Red_light_through_lens_on_fiber_Roberts_clipped.jpgRed laser light, invisibly guided by the fiber, expands in a cone and is collimated by a slide-on lens. The entire construction has a length of 1 mm.https://www.physik-astro.uni-bonn.de/fiberlab/en/media/red_light_through_lens_on_fiber_roberts_clipped.jpg/viewhttps://www.physik-astro.uni-bonn.de/fiberlab/en/media/red_light_through_lens_on_fiber_roberts_clipped.jpg/@@images/image-1200-11d5b1c0061ead6580a76f6ebe4fc01f.jpeg