Efficient cryogenic orange Pr3+:YLF lasers

We present experimental evidence that the efficiency of orange Pr3+ lasers is limited by losses due to ground state absorption. To this end, we determined the temperature-dependent orange reabsorption and performed laser experiments with orange Pr3+:YLF lasers at 604 nm and 607 nm in the temperature range between 78 K and 295 K. At 110 K, a slope efficiency of 67% and an optical-to-optical efficiency of 64% are obtained. These are the highest efficiencies of any orange-emitting Pr3+ lasers to the best of our knowledge, enabled by vanishing reabsorption for the orange laser emission at low temperatures.We present experimental evidence that the efficiency of orange Pr3+ lasers is limited by losses due to ground state absorption. To this end, we determined the temperature-dependent orange reabsorption and performed laser experiments with orange Pr3+:YLF lasers at 604 nm and 607 nm in the temperature range between 78 K and 295 K. At 110 K, a slope efficiency of 67% and an optical-to-optical efficiency of 64% are obtained. These are the highest efficiencies of any orange-emitting Pr3+ lasers to the best of our knowledge, enabled by vanishing reabsorption for the orange laser emission at low temperatures.