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Highlights • An optical fiber Mach-Zehnder interferometer has been proposed. • The RI and temperature can be measured without the cross-sensitivity. • The sensitivities are −18.1764 nm/RIU and 0.0733 nm/°C, respectively. • The advantages of cost effectiveness, robustness and easy fabrication. Abstract A Mach-Zehnder interferometer based on single-mode-multimode-thin-core-single-mode fiber structure is proposed and experimentally demonstrated for measuring refractive index and temperature simultaneously. The transmission dips of the sensor will shift when the ambient refractive index and temperature change, so it is possible to measure the refractive index and temperature by monitoring the wavelength shifts of the two transmission dips due to different interference orders. The experimental results show that the sensing sensitivities of refractive index and temperature are −18.1764 nm/RIU and 0.0733 nm/°C within the refractive index range from1.3105 to 1.3517 and the temperature range from 25 °C to 50 °C, respectively. Its cost effectiveness, robustness and easy fabrication will have attractive potential applications in chemical and biological sensing. [ABSTRACT FROM AUTHOR]

In this paper, a novel configuration of reflection L-band erbium-doped fiber amplifier (L-EDFA) via inserting a 980 nm pump laser diode (LD) in the input part was constructed. By selecting appropriate power ratio of the 980 and 1480 nm pump LD, gain and noise figure (NF) of the L-EDFA are greatly improved in different degree in the wavelength region from 1565 to 1615 nm. Compared to the configuration pumped by only 1480 nm pump LD with given power, the noise figure decreases 1.3–9.4 dB and the gain enhances 1.5–9.9 dB. [Copyright &y& Elsevier]

Abstract: A metallic cardiovascular stent cutting system based on fiber laser was designed in this study. In order to achieve the cutting of stent, the main modules and the key technologies were analyzed and achieved. Then with the cutting system, the kerf width size was studied for different cutting parameters including laser output power, pulse length, repeat frequency, cutting speed and assisting gas pressure. Finally, a high quality of cutting of 316L stainless steel cardiovascular stent was achieved. [Copyright &y& Elsevier]

In this paper, an efficient L-band multi-wavelength erbium-doped fiber ring laser is demonstrated by recycling backward 1550 nm band amplified spontaneous emission as secondary pump source for the unpumped EDF section. The lasing threshold is reduced and the slope efficiency is improved. A piece of multimode fiber is used as a spatial mode-beating filter. By adjusting the polarization state of the light, the number of lasing wavelength and their spaces are controlled. In dual-wavelength laser, the power of each channel is 4 mW with 40 dB side-mode-suppression-ratio. [Copyright &y& Elsevier]

An all-fiber comb filter with flat-top spectral response based on a Mach–Zehnder interferometer (MZI) cascading a Michelson interferometer (MI) is proposed. The proposed filter consists of a rotatable polarizer, two 3-dB couplers, and two fiber Faraday rotator mirrors (FRMs). The numerical simulation results show that the birefringence of the single mode fiber (SMF) can be neglected when the polarization state of linearly polarized incident light respect to one principle axe of fiber. By selecting the path difference of the MZI and MI and adjusting the rotation angle of the two FRMs, the flat-top comb spectral response can be obtained. [ABSTRACT FROM AUTHOR]

A novel optical fiber sensor for the detection of Fe3+ based on AIEgens was reported for the first time. A new anti-B 18 H 22 derivative ((5-NH 2 C 9 H 6 N) 2 B 18 H 20 , Referred as to S1) bearing 5-aminoisoquinoline was synthesized via a one-pot and its structure was verified by 1H NMR and HRMS, photophysical properties were characterized by UV–Vis, fluorescence spectrum and theoretical calculation. The fluorophore exhibits obvious aggregation-induced emission enhancement (AIEE) characteristics in THF/H 2 O solution by increasing the aqueous concentration from 70% to 90%. The aggregation-induced emission (AIE) molecule in THF/H 2 O (ƒw = 90%) solution shows high selectivity for detecting Fe3+ over other metal ions by forming a 1:1 metal-to-ligand complex, and the detection limit is 5.25 × 10−5 M. The optical fiber sensor based on S1 for the detection of Fe3+ was fabricated, and the detection limit of Fe3+ can reach to be 0.137 nM. The sensor can be used to detect Fe3+ in chemical, environmental and biological fields. 1. The amino-containing anti-B 18 H 22 derivative with AIE characteristics was synthesized for the first time. 2. A novel optical fiber sensor for the detection of Fe3+ based on AIEgens was reported for the first time. 3. The optical fiber sensor based on this AIEgen for the detection of Fe3+ was fabricated, and the detection limit of Fe3+ can reach 0.137 nM. Compared with other fluorescence methods for detecting iron ions, the detection limit of our technique has obvious advantage. [ABSTRACT FROM AUTHOR]

• The dew point sensor based on the thermal effect of humidity sensitive film is reported for the first time. • The sensor has the advantages of simple device and strong anti-interference ability. • The response time of the sensor can be shorten by the software settings. A novel dew point measurement method has been developed by using a temperature sensor covered by humidity sensitive thin film (referred as HSTF). The measurement mechanism is that the mutation of the temperature-time curve caused by the thermal effect of the HSTF can be used to detect dew points. The automatic measurement system of dew point and relative humidity (RH) based on LabVIEW is built. Compared with the existing dew point detection methods, the technique has the advantages of simple device and anti-interference. The experimental data were compared with the reference values with the satisfactory results, relative humidity deviations are less than 1%, the working range is 0–30 °C within 25–85% humidity environment and the maximum response time are less than 65 s which can be further shortened by software. The research provides an effective way for the construction of a simple and automatic dew point measurement system. [ABSTRACT FROM AUTHOR]