TY - JOUR AU - Fu, L. AU - Gan, X. AU - Gu, M. TI - Characterization of gradient-index lens-fiber spacing toward applications in two-photon fluorescence endoscopy JF - Applied Optics VL - 44 IS - 34 SP - 7270-7274 PY - 2005 UR - http://dx.doi.org/10.1364/AO.44.007270 ID - 111 ER -