A method of manufacturing a light guide assembly includes the steps of providing a light guide array made of a light-transmissive material and having a top portion and an integral bottom portion supporting the top portion, wherein grooves are formed on a top surface of the top, providing an optical isolation frame of interconnected slats made of an opaque material wherein the slats are arranged and profiled to correspondingly match the grooves in the light guide array, bonding the light guide array and the optical isolation frame to each other, and removing the bottom portion of the light guide array.