A simple plasma globe would amaze you enough. All you have to do is to find an ordinary electric bulb. Since these bulbs are filled with gases to prevent the filament from corrosion and make it much brighter, you can ionize the gas in the bulb and turn it to a plasma globe.
What is so special about this circuit? Well, the first third-brake light I installed I had to pull a wire from the Third Brake Light all the way underneath the carpet to the brake-pedal-switch and I thought it would be easier to pluck the signal of both brakelights via the trunk.
You could probably do this with the 500W floodlights but you'd have to watch the temperature as the glass on them gets to over 200 degrees C! There is a small amount of light reflecting off the rear of the gel frame but painting it matt black (high temp exhaust paint) should reduce it a lot.
Designed to detect very weak light pulses lasting 1uS.
Using a 4511, a specialized decoder IC, learn how to drive a 7-segment display. The article explains the technique for counting from zero to nine.
uses one tiny C-MOS inverter IC and PIN diode to form a modulated light receiver with a very fast response, can be used ad optical fiber receiver