All-solid-state CW doubly resonant sum-frequency mixing red-orange laser at 611 nm

We report for the first time a continuous wave (CW) coherent radiation at 611 nm by intracavity sum-frequency generation of 1064 nm Nd:YVO₄ laser and 1433 nm Nd:YAP laser. Red-orange laser is obtained by using a doubly cavity, type-II critical phase matching KTP crystal sum-frequency mixing. With total pump power of 27.9 W (17.8 W pump power for 1433 nm Nd:YAP laser and 10.1 W pump power for 1064 nm Nd:YVO₄ laser), TEM₀₀ mode red-orange laser at 611 nm of 1.15 W is obtained. The red-orange power stability in 30 min is better than 4.3%.