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.