@article{oai:nifs-repository.repo.nii.ac.jp:00011551, author = {LI, Enhao and YAO, Weichao and UEHARA, Hiyori and YASUHARA, Ryo}, issue = {9}, journal = {Applied Physics Express}, month = {Aug}, note = {0000-0001-6930-0843, We report the first watt-level, cryogenically cooled Er:YAP laser operating in the 3 μm spectral region. The spectroscopic properties of a 5 at% Er:YAP crystal were studied at cooling temperatures ranging from 77–290 K. The fluorescence lifetime of the 4I11/2 level associated with the 3 μm laser transition decreased with an increase in temperature; whereas, the lifetime of the 4I13/2 level increased with an increase in temperature. Moreover, over 1 W of output power at 2798 nm was achieved from the liquid-nitrogen-cooled Er:YAP laser with a slope efficiency of 20%, and the limitations to higher output power were discussed.}, title = {Cryogenically cooled 2.8 μm Er:YAP laser with watt-level output power}, volume = {15}, year = {2022} }