Wen-Yueh SuGia-Wei ChernLON A. WANG2018-09-102018-09-102002-111559128Xhttp://scholars.lib.ntu.edu.tw/handle/123456789/299271https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036848657&doi=10.1364%2fAO.41.006576&partnerID=40&md5=fa40c779d836912340cee4601cc66030The beam-propagation method (BPM) is employed to analyze the coupling behavior of our scheme proposed previously, which combines a lensed fiber and a long-period fiber grating (LPFG) [Chen and Wang, Appl. Opt. 39, 4490-4500 (2000)]. The influences of a core within the fiber lens are investigated. As for the fiber dependence of our coupling scheme, two typical fibers are studied: dispersion-shifted and single-mode, step-index fibers. With the BPM, the optimal coupling efficiencies for various source waists with corresponding lens radii and working distances are determined. We also compare the results with those obtained by use of the ABCD method and found that the BPM gives better agreement with experimental results. © 2002 Optical Society of America.application/pdfapplication/pdfCladding (coating); Fiber Bragg gratings; Interfaces (materials); Light propagation; Light reflection; Optical communication; Oscillations; Cladding-mode couplings; Single mode fibersjournal article10.1364/AO.41.0065762-s2.0-0036848657WOS:000178847600006