PICOSECOND LUMINESCENCE DETECTION USING TYPE-II PHASE-MATCHED FREQUENCY CONVERSION

Abstract

Author Institution: Department of Chemistry, University of PennsylvaniaFrequency conversion techniques have been adapted for use in picosecond optical gating applications, in particular, the measurement of subnanosecond fluorescence profiles. The major advantages over Kerr-cell methods are the higher intrinsic signal-to-background ratio and the facility for ultraviolet fluorescence time-resolution. Direct picosecond-time-resolved measurements have been made of the temperature-dependent Stokes shift of the fluorescence spectrum of 2-amino, 7-nitrofluorene in 2-propanol. Fluorescence decay times measured at different wavelengths were found to vary by up to an order of magnitude. These findings are interpreted in terms of two independent relaxation processes in 2-propanol: solvent polarization and solvent-assisted fluorescence quenching