Abstract

Fibre Bragg gratings inscribed with the point-by-point method using a Ti-sapphire femtosecond laser operating at 800 nm are shown to display strong increasing attenuation towards shorter wavelengths with a large and spectrally sharp recovery observed below 400 nm. The origin of this loss is shown to be Mie scattering, and the sharp recovery in the transmission results from wavelength dependent scattering within the numerical aperture of the core. The permanent losses from these Type II gratings have implications for high temperature sensors and fibre lasers.

© 2008 Optical Society of America

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References

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  1. C. G. Askins, T.-E. Tsai, G. M. Williams, M. A. Putnam, M. Bashkansky, and E. J. Friebele, "Fiber Bragg reflectors prepared by a single excimer pulse," Opt. Lett. 17, 833-835 (1992).
    [CrossRef] [PubMed]
  2. J.-L. Archambault, L. Reekie, and P. St.J. Russell, "100% reflectivity Bragg reflectors produced in optical fibres by single excimer laser pulses," Electron. Lett. 29, 453-455 (1993).
    [CrossRef]
  3. C. W. Smelser, S. J. Mihailov, and D. Grobnic, "Formation of Type I-IR and Type II-IR gratings with an ultrafast IR laser and a phase mask," Opt. Express 13, 5377-5386 (2005).
    [CrossRef] [PubMed]
  4. E. Wikszak, J. Burghoff, M. Will, S. Nolte, and A. Tünnermann, "Recording of fiber Bragg gratings with femtosecond pulses using a "point by point" technique," Conference on Lasers and Electro-Optics, 2004. (CLEO), 2, pp 2. CThM7, (2004).
  5. A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, "Direct writing of fibre Bragg gratings by femtosecond laser," Electron. Lett. 40, 1170 (2004).
    [CrossRef]
  6. E. N. Glezer and E. Mazur, "Ultrafast-laser driven micro-explosions in transparent materials," Appl. Phys. Lett.71, (1997).
    [CrossRef]
  7. R. R. Gattass and E. Mazur, "Femtosecond laser micromachining in transparent materials," Nature Photo. 2, 219-225 (2008).
    [CrossRef]
  8. A. Martinez, I. Y. Khrushchev, and I. Bennion, "Thermal properties of fibre Bragg gratings inscribed point-by-point by infrared femtosecond laser," Electron. Lett. 41, 176-178 (2005).
    [CrossRef]
  9. J. Canning, "New fibre and grating technologies for lasers and sensors," 1, 1-62, Frontiers in lasers and electro optics research, Nova science publishers, (2006).
  10. K. M. Davis, K. Miura, N. Sugimoto, and K. Hirao, "Writing waveguides in glass with a femtosecond laser," Opt. Lett. 21, 1729-1731 (1996).
    [CrossRef] [PubMed]
  11. G. Cerullo, R. Osellame, S. Taccheo, M. Marangoni, D. Polli, R. Ramponi, P. Laporta, and S. De Silvestri, "Femtosecond micromachining of symmetric waveguides at 1.5 μm by astigmatic beam focusing," Opt. Lett. 27, 1938-1940 (2002).
    [CrossRef]
  12. L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
    [CrossRef]
  13. N. Jovanovic, M. ?slund, A. Fuerbach, S. D. Jackson, G. D. Marshall, and M. J. Withford, "Narrow linewidth, 100W cw Yb3+-doped silica fiber laser with a point-by-point Bragg grating inscribed directly into the active core," Opt. Lett. 32, 2804-2806 (2007).
    [CrossRef] [PubMed]
  14. R. M. Atkins and V. Mizrahi, "Observations of changes in uv absorption bands of singlemode germanosilicate core optical fibers on writing and thermally erasing refractive index gratings," Electron. Lett. 28, 1743-1744 (1992).
    [CrossRef]
  15. J. Canning, A. L. G. Carter, and M. G. Sceats, "Correlation between photodarkening and index change during 193 nm irradiation of germanosilicate and phosphosilicate fibers," J. Lightwave Technol. 15, 1348-1356 (1997).
    [CrossRef]
  16. P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
    [CrossRef]
  17. A. Othonos and K. Kalli, Fibre Bragg Gratings: Fundamentals and Applications in Telecommunications and Sensing (Boston London: Artech House, 1999).
  18. M. ?slund, N. Jovanovic, N. Groothoff, J. Canning, G. D. Marshall, S. D. Jackson, A. Fuerbach, and M. J. Withford, "Photodarkening study of gratings written into rare-earth doped optical fibers using a femtosecond laser," in Proc. SPIE 6800, 32, Canberra, Australia, Dec., (2007).
    [CrossRef]
  19. N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
    [CrossRef]
  20. M. I. Mishchenko, L. D. Travis, and A. A. Lacis, Scattering, Absorption, and Emission of Light by Small Particles (Cambridge University Press, Cambridge, 2002).

