Twisted Optical Microfibers for Refractive Index Sensing

A simple, compact, and robust refractive index sensor is developed, by twisting a pair of silica microfibers to form a coupling device. The transmission spectrum of the device is highly sensitive to the surrounding refractive index and the highest sensitivity obtained is -2377 nm/refractive index unit (RIU), at the refractive index value of - 1.3680, for the fibers with diameter of ~4.2 μm, and the sensitivity can be further increased to - 2735 nm/RIU for a smaller fiber diameter of ~2.8 μm. Such a device is easy to construct, of low cost, and compatible with the optical fiber system.

[1]  Yuze Sun,et al.  Sensitive optical biosensors for unlabeled targets: a review. , 2008, Analytica chimica acta.

[2]  Limin Tong,et al.  All-fiber add-drop filters based on microfiber knot resonators. , 2007, Optics letters.

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

[4]  J. Knight,et al.  Phase-matched excitation of whispering-gallery-mode resonances by a fiber taper. , 1997, Optics letters.

[5]  Yuqing Wang,et al.  Tunable refractive index sensor with ultracompact structure twisted by poly(trimethylene terephthalate) nanowires. , 2009, ACS nano.

[6]  Limin Tong,et al.  Subwavelength-diameter silica wires for low-loss optical wave guiding , 2003, Nature.

[7]  M. Mansuripur,et al.  Evanescent field-based optical fiber sensing device for measuring the refractive index of liquids in microfluidic channels. , 2005, Optics letters.

[8]  R. Windeler,et al.  Optical liquid ring resonator sensor. , 2007, Optics express.

[9]  S. Ghalmi,et al.  Fabrication of miniature optical fiber and microfiber coils , 2010 .

[10]  Yongmin Jung,et al.  Adiabatically tapered splice for selective excitation of the fundamental mode in a multimode fiber. , 2009, Optics letters.

[11]  Fei Xu,et al.  Demonstration of a refractometric sensor based on optical microfiber coil resonator , 2008, 2008 Conference on Lasers and Electro-Optics and 2008 Conference on Quantum Electronics and Laser Science.

[12]  Limin Tong,et al.  Supported microfiber loops for optical sensing. , 2008, Optics express.

[14]  Yongmin Jung,et al.  Optical microfiber coupler for broadband single-mode operation. , 2009, Optics express.

[15]  Krishna Thyagarajan,et al.  Analysis of tunable single-mode fiber directional couplers using simple and accurate relations , 1986 .

[16]  David N. Payne,et al.  All-fibre polarising beamsplitter , 1985 .