laser dye

https://doi.org/10.1351/goldbook.LT07411
Organic dyes typically used dissolved in an organic solvent. The dye solution is circulated continuously through the @L03459@ chamber of the @D01870@, in which it is excited (pumped) by @F02417@ or by another @L03459@.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 362 [Terms] [Paper]