首页期刊导航|Optik
期刊信息/Journal information
Optik
Wissenschaftliche Verlagsgesellschaft
Optik

Wissenschaftliche Verlagsgesellschaft

0030-4026

Optik/Journal OptikSCIISTPEIAHCI
正式出版
收录年代

    Wide-range fiber Bragg grating strain sensor for load testing of aircraft landing gears

    Li W.Chen S.Chu Y.Huang P....
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHThe impact load borne by landing gear during the take-off and landing of aircraft is an important parameter in structural health monitoring. A wide-range fiber Bragg grating (FBG) strain sensor with a surface-attached carbon fiber matrix is designed to measure the strain and load of aircraft landing gear structures for monitoring requirements. The sensor's performance was tested, and its strain sensitivity is 1.14 pm/μɛ. In addition, a multivariate linear load regression method was proposed, which can simultaneously monitor and predict the three-way load of landing gear, and the ground static loading test was carried out to verify the feasibility of this method. The result shows that the regression load error calculated by this method is within 5%, which meets the actual engineering requirements.
      原文链接:
    • NSTL

    Photodegradation of tetracycline and doxycycline under visible radiation using MIL-MIL101Fe (NH2) @g-C3N4@CoFe2O4/GO as photocatalyst

    Samadi-Maybodi A.Khabazifard R.
    5页
    查看更多>>摘要：© 2022Today, the use of antibiotics around the world poses many threats to the environment and humans. Antibiotics are potentially environmental pollutants that play an important role in causing pollution with the development of new technologies and increasing use of these products. Photodegradation of antibiotics is a promising way to solve the contamination of antibiotics in water. In this study, the photodegradation efficiency of nanocomposites of contaminants such as tetracycline and doxycycline antibiotics was investigated using nanocomposites of CoFe2O4@GO, MIL-101Fe (NH2), g-C3N4, MIL-101Fe (NH2) @g-C3N4 and MIL-101Fe (NH2) @ g-C3N4@ CoFe2O4 / GO. The best efficiency of degradation was obtained by MIL-101Fe (NH2) @g-C3N4@CoFe2O4/GO (90% and 80% for tetracycline and doxycycline respectively). Photodegradation conditions of effective photocatalyst were optimized by experimental design (version 11) and results were found as follow: initial antibiotic concentration of 20 ppm, pH = 5, the dosage of photocatalyst 40 mg and irradiation time of 65 min. The quadratic model was proposed as a suitable model with coefficient of determination R2 = 0.9982, 0.962 for tetracycline and doxycycline respectively. The photocatalysts were characterized by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), UV-Vis spectroscopy and Fourier transform infrared spectroscopy (FT-IR) techniques. Zeta potential was also used to determine the surface charge. The final products of degradation process were analyzed by 1HNMR, MS and UV-Vis spectroscopic techniques.
      原文链接:
    • NSTL

    Measurement of target range and doppler shift by incorporating PDM-enabled FMCW-based photonic radar

    Sharma A.Chaudhary S.Parnianifard A.Wuttisittikulkij L....
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHMeasurement is an essential part of modern science as well as of engineering, commerce, and daily life. As per recent reports of world health organization (WHO), most accidents occur due to human negligence and hence need of a system which can access the surrounding environment and reflect exact measurement of obstacle is a must to enable fully autonomous vehicle (AV). Photonic radars have materialized as promising candidate to realize AVs via distinguishing traffic pattern, navigation, lane detection and self-parking etc. In this work, we have developed coherent detection-based linear frequency modulated continuous wave (LFMCW) photonic radar to detect multiple targets multiplexed over a single free space channel via polarization division multiplexing (PDM). Also, the proposed system is tested for detection under zero visibility conditions under the impact of atmospheric turbulences up to 140 m of range distance. The reported results in terms of range frequency peaks and signal to noise ratio (SNR) indicate successful detection of both the targets at 4 GHz of bandwidth. The system is further tested for moving traffic condition with the target speed of 50 km/hr and 100 km/hr, respectively. Lastly, the range resolution of the proposed system is tested and reported as 15 cm at 1 GHz and 6.75 cm with 4 GHz of bandwidth at a distance of 100 m.
      原文链接:
    • NSTL

