3 ms·
By sharp, do you mean a direct band-gap? I recall that you sometimes want to pump your atoms in a higher energy state than the one that corresponds to the outp
by MayeulC 7y ago
By sharp, do you mean a direct band-gap?
I recall that you sometimes want to pump your atoms in a higher energy state than the one that corresponds to the output energy, but I forgot its usefulness. Could someone enlighten me on this? Or is it just for optically pumped mediums (thus pumped with higher energy photons than the emitted ones)?
- fsh 7y agoIt is impossible to achieve inversion (and therefore gain) by optically pumping a medium exactly at the emission wavelength. Therefore, optically pumped laser gain media are at least three (usually four) level systems.