Abstract

We experimentally demonstrate a terahertz (THz) leaky mode directional coupler for future THz applications. The proposed directional coupler comprises two square pipe waveguides. The coupling efficiency is investigated for different frequencies, polarizations, and core sizes. Rectangular pipe-waveguide-based directional couplers and the issue of insertion loss are also discussed. It is found that the THz directional coupler works most efficiently in the minimal-attenuation wavelength regime.

© 2011 OSA

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  1. G. Gallot, S. P. Jamison, R. W. McGowan, and D. Grischkowsky, “Terahertz waveguides,” J. Opt. Soc. Am. B 17(5), 851–863 (2000).
    [CrossRef]
  2. K. Wang and D. M. Mittleman, “Metal wires for terahertz wave guiding,” Nature 432(7015), 376–379 (2004).
    [CrossRef] [PubMed]
  3. T.-I. Jeon, J. Zhang, and D. Grischkowsky, “THz Sommerfeld wave propagation on a single metal wire,” Appl. Phys. Lett. 86(16), 161904 (2005).
    [CrossRef]
  4. L.-J. Chen, H.-W. Chen, T.-F. Kao, J.-Y. Lu, and C.-K. Sun, “Low-loss subwavelength plastic fiber for terahertz waveguiding,” Opt. Lett. 31(3), 308–310 (2006).
    [CrossRef] [PubMed]
  5. B. Bowden, J. A. Harrington, and O. Mitrofanov, “Silver/polystyrene-coated hollow glass waveguides for the transmission of terahertz radiation,” Opt. Lett. 32(20), 2945–2947 (2007).
    [CrossRef] [PubMed]
  6. A. Hassani, A. Dupuis, and M. Skorobogatiy, “Porous polymer fibers for low-loss Terahertz guiding,” Opt. Express 16(9), 6340–6351 (2008).
    [CrossRef] [PubMed]
  7. S. Atakaramians, S. Afshar V, B. M. Fischer, D. Abbott, and T. M. Monro, “Porous fibers: a novel approach to low loss THz waveguides,” Opt. Express 16(12), 8845–8854 (2008).
    [CrossRef] [PubMed]
  8. K. Nielsen, H. K. Rasmussen, A. J. Adam, P. C. Planken, O. Bang, and P. U. Jepsen, “Bendable, low-loss Topas fibers for the terahertz frequency range,” Opt. Express 17(10), 8592–8601 (2009).
    [CrossRef] [PubMed]
  9. C.-H. Lai, Y.-C. Hsueh, H.-W. Chen, Y.-J. Huang, H.-C. Chang, and C.-K. Sun, “Low-index terahertz pipe waveguides,” Opt. Lett. 34(21), 3457–3459 (2009).
    [CrossRef] [PubMed]
  10. C.-H. Lai, B. You, J.-Y. Lu, T.-A. Liu, J.-L. Peng, C.-K. Sun, and H.-C. Chang, “Modal characteristics of antiresonant reflecting pipe waveguides for terahertz waveguiding,” Opt. Express 18(1), 309–322 (2010).
    [CrossRef] [PubMed]
  11. J.-Y. Lu, C.-C. Kuo, C.-M. Chiu, H.-W. Chen, Y.-J. Hwang, C.-L. Pan, and C.-K. Sun, “THz interferometric imaging using subwavelength plastic fiber based THz endoscopes,” Opt. Express 16(4), 2494–2501 (2008).
    [CrossRef] [PubMed]
  12. H.-W. Chen, C.-M. Chiu, J.-L. Kuo, P.-J. Chiang, H.-C. Chang, and C.-K. Sun, “Subwavelength dielectric-fiber-based terahertz coupler,” J. Lightwave Technol. 27(11), 1489–1495 (2009).