    Effect of Fe doping on the structural and optical properties of ZnS macro-spheres

    Zafar S.Shah S.M.Zubair M.Khan M.I....
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHObjective: Doping of ZnS by the transition metal ions has perceived considerable attention in industrial applications in light-emitting displays and optical sensors. Herein, we have studied the effect of Fe doping on structural and optical properties of ZnS macro-spheres. Methods: ZnS macro-sphere with and without Fe doping are synthesized by a simple and cost-effective co-precipitation method and characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and Fourier transform infrared (FTIR) spectroscopy to study the structural properties. Moreover, UV-Vis spectroscopy was performed to investigate the optical properties of un-doped and Fe-doped ZnS macro-spheres. Results: XRD confirms the polycrystalline nature of single-phase cubic structure of as-grown and Fe-doped ZnS macro-spheres. Moreover, the Fe substitute in ZnS inter-layer space thickness decreased and the crystallite size increased. FESEM shows the morphology of semi-spherical macro-spheres with wide micrometer-size distribution (~ 7–8 µm), agglomerated from several closely embedded primary nano-grains. FTIR spectra found that the specific functional groups associated with the vibrational modes of samples present in the range of 400–800 cm−1. UV-Visible spectroscopy shows that the absorption maximum is red-shifted in the case of Fe-doped ZnS. The band gap of as-grown ZnS macro-sphere was found to be 3.46 eV, which was significantly tuned to 3.22 eV by Fe dopant. Conclusions: The synthesized Fe-doped ZnS macro-spheres show improved structural and optical properties and potential optoelectronic device applications.
      原文链接:
    • NSTL

    Narrow-band optical band-pass filter using dual cascaded chirped FBGs

    Bhaskar C.V.N.Pal S.Pattnaik P.K.
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHIn this paper, cascaded chirped fiber Bragg grating or CFBG based narrow-band bandpass filter capable of operating in C-band is proposed and analyzed. Cascading one linearly increasing chirp (LIC) FBG with another linearly decreasing chirp (LDC) FBG reduces the FWHM almost by five folds with a change in the normalized reflectivity. Analytical formulation based on a piecewise uniform approach (PUA) for the proposed structure(s) is also discussed. Extension of PUA approach for tilted FBGs is also presented in the paper. For the proposed structures, we have considered each CFBGs may have equal or different chirp rates keeping all other design parameters same. As per the simulation results, the narrowest and widest FWHM achieved by the proposed structures are 1.56 nm and 1.77 nm, respectively. In such designs, the highest and lowest normalized reflectivity offered by the cascaded CFBG structures is approximately 0.81 and 0.39, respectively. The effect of temperature on the spectral characteristics for all the proposed structures is also studied. Simulation results reveal that the Bragg wavelength of the proposed cascaded structures will shift +1.701 nm for 100°C increment in operating temperature in the absence of strain. The thermal sensitivity of all the proposed structures is estimated to be 17.01 pm/∘C.
      原文链接:
    • NSTL

    Design and fabrication of self-compensating ZnSe beam splitter in LWIR region

    Mahendra R.Kumar D.SatyavirNautiyal B.B....
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHThe design and fabrication of a self-compensating beam splitter in the Long-wave infrared (LWIR) wavelength range is discussed in the article. The self-compensating plate beam splitter finds its application in a passive Fourier Transform Infrared (FTIR) system for the detection of chemical warfare clouds from a distance of up to a few kilometers. The beam splitter was designed for the LWIR wavelength band of 8.0–12.0 µm, with a beam splitting ratio of 50:50, i.e., for 50% transmission and 50% reflection @ 45° angle of incidence (AOI). The zinc selenide (ZnSe) based beam splitter was developed using an ion-assisted e-beam evaporation technique. A Perkin Elmer FTIR spectrometer was used to measure the average transmission/reflection of 50:50 in the 8.0–12.0 µm wavelength band. The fabricated beam splitter complied with MIL-F-48616 environmental tests with no visible damage to the coated optics. The fabricated ZnSe self-compensating beam splitter was integrated in the Michelson interferometer set-up and the interferogram is recorded.
      原文链接:
    • NSTL

    Highly sensitive bending sensor based on Mach-Zehnder interferometer built in Sagnac loop with specified offset

