Temperature-Insensitive Microfiber Mach–Zehnder Interferometer for Absolute Strain Measurement

A temperature-insensitive microfiber Mach-Zehnder interferometer (MZI) for absolute strain measurement is investigated theoretically and experimentally depending on the diameter of the microfiber. The thermo-optic quantity of the microfiber MZI is effectively controlled by optimizing the diameter of the microfiber within the MZI incorporating an external coating overlay. Consequently, the positive thermal property of the microfiber MZI is successfully compensated by the negative thermo-optic factor of the microfiber resulting in suppression of the temperature sensitivity of the microfiber MZI. The transmission spectra of the microfiber MZI with variations in temperature are converted to the spatial frequency spectra by using the fast Fourier transform. When the diameter of the microfiber is ~7 μm, the temperature sensitivity of the spatial frequency of the microfiber MZI is dramatically mitigated to be 1.94 × 10-6 nm-1 · °C-1. We apply the proposed microfiber MZI for absolute strain measurement and its strain sensitivity is measured to be 7.53 × 10-4 nm-1 · μϵ-1 in the spatial frequency domain.

[1]  Aaas News,et al.  Book Reviews , 1893, Buffalo Medical and Surgical Journal.

[2]  P. K. Bachmann,et al.  Thermal expansion coefficients of doped and undoped silica prepared by means of PCVD , 1988 .

[3]  G. Hocker,et al.  Fiber optics strain gauge. , 1978, Applied optics.

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

[6]  Bai-Ou Guan,et al.  193 nm excimer laser inscribed Bragg gratings in microfibers for refractive index sensing. , 2011, Optics express.

[7]  M. Sumetsky,et al.  Optical fiber microcoil resonators. , 2004, Optics express.

[8]  Bo Dong,et al.  Temperature Insensitive All-Fiber Compact Polarization-Maintaining Photonic Crystal Fiber Based Interferometer and Its Applications in Fiber Sensors , 2010, Journal of Lightwave Technology.

[9]  W Drexler,et al.  Ultrahigh resolution Fourier domain optical coherence tomography. , 2004, Optics express.

[10]  Deming Liu,et al.  Refractive index sensor using microfiber-based Mach-Zehnder interferometer. , 2012, Optics letters.

[11]  Yuhang Li,et al.  Mach-Zehnder interferometers assembled with optical microfibers or nanofibers. , 2008, Optics letters.

[12]  Anbo Wang,et al.  Temperature compensation of optical microresonators using a surface layer with negative thermo-optic coefficient. , 2007, Optics letters.

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

[14]  G. Brambilla,et al.  Optical fibre nanowires and microwires: a review , 2010 .

[15]  David J. Richardson,et al.  Optical fiber nanowires and microwires: fabrication and applications , 2009 .

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

[17]  Young-Geun Han,et al.  Simultaneous Measurement of Strain and Temperature by Using a Micro-Tapered Fiber Grating , 2012, Journal of Lightwave Technology.

[18]  Vittoria Finazzi,et al.  Temperature-insensitive photonic crystal fiber interferometer for absolute strain sensing , 2007 .

[19]  Yongmin Jung,et al.  Broadband single-mode operation of standard optical fibers by using a sub-wavelength optical wire filter. , 2008, Optics express.