Femtosecond Optical Kerr Shutter

Abstract

The overarching aims of ultrafast spectroscopy include a full understanding of the electronic and vibrational dynamics of molecules in the condensed phase. Optical Kerr shutters have been shown to be a promising method in time-resolved spectroscopy, mostly for transient absorption experiments and for gating the luminescence measurements from photoexcited molecules. As an intense optical pulse travels through a Kerr material, birefringence is induced in the medium. This is known as the Kerr effect. When placed between two crossed polarizers the pulse acts as a gating pulse, and during its presence the shutter opens. Due to the ultrafast electronic response of the Kerr effect in glass materials, the instrument response of such setups is in ~100 fs time scale. This thesis reports the successfully construction of an optical Kerr shutter using SrTiO3, quartz, and fused silica which have correspondingly demonstrated instrument responses of ~250 fs, ~180 fs, and ~170 fs.