A blue laser diode is a semiconductor laser that produces a concentrated photon beam with a wavelength of about 400 to 500 nanometers-the visible electromagnetic spectrum that the human eye perceives is blue or violet.

Laser is especially suitable for material processing because of its characteristics of monochromatic, coherence and parallelism. In addition, its good space control and time control, processing object material, shape, size and environment of freedom are very large, especially suitable for automatic processing.

The technology of semiconductor laser develops comprehensively, and it is more competitive as the light source of laser display. Semiconductor lasers can be directly excited by current, which is more efficient than solid-state lasers. The working material attenuates slowly and has a longer service life; The light source system is smaller and suitable for high integration; Mass production with a semiconductor process can make the device cost lower.

A laser generally consists of three parts.laser working medium, Incentive source, resonant cavity. Lasers are classified according to power into Class I, Class II, Class IIIA, Class IIIB, and Class IV.

For the laser with a wavelength in visible and near-infrared light​, the absorption rate of refractive media is low, the transmission rate is high, and the refractive media has a strong focusing ability.

When certain electrons are stimulated, they emit a beam of light. A laser beam is created when a mirror or prism collects this light and points it in one direction. The laser level casts a beam of light, which can be used as a visual chalk line when a straight line and level reference point are needed. The size of the beam depends on the size of the diode.

The dry fire training laser bullet is designed for home shooting practice to response the Laser Trainer Target System. Built to fit inside chamber of pistols, rifles and shotguns, the Dry Fire Laser Bullet simulates the bullet impact with a red laser dot on paper target or laser target. Each time the firing pin strikes the hardened rubber switch; the Laser Trainer Cartridge is activated and light on for 50 milliseconds then off.

Laser at 1064nm is the best wavelength for removing blue and black lip lines because of its strong penetration of skin tissue. The 532nm laser has a shallower penetration depth, which is the strongest absorption of red pigment, so the removal of the red lip liner is the best. However, 532nm wavelength of light will damage normal skin, and lip tissue is thin skin, rich blood vessels,

Laser welding has unique advantages, including low heat input, narrow fusion zone, and heat-affected zone performance so that the weld formed by laser welding is stronger and more attractive, laser welding time is greatly shortened; Laser tracking sensor, can realize automation, reduce product cost. These new technologies have further expanded the application range of laser welding.

The laser linewidth is determined by the quality factor of the resonator, the higher the quality factor of the cavity, the narrower the laser linewidth. After considering the gain of the laser medium, the theoretical limit of the linewidth of the laser is determined by the spontaneous radiation of the gain medium.