Author Affiliations
Abstract
1 Key Laboratory of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, Taiyuan 030024, China
2 College of Physics & Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
We propose and experimentally demonstrate a novel Raman-based distributed fiber-optics temperature sensor (RDTS) for improving the temperature measurement accuracy and engineering applicability. The proposed method is based on double-ended demodulation with a reference temperature and dynamic dispersion difference compensation method, which can suppress the effect of local external physics perturbation and intermodal dispersion on temperature demodulation results. Moreover, the system can omit the pre-calibration process by using the reference temperature before the temperature measurement. The experimental results of dispersion compensation indicate that the temperature accuracy optimizes from 5.6°C to 1.2°C, and the temperature uncertainty decreases from 16.8°C to 2.4°C. Moreover, the double-ended configuration can automatically compensate the local external physics perturbation of the sensing fiber, which exhibits a distinctive improvement.
060.2370 Fiber optics sensors 120.5820 Scattering measurements 280.4788 Optical sensing and sensors 290.5860 Scattering, Raman Chinese Optics Letters
2019, 17(7): 070602
Author Affiliations
Abstract
1 State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China
2 Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
The so-called “phase difference” is commonly introduced as a phenomenological parameter in Raman tensor theory, so as to fit the experimental data well. Although phase difference is widely recognized as an intrinsic property of crystals, its physics still remains ambiguous. Recently, Kranert et al. have presented a new formalism to explain the origin of phase difference theoretically. Here, we systematically conducted experimental research with polar phonons in wurtzite crystals, the results of which strongly suggest that the phase difference should be predetermined in a Raman tensor, rather than be treated as Raman tensor elements traditionally or as an intrinsic property. On the grounds of pinpointing existing logical flaws in Raman tensor study, we provide a logically clear paradigm.
Scattering, Raman Spectroscopy, Raman Photonics Research
2018, 6(7): 07000709
Author Affiliations
Abstract
1 Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai University, Shanghai 200072, China
2 Laboratory for Microstructures, Shanghai University, Shanghai 200444, China
Two kinds of Nb-doped silica fibers, an NbCl5-doped fiber and an Nb2O5-doped fiber, are fabricated and characterized in this Letter. First, the refractive index profiles of both fibers are obtained, and then their Raman spectra are measured with 785 nm exciting light. The Nb-doped fibers’ Raman spectra are compared with a conventional GeO2-doped single-mode silica fiber that is prepared with the same method and under the same conditions. As a result, the Raman gain coefficients of the Nb-doped silica fiber core are obtained. The experimental results show that Nb2O5 doping can enhance the Raman scattering intensity of the optical fibers.
060.2270 Fiber characterization 290.5860 Scattering, Raman 060.2400 Fiber properties 060.2290 Fiber materials Chinese Optics Letters
2016, 14(10): 100602
Author Affiliations
Abstract
Laboratory of Nanophotonic Functional Materials and Devices (SIPSE) and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
In the quantum key distribution system, quantum channel is always affected by spontaneous Raman scattering noise when it transmits with classical channels that act as synchronization and data channels on a shared fiber. To study the effect of the noise exactly, the temporal distribution characteristics of the Raman scattering noise are analyzed theoretically and measured by a single-photon detector. On the basis of this, a scheme to decrease the noise is proposed.
270.0270 Quantum optics 060.5565 Quantum communications 290.5860 Scattering, Raman Chinese Optics Letters
2014, 12(10): 102703
Author Affiliations
Abstract
1 School of Materials and Metallurgy, Northeastern University, Shenyang 110819, China
2 Engineering Research Center for Process Technology of Nonferrous Metallurgy, Ministry of Education, Shenyang 110819, China
We study ionic structure of KNO3–NaNO2 melts under air atmosphere by using Raman spectroscopy. Molar fraction of NO3- and NO2- is obtained and thermal stability of this kind of melts system is then analyzed. The results show that when the temperature is increased to a certain value, equilibrium between the decom-position of NO3- and the oxidation of NO2- exists in KNO3–NaNO2 melts. When temperature is higher than 644 K, the molar fraction of NO3- decreases a little with temperature increasing for the melts in which the initial fraction of KNO3 is 90 wt%, but for the melts in which the initial fraction of KNO3 is 10–80 wt%, the molar fraction of NO3- increases with temperature, and the increasing rate is slower for a higher initial frac-tion of KNO3. Molar fraction of NO3- increment increases linearly with initial fraction of NaNO2. The sample in which the initial fractions of NaNO2 are 11.3 and 14.5 wt% under air atmosphere shows the best thermal stability at 762 and 880 K, respectively.
