Not a totally basic question here. I have been playing with HeNe's for over 15yrs. I have had red ones only ranging from .3mw to 9.7mw. I have always thought the wavelength was 632.3um. Well today I am working on a CO2 LASER system that has the old school alignment system. (ALL newer ones have crappy LD's). The laser module says 1mw 632.8um. Is there a small range that varies from maker to maker? Or have I always been wrong on the actual wavelength?