Analysis of transmission characteristics of image fiber‐dependence on higher modes and wavelength
Shoji Yamaguchi, Akira Shimojima, Toshio Hosono · Electronics and Communications in Japan (Part II Electronics) · 1989
Abstract In transmission by image fiber, the image is blurred by mode coupling due to the crosstalk cores, which impairs the resolution. The analysis of such crosstalk phenomena by geometrical optics is very difficult, and wave theory must be employed. There are infinite modes excited in each element fiber of the image fiber. In case of low resolution, that is, when the period of spatial harmonics of the image is small compared with the size of element fiber, higher modes are excited in the fiber. In this paper, the effects of higher modes upon image transmission characteristics of one‐dimensional image fiber are analyzed using vector wave theory. Since the crosstalk characteristics vary widely with wavelength, and various wavelength components are involved in the input image, the analysis of wavelength dependency of the crosstalk is important. By the numerical method, various characteristics are analyzed, and improvement methods are also discussed.