scholarly journals Improving the Sensitivity of Humidity Sensor Based on Mach-Zehnder Interferometer Coated with a Methylcellulose

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Jun Huang ◽  
Bowen Wang ◽  
Kai Ni
Keyword(s):  
Refractive Index ◽  
Humidity Sensor ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Zehnder Interferometer ◽  
Core Mode ◽  
The Core ◽  
Intensity Changes ◽  
Practical Measurement ◽  
Mach Zehnder Interferometer

A novel humidity sensor based on Mach-Zehnder interferometer (MZI) with the single-mode fiber (SMF) coated with methylcellulose (MC) is proposed and experimentally demonstrated. The MZI consists of two waist enlarged structures. Such an all-fiber MZI incorporates an intermodal interference between the core mode and cladding modes. The MC is coated on the surface of the SMF. External humidity changes the refractive index of MC, causing the intensity changes of the interference pattern. The proposed sensor is linearly responsive to refractive humidity (RH) within the range from 45% to 85% RH, with sensitivity of 0.094 dB/%RH. Moreover the insensitivity of the fiber to the temperature makes this structure more suitable for practical measurement.

A Novel In-Line Fiber Mach–Zehnder Interferometer Temperature Sensor Made of Thermally Expanded Core Fiber

2014 ◽  
Vol 635-637 ◽  
pp. 856-859 ◽  
Author(s):  
Ying Wu Zhou ◽  
Sheng Yu Chen
Keyword(s):  
Temperature Sensor ◽  
Low Cost ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Zehnder Interferometer ◽  
Core Mode ◽  
Temperature Changes ◽  
The Core ◽  
Core Fiber ◽  
Mach Zehnder Interferometer

A novel in-line fiber temperature sensor by splicing a piece of single mode fiber between two thermally expanded core fibers at their core-expanded ends is proposed and demonstrated. This structure forms an all fiber Mach–Zehnder interferometer due to the interference between the core mode and the cladding modes of the single mode fiber. The fabricated sensor is applied to measure temperature changes. The temperature sensitivity of the sensor at a length of 6.3cm is about 65.3 pm/°C. The proposed sensor is low cost, easily fabricated, and may be useful for detection of temperature.

scholarly journals Dual Demodulation of Temperature and Refractive Index Using Ring Core Fiber Based Mach-Zehnder Interferometer

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 258
Author(s):  
Weihao Yuan ◽  
Changyuan Yu
Keyword(s):  
Refractive Index ◽  
Extinction Ratio ◽  
Linear Equations ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Zehnder Interferometer ◽  
Wavelength Shift ◽  
Core Fiber ◽  
Ring Core ◽  
Mach Zehnder Interferometer

We report the ring core fiber spliced with single mode fiber and no core fiber which is used for temperature and refractive index (RI) sensing. The Mach-Zehnder interferometer (MZI) is formed with this kind of sandwich fiber structure and the maximum extinction ratio of the interference spectra reaches 27 dB with the free spectra range of 12 nm. The MZI fiber sensor is applied for temperature sensing with the sensitivity of 69 pm/°C and 0.051 dB/°C. The RI sensitivity reaches 182.07 dB/RIU and −31.44 nm/RIU with the RI ranging from 1.33 to 1.38. The RI value can be directly demodulated with the interference dip intensity which shows insensitivity to temperature. The demodulation of temperature can be achieved by using the linear equations between dip wavelength shift with the variation of temperature and RI.

Refractive Index Sensing With Mach–Zehnder Interferometer Based on Concatenating Two Single-Mode Fiber Tapers

2008 ◽  
Vol 20 (8) ◽  
pp. 626-628 ◽  
Author(s):  
Zhaobing Tian ◽  
Scott S.-H. Yam ◽  
Jack Barnes ◽  
Wojtek Bock ◽  
Patricia Greig ◽  
...  
Keyword(s):  
Refractive Index ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Zehnder Interferometer ◽  
Refractive Index Sensing ◽  
Mach Zehnder Interferometer

scholarly journals In-line Mach-Zehnder Interferometer based on Hybrid Structures for Refractive Index Sensin

2019 ◽  
Vol 8 (3S) ◽  
pp. 36-40
Keyword(s):  
Refractive Index ◽  
High Sensitivity ◽  
Single Mode ◽  
Cost Effective ◽  
Single Mode Fiber ◽  
Zehnder Interferometer ◽  
Refractive Index Sensor ◽  
Compact Size ◽  
Index Changes ◽  
Mach Zehnder Interferometer

A Mach-Zehnder interferometer (MZI) built using several concatenated different structures is proposed as a refractive index sensor. This sensor is comprised of a microbubble, a section of reduced cladding fiber (RCF) and a core-offset single-mode fiber (SMF). These structures are joined together through specialized arc fusion splicing procedures. The sensor is characterised by immersing it in Cargille oil with refractive index values ranging from 1.30 to 1.39. The sensor exhibits linearity in respect to the refractive index changes, with a good sensitivity of 144.42 nm/RIU. The proposed MZI has the advantages of cost effective, repeatable fabrication, compact size and high sensitivity, which make it a promising sensor.

scholarly journals High-Sensitivity Refractive Index Sensor Based on a Cascaded Core-Offset and Macrobending Single-Mode Fiber Interferometer

2021 ◽  
Vol 7 ◽  
Author(s):  
Chuanxin Teng ◽  
Yongjie Zhu ◽  
Fangda Yu ◽  
Shijie Deng ◽  
Libo Yuan ◽  
...  
Keyword(s):  
Refractive Index ◽  
High Sensitivity ◽  
Single Mode ◽  
Spectral Shift ◽  
Single Mode Fiber ◽  
Refractive Index Sensor ◽  
Core Mode ◽  
Fiber Core ◽  
The Core ◽  
Modal Interference

A high-sensitivity Mach–Zehnder interferometer (MZI) based on the cascaded core-offset and macrobending fiber structure is proposed for refractive index (RI) measurement. The core-offset structure makes the fiber core mode couple to the cladding modes, and some of them recouple back to the fiber core at the macrobending structure forming a model interference effect. The liquid RI can be measured by monitoring the spectral shift of the modal interference. The RI sensing performances for the interferometers with different macrobending radii and core offsets are investigated experimentally. Experimental results show that when the core offset is 2 μm and the macrobending radius is 5.5 mm, the sensitivity can reach 699.95 nm/RIU for the RI of 1.43. The temperature dependence for the proposed sensor is also tested, and a temperature sensitivity of 0.112 nm/°C is obtained.

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