    Ruan J.Li H.Chen J.Yang W....
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHA high sensitivity bending sensor based on Mach-Zehnder interferometer (MZI) built in Sagnac loop is proposed and experimentally demonstrated. One stress zone in Panda type polarization maintaining fiber (PMF) was intentionally collimated to the core of single mode fiber (SMF) and then the discharge was performed by fusion splicer. A commercial fiber Bragg grating (FBG) acting as phase shift monitor was fusion spliced to the PMF. The prepared fiber optical configuration was connected to a 3 dB coupler to construct a Sagnac loop. The spectral characteristics of the proposed bending sensor as a function of curvature were investigated experimentally. The bending sensitivity of 12.5 nm/m−1 was obtained experimentally. Furthermore, the π phase shift was detected when the curvature was 0.587 m−1. Such bending sensor with simple fabrication and cost-efficient could be a good candidate in the field of curvature measurements.
      原文链接:
    • NSTL

    Quantitative analysis of trace elements in human hair based on LIPS

    Wang X.Guo Z.Xiang Y.Li C....
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHBased on Laser Induced Plasma Spectroscopy ( LIPS), combined with Calibration-Free Method ( CFM),the content of trace elements in human hair was quantitatively analyzed. a LIPS spectrum acquisition system was established, which was composed of 1064 nm ns pulsed laser, HR4000optical fiber spectrometer and supporting optical components, and the aluminum alloy standard sample was introduced to calibrate the content. The plasma spectrum of the hair samples induced by laser with 15 ns pulse width was detected, the corrected spectral information was extracted, the content of hair trace elements was calculated by the CFM. The result shows that the content of hair trace elements can be analyzed efficiently and quickly through the CF-LIPS.
      原文链接:
    • NSTL

    Highly-sensitive fiber Bragg grating temperature sensors with metallic coatings

    Wang X.Sun X.Hu Y.Zeng L....
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHTemperature monitoring is an important task in temperature engineering to ensure the safety of equipment, where high-sensitivity and high-reliability sensors are required to provide real-time and accurate temperature information. Direct-write FBG fiber optic sensors have good temperature sensitivity and good temperature resistance, but bare FBGs are fragile. Four kinds of metal coatings were prepared on the surface of the optical fiber by chemical deposition and electroplating, and the grating was directly written by femtosecond laser. The thermal characteristics of the sensors were investigated. The metal coating sensor has higher sensitivity than that of the bare FBG sensor, because it can improve the temperature sensitivity of FBG sensor is more than twice times. The reflectance spectrum of the sensor does not change significantly from room temperature to 800 °C. An analytical model of temperature sensitivity of metal coated optical fiber is proposed and four kinds of electroplated metal FBG sensors are tested respectively. The experimental results are in good agreement with the analytical model. The results show that metal coated FBG sensors have great potential for temperature measurement or temperature compensation in temperature engineering by rationally selecting metal coating with different material properties.
      原文链接:
    • NSTL

    On-demand measurement of higher topological charges using Hadamard-coded apertures with a DMD

    Banguilan D.G.C.Estrada V.G.Hermosa N.P.
    5页
    查看更多>>摘要：© 2022 Elsevier GmbHThe diffraction of an orbital angular momentum (OAM) beam behind slits and polygon apertures has enabled the measurement of light's topological charge (TC). In this work, we present a simple technique to measure higher TCs using Hadamard-coded apertures programmed in a digital micromirror device (DMD). Apart from pattern recognition, a common approach in relating the topological properties of the beam with its diffraction, we demonstrate that we can determine TCs from m=±1 to ±10 using the position of diffracted intensity centroid R. We show thru experiments and simulations that indeed the centroids of the diffracted beams move depending on the magnitude and the sign of the TC, and the order N of the Hadamard aperture. Based on our results, distinguishing the TC of a beam is easier when |m|>5. Lastly, we infer the source of the movement of the centroid using simple interference of three points derived from a Hadamard N = 2. By tracing the position of the zeroth-order maxima in the interference, we relate the maximum intensity position with the intensity centroid position in the diffraction. Our technique is crucial for determining higher-order modes whose TC are difficult to determine with the currently available methods.
      原文链接:
    • NSTL