    [CrossRef]
  13. A. Dupuis, J.-F. Allard, D. Morris, K. Stoeffler, C. Dubois, and M. Skorobogatiy, “Fabrication and THz loss measurements of porous subwavelength fibers using a directional coupler method,” Opt. Express 17(10), 8012–8028 (2009).
    [CrossRef] [PubMed]
  14. Y.-W. Huang, T.-F. Tseng, C.-C. Kuo, Y.-J. Hwang, and C.-K. Sun, “Fiber-based swept-source terahertz radar,” Opt. Lett. 35(9), 1344–1346 (2010).
    [CrossRef] [PubMed]
  15. T.-F. Tseng, C.-H. Lai, J.-T. Lu, Y.-R. Huang, H. Chen, Y.-F. Tsai, Y.-J. Hwang, and C.-K. Sun, “THz Sub-wavelength fiber-based directional coupler with a high power transfer ratio and a low insertion loss,” Appl. Phys. Lett. (submitted to).
  16. J. L. Hesler and A. W. Lichtenberger, “THz Waveguide Couplers Using Quartz Micromachining,” in Proceedings of 21st International Symposium on Space Terahertz Technology (Oxford, UK, 2010), pp. 358–359.
  17. M. A. Duguay, Y. Kokubun, T. L. Koch, and L. Pfeiffer, “Antiresonant reflecting optical waveguides in SiO2–Si multilayer structures,” Appl. Phys. Lett. 49(1), 13–15 (1986).
    [CrossRef]
  18. J.-T. Lu, Y.-C. Hsueh, Y.-R. Huang, Y.-J. Hwang, and C.-K. Sun, “Bending loss of terahertz pipe waveguides,” Opt. Express 18(25), 26332–26338 (2010).
    [CrossRef] [PubMed]
  19. E. Nguema, D. Férachou, G. Humbert, J.-L. Auguste, and J.-M. Blondy, “Broadband terahertz transmission within the air channel of thin-wall pipe,” Opt. Lett. 36(10), 1782–1784 (2011).
    [CrossRef] [PubMed]
  20. J.-T. Lu, C.-H. Lai, T.-F. Tseng, H. Chen, Y.-F. Tsai, I.-J. Chen, Y.-J. Hwang, H.-C. Chang, and C.-K. Sun, “Terahertz polarization-sensitive rectangular pipe waveguides,” Opt. Express 19(22), 21532–21539 (2011).
    [CrossRef] [PubMed]
  21. M. Mann, U. Trutschel, C. Wächter, L. Leine, and F. Lederer, “Directional coupler based on an antiresonant reflecting optical waveguide,” Opt. Lett. 16(11), 805–807 (1991).
    [CrossRef] [PubMed]
  22. M. Shamonin, M. Lohmeyer, and P. Hertel, “Directional coupler based on radiatively coupled waveguides,” Appl. Opt. 36(3), 635–641 (1997).
    [CrossRef] [PubMed]
  23. Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
    [CrossRef]
  24. C.-H. Lai, C.-K. Sun, and H.-C. Chang, “Terahertz antiresonant-reflecting-hollow-waveguide-based directional coupler operating at antiresonant frequencies,” Opt. Lett. 36(18), 3590–3592 (2011).
    [CrossRef] [PubMed]
  25. J.-T. Lu, C.-H. Lai, Y.-R. Huang, Y.-C. Hsueh, Y.-J. Huang, H.-C. Chang, and C.-K. Sun, “Investigation on Mode Coupling and Bending Loss Characteristics of Terahertz Air-Core Pipe Waveguides,” in Conference on Lasers and Electro-Optics, OSA Technical Digest (CD) (Optical Society of America, 2010), paper JWA118. http://www.opticsinfobase.org/abstract.cfm?URI=CLEO-2010-JWA118 .

