Abstract

This paper reports the demonstration of a widely-translatable fiber-optic mirror based on the motion of liquid metal through the hollow core of a photonic bandgap fiber. By moving a liquid metal mirror within the hollow core of an optical fiber, large, continuous changes in optical path length are achieved in a comparatively small package. A fiber-optic device is demonstrated which provided a continuously-variable optical path length of over 3.6 meters, without the use of free-space optics or resonant optical techniques (i.e. slow light). This change in path length corresponds to a continuously-variable true-time delay of over 12 ns, or 120 periods at a modulation frequency of 10 GHz. Wavelength dependence was shown to be negligible across the C and L bands.

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  1. A. J. Seeds and K. J. Williams, “Microwave photonics,” J. Lightwave Technol.24(12), 4628–4641 (2006).
    [CrossRef]
  2. J. Capmany, B. Ortega, and D. Pastor, “A tutorial on microwave photonic filters,” J. Lightwave Technol.24(1), 201–229 (2006).
    [CrossRef]
  3. R. A. Minasian, “Photonic signal processing of microwave signals,” IEEE Trans. Microw. Theory Tech.54(2), 832–846 (2006).
    [CrossRef]
  4. J. Capmany, B. Ortega, D. Pastor, and S. Sales, “Discrete-time optical processing of microwave signals,” J. Lightwave Technol.23(2), 702–723 (2005).
    [CrossRef]
  5. R. S. Tucker, “The role of optics and electronics in high-capacity routers,” J. Lightwave Technol.24(12), 4655–4673 (2006).
    [CrossRef]
  6. R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
    [CrossRef] [PubMed]
  7. J. N. Israelachvili, Intermolecular and Surface Forces, 3rd ed. (Academic Press, 2011).
  8. G. K. Batchelor, An Introduction to Fluid Dynamics (Cambridge, 2000).
  9. F. E. Bartell and J. T. Smith, “Alteration of surface properties of gold and silver as indicated by contact angle measurements,” 121st Meeting of the American Chemical Society 165–172 (1952).
  10. T. Inagaki, E. T. Arakawa, and M. W. Williams, “Optical properties of liquid mercury,” Phys. Rev. B23(10), 5246–5262 (1981).
    [CrossRef]
  11. A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
    [CrossRef]
  12. M. Stepanova and S. Dew, Nanofabrication: Techniques and Principles (Springer, 2011).
  13. S. Usui and T. Yamasaki, “Adhesion of mercury and glass in aqueous solutions,” J. Colloid Interface Sci.29(4), 629–638 (1969).
    [CrossRef]
  14. T. Tsukamoto, M. Esashi, and S. Tanaka, “Long working range mercury droplet actuation,” J. Micromech. Microeng.19(9), 094016 (2009).
    [CrossRef]
  15. NKT Photonics data sheet, “HC-1550-02 hollow-core photonic bandgap fiber” (NKT Photonics 2012).

2009

T. Tsukamoto, M. Esashi, and S. Tanaka, “Long working range mercury droplet actuation,” J. Micromech. Microeng.19(9), 094016 (2009).
[CrossRef]

2006

2005

1999

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

1981

T. Inagaki, E. T. Arakawa, and M. W. Williams, “Optical properties of liquid mercury,” Phys. Rev. B23(10), 5246–5262 (1981).
[CrossRef]

1969

S. Usui and T. Yamasaki, “Adhesion of mercury and glass in aqueous solutions,” J. Colloid Interface Sci.29(4), 629–638 (1969).
[CrossRef]

1967

A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
[CrossRef]

Allan, D. C.

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Arakawa, E. T.

T. Inagaki, E. T. Arakawa, and M. W. Williams, “Optical properties of liquid mercury,” Phys. Rev. B23(10), 5246–5262 (1981).
[CrossRef]

Birks, T. A.

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Capmany, J.

Cregan, R. F.

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Ellison, A. H.

A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
[CrossRef]

Esashi, M.

T. Tsukamoto, M. Esashi, and S. Tanaka, “Long working range mercury droplet actuation,” J. Micromech. Microeng.19(9), 094016 (2009).
[CrossRef]

Grubb, L. S.

A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
[CrossRef]

Inagaki, T.

T. Inagaki, E. T. Arakawa, and M. W. Williams, “Optical properties of liquid mercury,” Phys. Rev. B23(10), 5246–5262 (1981).
[CrossRef]

Klemm, R. B.

A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
[CrossRef]

Knight, J. C.

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Mangan, B. J.

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Minasian, R. A.

R. A. Minasian, “Photonic signal processing of microwave signals,” IEEE Trans. Microw. Theory Tech.54(2), 832–846 (2006).
[CrossRef]

Ortega, B.

Pastor, D.

Petrash, D. A.

A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
[CrossRef]

Roberts, P. J.

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Russell, P. St. J.

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Sales, S.

Schwartz, A. M.

A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
[CrossRef]

Seeds, A. J.

Tanaka, S.

T. Tsukamoto, M. Esashi, and S. Tanaka, “Long working range mercury droplet actuation,” J. Micromech. Microeng.19(9), 094016 (2009).
[CrossRef]

Tsukamoto, T.

T. Tsukamoto, M. Esashi, and S. Tanaka, “Long working range mercury droplet actuation,” J. Micromech. Microeng.19(9), 094016 (2009).
[CrossRef]

Tucker, R. S.

Usui, S.

