A nitrogen laser is a gas laser operating in the ultraviolet (UV) range by using molecular nitrogen as its gain medium. Nitrogen lasers were first developed in 1963, and began to be used commercially in 1972.
Nitrogen lasers operate based on a fast electrical discharge through nitrogen gas. The nitrogen gas can be supplied through a gas cylinder, or from liquid nitrogen. The laser light emitted is in the UV range, with a short pulse width and high intensity.
The nitrogen laser uses electricity to excite the nitrogen. When an electric spark crosses a spark gap in the laser, the electrons hit the nitrogen atoms in air thereby exciting them into a metastable state. When a photon with a wavelength of 337 nm passes the excited nitrogen atoms, stimulated emission occurs and a laser state is generated.
Nitrogen lasers find applications in research in medicine, chemistry and physics.
Nitrogen lasers can be used for a wide range of applications in the UV-visible region. They can be easily coupled to a microscope for carrying out experiments in life science laboratories. They are also efficient sources for laser-induced fluorescence and photochemistry and general spectroscopy.
Other major applications of nitrogen lasers include:
- Measurement of air pollution
- Treatment of nonhealing wounds, pulmonary tuberculosis, etc
- Transverse optical pumping of dye lasers.