Enhancement of a two-photon absorption cross section (TPACS) — design and synthesis of a novel class of photochromic molecules with large TPACS

Abstract

Two novel photochromic compounds were designed and synthesized; the two-photon absorption (TPA) cross section of both were measured with a nanosecond laser pulse; their TPACS (δ) values are around 25 × 10⁻⁴⁶ cm⁴ s photon⁻¹ molecule⁻¹ in acetonitrile; the molecular structure of the target compounds have a 3-methyl-1-benzothiophen-2-yl moiety, which can greatly enhance the two-photon absorption cross section.