Light pollution is one of the biggest sources of pollution worldwide. Because some chemical processes that cleanse the atmosphere only occur in the dark, light pollution prevents these chemical reactions to happen, thus contributing to the chemical pollution throughout the next day and so on.
New streetlights designed by scientists in Mexico and Taiwan are now trying to solve this issue by eliminating the chance that light gets emitted upwards or beyond the intended area. They reported their findings in today’s Optics Express journal.
The newly-designed LED streetlight is based on an innovative three-part lighting fixture. The first part contains an array of LEDs which have a special lens each (a Total Internal Reflection lens) that focuses the light rays so that they’re parallel to one another (the process is called collimation).
The second part consists of a reflecting cavity that the LEDs are mounted in, which focus the light onto the desired area. The third part is made of a filter that cuts unwanted glare. The combination of collimation and glare reduction has allowed the scientists to give light a rectangular pattern, that they discovered is ideal for street lighting.
In addition to cutting down light pollution, the new LED fixture also cuts down electricity use, by being LED-based. “A general LED street light could reduce power consumption by 40 to 60 percent,” says co-author Ching-Cherng Sun of National Central University in Taiwan. Their own technology applied to the already-amazing LED savings could yield another 10 to 50 percent savings.
A prototype is expected to be ready in the next three to six months and a marketable product as soon as next year.