CdTe/CdS Quantum Dots: Effective Saturable Absorber for Visible Lasers

We report on passive Q-switching of diode-pumped Pr:YLF visible lasers at 721 nm, 640 nm and 607 nm using CdTe/CdS quantum dot as saturable absorber. At the three wavelengths, the maximum average output powers and the shortest pulse widths are (38.7 mW, 235 ns), (48.3 mW, 226 ns), and (39.6 mW, 295 ns), respectively. The laser results represent the best laser performance of nano-material based Q-switched ${\rm{Pr}}^{3+ }$ visible lasers, to the best of our knowledge. CdTe/CdS quantum dot could be very promising in generating ultrashort pulse visible lasers.