A compact fluorescent lamp employs an inner exhaust tubulation formed from glass which is opaque to a given range of electromagnetic radiation. The exhaust tubulation is non-invasively sealed after an outer lamp envelope is sealed by directing upon the exhaust tubulation an amount of such radiation sufficient to heat the tubulation to its softening point. The outer envelope is transparent to the given radiation which, in a preferred embodiment, is in the range of 400 nm to 2500 nm.