Gas laser

This can be done by adjusting the spectral response of the mirrors or by using a dispersive element (Littrow prism) in the cavity.

Units operating at 633 nm are very common in schools and laboratories because of their low cost and near-perfect beam qualities.

TEA lasers are energized by a high voltage electrical discharge in a gas mixture generally at or above atmospheric pressure.

Further, continuous-wave chemical lasers at very high power levels, fed by streams of gasses, have been developed and have some industrial applications.

They typically produce ultraviolet light, and are used in semiconductor photolithography and in LASIK eye surgery.

These lasers have particularly narrow oscillation linewidths of less than 3 GHz (500 femtometers),[4] making them candidates for use in fluorescence suppressed Raman spectroscopy.

A helium-neon laser is a well-known type of gas laser
A gas laser cycles molecules from a low to a high energy state to create a laser beam, this is opposed to lasers that cycle an electron inside an atom.
A gas laser cycles molecules from a low to a high energy state to create a laser beam, this is opposed to lasers that cycle an electron inside an atom.