利用VCM法(volume current method)分析了矩形芯倾斜光纤光栅的辐射场特性.数值仿真了辐射场的二维空间分布,分析了矩形芯倾斜光纤光栅对不同偏振输入光的偏振敏感性.仿真结果表明,矩形芯倾斜光纤光栅对y偏振光的辐射效率比x偏振光的高...利用VCM法(volume current method)分析了矩形芯倾斜光纤光栅的辐射场特性.数值仿真了辐射场的二维空间分布,分析了矩形芯倾斜光纤光栅对不同偏振输入光的偏振敏感性.仿真结果表明,矩形芯倾斜光纤光栅对y偏振光的辐射效率比x偏振光的高;光栅的倾斜角越小,对不同偏振输入光的偏振敏感性也越小.X偏振光和Y偏振光的峰值辐射功率差在光栅倾角为3°时为1.8%,当光栅倾角增大到15°时达到16%.而在倾斜角小于7°的情况下,X和Y偏振光的辐射功率峰值差小于5%.展开更多
High sensitivity biological sample measurement has been achieved by using a 10° tilted fiber Bragg grating sensing probe. Human acute leukemia cells with different intracellular densities were clearly discriminat...High sensitivity biological sample measurement has been achieved by using a 10° tilted fiber Bragg grating sensing probe. Human acute leukemia cells with different intracellular densities were clearly discriminated by identifying their slight refraction index (RI) perturbations in the range from 1.3342 to 1.3344, combining with a temperature self-calibration property. We studied the relationship between the intracellular density of cells (S50 and S60) and their RIs, the experimental results provide a potential way to verify the hypothesis for "density alteration in non-physiological cells (DANCE)".展开更多
Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,afte...Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,after the inscription,there are a large number of hydroxyl compounds and hydrogen molecules in CTFBGs that cause significant heating due to their strong infrared absorption.Secondly,CTFBGs can couple Stokes light from the core to the cladding and the coating,which causes serious heating in the coating of the CTFBG.Aimed at overcoming these bottlenecks,a process that combines constant-low-temperature and variable-high-temperature annealing is used to reduce the thermal slope of the CTFBG.Also,a segmented-corrosion cladding power stripping technology is used on the CTFBG to remove the Stokes light which is coupled to the cladding,which solves the problem of overheating in the coating of the CTFBG.Thereby,a CTFBG with both a kilowatt-level power-carrying load and the ability to suppress SRS in a fiber laser has been developed.Further,we establish a kW-level CW oscillator to test the CTFBG.Experimental results demonstrate that the power-carrying load of the CTFBG is close to 1 kW,the thermal slope is lower than 0.015 ℃/W,and the SRS suppression ratio is nearly 23 dB.展开更多
文摘利用VCM法(volume current method)分析了矩形芯倾斜光纤光栅的辐射场特性.数值仿真了辐射场的二维空间分布,分析了矩形芯倾斜光纤光栅对不同偏振输入光的偏振敏感性.仿真结果表明,矩形芯倾斜光纤光栅对y偏振光的辐射效率比x偏振光的高;光栅的倾斜角越小,对不同偏振输入光的偏振敏感性也越小.X偏振光和Y偏振光的峰值辐射功率差在光栅倾角为3°时为1.8%,当光栅倾角增大到15°时达到16%.而在倾斜角小于7°的情况下,X和Y偏振光的辐射功率峰值差小于5%.
基金supported by the National Natural Science Foundation of China (61205080, 61235005 and 61036012)the National Innovation Fund for Technology (2C26214405312)+2 种基金Guangdong Natural Science Foundation of China (S201101000163 and S2012010008385)the Specialized Research Fund for the Doctoral Program of Higher Education of China(20114401120006)the Pearl River Scholar for Distinguished Young Scientist (2011J2200014)
文摘High sensitivity biological sample measurement has been achieved by using a 10° tilted fiber Bragg grating sensing probe. Human acute leukemia cells with different intracellular densities were clearly discriminated by identifying their slight refraction index (RI) perturbations in the range from 1.3342 to 1.3344, combining with a temperature self-calibration property. We studied the relationship between the intracellular density of cells (S50 and S60) and their RIs, the experimental results provide a potential way to verify the hypothesis for "density alteration in non-physiological cells (DANCE)".
基金supported by the National Key Research and Development Program of China(No.2017YFB1104400)
文摘Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,after the inscription,there are a large number of hydroxyl compounds and hydrogen molecules in CTFBGs that cause significant heating due to their strong infrared absorption.Secondly,CTFBGs can couple Stokes light from the core to the cladding and the coating,which causes serious heating in the coating of the CTFBG.Aimed at overcoming these bottlenecks,a process that combines constant-low-temperature and variable-high-temperature annealing is used to reduce the thermal slope of the CTFBG.Also,a segmented-corrosion cladding power stripping technology is used on the CTFBG to remove the Stokes light which is coupled to the cladding,which solves the problem of overheating in the coating of the CTFBG.Thereby,a CTFBG with both a kilowatt-level power-carrying load and the ability to suppress SRS in a fiber laser has been developed.Further,we establish a kW-level CW oscillator to test the CTFBG.Experimental results demonstrate that the power-carrying load of the CTFBG is close to 1 kW,the thermal slope is lower than 0.015 ℃/W,and the SRS suppression ratio is nearly 23 dB.
