The main forms of lasers are solid state lasers, gas lasers and liquid lasers. A great, liquid, gas or semiconductor can act as the laser medium.
Solid state lasers are produced with hard materials like garnet or ruby. Solid state lasers are used for detecting ecological pollution, in scientific researches and a number of other applications. Solid state lasers have laser emitting materials arranged in solid matrix. Examples for solid state lasers would be the ruby or neodymium-Yttrium Aluminum Garnet (YAG) lasers. The lasing materials are pumped with flashlights, making the laser give either pulsed or continuous beam of light.

Gas lasers are lasers by which an household current is passed through a gas to make light. In the early days gas lasers used a combination of helium and neon with carbon dioxide. At present gas lasers may use more strong and volatile mediums like hydrogen and fluorine. Gas lasers have great military applications. The cutting of hard materials becomes easy through gas lasers.
Liquid lasers or dye lasers take advantage of liquid organic dyes. These emit a broad, continuous array of colors, mainly in the visible area of the spectrum. Dye lasers are excellent for applications by which a specific color is required Certified Lasers. Another laser source such as for example copper vapor laser is employed to excite the dye. Liquid lasers can be tuned over a broad array of wavelengths.
Excimer lasers are generated by using gases like fluorine and chlorine in combination with other gases such as for example krypton, argon or xenon. Excimer lasers are extremely helpful for the medical profession. To regulate the wavelength of the lasers compound natural dyes are used extensively.
Semiconductor lasers are usually very small devices and use only low power. Semiconductor lasers may also be called diode lasers. The writing sources in some CD players and in some laser printers are examples for this. Semiconductor lasers are extremely helpful for electronic devices like CD players, laser printers etc.