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
Laser Doppler vibrometer accelerometer are that the LDV can be directed at targets that are difficult to access, or that may be too small or too hot to attach a physical transducer. Also, the LDV makes the vibration measurement without mass-loading the target, which is especially important for MEMS devices. A vibrometer is generally a two beam laser interferometer that measures the frequency (or phase) difference between an internal reference beam and a test beam. The most common type of laser in an LDV is the helium–neon laser, although laser diodes, fiber lasers, and s are also used. The test beam is directed