: When electricity hits the diode, it excites electrons, which release photons (light particles).
: Mirrors at either end of a small chamber bounce these photons back and forth, creating a chain reaction that intensifies the light. 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
: A lens at the tip focuses the scattered light into a tight, parallel beam that stays concentrated over long distances. A Spectrum of Colors : When electricity hits the diode