2008

R. R. Gattass and E. Mazur, "Femtosecond laser micromachining in transparent materials," Nature Photo. 2, 219-225 (2008).
[CrossRef]

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

2007

2006

L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
[CrossRef]

2005

A. Martinez, I. Y. Khrushchev, and I. Bennion, "Thermal properties of fibre Bragg gratings inscribed point-by-point by infrared femtosecond laser," Electron. Lett. 41, 176-178 (2005).
[CrossRef]

C. W. Smelser, S. J. Mihailov, and D. Grobnic, "Formation of Type I-IR and Type II-IR gratings with an ultrafast IR laser and a phase mask," Opt. Express 13, 5377-5386 (2005).
[CrossRef] [PubMed]

2004

A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, "Direct writing of fibre Bragg gratings by femtosecond laser," Electron. Lett. 40, 1170 (2004).
[CrossRef]

2002

1997

E. N. Glezer and E. Mazur, "Ultrafast-laser driven micro-explosions in transparent materials," Appl. Phys. Lett.71, (1997).
[CrossRef]

J. Canning, A. L. G. Carter, and M. G. Sceats, "Correlation between photodarkening and index change during 193 nm irradiation of germanosilicate and phosphosilicate fibers," J. Lightwave Technol. 15, 1348-1356 (1997).
[CrossRef]

1996

1995

P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
[CrossRef]

1993

J.-L. Archambault, L. Reekie, and P. St.J. Russell, "100% reflectivity Bragg reflectors produced in optical fibres by single excimer laser pulses," Electron. Lett. 29, 453-455 (1993).
[CrossRef]

1992

C. G. Askins, T.-E. Tsai, G. M. Williams, M. A. Putnam, M. Bashkansky, and E. J. Friebele, "Fiber Bragg reflectors prepared by a single excimer pulse," Opt. Lett. 17, 833-835 (1992).
[CrossRef] [PubMed]

R. M. Atkins and V. Mizrahi, "Observations of changes in uv absorption bands of singlemode germanosilicate core optical fibers on writing and thermally erasing refractive index gratings," Electron. Lett. 28, 1743-1744 (1992).
[CrossRef]

?slund, M.

Archambault, J.-L.

J.-L. Archambault, L. Reekie, and P. St.J. Russell, "100% reflectivity Bragg reflectors produced in optical fibres by single excimer laser pulses," Electron. Lett. 29, 453-455 (1993).
[CrossRef]

Ashcom, J. B.

L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
[CrossRef]

Askins, C. G.

Atkins, G. R.

P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
[CrossRef]

Atkins, R. M.

R. M. Atkins and V. Mizrahi, "Observations of changes in uv absorption bands of singlemode germanosilicate core optical fibers on writing and thermally erasing refractive index gratings," Electron. Lett. 28, 1743-1744 (1992).
[CrossRef]

Bashkansky, M.

Bennetts, S.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

Bennion, I.

