NITROGEN  LASERS

     The nitrogen laser was developed in 1963 by H. G. Heard, who succeeded in producing 10-W pulses of UV light (which sounds impressive enough but with pulse widths in the nanosecond range, the average power of such a laser was incredibly low). Within four years a radical shift in the design methodology of these lasers had been developed, yielding peak powers in the megawatt range! Development continued and TEA (transverse electrical discharge at atmospheric pressure) nitrogen lasers capable of producing megawatt powers using nitrogen at atmospheric pressures appeared. This laser was an important milestone in UV laser development that led directly to the more powerful excimer laser. Among other things, development of the nitrogen laser led to advances in the production of high-speed, high current discharges required for a high-efficiency nitrogen laser and later for the excimer laser.

       Today, the nitrogen laser is found primarily in the lab and is still a useful source of coherent UV light, producing pulses with milli joule energies and pulse widths around 10 to 20 ns. Owing to the ease of construction, it is also a favorite home-built laser for both amateur laser constructors and small labs on a budget. These inexpensive lasers are commonly used as workhorses in biology and chemistry labs.