300.6450 Spectroscopy, Raman 290.5860 Scattering, Raman Chinese Optics Letters
2014, 12(9): 093001
Author Affiliations
Abstract
National Laboratory of High Power Laser Physics, Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences, Shanghai 201800, China
A dual-source distributed optical fiber sensor system with combined Raman and Brillouin scatterings is designed for simultaneous temperature and strain measurements. The optimal Raman and Brillouin signals can be separately obtained by adjusting the powers of the two sources using an optical switch. The temperature and strain can be determined by processing the optimal Raman and Brillouin signals. The experimental result shows that 1.7 ℃ temperature resolution and 60-με" strain resolution can be achieved at a 24.7-km distance.
060.2370 Fiber optics sensors 290.5860 Scattering, Raman 290.5830 Scattering, Brillouin Collection Of theses on high power laser and plasma physics
2012, 10(1): 060601
Author Affiliations
Abstract
A spinel LiMn2O4 is investigated via Raman spectroscopy at 514.5-nm excitation and X-ray diffraction. The dependence of Raman spectra on the different irradiated laser powers is determined and found to be different from that at 632.8-nm excitation. Based on our extensive analysis, our experimental results can be attributed to the laser heating effect, which reduces the Mn4+ cation concentration in the local area. Consequently, the decrease in average Mn valence in the local area unavoidably induces the Jahn-Teller effect and local lattice distortion, which accounts for the evolution of the measured Raman spectra of spinel LiMn2O4.
300.6450 Spectroscopy, Raman 290.5860 Scattering, Raman Chinese Optics Letters
2012, 10(8): 083001
Author Affiliations
Abstract
National Laboratory of High Power Laser Physics, Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences, Shanghai 201800, China
A dual-source distributed optical fiber sensor system with combined Raman and Brillouin scatterings is designed for simultaneous temperature and strain measurements. The optimal Raman and Brillouin signals can be separately obtained by adjusting the powers of the two sources using an optical switch. The temperature and strain can be determined by processing the optimal Raman and Brillouin signals. The experimental result shows that 1.7 ℃ temperature resolution and 60-με" strain resolution can be achieved at a 24.7-km distance.
060.2370 Fiber optics sensors 290.5860 Scattering, Raman 290.5830 Scattering, Brillouin Chinese Optics Letters
2012, 10(6): 060601
Author Affiliations
Abstract
1 Advanced Photonics Center, Southeast University, Nanjing 210096, China
2 Clinical Laboratory Center of the First Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China
A novel drug carrier based on SiO2-coated silver nanoparticle aggregates and antitumor drug is successfully synthesized. The surface-enhanced Raman scattering (SERS) spectra of the antitumor drug in living cells are obtained. By using silver nano-aggregates as SERS substrates instead of dispersed silver particles, a great improvement of SERS signal intensity is achieved. It is found that the chemical stability of the drug carrier can also be increased with the existence of SiO2 shell. The adsorbing effect between antitumor drug 9-aminoacridine (9AA) and silver particles is investigated to optimize the SERS signal. The core/shell structure of the drug carrier is characterized by ultraviolet-visible (UV-Vis) spectroscopy and transmission electron microscopy (TEM) pictures. The experimental results show that the drug carrier offers biocompatibility, stability, and high SERS activity, holding the potential for realizing the intracellular drug tracing.
银纳米聚集体 表面增强拉曼散射 药物载体 160.4236 Nanomaterials 290.5860 Scattering, Raman 170.5660 Raman spectroscopy Chinese Optics Letters
2010, 8(4): 357
Author Affiliations
Abstract
Advanced Photonics Center, Southeast University, Nanjing 210096, China
A novel structure with high surface enhanced Raman scattering (SERS) activity and bio-specificity as a SERS-based immuno-sensor (named as Raman reporter-labeled immuno-Au aggregate) is demonstrated and employed for protein detection. In each fabrication process, the features of those aggregates are obtained and characterized by ultraviolet-visible (UV-Vis) extinction spectra, transmission electron microscopy (TEM) images, scanning electron microscopy (SEM) pictures, and SERS spectra. Experimental results indicate that proper amounts of the reporter molecules can result in the moderate aggregation morphologies of gold nanoparticles. Compared with the previously reported method using Raman reporterlabeled immuno-Au nanoparticles, more sensitive SERS-based protein detection is realized with this novel immuno-sensor.
表面增强拉曼散射 免疫传感器 聚集体 拉曼探针 160.4236 Nanomaterials 290.5860 Scattering, Raman 300.6450 Spectroscopy, Raman Chinese Optics Letters
2010, 8(3): 309
