Fabrication and characterization of laser-ablated cladding resonances of two different-diameter photosensitive optical fibers

In this work, we demonstrate the inscription of grating in both cladding and core of photosensitive single-mode optical fibers with diameter 4.4/125 μm and 4.2/80 μm. Such inscription is made possible through a hydrogenation process for the photosensitive fiber and employ high energy focused pulsed laser from an ArF excimer laser. In the fabrication, a periodic ablation is formed on the fiber surface and the optical damage is extended from the fiber surface towards the core of the fiber, observable under an optical microscope. As a result, cladding modes are excited and cladding resonances are produced in the output spectra. The response of cladding resonances to ambient refractive index (RI) is characterized and investigated through simulation and experiment. It is observed that cladding resonances in the fiber with smaller diameter are more sensitive to the ambient RI variation.

[1]  Shuisheng Jian,et al.  Single-polarization, switchable dual-wavelength erbium-doped fiber laser with two polarization-maintaining fiber Bragg gratings. , 2008, Optics express.

[2]  C. Liao,et al.  Femtosecond laser fabricated fiber Bragg grating in microfiber for refractive index sensing. , 2010, Optics letters.

[3]  Wenjun Zhou,et al.  Au-coated tilted fiber Bragg grating twist sensor based on surface plasmon resonance , 2014 .

[4]  David J. Richardson,et al.  Characterization of Mode Coupling in Few-Mode FBG With Selective Mode Excitation , 2015, IEEE Photonics Technology Letters.

[5]  Wide-range in-fibre Fabry-Perot resonator for ultrasonic sensing , 2015 .

[6]  Kok-Sing Lim,et al.  Tilted Fiber Bragg Grating Sensors for Reinforcement Corrosion Measurement in Marine Concrete Structure , 2015, IEEE Transactions on Instrumentation and Measurement.

[8]  Gilberto Brambilla,et al.  Fiber Bragg grating inscription by high-intensity femtosecond UV laser light: comparison with other existing methods of fabrication , 2005 .

[9]  S. Gupta,et al.  Bragg gratings in multimode and few-mode optical fibers , 2000, Journal of Lightwave Technology.

[10]  Kok-Sing Lim,et al.  Optimized Tapered Optical Fiber for Ethanol (C$_{\bf 2}$ H$_{\bf 5}$OH) Concentration Sensing , 2014, Journal of Lightwave Technology.

[11]  Yu Zhang,et al.  Refractive index sensing based on higher-order mode reflection of a microfiber Bragg grating. , 2010, Optics express.

[12]  Wei Jin,et al.  Long-period gratings in wavelength-scale microfibers. , 2010, Optics letters.

[13]  K. Schuster,et al.  High-reflectivity draw-tower fiber Bragg gratings—arrays and single gratings of type II , 2005 .

[14]  David N. Payne,et al.  Modal characteristics of three-layered optical fiber waveguides: a modified approach , 1989 .

[15]  W H Loh,et al.  Efficient single-frequency fiber lasers with novel photosensitive Er/Yb optical fibers. , 1997, Optics letters.

[16]  Turan Erdogan,et al.  Cladding-mode resonances in short- and long-period fiber grating filters , 2000 .