2011 (3)

2010 (3)

2009 (4)

2008 (3)

2007 (1)

2006 (2)

L.-J. Chen, H.-W. Chen, T.-F. Kao, J.-Y. Lu, and C.-K. Sun, “Low-loss subwavelength plastic fiber for terahertz waveguiding,” Opt. Lett. 31(3), 308–310 (2006).
[CrossRef] [PubMed]

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

2005 (1)

T.-I. Jeon, J. Zhang, and D. Grischkowsky, “THz Sommerfeld wave propagation on a single metal wire,” Appl. Phys. Lett. 86(16), 161904 (2005).
[CrossRef]

2004 (1)

K. Wang and D. M. Mittleman, “Metal wires for terahertz wave guiding,” Nature 432(7015), 376–379 (2004).
[CrossRef] [PubMed]

2000 (1)

1997 (1)

1991 (1)

1986 (1)

M. A. Duguay, Y. Kokubun, T. L. Koch, and L. Pfeiffer, “Antiresonant reflecting optical waveguides in SiO2–Si multilayer structures,” Appl. Phys. Lett. 49(1), 13–15 (1986).
[CrossRef]

Abbott, D.

Adam, A. J.

Afshar V, S.

Allard, J.-F.

Atakaramians, S.

Auguste, J.-L.

Bang, O.

Blondy, J.-M.

Bowden, B.

Chang, H.-C.

Chen, H.

J.-T. Lu, C.-H. Lai, T.-F. Tseng, H. Chen, Y.-F. Tsai, I.-J. Chen, Y.-J. Hwang, H.-C. Chang, and C.-K. Sun, “Terahertz polarization-sensitive rectangular pipe waveguides,” Opt. Express 19(22), 21532–21539 (2011).
[CrossRef] [PubMed]

T.-F. Tseng, C.-H. Lai, J.-T. Lu, Y.-R. Huang, H. Chen, Y.-F. Tsai, Y.-J. Hwang, and C.-K. Sun, “THz Sub-wavelength fiber-based directional coupler with a high power transfer ratio and a low insertion loss,” Appl. Phys. Lett. (submitted to).

Chen, H.-W.

Chen, I.-J.

Chen, L.-J.

Chiang, P.-J.

Chiu, C.-M.

Chung, H.-S.

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

Dubois, C.

Duguay, M. A.

M. A. Duguay, Y. Kokubun, T. L. Koch, and L. Pfeiffer, “Antiresonant reflecting optical waveguides in SiO2–Si multilayer structures,” Appl. Phys. Lett. 49(1), 13–15 (1986).
[CrossRef]

Dupuis, A.

Férachou, D.

Fischer, B. M.

Gallot, G.

Grischkowsky, D.

T.-I. Jeon, J. Zhang, and D. Grischkowsky, “THz Sommerfeld wave propagation on a single metal wire,” Appl. Phys. Lett. 86(16), 161904 (2005).
[CrossRef]

G. Gallot, S. P. Jamison, R. W. McGowan, and D. Grischkowsky, “Terahertz waveguides,” J. Opt. Soc. Am. B 17(5), 851–863 (2000).
[CrossRef]

Harrington, J. A.

Hassani, A.

Hertel, P.

Hsueh, Y.-C.

Huang, Y.-J.

Huang, Y.-R.

J.-T. Lu, Y.-C. Hsueh, Y.-R. Huang, Y.-J. Hwang, and C.-K. Sun, “Bending loss of terahertz pipe waveguides,” Opt. Express 18(25), 26332–26338 (2010).
[CrossRef] [PubMed]

T.-F. Tseng, C.-H. Lai, J.-T. Lu, Y.-R. Huang, H. Chen, Y.-F. Tsai, Y.-J. Hwang, and C.-K. Sun, “THz Sub-wavelength fiber-based directional coupler with a high power transfer ratio and a low insertion loss,” Appl. Phys. Lett. (submitted to).

Huang, Y.-W.

Humbert, G.

Hwang, Y.-J.

Jamison, S. P.

Jeon, T.-I.

T.-I. Jeon, J. Zhang, and D. Grischkowsky, “THz Sommerfeld wave propagation on a single metal wire,” Appl. Phys. Lett. 86(16), 161904 (2005).
[CrossRef]

Jepsen, P. U.

Kao, T.-F.

Koch, T. L.

M. A. Duguay, Y. Kokubun, T. L. Koch, and L. Pfeiffer, “Antiresonant reflecting optical waveguides in SiO2–Si multilayer structures,” Appl. Phys. Lett. 49(1), 13–15 (1986).
[CrossRef]

Kokubun, Y.

