A High-Quality Mach-Zehnder Interferometer Fiber Sensor by Femtosecond Laser One-Step Processing

During new fiber sensor development experiments, an easy-to-fabricate simple sensing structure with a trench and partially ablated fiber core is fabricated by using an 800 nm 35 fs 1 kHz laser. It is demonstrated that the structure forms a Mach-Zehnder interferometer (MZI) with the interference between the laser light passing through the air in the trench cavity and that in the remained fiber core. The fringe visibilities are all more than 25 dB. The transmission spectra vary with the femtosecond (fs) laser ablation scanning cycle. The free spectral range (FSR) decreases as the trench length increases. The MZI structure is of very high fabrication and sensing repeatability. The sensing mechanism is theoretically discussed, which is in agreement with experiments. The test sensitivity for acetone vapor is about 104 nm/RIU, and the temperature sensitivity is 51.5 pm/°C at 200 ∼ 875 °C with a step of 25 °C.

[1]  Jaw-Luen Tang,et al.  Novel D-type Fiber Optic Localized Plasmon Resonance Sensor Realized by Femtosecond Laser Engraving , 2010 .

[2]  Byeong Ha Lee,et al.  Ultracompact in-line broadband Mach-Zehnder interferometer using a composite leaky hollow-optical-fiber waveguide. , 2008, Optics letters.

[3]  Kwang-Taek Kim,et al.  Optical fiber sensor for water detection using a side-polished fiber coupler with a planar glass-overlay-waveguide , 2002 .

[4]  Tao Zhu,et al.  Micro Fabry-Perot interferometers in silica fibers machined by femtosecond laser. , 2007, Optics express.

[5]  W. Johnstone,et al.  A Tunable Fiber-Optic Bandpass Filter Based on Polished Fiber to Planar Waveguide Coupling Techniques , 1995 .

[6]  Andrey Andreev,et al.  Single-mode fiber polished into the core as a sensor element , 1998 .

[7]  Lan Jiang,et al.  Repeatable nanostructures in dielectrics by femtosecond laser pulse trains , 2005 .

[8]  H. S. Wolff,et al.  iRun: Horizontal and Vertical Shape of a Region-Based Graph Compression , 2022, Sensors.

[9]  Antao Chen,et al.  All-Dielectric Electrooptic Sensor Based on a Polymer Microresonator Coupled Side-Polished Optical Fiber , 2007, IEEE Sensors Journal.

[10]  N. Chen,et al.  Wideband tunable fiber short-pass filter based on side-polished fiber with dispersive polymer overlay. , 2004, Optics letters.

[11]  C L Chen,et al.  Side-polished fibers. , 1992, Applied optics.

[12]  Chien-Hsing Chen,et al.  A Multi-D-Shaped Optical Fiber for Refractive Index Sensing , 2010, Sensors.

[13]  W Johnstone,et al.  Tunable in-line fiber-optic bandpass filter. , 1994, Optics letters.

[14]  Lan Jiang,et al.  Laser-treated substrate with nanoparticles for surface-enhanced Raman scattering. , 2010, Optics letters.

[15]  Tao Wei,et al.  Temperature-insensitive miniaturized fiber inline Fabry-Perot interferometer for highly sensitive refractive index measurement. , 2008, Optics express.

[16]  Tao Wei,et al.  Miniaturized fiber inline Fabry-Perot interferometer fabricated with a femtosecond laser. , 2008, Optics letters.

[17]  Lei Shi,et al.  Modeling of an Optical Sensor Based on Whispering Gallery Modes (WGMs) on the Surface Guiding Layer of Glass Filaments , 2008, Sensors.

[18]  Jaw-Luen Tang,et al.  Novel U-shape gold nanoparticles-modified optical fiber for localized plasmon resonance chemical sensing , 2010, DTIP 2010.