Single-mode tellurite optical fiber for temperature measurement based on the self-phase modulation effect.

In this paper, the self-phase modulation (SPM) effect in a double-cladding single-mode tellurite optical fiber (DC-SMTOF) was exploited for temperature sensing. The DC-SMTOF was fabricated based on a TeO2-ZnO-Li2O-Bi2O3 (TZLB) glass material that has a thermo-optical coefficient as high as -16.4×10-6/°C. The temperature sensing performance was evaluated by detecting the 3-dB bandwidth of the SPM spectra with the variation of temperature at different pump wavelength and different average pump power. The temperature sensitivity was obtained to be -2.971 nm/°C with a resolution of 0.0168°C. Both simulation and experiment confirmed that a longer pump wavelength and higher average pump power will result in a higher temperature sensitivity. To the best of our knowledge, this is the first study concerning SPM-based temperature sensing in a tellurite optical fiber. The proposed temperature sensor has a compact structure, and it can realize temperature sensing of high sensitivity without any fiber modification. This work opens the road toward explorations of a novel temperature sensing technology combined with soft glass fibers and nonlinear phenomenon, and is expected to deepen our understanding in the application of these complex nonlinear phenomena.

Experimental investigation of supercontinuum generation in a birefringence tellurite microstructured optical fiber.

A four-hole birefringence tellurite microstructured optical fiber (BTMOF) was designed and fabricated based on 76.5T e O 2-6Z n O-11.5L i 2 O-6B i 2 O 3 glass, and its core (slow and fast axes were) measured to be approximately 4.74 µm and 4.29 µm, respectively. The experimentally measured results demonstrated that the maximum supercontinuum (SC) spectra extended from ∼914.1n m to ∼1885.1n m when the polarization state of the pump pulse was parallel to the fast axis at 1400 nm with an average power of 460 mW. We performed numerical simulations based on the nonlinear Schrödinger equation, which support the experimentally measured results. The SC generation in birefringent silica microstructured fiber with the same geometric parameters was simulated, and the results showed that the enhanced nonlinear refractive index of the BTMOF yielded a spectrum with a significantly larger bandwidth. Furthermore, the two polarization states along the fast axis and slow axis exhibit different dispersion characteristics, which provide a convenient way of tuning the properties of the generated SC. This work highlights BTMOF as a promising platform for the development of a SC light source, which can be widely used in food quality inspection, early cancer diagnostics, gas sensing, and high-spatial-resolution imaging.