brightness

of a laser dye
https://doi.org/10.1351/goldbook.BT07338
Product of the @F02453@ @Q04991@ (\(\varPhi _{\text{f}}\)) of a dye and the @M03972@ at the excitation @W06659@, \(\varepsilon\left(\lambda \right)\), i.e., \(\varPhi _{\text{f}}\ \varepsilon\left(\lambda \right)\).
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 310 [Terms] [Paper]