M. A. Duguay, Y. Kokubun, T. L. Koch, and L. Pfeiffer, “Antiresonant reflecting optical waveguides in SiO2–Si multilayer structures,” Appl. Phys. Lett. 49(1), 13–15 (1986).
[CrossRef]

Kuo, C.-C.

Kuo, J.-L.

Lai, C.-H.

Lederer, F.

Leine, L.

Liu, T.-A.

Lohmeyer, M.

Lu, J.-T.

Lu, J.-Y.

Mann, M.

McGowan, R. W.

Mitrofanov, O.

Mittleman, D. M.

K. Wang and D. M. Mittleman, “Metal wires for terahertz wave guiding,” Nature 432(7015), 376–379 (2004).
[CrossRef] [PubMed]

Monro, T. M.

Morris, D.

Nguema, E.

Nielsen, K.

Paek, M. C.

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

Pan, C.-L.

Park, M. Y.

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

Park, Y.

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

Peng, J.-L.

Pfeiffer, L.

M. A. Duguay, Y. Kokubun, T. L. Koch, and L. Pfeiffer, “Antiresonant reflecting optical waveguides in SiO2–Si multilayer structures,” Appl. Phys. Lett. 49(1), 13–15 (1986).
[CrossRef]

Planken, P. C.

Rasmussen, H. K.

Shamonin, M.

Skorobogatiy, M.

Sohn, Y.

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

Stoeffler, K.

Suh, D.

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

Sun, C.-K.

C.-H. Lai, C.-K. Sun, and H.-C. Chang, “Terahertz antiresonant-reflecting-hollow-waveguide-based directional coupler operating at antiresonant frequencies,” Opt. Lett. 36(18), 3590–3592 (2011).
[CrossRef] [PubMed]

J.-T. Lu, C.-H. Lai, T.-F. Tseng, H. Chen, Y.-F. Tsai, I.-J. Chen, Y.-J. Hwang, H.-C. Chang, and C.-K. Sun, “Terahertz polarization-sensitive rectangular pipe waveguides,” Opt. Express 19(22), 21532–21539 (2011).
[CrossRef] [PubMed]

J.-T. Lu, Y.-C. Hsueh, Y.-R. Huang, Y.-J. Hwang, and C.-K. Sun, “Bending loss of terahertz pipe waveguides,” Opt. Express 18(25), 26332–26338 (2010).
[CrossRef] [PubMed]

Y.-W. Huang, T.-F. Tseng, C.-C. Kuo, Y.-J. Hwang, and C.-K. Sun, “Fiber-based swept-source terahertz radar,” Opt. Lett. 35(9), 1344–1346 (2010).
[CrossRef] [PubMed]

C.-H. Lai, B. You, J.-Y. Lu, T.-A. Liu, J.-L. Peng, C.-K. Sun, and H.-C. Chang, “Modal characteristics of antiresonant reflecting pipe waveguides for terahertz waveguiding,” Opt. Express 18(1), 309–322 (2010).
[CrossRef] [PubMed]

C.-H. Lai, Y.-C. Hsueh, H.-W. Chen, Y.-J. Huang, H.-C. Chang, and C.-K. Sun, “Low-index terahertz pipe waveguides,” Opt. Lett. 34(21), 3457–3459 (2009).
[CrossRef] [PubMed]

H.-W. Chen, C.-M. Chiu, J.-L. Kuo, P.-J. Chiang, H.-C. Chang, and C.-K. Sun, “Subwavelength dielectric-fiber-based terahertz coupler,” J. Lightwave Technol. 27(11), 1489–1495 (2009).
[CrossRef]

J.-Y. Lu, C.-C. Kuo, C.-M. Chiu, H.-W. Chen, Y.-J. Hwang, C.-L. Pan, and C.-K. Sun, “THz interferometric imaging using subwavelength plastic fiber based THz endoscopes,” Opt. Express 16(4), 2494–2501 (2008).
[CrossRef] [PubMed]

L.-J. Chen, H.-W. Chen, T.-F. Kao, J.-Y. Lu, and C.-K. Sun, “Low-loss subwavelength plastic fiber for terahertz waveguiding,” Opt. Lett. 31(3), 308–310 (2006).
[CrossRef] [PubMed]

T.-F. Tseng, C.-H. Lai, J.-T. Lu, Y.-R. Huang, H. Chen, Y.-F. Tsai, Y.-J. Hwang, and C.-K. Sun, “THz Sub-wavelength fiber-based directional coupler with a high power transfer ratio and a low insertion loss,” Appl. Phys. Lett. (submitted to).

