Abstract

The atomic layer deposition (ALD) technology is introduced to enhance the sensitivity of optical fiber cladding mode to surrounding refractive index (SRI) variation. The highly uniform Al2O3 nanofilm was deposited around the double cladding fiber (DCF) which presents cladding mode resonant feature. With the high refractive index coating, the cladding mode resonant spectrum was tuned. And the sensitivity enhancement for SRI sensor was demonstrated. Through adjusting the deposition cycles, a maximum sensitivity of 723 nm/RIU was demonstrated in the DCF with 2500 deposition cycles at the SRI of 1.34. Based on the analysis of cladding modes reorganization, the cladding modes transition of the coated DCF was investigated theoretically. With the high performance nanofilm coating, the proposed SRI sensor is expected to have wide applications in chemical sensors and biosensors.

© 2013 Optical Society of America

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  1. X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
    [CrossRef] [PubMed]
  2. P. Wang, G. Brambilla, M. Ding, Y. Semenova, Q. Wu, and G. Farrell, “High-sensitivity, evanescent field refractometric sensor based on a tapered, multimode fiber interference,” Opt. Lett.36(12), 2233–2235 (2011).
    [CrossRef] [PubMed]
  3. V. V. R. Sai, T. Kundu, and S. Mukherji, “Novel U-bent fiber optic probe for localized surface plasmon resonance based biosensor,” Biosens. Bioelectron.24(9), 2804–2809 (2009).
    [CrossRef] [PubMed]
  4. H. S. Jang, K. N. Park, J. P. Kim, S. J. Sim, O. J. Kwon, Y. G. Han, and K. S. Lee, “Sensitive DNA biosensor based on a long-period grating formed on the side-polished fiber surface,” Opt. Express17(5), 3855–3860 (2009).
    [CrossRef] [PubMed]
  5. D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).
  6. A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
    [CrossRef]
  7. Z. Y. Wang, J. R. Heflin, R. H. Stolen, and S. Ramachandran, “Analysis of optical response of long period fiber gratings to nm-thick thin-film coating,” Opt. Express13(8), 2808–2813 (2005).
    [CrossRef] [PubMed]
  8. J. Yang, L. Yang, C. Q. Xu, and Y. F. Li, “Optimization of Cladding-Structure-Modified Long-Period-Grating Refractive-Index Sensors,” J. Lightwave Technol.25(1), 372–380 (2007).
    [CrossRef]
  9. I. Del Villar, I. R. Matias, and F. J. Arregui, “Enhancement of sensitivity in long-period fiber gratings with deposition of low-refractive-index materials,” Opt. Lett.30(18), 2363–2365 (2005).
    [CrossRef] [PubMed]
  10. L. L. Xue and Y. Li, “Sensitivity Enhancement of RI Sensor Based on SMS Fiber Structure With High Refractive Index Overlay,” J. Lightwave Technol.30(10), 1463–1469 (2012).
    [CrossRef]
  11. I. Del Villar, M. Achaerandio, I. R. Matías, and F. J. Arregui, “Deposition of overlays by electrostatic self-assembly in long-period fiber gratings,” Opt. Lett.30(7), 720–722 (2005).
    [CrossRef] [PubMed]
  12. P. Pilla, V. Malachovská, A. Borriello, A. Buosciolo, M. Giordano, L. Ambrosio, A. Cutolo, and A. Cusano, “Transition mode long period grating biosensor with functional multilayer coatings,” Opt. Express19(2), 512–526 (2011).
    [CrossRef] [PubMed]
  13. A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
    [CrossRef]
  14. R. L. Puurunen, “Surface chemistry of atomic layer deposition: A case study for the trimethylaluminum/water process,” Appl. Phys. Rev.97(12), 121301 (2005).
    [CrossRef]
  15. S. M. George, “Atomic Layer Deposition: An Overview,” Chem. Rev.110(1), 111–131 (2010).
    [CrossRef] [PubMed]
  16. F. Pang, W. Xiang, H. Guo, N. Chen, X. Zeng, Z. Chen, and T. Wang, “Special optical fiber for temperature sensing based on cladding-mode resonance,” Opt. Express16(17), 12967–12972 (2008).
    [CrossRef] [PubMed]
  17. H. H. Liu, F. F. Pang, H. R. Guo, W. X. Cao, Y. Q. Liu, N. Chen, Z. Y. Chen, and T. Y. Wang, “In-series double cladding fibers for simultaneous refractive index and temperature measurement,” Opt. Express18(12), 13072–13082 (2010).
    [CrossRef] [PubMed]
  18. I. Del Villar, I. R. Matías, F. J. Arregui, and P. Lalanne, “Optimization of sensitivity in long period fiber gratings with overlay deposition,” Opt. Express13(1), 56–69 (2005).
    [CrossRef] [PubMed]
  19. H. Guo, F. Pang, X. Zeng, N. Chen, Z. Chen, and T. Wang, “Temperature sensor using an optical fiber coupler with a thin film,” Appl. Opt.47(19), 3530–3534 (2008).
    [CrossRef] [PubMed]
  20. P. Pilla, P. F. Manzillo, V. Malachovska, A. Buosciolo, S. Campopiano, A. Cutolo, L. Ambrosio, M. Giordano, and A. Cusano, “Long period grating working in transition mode as promising technological platform for label-free biosensing,” Opt. Express17(22), 20039–20050 (2009).
    [CrossRef] [PubMed]

