Diode Lasers
Diode lasers, also referred to as "semiconductor lasers," utilize microscopic chips made of gallium-arsenide or another semiconductor to generate their source of coherent light. Diode lasers are usually smaller and less powerful than other lasers and can be found in CD-ROM drives, CD players, barcode scanners, and laser printers.
Important factors to consider when selecting diode lasers are its beam divergence, wavelength, beam size, operating current range, operating temperature range, and pulse energy. Beam divergence represents the change in beam diameter. The output wavelength of the laser diode is identified by wavelength. As the beam leaves the laser, the largest measurement recorded is the beam size. Operating current range is the geographical range that the lasers diode can cover. Operating temperature range is the range of temperatures at which the
diode lasers were made to use. The diode lasers pulse energy is measured by its energy per pulse.
Exposure to diode lasers can cause severe damage, so built-in engineering controls in diode lasers are required to provide safety.
Diode lasers are divided into six classes, according to their power output: Class I, Class I.A, Class II, Class IIIA, Class IIIB, and Class IV. Class IV systems contain the most dangerous
diode lasers and require a master switch that, when disabled, prohibits all but authorized personnel from operating the
diode laser. A beam stop or attenuator, which significantly reduces beam emission when the
diode laser is on standby, is permanently attached to all Class IV diode lasers and is recommended for Classes IIIA and IIIB
diode lasers as well. Other safety controls that may be instituted include access restriction to the lasing area, eye protection, area controls, barriers, shrouds, and education and training.