Mode exciters which consist of alternate concatenation of step‐index (S) and graded‐index (G) fibers are used widely for the measurement of transmission characteristics (optical loss and baseband frequency response) of multimode fibers. This paper presents a theoretical analysis for the mode exciters based on geometrical ray optics approximation. The mode power distribution controlling effect of the exciters, excited mode power distribution in the test fiber, and accuracy and reproducibility of optical loss measurements are clarified theoretically. It is shown that optical loss measurements under steady‐state distribution can be done by using either SGS or GSG mode exciters which consist of either small core or low NA fibers.
|ジャーナル||Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)|
|出版物ステータス||Published - 1985|
ASJC Scopus subject areas
- Computer Networks and Communications
- Electrical and Electronic Engineering