2012

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

L. L. Xue and Y. Li, “Sensitivity Enhancement of RI Sensor Based on SMS Fiber Structure With High Refractive Index Overlay,” J. Lightwave Technol.30(10), 1463–1469 (2012).
[CrossRef]

2011

2010

2009

2008

2007

2006

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

2005

Achaerandio, M.

Ambrosio, L.

Arregui, F. J.

Borriello, A.

Brambilla, G.

Buosciolo, A.

Campopiano, S.

P. Pilla, P. F. Manzillo, V. Malachovska, A. Buosciolo, S. Campopiano, A. Cutolo, L. Ambrosio, M. Giordano, and A. Cusano, “Long period grating working in transition mode as promising technological platform for label-free biosensing,” Opt. Express17(22), 20039–20050 (2009).
[CrossRef] [PubMed]

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Cao, W. X.

Chen, N.

Chen, Z.

Chen, Z. Y.

Contessa, L.

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Cusano, A.

P. Pilla, V. Malachovská, A. Borriello, A. Buosciolo, M. Giordano, L. Ambrosio, A. Cutolo, and A. Cusano, “Transition mode long period grating biosensor with functional multilayer coatings,” Opt. Express19(2), 512–526 (2011).
[CrossRef] [PubMed]

P. Pilla, P. F. Manzillo, V. Malachovska, A. Buosciolo, S. Campopiano, A. Cutolo, L. Ambrosio, M. Giordano, and A. Cusano, “Long period grating working in transition mode as promising technological platform for label-free biosensing,” Opt. Express17(22), 20039–20050 (2009).
[CrossRef] [PubMed]

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Cutolo, A.

P. Pilla, V. Malachovská, A. Borriello, A. Buosciolo, M. Giordano, L. Ambrosio, A. Cutolo, and A. Cusano, “Transition mode long period grating biosensor with functional multilayer coatings,” Opt. Express19(2), 512–526 (2011).
[CrossRef] [PubMed]

P. Pilla, P. F. Manzillo, V. Malachovska, A. Buosciolo, S. Campopiano, A. Cutolo, L. Ambrosio, M. Giordano, and A. Cusano, “Long period grating working in transition mode as promising technological platform for label-free biosensing,” Opt. Express17(22), 20039–20050 (2009).
[CrossRef] [PubMed]

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Del Villar, I.

Ding, M.

Fan, X.

X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
[CrossRef] [PubMed]

Farrell, G.

George, S. M.

S. M. George, “Atomic Layer Deposition: An Overview,” Chem. Rev.110(1), 111–131 (2010).
[CrossRef] [PubMed]

Giordano, M.

P. Pilla, V. Malachovská, A. Borriello, A. Buosciolo, M. Giordano, L. Ambrosio, A. Cutolo, and A. Cusano, “Transition mode long period grating biosensor with functional multilayer coatings,” Opt. Express19(2), 512–526 (2011).
[CrossRef] [PubMed]

P. Pilla, P. F. Manzillo, V. Malachovska, A. Buosciolo, S. Campopiano, A. Cutolo, L. Ambrosio, M. Giordano, and A. Cusano, “Long period grating working in transition mode as promising technological platform for label-free biosensing,” Opt. Express17(22), 20039–20050 (2009).
[CrossRef] [PubMed]

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Guerra, G.

