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• $1,500 for a 30-watt laser-light show ($4,500 value)
• $1,800 for a 40-watt laser-light show ($5,500 value)

Lasers: A Solution Looking for a Problem

Nowadays laser light is the answer for everything from hair-removal to eye surgery. Check out Groupon’s guide to lasers to learn more.

The laser has gone a bit soft in its middle age. Since its invention, it’s gone from inspiring sci-fi epics full of death-rays to scanning gallons of milk at supermarkets. If it’s lost a little of its coolness, its ubiquity surely offers some consolation. Originally an acronym for “light amplification by stimulated emission of radiation,” the laser is a source of high-energy light of a single wavelength. The fact that laser beams consist of a single wavelength of light means that they are monochromatic, with colors that range from infrared through the visible spectrum’s rainbow. 

Theodore Maiman debuted the first laser in 1960. He wrapped a cylindrical crystal of ruby in a spiral-bulbed, high-intensity lamp, with a solid mirror on one end and a partially reflecting mirror on the other end. When the lamp flashed, it began a chain reaction in the atoms of the ruby. They absorbed the blue and green energy of the light and released photons of red light. Those photons bounced back and forth between the mirrors and through the crystal’s atoms, the light becoming amplified with every reflection. Some of that red light escaped through the partially reflecting mirror, creating a beam that could produce 10,000 watts at its peak. (A lighthouse’s 1,000-watt bulb can be seen from 20 miles away on the other side of the ocean.) 

Today, lasers can produce light that is billions of times more powerful. Scientists in 1969 bounced a laser off a reflector on the moon, measuring its distance of more than 250,000 miles. Even at such lengths, the laser beam stays roughly the same size thanks to the orderliness of its light waves.

The first laser was invented in the spirit of pure scientific discovery, and some scientists teased that it was “a solution looking for a problem.” It’s found hundreds of problems to solve in the decades since then—many in the realm of cosmetic medicine. The cosmetic potential of laser light lies in its color. Wavelengths and frequencies can be set in sync with the color of their target, producing heat that destroys only one specific type of tissue. During hair-removal treatments, for example, lasers that penetrate into the upper tissue without damaging it seek out the dark brown of the melanin in the hair root, creating heat that damages its ability to grow. Likewise, during laser tattoo removal, lasers target the pigment in the ink, breaking up the colors until the tattoo fades.