A catheter includes proximal and distal sections, a shaft coupled between the proximal and distal sections, and optical fibers extending through the shaft and to the distal section of the catheter. The distal section includes a support structure that includes a proximal end, a distal end, reflective elements, and a cap disposed over a portion of the distal end of the support structure. The proximal end includes alignment receptacles. Each of the optical fibers is inserted into corresponding ones of the alignment receptacles and the alignment receptacles are shaped to maintain the optical fibers straight in the support structure. The distal end includes orifices facing different directions. Each of the optical fibers is optically aligned with corresponding ones of the lenses, reflective elements, and orifices such that the optical fibers in the support structure are straight. The cap includes optical ports aligned with the orifices.