Nonlinear optical characteristics and lasing ability of merocyanine dyes having different solvatochromic behaviour

Lasing characteristics and two-photon absorption (TPA) of merocyanine dyes with solvatochromism of different types are first investigated. Efficient lasing is excited in solutions pumped by radiation of the 2nd harmonic of a Nd-YAG laser (532 nm) with the lasing efficiency exceeding 40% and by XeCl laser radiation (308 nm) with the lasing efficiency up to 19%. The TPA cross-section at a wavelength of 1064 nm is determined. It is established that for merocyanines possessing the highest positive and negative values of solvatochromism, the TPA cross-section reaches maximum values of 115 and 125 GM, respectively. Influence of the special features of the electronic structure, spectral and luminescent properties, solvatochromic behavior, and nature of the medium on the lasing characteristics and nonlinear absorption of merocyanine dyes is investigated. Prospects for merocyanine application in modern optical technologies are demonstrated.