Earlier this year, Strike Industries emailed me the above photo and asked if I could guess what they had done to make the fiber optic sights on the right brighter than the standard factory fiber optic sight on the far left (with the black mark underneath it). I had a few courageous guesses, but I was wrong, and the answer is far simpler than any of my guesses.
Think back to high school science when they taught you about angle of reflection and Total Internal Reflection. As you increase the angle of light hitting a transparent boundary (like glass) less light travels through the boundary and more light is reflected (up until the Critical Angle is reached where Total Internal Reflection occurs and all the light is reflected back).
Strike Industries experimented with fiber optic sights (light pipes) with angles cut into the end of the pipe which increased the angle of light as it bounced through the pipe. As you can see above, it works!
Light loss is reduced even further because an increased angle of internal reflection decreases the frequency that the light hits the light pipe, so even less light is lost.
They also experimented with different cross sections, and adding foil or reflective paint to the underside of the light pipe.
Strike Industries shared their research with us because they want to encourage folks to experiment with these techniques. Their experiments concluded that this concept does not help much indoors, possibly because artificial light is a lot less diffused, but outdoors it is very effective.
Light pipes can be purchased cheaply online. I have seen them selling for $2.60/meter (3.2 ft), which is enough pipe for about 40 front sights. Good luck experimenting!