19.1 (a) A dye molecule has emission cross section

4\\\\times 10^(-16)cm^(2)

at

\\\\lambda =550nm

, and flu-\ orescence lifetime

3ns

. Assuming the transition is homogeneously broadened, cal-\ culate the signal intensity at which the gain is reduced by a factor of two. (b) The\ Nd:glass transition has peak emission cross section

4\\\\times 10^(-20)cm^(2)

at

\\\\lambda =1054nm

,\ and fluorescence lifetime

290\\\\mu s

. If the transition is homogeneously broadened, de-\ termine the signal intensity at which the Nd:glass gain is reduced by a factor of two.\ Repeat if the transition is inhomogeneously broadened.

9.1 (a) A dye molecule has emission cross section 41016cm2 at =550nm, and fluorescence lifetime 3ns. Assuming the transition is homogeneously broadened, calculate the signal intensity at which the gain is reduced by a factor of two. (b) The Nd:glass transition has peak emission cross section 41020cm2 at =1054nm, and fluorescence lifetime 290 s. If the transition is homogeneously broadened, determine the signal intensity at which the Nd:glass gain is reduced by a factor of two. Repeat if the transition is inhomogeneously broadened