Regular ArticlesTwist and temperature characteristics of the PD-NSN fiber structure based on in-line Mach-Zehnder interferometer

- A novel polarization-dependent no core-single mode-no core fiber structure for twist and temperature sensing is proposed.
- The related theory is explained and the experiment results are analyzed.
- The proposed sensor has advantages of using the peak-wavelength discrimination method and a simple fabrication process.

A novel polarization-dependent (PD) no core-single mode-no core (NSN) fiber structure for twist and temperature sensing has been experimentally investigated. The proposed structure simply involves a section of polarization maintain fiber sandwiched into NSN fiber structure, only using the splicing method. We have analyzed and demonstrated the transmission characteristics of the no core fiber (NCF) with the different lengths. Experimental results indicate that the extinction ratio of the PD-NSN fiber structure comb spectrum based on Mach-Zehnder interferometer (MZI) various with twist rate. The maximum sensitivity of 0.33904 dB/(rad/m) for range from −240° to 360° is achieved. The temperature sensitivity of the proposed structure reaches 41.89 pm/°C for temperature ranging from 20 to 70 °C in the experiment. By using the peak-wavelength discrimination method, the proposed sensor can overcome the temperature and twist cross-sensitivity effects.