6
Fig. 6

Cutoff frequency for the thick conductive slit with TM polarization: waveguide prediction (solid curve) versus measured cutoff frequencies (points).

Fig. 7
Fig. 7

TM diffraction: thin (left, l=0.1 mm) versus thick (right, l=1.7 mm) conductive apertures. The aperture width is d=0.5 mm in both cases.

Fig. 8
Fig. 8

TM pulse shaping in variable-thickness conductive apertures: the 0.5-mm-wide aperture thickness is increased from 283 μm (thin) to 1698 μm (thick).

Fig. 9
Fig. 9

TM pulse shaping in variable-width apertures: the 1.7-mm-thick aperture width is 300 μm (upper row), 700 μm (middle row), and 1100 μm (bottom row).

Equations (13)

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

Hxn+1/2(i, j+1/2)
=Hxn-1/2(i, j+1/2)+Δtμ(i, j+1/2)ΔL×[Ezn(i, j)-Ezn(i, j+1)],
Hyn+1/2(i+1/2, j)
=Hyn-1/2(i+1/2,j)+Δtμ(i+1/2,j)ΔL×[Ezn(i+1,j)-Ezn(i, j)],
Ezn+1(i, j)
=Ezn(i, j)+Δtε(i+1/2,j)ΔL [Hyn+1/2(i+1/2,j)-Hyn+1/2(i-1/2,j)+Hxn+1/2(i, j-1/2)-Hxn+1/2(i, j+1/2)],
Exn+1(i+1/2,j)
=Exn(i+1/2,j)+Δtε(i+1/2,j)ΔL×[Hzn+1/2(i+1/2,j+1/2)-Hzn+1/2(i+1/2,j-1/2)],
Eyn+1(i, j+1/2)
=Eyn(i, j+1/2)+Δtε(i, j+1/2)ΔL×[Hzn+1/2(i-1/2,j+1/2)-Hzn+1/2(i+1/2,j+1/2)],
Hzn+1/2(i+1/2,j+1/2)
=Hzn-1/2(i+1/2,j+1/2)+Δtμ(i+1/2,j+1/2)ΔL [Exn(i+1/2,j+1)-Exn(i+1/2,j)+Eyn(i, j+1/2)-Eyn(i+1,j+1/2)].
β(ν)=πd [(ν/νc)2-1]1/2ν>νci πd [1-(ν/νc)2]1/2ννc,

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