In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light...In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light deflection angle and compare it with previous works. These results are useful for precision astrometry missions like ASTROD, GALA, Darwin and SIM which aim at astrometry with micro-arcsecond and nano-aresecond accuracies, and need for the second post-Newtonian framework and ephemeris for observations to determine the stellar and spacecraft positions.展开更多
The mode theory is the main way to study the propagation characteristics of light in fiber so far,but it is not suitable for analysis of light in duct.By using ray-tracing method,the rotary propagation characteristics...The mode theory is the main way to study the propagation characteristics of light in fiber so far,but it is not suitable for analysis of light in duct.By using ray-tracing method,the rotary propagation characteristics of light in multimode-single mode-multimode(MSM) fiber structures are analyzed in this paper.Firstly,the light ray in fiber can propagate around an inscribed circle,and the central axis of this fiber is the propagation axis.Secondly,the radius of the inscribed circle is decided by both incident angle and incident position,and its variation is between 0 and RM,where RM is the radius of the multimode fiber.Lastly,the bigger the ratio of core and cladding diameter is,the higher the propagation efficiency is.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 10875171
文摘In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light deflection angle and compare it with previous works. These results are useful for precision astrometry missions like ASTROD, GALA, Darwin and SIM which aim at astrometry with micro-arcsecond and nano-aresecond accuracies, and need for the second post-Newtonian framework and ephemeris for observations to determine the stellar and spacecraft positions.
基金supported by the National Natural Science Foundation of China(No.61177076)the Fundamental Research Funds for the Central Universities(Nos.2013-Ia-038 and 2013-Ia-006)
文摘The mode theory is the main way to study the propagation characteristics of light in fiber so far,but it is not suitable for analysis of light in duct.By using ray-tracing method,the rotary propagation characteristics of light in multimode-single mode-multimode(MSM) fiber structures are analyzed in this paper.Firstly,the light ray in fiber can propagate around an inscribed circle,and the central axis of this fiber is the propagation axis.Secondly,the radius of the inscribed circle is decided by both incident angle and incident position,and its variation is between 0 and RM,where RM is the radius of the multimode fiber.Lastly,the bigger the ratio of core and cladding diameter is,the higher the propagation efficiency is.
