Lazer Pen -

: The most common and least expensive. They use simple diodes and are widely used in low-power pointers and barcode scanners.

: When electricity hits the diode, it excites electrons, which release photons (light particles). lazer pen

: Typically AAA or lithium-ion batteries that provide the electrical energy. : The most common and least expensive

Laser pens come in various colors, each with different properties: it excites electrons