S. Usui and T. Yamasaki, “Adhesion of mercury and glass in aqueous solutions,” J. Colloid Interface Sci.29(4), 629–638 (1969).
[CrossRef]

Williams, K. J.

Williams, M. W.

T. Inagaki, E. T. Arakawa, and M. W. Williams, “Optical properties of liquid mercury,” Phys. Rev. B23(10), 5246–5262 (1981).
[CrossRef]

Yamasaki, T.

S. Usui and T. Yamasaki, “Adhesion of mercury and glass in aqueous solutions,” J. Colloid Interface Sci.29(4), 629–638 (1969).
[CrossRef]

IEEE Trans. Microw. Theory Tech.

R. A. Minasian, “Photonic signal processing of microwave signals,” IEEE Trans. Microw. Theory Tech.54(2), 832–846 (2006).
[CrossRef]

J. Chem. Eng. Data

A. H. Ellison, R. B. Klemm, A. M. Schwartz, L. S. Grubb, and D. A. Petrash, “Contact angles of mercury on various surfaces and the effect of temperature,” J. Chem. Eng. Data12(4), 607–609 (1967).
[CrossRef]

J. Colloid Interface Sci.

S. Usui and T. Yamasaki, “Adhesion of mercury and glass in aqueous solutions,” J. Colloid Interface Sci.29(4), 629–638 (1969).
[CrossRef]

J. Lightwave Technol.

J. Micromech. Microeng.

T. Tsukamoto, M. Esashi, and S. Tanaka, “Long working range mercury droplet actuation,” J. Micromech. Microeng.19(9), 094016 (2009).
[CrossRef]

Phys. Rev. B

T. Inagaki, E. T. Arakawa, and M. W. Williams, “Optical properties of liquid mercury,” Phys. Rev. B23(10), 5246–5262 (1981).
[CrossRef]

Science

R. F. Cregan, B. J. Mangan, J. C. Knight, T. A. Birks, P. St. J. Russell, P. J. Roberts, and D. C. Allan, “Single-mode photonic band gap guidance of light in air,” Science285(5433), 1537–1539 (1999).
[CrossRef] [PubMed]

Other

J. N. Israelachvili, Intermolecular and Surface Forces, 3rd ed. (Academic Press, 2011).

G. K. Batchelor, An Introduction to Fluid Dynamics (Cambridge, 2000).

F. E. Bartell and J. T. Smith, “Alteration of surface properties of gold and silver as indicated by contact angle measurements,” 121st Meeting of the American Chemical Society 165–172 (1952).

NKT Photonics data sheet, “HC-1550-02 hollow-core photonic bandgap fiber” (NKT Photonics 2012).

M. Stepanova and S. Dew, Nanofabrication: Techniques and Principles (Springer, 2011).

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Figures (7)

Fig. 1
Fig. 1

Schematic diagram of the liquid metal fiber mirror. The hollow core of a HCPBG fiber, shown with expanded cross-section, is partially-filled by a droplet of liquid metal. Light propagating in the core of the HCPBG fiber (red) reflects from the surface of the liquid metal (gray) and back along the fiber core. The liquid metal can be moved along the fiber to reposition the mirror surface, such as by gas pressure. Motion of the liquid metal alters the round-trip optical path length, or equivalently, the round-trip phase and group delay.

Fig. 2
Fig. 2

(a) LMFM connected to a fiber-optic circulator to produce a fiber-optic continuously-variable true-time delay. (b) Analogous device based on free-space optics (lens and translatable mirror). Unlike the LMFM, the free-space device is fundamentally limited by misalignment, size constraints, and diffractive loss.

Fig. 3
Fig. 3

(a) Microscope image of the HCPBG fiber cross section, cleaved where mercury filled the fiber core. (b) Surface profile of the mercury-air meniscus within the cleaved, mercury-filled HCPBG fiber, measured using a scanning confocal microscope. The dotted lines indicate the limits of the 9 µm mode field diameter (1/e2 intensity) of the HCPBG fiber, over which the meniscus varied by approximately 1.0 µm.

Fig. 4
Fig. 4

Test setup for translating the LMFM and characterizing its motion. Gas pressure applied by a piston pushed/pulled a liquid metal droplet along the HCPBG fiber core. The location of the mirror reflection point (air-metal interface) was monitored using an optical frequency-domain reflectometer (OFDR).

Fig. 5
Fig. 5

OFDR scans recorded at different times as the liquid metal droplet was translated along the HCPBG fiber. The reflection from the SMF28-to-HCPBG fiber interface, located at the horizontal axis origin, serves as a reference. The location of the air-liquid metal interface (i.e. mirror reflection point) is indicated by second reflection peak from the left. This interface was translated 1.8 m along the HCPBG fiber, producing a round-trip true time delay tuning range of 12 ns.

Fig. 6
Fig. 6

Device reflectivity versus position of the liquid metal mirror within the HCPBG fiber. Device reflectivity decreased with distance from the SMF28-HCPBG interface (the horizontal origin), presumably due to attenuation of leaky modes excited in the HCPBG fiber. Device reflectivity stabilized at a distance of approximately 1.2 m from the fiber-fiber interface.

Fig. 7
Fig. 7

(a) Group delay and (b) device reflectivity vs. wavelength, when the liquid metal mirror was located 1.89 m from the SMF28-HCPBG fiber interface. Data has been smoothed using a 1.0 nm window to reduce noise.

Equations (1)

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R d = P m P in = P t P f P in

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