A typical red laser would contain a long crystal made of ruby (the medium, shown in the artwork below as a red bar) with a flash tube (yellow zig-zag lines) wrapped around it. read more
In 1962, Robert N. Hall demonstrated the first laser diode device, made of gallium arsenide and emitting at 850 nm in the near-infrared band of the spectrum. read more
Laser goggles are in the complementary color of the beam: green for a red 650 nm laser, orange-red for a blue 405 nm laser. Do not substitute a welding mask, smoked glass, or sunglasses for laser goggles. read more
Most LASERs in CD drives, pointers are diode LASERs. Like the name suggests, they have a diode that, unlike normal LEDs, emits light at a very specific frequency. The light is passed through a lens called a collimating lens to make it coherent and viola, you have a simple, cheap and efficient LASER. read more