Two-photon-pumped frequency-upconverted blue lasing in coumarin dye solution

Two-photon-pumped (TPP) frequency-upconverted blue lasing of Coumarin 500 dye solution has been experimentally investigated. The shortest lasing wavelength was measured to be ˜479 nm from a Coumarin 500 solution in chloroform pumped with ˜800-nm laser pulses of ˜5-ns duration. The spectral, temporal, and spatial structures as well as the output—input characteristics of TPP cavity lasing were measured with a 1-cm-long Coumarin 500 solution—filled quartz cuvette. The cavity lasing spectral structure and the numbers of longitudinal modes were easily controlled simply by attachment of an optical plate to the output window of the dye-solution cuvette. The net conversion efficiency from the absorbed 800-nm pump pulse energy to the blue-upconverted cavity lasing energy was ˜4.8%.