Diode-pumped thulium laser research at Lightwave Electronics

Our work with Tm:YAG lasers has not been without difficulties. We see evidence of parasitic processes in Tm:YAG. Gain seems to clamp at about 1% per millimeter, well below the approximately 10% per millimeter which would be expected if all the atoms in 4%-doped material were in the upper laser level. Thermal focusing has made the design of cw-pumped lasers with large mode areas very difficult. We have been unable to use injection-seeding alone to cause unidirectionality in Q-switched ring lasers.<
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