A. Martinez, I. Y. Khrushchev, and I. Bennion, "Thermal properties of fibre Bragg gratings inscribed point-by-point by infrared femtosecond laser," Electron. Lett. 41, 176-178 (2005).
[CrossRef]

A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, "Direct writing of fibre Bragg gratings by femtosecond laser," Electron. Lett. 40, 1170 (2004).
[CrossRef]

Canning, J.

J. Canning, A. L. G. Carter, and M. G. Sceats, "Correlation between photodarkening and index change during 193 nm irradiation of germanosilicate and phosphosilicate fibers," J. Lightwave Technol. 15, 1348-1356 (1997).
[CrossRef]

P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
[CrossRef]

Carter, A. L. G.

J. Canning, A. L. G. Carter, and M. G. Sceats, "Correlation between photodarkening and index change during 193 nm irradiation of germanosilicate and phosphosilicate fibers," J. Lightwave Technol. 15, 1348-1356 (1997).
[CrossRef]

Cerullo, G.

Cox, G. C.

P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
[CrossRef]

Davis, K. M.

De Silvestri, S.

Dubov, M.

A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, "Direct writing of fibre Bragg gratings by femtosecond laser," Electron. Lett. 40, 1170 (2004).
[CrossRef]

Friebele, E. J.

Fuerbach, A.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

N. Jovanovic, M. ?slund, A. Fuerbach, S. D. Jackson, G. D. Marshall, and M. J. Withford, "Narrow linewidth, 100W cw Yb3+-doped silica fiber laser with a point-by-point Bragg grating inscribed directly into the active core," Opt. Lett. 32, 2804-2806 (2007).
[CrossRef] [PubMed]

Gattass, R. R.

R. R. Gattass and E. Mazur, "Femtosecond laser micromachining in transparent materials," Nature Photo. 2, 219-225 (2008).
[CrossRef]

L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
[CrossRef]

Glezer, E. N.

E. N. Glezer and E. Mazur, "Ultrafast-laser driven micro-explosions in transparent materials," Appl. Phys. Lett.71, (1997).
[CrossRef]

Grobnic, D.

Hill, P. C.

P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
[CrossRef]

Hirao, K.

Jackson, S. D.

Jovanovic, N.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

N. Jovanovic, M. ?slund, A. Fuerbach, S. D. Jackson, G. D. Marshall, and M. J. Withford, "Narrow linewidth, 100W cw Yb3+-doped silica fiber laser with a point-by-point Bragg grating inscribed directly into the active core," Opt. Lett. 32, 2804-2806 (2007).
[CrossRef] [PubMed]

Khrushchev, I.

A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, "Direct writing of fibre Bragg gratings by femtosecond laser," Electron. Lett. 40, 1170 (2004).
[CrossRef]

Khrushchev, I. Y.

A. Martinez, I. Y. Khrushchev, and I. Bennion, "Thermal properties of fibre Bragg gratings inscribed point-by-point by infrared femtosecond laser," Electron. Lett. 41, 176-178 (2005).
[CrossRef]

Lancaster, D. G.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

Laporta, P.

Marangoni, M.

Marshall, G. D.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

N. Jovanovic, M. ?slund, A. Fuerbach, S. D. Jackson, G. D. Marshall, and M. J. Withford, "Narrow linewidth, 100W cw Yb3+-doped silica fiber laser with a point-by-point Bragg grating inscribed directly into the active core," Opt. Lett. 32, 2804-2806 (2007).
[CrossRef] [PubMed]

Martinez, A.

A. Martinez, I. Y. Khrushchev, and I. Bennion, "Thermal properties of fibre Bragg gratings inscribed point-by-point by infrared femtosecond laser," Electron. Lett. 41, 176-178 (2005).
[CrossRef]

A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, "Direct writing of fibre Bragg gratings by femtosecond laser," Electron. Lett. 40, 1170 (2004).
[CrossRef]

Maxwell, I. Z.

L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
[CrossRef]

Mazur, E.

