Supermodes coupling characterizaion of optical fiber brush

A special kind of fiber device which we called it as optical fiber brush which would like to be used in astronomy is introduced in our paper. In this paper, we investigate its fabricating technique and the supermodes coupling characterization. In order to investigate and compare the divergence angle of different supermodes, near-field and far-field distributions of them are also calculated. Comparing with the far-field mode radius, we find the in-phase supermode has the least divergence angle and the best beam quality. The research could be helpful to improve the beam quality and to transmit stars´ images in astronomy.