The triangular differential quadrature method based on a non-uniform grid is proposed in the paper. Explicit expressions of the non-uniform grid point coordinates are given and the weighting coefficients of the triang...The triangular differential quadrature method based on a non-uniform grid is proposed in the paper. Explicit expressions of the non-uniform grid point coordinates are given and the weighting coefficients of the triangular differential quadrature method are determined with the aid of area coordinates. Two typical examples are presented to testify the effectiveness of the non-uniform grid. It is shown that rapid convergence is achieved under the non-uniform grid in comparison with those from the uniform grid with the same order of approximation.展开更多
A new method is presented to fabricate the triangular fiber Bragg grating(TFBG).The fabrication device is simple,only requires a single exposure and does not need to write complicated program.The transfer matrix metho...A new method is presented to fabricate the triangular fiber Bragg grating(TFBG).The fabrication device is simple,only requires a single exposure and does not need to write complicated program.The transfer matrix method is used to design the fiber Bragg grating,and the grating resonant wavelength and the grating reflectivity can be controlled in order to achieve the triangular spectrum.With different fiber tilt angles,the available bandwidth of TFBG,the linearity and the oblique gradient are also different.In the experiment,the angles 1°,1.5° and 2° are chosen.The results show that the best angle value is 1.5°,and the TFBG has a good linearity,greater gradient and wider available bandwidth.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 51178247 and 51378294)
文摘The triangular differential quadrature method based on a non-uniform grid is proposed in the paper. Explicit expressions of the non-uniform grid point coordinates are given and the weighting coefficients of the triangular differential quadrature method are determined with the aid of area coordinates. Two typical examples are presented to testify the effectiveness of the non-uniform grid. It is shown that rapid convergence is achieved under the non-uniform grid in comparison with those from the uniform grid with the same order of approximation.
基金supported by the National Natural Science Foundation of China (Nos.60771008 and 60837002)the Natural Science Foundation of Beijing (No.4082024)+1 种基金the Ph.D. Programs Foundation of Ministry of Education of China (No.20090009110003)the Foundation for the Returning Scholars (No.2008890)
文摘A new method is presented to fabricate the triangular fiber Bragg grating(TFBG).The fabrication device is simple,only requires a single exposure and does not need to write complicated program.The transfer matrix method is used to design the fiber Bragg grating,and the grating resonant wavelength and the grating reflectivity can be controlled in order to achieve the triangular spectrum.With different fiber tilt angles,the available bandwidth of TFBG,the linearity and the oblique gradient are also different.In the experiment,the angles 1°,1.5° and 2° are chosen.The results show that the best angle value is 1.5°,and the TFBG has a good linearity,greater gradient and wider available bandwidth.