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Guo, H.

Guo, H. R.

Han, Y. G.

Heflin, J. R.

Hu, D. J. J.

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

Iadicicco, A.

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Jang, H. S.

Kao, L. T.

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

Kim, J. P.

Kundu, T.

V. V. R. Sai, T. Kundu, and S. Mukherji, “Novel U-bent fiber optic probe for localized surface plasmon resonance based biosensor,” Biosens. Bioelectron.24(9), 2804–2809 (2009).
[CrossRef] [PubMed]

Kwon, O. J.

Lalanne, P.

Lee, K. S.

Li, Y.

Li, Y. F.

Lim, J. L.

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

Liu, H. H.

Liu, Y. Q.

Malachovska, V.

Malachovská, V.

Manzillo, P. F.

Matias, I. R.

Matías, I. R.

Mukherji, S.

V. V. R. Sai, T. Kundu, and S. Mukherji, “Novel U-bent fiber optic probe for localized surface plasmon resonance based biosensor,” Biosens. Bioelectron.24(9), 2804–2809 (2009).
[CrossRef] [PubMed]

Pang, F.

Pang, F. F.

Park, K. N.

Park, M. K.

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

Pilla, P.

P. Pilla, V. Malachovská, A. Borriello, A. Buosciolo, M. Giordano, L. Ambrosio, A. Cutolo, and A. Cusano, “Transition mode long period grating biosensor with functional multilayer coatings,” Opt. Express19(2), 512–526 (2011).
[CrossRef] [PubMed]

P. Pilla, P. F. Manzillo, V. Malachovska, A. Buosciolo, S. Campopiano, A. Cutolo, L. Ambrosio, M. Giordano, and A. Cusano, “Long period grating working in transition mode as promising technological platform for label-free biosensing,” Opt. Express17(22), 20039–20050 (2009).
[CrossRef] [PubMed]

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Puurunen, R. L.

R. L. Puurunen, “Surface chemistry of atomic layer deposition: A case study for the trimethylaluminum/water process,” Appl. Phys. Rev.97(12), 121301 (2005).
[CrossRef]

Ramachandran, S.

Sai, V. V. R.

V. V. R. Sai, T. Kundu, and S. Mukherji, “Novel U-bent fiber optic probe for localized surface plasmon resonance based biosensor,” Biosens. Bioelectron.24(9), 2804–2809 (2009).
[CrossRef] [PubMed]

Semenova, Y.

Shopova, S. I.

X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
[CrossRef] [PubMed]

Sim, S. J.

Stolen, R. H.

Sun, Y.

X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
[CrossRef] [PubMed]

Suter, J. D.

X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
[CrossRef] [PubMed]

Tong, W.

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

Wang, P.

Wang, T.

Wang, T. Y.

Wang, Y.

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

Wang, Z. Y.

Wei, H.

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

White, I. M.

X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
[CrossRef] [PubMed]

Wu, Q.

Xiang, W.

Xu, C. Q.

Xue, L. L.

Yang, J.

Yang, L.

Zeng, X.

Zhu, H.

X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
[CrossRef] [PubMed]

Anal. Chim. Acta

X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, “Sensitive optical biosensors for unlabeled targets: a review,” Anal. Chim. Acta620(1-2), 8–26 (2008).
[CrossRef] [PubMed]

Appl. Opt.

Appl. Phys. Lett.

A. Cusano, A. Iadicicco, P. Pilla, A. Cutolo, M. Giordano, and S. Campopiano, “Sensitivity characteristics in nanosized coated long period gratings,” Appl. Phys. Lett.89(20), 201116 (2006).
[CrossRef]

A. Cusano, P. Pilla, L. Contessa, A. Iadicicco, S. Campopiano, A. Cutolo, M. Giordano, and G. Guerra, “High-sensitivity optical chemosensor based on coated long-period gratings for sub-ppm chemical detection in water,” Appl. Phys. Lett.87(23), 234105 (2005).
[CrossRef]

Appl. Phys. Rev.

