In part, the invention relates to optical caps having at least one lensed surface configured to redirect and focus light outside of the cap. The cap is placed over an optical fiber. Optical radiation travels through the fiber and interacts with the optical surface or optical surfaces of the cap, resulting in a beam that is either focused at a distance outside of the cap or substantially collimated. The optical elements such as the elongate caps described herein can be used with various data collection modalities such optical coherence tomography. In part, the invention relates to a lens assembly that includes a micro-lens； a beam director in optical communication with the micro-lens； and a substantially transparent film or cover. The substantially transparent film is capable of bi-directionally transmitting light, and generating a controlled amount of backscatter. The film can surround a portion of the beam director.
