G.  HeNe laser wavelengths

The most often used laser transition in neon is the red-colored laser operating at 632.8 nm. It is the easiest visible HeNe laser wavelength to produce since it has the highest gain. Additional visible wavelengths are the green laser at 543.5 nm, the yellow laser at 594 nm, and the orange laser at 612 nm. In the near infrared there are several laser transitions in the 1.15-mm region and one at 1.523 mm, and a strong transition at 3.39 mm.