R. R. Gattass and E. Mazur, "Femtosecond laser micromachining in transparent materials," Nature Photo. 2, 219-225 (2008).
[CrossRef]

L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
[CrossRef]

E. N. Glezer and E. Mazur, "Ultrafast-laser driven micro-explosions in transparent materials," Appl. Phys. Lett.71, (1997).
[CrossRef]

Mihailov, S. J.

Miura, K.

Mizrahi, V.

R. M. Atkins and V. Mizrahi, "Observations of changes in uv absorption bands of singlemode germanosilicate core optical fibers on writing and thermally erasing refractive index gratings," Electron. Lett. 28, 1743-1744 (1992).
[CrossRef]

Osellame, R.

Polli, D.

Putnam, M. A.

Ramponi, R.

Reekie, L.

J.-L. Archambault, L. Reekie, and P. St.J. Russell, "100% reflectivity Bragg reflectors produced in optical fibres by single excimer laser pulses," Electron. Lett. 29, 453-455 (1993).
[CrossRef]

Russell, P. St.J.

J.-L. Archambault, L. Reekie, and P. St.J. Russell, "100% reflectivity Bragg reflectors produced in optical fibres by single excimer laser pulses," Electron. Lett. 29, 453-455 (1993).
[CrossRef]

Sceats, M. G.

J. Canning, A. L. G. Carter, and M. G. Sceats, "Correlation between photodarkening and index change during 193 nm irradiation of germanosilicate and phosphosilicate fibers," J. Lightwave Technol. 15, 1348-1356 (1997).
[CrossRef]

P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
[CrossRef]

Smelser, C. W.

Sugimoto, N.

Taccheo, S.

Tong, L.

L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
[CrossRef]

Town, G. E.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

Tsai, T.-E.

Williams, G. M.

Withford, M. J.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

N. Jovanovic, M. ?slund, A. Fuerbach, S. D. Jackson, G. D. Marshall, and M. J. Withford, "Narrow linewidth, 100W cw Yb3+-doped silica fiber laser with a point-by-point Bragg grating inscribed directly into the active core," Opt. Lett. 32, 2804-2806 (2007).
[CrossRef] [PubMed]

Appl. Opt.

P. C. Hill, G. R. Atkins, J. Canning, G. C. Cox, and M. G. Sceats, "Writing and visualization of low-threshold type II Bragg gratings in stressed optical fibers," Appl. Opt. 33, 7689-7694 (1995).
[CrossRef]

Appl. Phys. Lett.

E. N. Glezer and E. Mazur, "Ultrafast-laser driven micro-explosions in transparent materials," Appl. Phys. Lett.71, (1997).
[CrossRef]

Electron. Lett.

A. Martinez, I. Y. Khrushchev, and I. Bennion, "Thermal properties of fibre Bragg gratings inscribed point-by-point by infrared femtosecond laser," Electron. Lett. 41, 176-178 (2005).
[CrossRef]

J.-L. Archambault, L. Reekie, and P. St.J. Russell, "100% reflectivity Bragg reflectors produced in optical fibres by single excimer laser pulses," Electron. Lett. 29, 453-455 (1993).
[CrossRef]

A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, "Direct writing of fibre Bragg gratings by femtosecond laser," Electron. Lett. 40, 1170 (2004).
[CrossRef]

R. M. Atkins and V. Mizrahi, "Observations of changes in uv absorption bands of singlemode germanosilicate core optical fibers on writing and thermally erasing refractive index gratings," Electron. Lett. 28, 1743-1744 (1992).
[CrossRef]

J. Lightwave Technol.

J. Canning, A. L. G. Carter, and M. G. Sceats, "Correlation between photodarkening and index change during 193 nm irradiation of germanosilicate and phosphosilicate fibers," J. Lightwave Technol. 15, 1348-1356 (1997).
[CrossRef]

Nature Photo.

