Design of fused optical fiber bundle for ground based lidar receiver to profile the lower atmosphere

Abstract In this paper, we propose an optical fiber design for a wide field of view (WFOV) lidar receiver. The proposed system intends to collect aerosol backscatter and aims to profile the lower atmosphere from 8 m onwards. We determined overlap function of lidar for various aperture stop diameters. As per our analysis, a fiber diameter of 21 mm is required at the focus point of telescope to obtain the full overlap at 8 m altitude. Since, it is impractical to realize such a large core diameter fiber of 21 mm, we propose a field lens to converge the blur disk to 3 mm spot size. To collect the focused beam, we propose to use a fused fiber bundle of 3.5 mm diameter. The fused fiber offers extraordinary capturing efficiency and projects an effective mode capturing area of 5 × 10 −8  mm 2 . We present the fused fiber design details and compare its performance with hexagonal array fiber bundle.