Watch Nova season 5 episode 15 online for free. When first invented 18 years ago, lasers were called “a solution looking for a problem;” nobody could think what to do with them. But in fact research scientists immediately began to exploit their pure colors and near-perfect focusing ability. Today lasers have grown into a billion-dollar business. They are used in construction, manufacturing, clothing, dentistry and medicine. And the future uses of lasers are likely to be of major significance as the means of achieving nuclear fusion and as a very high efficiency communications medium.