R. L. Puurunen, “Surface chemistry of atomic layer deposition: A case study for the trimethylaluminum/water process,” Appl. Phys. Rev.97(12), 121301 (2005).
[CrossRef]

Biosens. Bioelectron.

V. V. R. Sai, T. Kundu, and S. Mukherji, “Novel U-bent fiber optic probe for localized surface plasmon resonance based biosensor,” Biosens. Bioelectron.24(9), 2804–2809 (2009).
[CrossRef] [PubMed]

Chem. Rev.

S. M. George, “Atomic Layer Deposition: An Overview,” Chem. Rev.110(1), 111–131 (2010).
[CrossRef] [PubMed]

IEEE J. SEL. TOP QUANT

D. J. J. Hu, J. L. Lim, M. K. Park, L. T. Kao, Y. Wang, H. Wei, and W. Tong, “Photonic crystal fiber-based interferometric biosensor for streptavidin and biotin detection,” IEEE J. SEL. TOP QUANT18, 1293–1297 (2012).

J. Lightwave Technol.

Opt. Express

F. Pang, W. Xiang, H. Guo, N. Chen, X. Zeng, Z. Chen, and T. Wang, “Special optical fiber for temperature sensing based on cladding-mode resonance,” Opt. Express16(17), 12967–12972 (2008).
[CrossRef] [PubMed]

H. S. Jang, K. N. Park, J. P. Kim, S. J. Sim, O. J. Kwon, Y. G. Han, and K. S. Lee, “Sensitive DNA biosensor based on a long-period grating formed on the side-polished fiber surface,” Opt. Express17(5), 3855–3860 (2009).
[CrossRef] [PubMed]

P. Pilla, P. F. Manzillo, V. Malachovska, A. Buosciolo, S. Campopiano, A. Cutolo, L. Ambrosio, M. Giordano, and A. Cusano, “Long period grating working in transition mode as promising technological platform for label-free biosensing,” Opt. Express17(22), 20039–20050 (2009).
[CrossRef] [PubMed]

H. H. Liu, F. F. Pang, H. R. Guo, W. X. Cao, Y. Q. Liu, N. Chen, Z. Y. Chen, and T. Y. Wang, “In-series double cladding fibers for simultaneous refractive index and temperature measurement,” Opt. Express18(12), 13072–13082 (2010).
[CrossRef] [PubMed]

P. Pilla, V. Malachovská, A. Borriello, A. Buosciolo, M. Giordano, L. Ambrosio, A. Cutolo, and A. Cusano, “Transition mode long period grating biosensor with functional multilayer coatings,” Opt. Express19(2), 512–526 (2011).
[CrossRef] [PubMed]

Z. Y. Wang, J. R. Heflin, R. H. Stolen, and S. Ramachandran, “Analysis of optical response of long period fiber gratings to nm-thick thin-film coating,” Opt. Express13(8), 2808–2813 (2005).
[CrossRef] [PubMed]

I. Del Villar, I. R. Matías, F. J. Arregui, and P. Lalanne, “Optimization of sensitivity in long period fiber gratings with overlay deposition,” Opt. Express13(1), 56–69 (2005).
[CrossRef] [PubMed]

Opt. Lett.

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Figures (8)

Fig. 1
Fig. 1

The refractive index profile of the coated DCF.

Fig. 2
Fig. 2

Effective refractive index as a function of the overlay thickness of (a) the first eight cladding modes, (b) LP05 mode in DCF with different coating refractive index, (c) the first eight cladding mode in a wider scale.

Fig. 3
Fig. 3

Transversal electric field before and after transition point (a) LP05 in bare DCF, (b) LP06 in 400nm film coated DCF, (c) guided mode in 400nm film.

Fig. 4
Fig. 4

Sensitivity of DCF coated with nanofilm to SRI.

Fig. 5
Fig. 5

(a) schematic diagram of the DCF fiber sensor head, (b) SEM picture of the coated DCF end face, (c) relationship of coating thickness and deposition cycle.

Fig. 6
Fig. 6

The dependence of transmission spectrum on deposition cycles, (a) transmission spectrum shift, (b) dip wavelength shift.

Fig. 7
Fig. 7

RI sensing spectra of the coated DCF sensor (a) 500 layers (b) 1000 layers.

Fig. 8
Fig. 8

Response of the resonant wavelength to SRI for different deposition cycles.

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