Trutschel, U.

Tsai, Y.-F.

J.-T. Lu, C.-H. Lai, T.-F. Tseng, H. Chen, Y.-F. Tsai, I.-J. Chen, Y.-J. Hwang, H.-C. Chang, and C.-K. Sun, “Terahertz polarization-sensitive rectangular pipe waveguides,” Opt. Express 19(22), 21532–21539 (2011).
[CrossRef] [PubMed]

T.-F. Tseng, C.-H. Lai, J.-T. Lu, Y.-R. Huang, H. Chen, Y.-F. Tsai, Y.-J. Hwang, and C.-K. Sun, “THz Sub-wavelength fiber-based directional coupler with a high power transfer ratio and a low insertion loss,” Appl. Phys. Lett. (submitted to).

Tseng, T.-F.

Wächter, C.

Wang, K.

K. Wang and D. M. Mittleman, “Metal wires for terahertz wave guiding,” Nature 432(7015), 376–379 (2004).
[CrossRef] [PubMed]

You, B.

Zhang, J.

T.-I. Jeon, J. Zhang, and D. Grischkowsky, “THz Sommerfeld wave propagation on a single metal wire,” Appl. Phys. Lett. 86(16), 161904 (2005).
[CrossRef]

Appl. Opt. (1)

Appl. Phys. Lett. (3)

T.-I. Jeon, J. Zhang, and D. Grischkowsky, “THz Sommerfeld wave propagation on a single metal wire,” Appl. Phys. Lett. 86(16), 161904 (2005).
[CrossRef]

T.-F. Tseng, C.-H. Lai, J.-T. Lu, Y.-R. Huang, H. Chen, Y.-F. Tsai, Y.-J. Hwang, and C.-K. Sun, “THz Sub-wavelength fiber-based directional coupler with a high power transfer ratio and a low insertion loss,” Appl. Phys. Lett. (submitted to).

M. A. Duguay, Y. Kokubun, T. L. Koch, and L. Pfeiffer, “Antiresonant reflecting optical waveguides in SiO2–Si multilayer structures,” Appl. Phys. Lett. 49(1), 13–15 (1986).
[CrossRef]

IEEE Photon. Technol. Lett. (1)

Y. Park, D. Suh, Y. Sohn, H.-S. Chung, M. C. Paek, and M. Y. Park, “Leaky Mode Directional Coupler for Prism Coupling Interconnection,” IEEE Photon. Technol. Lett. 18(1), 34–36 (2006).
[CrossRef]

J. Lightwave Technol. (1)

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

Nature (1)

K. Wang and D. M. Mittleman, “Metal wires for terahertz wave guiding,” Nature 432(7015), 376–379 (2004).
[CrossRef] [PubMed]

Opt. Express (8)

A. Hassani, A. Dupuis, and M. Skorobogatiy, “Porous polymer fibers for low-loss Terahertz guiding,” Opt. Express 16(9), 6340–6351 (2008).
[CrossRef] [PubMed]

S. Atakaramians, S. Afshar V, B. M. Fischer, D. Abbott, and T. M. Monro, “Porous fibers: a novel approach to low loss THz waveguides,” Opt. Express 16(12), 8845–8854 (2008).
[CrossRef] [PubMed]

K. Nielsen, H. K. Rasmussen, A. J. Adam, P. C. Planken, O. Bang, and P. U. Jepsen, “Bendable, low-loss Topas fibers for the terahertz frequency range,” Opt. Express 17(10), 8592–8601 (2009).
[CrossRef] [PubMed]

