Krypton, like the other noble gases, is used in lighting and photography. Krypton light has many spectral lines, and krypton plasma is useful in bright, high-powered gas lasers (krypton ion and excimer lasers), each of which resonates and amplifies a single spectral line. Krypton fluoride also makes a useful laser medium. From 1960 to 1983, the official length of a meter was defined by the 606-nanometer wavelength of the orange spectral line of krypton-86, because of the high power and relative ease of operation of krypton discharge tubes.