Reflective tilted fiber Bragg grating refractometer based on strong cladding to core recoupling.

A novel in-fiber structure for power-referenced refractometry with the capability to measure surrounding refractive index (SRI) as low as 1.33 is proposed and demonstrated. A short optical fiber stub containing a weakly tilted Bragg grating is spliced to another fiber with a large lateral offset. The reflection from this structure occurs in two well-defined wavelength bands, the Bragg reflected core mode and the cladding modes. The cladding modes reflect different amounts of power as the SRI changes, while the core-mode reflection from the same weakly tilted FBG remains unaffected by the SRI. The power reflected in the core mode band can be used as a reliable reference to cancel out any possible power fluctuations. The proposed refractometer with improved sensitivity for low SRI measurement together with the tip-reflection sensing feature, is a good candidate for sensing in chemical and biological applications.

[1]  Gilberto Brambilla,et al.  An embedded optical nanowire loop resonator refractometric sensor. , 2008, Optics express.

[2]  Jean-Marc Blondy,et al.  Fibre Bragg grating photowriting in microstructured optical fibres for refractive index measurement , 2006 .

[3]  Ignacio Del Villar,et al.  Enhancement of sensitivity in long-period fiber gratings with deposition of low-refractive-index materials. , 2005, Optics letters.

[4]  D. Thomson,et al.  Optical fiber refractometer using narrowband cladding-mode resonance shifts. , 2007, Applied optics.

[5]  Reginald K. Lee,et al.  Highly sensitive fiber Bragg grating refractive index sensors , 2005 .

[6]  Tuan Guo,et al.  Power-Referenced and Temperature-Calibrated Optical Fiber Refractometer , 2008, IEEE Photonics Technology Letters.

[7]  O. Bang,et al.  Highly sensitive refractometer with a photonic-crystal-fiber long-period grating. , 2007, Optics letters.

[8]  Guillaume Laffont,et al.  Tilted Fiber Bragg Grating photowritten in microstructured optical fiber for improved refractive index measurement. , 2006, Optics express.

[9]  I. Bennion,et al.  Optical chemsensor based on etched tilted Bragg grating structures in multimode fiber , 2005, IEEE Photonics Technology Letters.

[10]  G. Laffont,et al.  Tilted short-period fibre-Bragg-grating-induced coupling to cladding modes for accurate refractometry , 2001 .

[11]  M. Dagenais,et al.  High sensitivity evanescent field fiber Bragg grating sensor , 2004, The 17th Annual Meeting of the IEEELasers and Electro-Optics Society, 2004. LEOS 2004..

[12]  A. Cusano,et al.  Thinned fiber Bragg gratings as refractive index sensors , 2005, IEEE Sensors Journal.

[13]  Jacques Albert,et al.  Plasmon resonances in gold-coated tilted fiber Bragg gratings. , 2007, Optics letters.

[14]  Guillaume Laffont,et al.  Three-hole microstructured optical fiber for efficient fiber Bragg grating refractometer. , 2007, Optics letters.

[15]  Alan D. Kersey,et al.  Analysis of the response of long period fiber gratings to external index of refraction , 1998 .

[16]  Denis Donlagić,et al.  Multimode all-fiber quasi-distributed refractometer sensor array and cross-talk mitigation. , 2007, Applied optics.

[17]  Amadeu Griol,et al.  Slot-waveguide biochemical sensor. , 2007, Optics letters.

[18]  G. Farrell,et al.  All-fiber multimode-interference-based refractometer sensor: proposal and design. , 2006, Optics letters.

[19]  Jacques Albert,et al.  Temperature-independent tilted fiber grating vibration sensor based on cladding-core recoupling. , 2008, Optics letters.

[20]  Ian Bennion,et al.  Generation of infrared surface plasmon resonances with high refractive index sensitivity utilizing tilted fiber Bragg gratings. , 2007, Applied optics.