Helium-neon lasers, explained by RP Photonics Encyclopedia; He-Ne laser ..
Helium–neon lasers, particularly the standard devices emitting at 632..8 nm, are still used for alignment and in interferometers..However, they are more and more replaced with laser diodes, which are much cheaper, more compact and efficient..Remaining advantages of the He–Ne laser can be the smaller emission linewidth (particularly in case of single-mode emission), which is associated with a ..