We have investigated the use of multimode fiber in optical coherence tomography (OCT) with a mode filter that selectively suppresses the power of the high-order modes (HOMs). A large-core fiber (LCF) that has a moderate number of guiding modes was found to be an attractive alternative to the conventional single-mode fiber for its large mode area and the consequentially wide Rayleigh range of the output beam if the HOMs of the LCF were efficiently filtered out by a mode filter installed in the middle. For this, a simple mode filtering scheme of a fiber-coil mode filter was developed in this study. The LCF was uniformly coiled by an optimal bend radius with a fiber winder, specially devised for making a low-loss mode filter. The feasibility of the mode-filtered LCF in OCT imaging was tested with a common-path OCT system. It has been successfully demonstrated that our mode-filtered LCF can provide a useful imaging or sensing probe without an objective lens that greatly simplifies the structure of the probing optics.
© 2012 Optical Society of AmericaFull Article | PDF Article
John M. Fini
J. Opt. Soc. Am. B 24(8) 1669-1676 (2007)
Liang Dong, Xiang Peng, and Jun Li
J. Opt. Soc. Am. B 24(8) 1689-1697 (2007)
Tsai-wei Wu, Liang Dong, and Herbert Winful
Opt. Express 16(6) 4278-4285 (2008)