R. R. Gattass and E. Mazur, "Femtosecond laser micromachining in transparent materials," Nature Photo. 2, 219-225 (2008).
[CrossRef]

Opt. Commun.

L. Tong, R. R. Gattass, I. Z. Maxwell, J. B. Ashcom, and E. Mazur, "Optical loss measurements in femtosecond laser written waveguides in glass," Opt. Commun. 259, 626-630 (2006).
[CrossRef]

Opt. Express

Opt. Lett.

Photon. Technol. Lett.

N. Jovanovic, G. D. Marshall, A. Fuerbach, G. E. Town, S. Bennetts, D. G. Lancaster, and M. J. Withford, "Highly-narrow linewidth, CW, all-fiber oscillator with a switchable linear polarization," Photon. Technol. Lett. 20, 809-811 (2008).
[CrossRef]

Other

M. I. Mishchenko, L. D. Travis, and A. A. Lacis, Scattering, Absorption, and Emission of Light by Small Particles (Cambridge University Press, Cambridge, 2002).

A. Othonos and K. Kalli, Fibre Bragg Gratings: Fundamentals and Applications in Telecommunications and Sensing (Boston London: Artech House, 1999).

M. ?slund, N. Jovanovic, N. Groothoff, J. Canning, G. D. Marshall, S. D. Jackson, A. Fuerbach, and M. J. Withford, "Photodarkening study of gratings written into rare-earth doped optical fibers using a femtosecond laser," in Proc. SPIE 6800, 32, Canberra, Australia, Dec., (2007).
[CrossRef]

E. Wikszak, J. Burghoff, M. Will, S. Nolte, and A. Tünnermann, "Recording of fiber Bragg gratings with femtosecond pulses using a "point by point" technique," Conference on Lasers and Electro-Optics, 2004. (CLEO), 2, pp 2. CThM7, (2004).

J. Canning, "New fibre and grating technologies for lasers and sensors," 1, 1-62, Frontiers in lasers and electro optics research, Nova science publishers, (2006).

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Figures (5)

Fig. 1.
Fig. 1.

Femtosecond laser induced refractive index modulations written with a pulse energy of 260 nJ in SMF28. (a) Top view (laser pulse entered glass in the plane of the image), (b) Side view.

Fig. 2.
Fig. 2.

Normalised broad-band transmission spectra for femtosecond laser inscribed PbP FBGs written in (a) Ge-doped fibre and (b) 1.18 %wt Yb3+-, Ge-, Al-doped fibre for various pulse energies as a function of wavelength (red=160nJ, blue=180nJ, green=200nJ, yellow=220nJ, pink=260nJ and black=300nJ) shown in same scale. Top inset in (a) shows the transmission (T) minimum wavelength (red=Ge, black=Yb) and the bottom inset shows the respective transmission losses, both as a function of pulse energy. Inset in (b) shows the transmission spectra of pristine Ge-doped fibre (SMF 28) for the normalised L=25 cm.

Fig. 3.
Fig. 3.

Change in spectral transmissivity (T) for gratings written in the Ge (a) and Yb, Al (b) fibres after 1hr annealing, including: 160 nJ gratings at 300 °C (green), 160 nJ at 400 °C (blue), 300 nJ at 300 °C (black), 300 nJ at 400 °C (red) shown in same scale. Inset shows the raw data for both the 300 nJ-400 °C experiments before and after heating (Ge: red→black; Yb:green→blue), compared with an identical annealing study of a UV 193 nm written grating (pink→ yellow).

Fig. 4.
Fig. 4.

Photo of diffraction orders of 632.8 nm light emanating from a 20th order PbP FBG onto a screen parallel to the fibre.

Fig. 5.
Fig. 5.

Theoretical simulation of the transmitted unscattered light for a single spherical scatterer in bulk media (black) compared with the sum of the transmitted unscattered light and the light scattered within the NA of the fibre core (red).

Tables (1)

Tables Icon

Table 1. Optical fibres used in the experiments.

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