A. Dupuis, J.-F. Allard, D. Morris, K. Stoeffler, C. Dubois, and M. Skorobogatiy, “Fabrication and THz loss measurements of porous subwavelength fibers using a directional coupler method,” Opt. Express 17(10), 8012–8028 (2009).
[CrossRef] [PubMed]

C.-H. Lai, B. You, J.-Y. Lu, T.-A. Liu, J.-L. Peng, C.-K. Sun, and H.-C. Chang, “Modal characteristics of antiresonant reflecting pipe waveguides for terahertz waveguiding,” Opt. Express 18(1), 309–322 (2010).
[CrossRef] [PubMed]

J.-Y. Lu, C.-C. Kuo, C.-M. Chiu, H.-W. Chen, Y.-J. Hwang, C.-L. Pan, and C.-K. Sun, “THz interferometric imaging using subwavelength plastic fiber based THz endoscopes,” Opt. Express 16(4), 2494–2501 (2008).
[CrossRef] [PubMed]

J.-T. Lu, Y.-C. Hsueh, Y.-R. Huang, Y.-J. Hwang, and C.-K. Sun, “Bending loss of terahertz pipe waveguides,” Opt. Express 18(25), 26332–26338 (2010).
[CrossRef] [PubMed]

J.-T. Lu, C.-H. Lai, T.-F. Tseng, H. Chen, Y.-F. Tsai, I.-J. Chen, Y.-J. Hwang, H.-C. Chang, and C.-K. Sun, “Terahertz polarization-sensitive rectangular pipe waveguides,” Opt. Express 19(22), 21532–21539 (2011).
[CrossRef] [PubMed]

Opt. Lett. (7)

Other (2)

J. L. Hesler and A. W. Lichtenberger, “THz Waveguide Couplers Using Quartz Micromachining,” in Proceedings of 21st International Symposium on Space Terahertz Technology (Oxford, UK, 2010), pp. 358–359.

J.-T. Lu, C.-H. Lai, Y.-R. Huang, Y.-C. Hsueh, Y.-J. Huang, H.-C. Chang, and C.-K. Sun, “Investigation on Mode Coupling and Bending Loss Characteristics of Terahertz Air-Core Pipe Waveguides,” in Conference on Lasers and Electro-Optics, OSA Technical Digest (CD) (Optical Society of America, 2010), paper JWA118. http://www.opticsinfobase.org/abstract.cfm?URI=CLEO-2010-JWA118 .

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Figures (5)

Fig. 1
Fig. 1

(a) General setup for the pipe-waveguide-based directional couplers. (b) Modified experimental setup for the directional couplers.

Fig. 2
Fig. 2

The attenuation spectra of PE square pipe waveguides for t=1mm (blue circles) and t=2mm (red squares). The core sizes were kept the same (S=6mm).

Fig. 3
Fig. 3

Measurement of the THz directional coupler for (a) TM polarization and (b) TE polarization to the coupling cladding. The directional coupler was with S=6mm and t=1mm. The red double-dashed arrow indicates the direction of polarization. The blue circles, red squares, and black triangles represent data obtained at 376, 368, and 360 GHz, respectively.

Fig. 4
Fig. 4

(a) Measurement of the THz directional couplers for S=6mm (blue circles), S = 8mm (red squares) and S=10mm (black triangles). The cladding thickness was 1mm and the operating frequency was 376GHz. THz waves were TM-polarized to the coupling cladding. (b) The relation between air core size and coupling length.

Fig. 5
Fig. 5

Measurement of the longer-side-coupled (blue circles) and shorter-side coupled (red squares) THz directional coupler. The air core size was 10mmx6mm and the cladding thickness was 1mm. The operating frequency was 376GHz. Polarization of THz waves was TM polarization to the coupling cladding.

Tables (2)

Tables Icon

Table 1 Insertion loss for pipe-waveguide-based 3 dB directional couplers (Measurement frequency was 376GHz and THz waves were TM-polarized to the coupling cladding)

Tables Icon

Table 2 Insertion loss for square (S = 6 mm) pipe-waveguide-based 3 dB directional couplers for different frequencies

Equations (2)

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C= P B /( P A + P B )
L= 10×log( P O P A + P B ) (in dB)

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