Various implementations of illumination systems are described herein. For example, the illumination system includes a light guide having an outer surface and an inner surface that extend between a first end and a second end of the light guide, and at least one light source disposed adjacent the first end of the light guide. The light source emits infrared or visible light into the first end of the light guide. The light guide transmits the light from the light source through at least a portion of the outer surface of the light guide. In addition, the system may include a second light source disposed adjacent the second end of the light guide. The second light source emits infrared or visible light into the second end of the light guide.