Lasers are categorized based on their active medium and application:

  • Solid-State Lasers:

    • Use crystals or glass as the gain medium (e.g., Nd:YAG, Ruby).
    • Commonly used in surgical procedures and industrial cutting.
  • Gas Lasers:

    • Utilize gases such as helium, neon, carbon dioxide, or argon (e.g., CO₂ lasers).
    • Employed in cutting, engraving, and welding applications.
  • Semiconductor Lasers:

    • Also known as diode lasers, these are used in data storage devices, laser printers, and fiber optics.
  • Dye Lasers:

    • Liquid dye solutions are used to generate tunable laser light for scientific research.