Dual-peak long-period fiber gratings with enhanced refractive index sensitivity by finely tailored mode dispersion that uses the light cladding etching technique.

We have experimentally investigated the mode dispersion property and refractive index sensitivity of dual-peak long-period fiber gratings (LPGs) that were sensitized by hydrofluoric acid (HF) etching. The nature of the coupled cladding modes close to the dispersion turning point makes the dual-peak LPGs ultrasensitive to cladding property, permitting a fine tailoring of the mode dispersion and index sensitivity by the light cladding etching method using HF acid of only 1% concentration. As an implementation of an optical biosensor, the etched device was used to detect the concentration of hemoglobin protein in a sugar solution, showing a sensitivity as high as 20 nm/1%.

[1]  Ian Bennion,et al.  Simultaneous measurement of temperature and external refractive index by use of a hybrid grating in D fiber with enhanced sensitivity by HF etching. , 2005, Applied optics.

[2]  A. Vengsarkar,et al.  Optical fiber long-period grating sensors. , 1996, Optics letters.

[3]  M. Dagenais,et al.  High sensitivity evanescent field fiber Bragg grating sensor , 2005, IEEE Photonics Technology Letters.

[4]  M. Dagenais,et al.  Detecting hybridization of DNA by highly sensitive evanescent field etched core fiber Bragg grating sensors , 2005, IEEE Journal of Selected Topics in Quantum Electronics.

[5]  Shan Jiang,et al.  Dual resonant peaks of LP/sub 015/ cladding mode in long-period gratings , 1999 .

[6]  I. Bennion,et al.  Optical chemsensors utilizing long-period fiber gratings UV-inscribed in D-fiber with enhanced sensitivity through cladding etching , 2004, IEEE Photonics Technology Letters.

[7]  N. Park,et al.  Control of the characteristics of a long-period grating by cladding etching. , 2000, Applied optics.

[8]  Lin Zhang,et al.  High-sensitivity optical chemsensor based on etched D-fibre Bragg gratings , 2004 .

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

[10]  L Zhang,et al.  Sensitivity characteristics near the dispersion turning points of long-period fiber gratings in B/Ge codoped fiber. , 2001, Optics letters.

[11]  John E. Sipe,et al.  Long-period fiber gratings as band-rejection filters , 1995 .

[12]  N. S. Bergano,et al.  Long-period fiber-grating-based gain equalizers. , 1996, Optics letters.

[13]  Kin Seng Chiang,et al.  Analysis of etched long-period fibre grating and its response to external refractive index , 2000 .

[14]  Ian Bennion,et al.  Sensitivity characteristics of long-period fiber gratings , 2002 .

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

[16]  Shan Jiang,et al.  High sensitivity of dual resonant peaks of long-period fibre grating to surrounding refractive index changes , 1999 .

[17]  Yiping Cui,et al.  Cladding mode resonances of etch-eroded fiber Bragg grating for ambient refractive index sensing , 2006 .