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.

A laser pointer, also known as a laser pointer, is a portable device that uses a battery and a laser module (light-emitting diode) to emit a visible light beam.The range distance is relatively long, as an indication, but also can control PPT or Word and other documents page turning and black screen, quick play function.