Types of laser

A laser is a coherent and highly directional radiation source. LASER stands for Light Amplification by Stimulated Emission of Radiation. A laser consists of at least three components:

• A gain medium, the light that passes through it may increase
  
• Pump source is a population inversion in the gain medium build
  
• Two mirrors that form H? ¶ hle resonator

The gain medium may be solid, liquid or gas and the pump source can be an electric discharge, a flash lamp or another laser, the specific components of a laser vary depending on the gain medium and whether the laser is operated continuously (cw) or pulsed. The following Headings describe specific laser designs.

Gas lasers and solid-state laser

Gas lasers are begeistert.Das usually by an electric discharge Gain medium of a solid-state lasers is an impurity in a crystal or Glass. Semiconductors made from solid-state lasers are described below. The first laser was a ruby ​​crystal (Cr3 + in Al2O3), the Lased nm at 694, when pumped by a flash lamp. The most common Solid-state laser is one with Nd3 + in a crystal Y3Al5O8 (YAG) or YLiF4 (YLF) or in a glass. These lasers operate either pulsed Nd3 + or cw and about 1064 nm lase. The high energies of pulsed Nd3 +: YAG Lasers allow efficient frequency doubling (532 nm), tripled (355 nm) or quadrupled (266 nm), and are 532 nm and 355 nm beams tunable dye laser pump frequently.

Dye Laser

The gain medium in a dye laser is an organic dye molecule dissolved in a solvent. The dye and solvent are by a cell or a jet spread, and the dye molecules are excited by flash lamps or other laser pulsed dye laser with a Cell and cw dye lasers typically use a jet. The organic Dye molecules have broad fluorescence bands and dye laser are Usually 30 to 80 nm tunable dye to cover the near-uv, almost infrared spectral range available: 330-1020 nm

Semiconductor laser

Semiconductor laser diodes are within H? ¶ hle resonator on either the surfaces of the diode, or made external. An electric current Distribution generated by the light-emitting diode, when the pn-junction Electrons and holes recombine. Due to the small size of the active Medium, the laser power is very different and requires special Optics produce a good beam shape. These lasers are in optical fiber Communications, CD player, and high-resolution molecular spectroscopy in the near infrared used.