Random laser action in bovine semen

Experiments using bovine semen reveal that the addition of a high-gain water soluble dye results in random laser action when excited by a Q-switched, frequency doubled, Nd:Yag laser. The data shows that the linewidth collapse of the emission is correlated to the sperm count of the individual samples, potentially making this a rapid, low sample volume approach to count determination. ► Bovine semen and laser dyes as random laser media. ► Sperm acts as a scattering medium to create long paths and closed paths. ► Excitation by 532nm Q-switched laser results in narrowing of the emission. ► Line-width is narrower with higher sperm count. ► Provides a simple ultra-fast sperm count measurement method.