Ruby laser weaknesses in the lining. Ruby lasers were used extensively in tattoo and hair removal, but are being replaced by alexandrite and s in this application. The ruby laser was the first laser to be made functional. Built by Theodore Maiman in 1960, the device was created out of the concept of an "optical maser," a maser that could operate in the visual or infrared regions of the spectrum. In 1958, after the inventor of the maser, Charles Townes, and his colleague, Arthur Schawlow, published an article in the "Physical Review" regarding the idea of optical masers, the race to build
Blue laser laser diodes are currently available on the open market. The devices are significantly brighter than 405 nm laser diodes, since the longer wavelength is closer to the peak sensitivity of the human eye. Commercial devices like laser projectors have driven down the prices on these diodes. Violet lasers may be constructed directly with GaN (gallium nitride) semiconductors, as noted. However, a few higher-powered (120 mW) 404–405 nm "violet" laser pointers have become available which are not based on GaN, but also use DPSS frequency-doubler technology starting from 1 watt 808 nm gallium arsenide infrared diode lasers being directly doubled, without