A refractive index in bent fibre optics and curved space

The refractive index in the bent fibre optics and in curved space of the gravitational field are studied. We obtain the results that refractive index in the bent fibre optics is similar with refractive index in curved space of the gravitational field. Both results show that refractive index increases when light traverses through the bent fibre optics and curved space of the gravitational field. Based on analogy reasoning taken from fibre optics bending loss phenomena, we propose that if light traverses through curved space of the gravitational field, light will loss its energy. We calculate this energy loss numerically using bending loss model of Faustini-Martini. We find that light losses its energy around 467.7073 dB/m, when it traverses through curved space with radius of curvature R = 0:01 m due to massive object around 8.7 x 10(20) kg.