Two-photon spectroscopy using picosecond light continua

Abstract

Two-photon absorption is measured using two picosecond pulses: a monochromatic pulse and a pulse with broad frequency spectrum. Single pulses of high peak intensity were applied to crystalline samples without damage. Introducing a time delay of several picoseconds between the two pulses, possible two-step processes can be elucidated. As an example, two-photon absorption in CdS was investigated over an energy range from 2.4 to 3.5 eV.