Picosecond Laser Study of Thioindigoid Dyes Photoisomerization

Picosecond Transient Absorption of Xanthene Dyes*

After oneand two-colour ps-excitation the transient absorption of rose bengal, erythrosin B and eosin Y in the spectral range from 450 to 670 nm was probed using picosecond continuum pulses generated in H2O—D 2 O mixture. Our experiments showed for all dyes a high T1—Tn absorption signal above 590 nm where no ground state absorption occurs. These excited triplet states can be effectively popula...

Picosecond Fluorescence Studies of Xanthene Dyes

Subnanosecond lifetime measurements using picosecond pulses from a mode locked Nd3+/glass laser together with conventional absorption and fluorescence yield methods have been used to study the photophysics of fluorescein and three of its halogenated derivatives (eosin, erythrosin, and rose bengal) in aqueous and simple alcoholic solvents. For each of the dye molecules absorption and fluorescenc...

Picosecond photoisomerization and rotational reorientation dynamics in solution

Electronically tuned picosecond Ti:sapphire laser

A widely electronically tunable picosecond Ti:sapphire laser is demonstrated without any mechanical rotation or movement for the first time. With the second harmonics of the Nd:YAG laser as a pump source, the laser produces 10 ps pulses with a maximum output power of 350 mW. The wavelength of the self-starting ultrashort laser pulses can be rapidly and arbitrarily accessed in the region from 76...

Fluorescence Efficiency of Laser Dyes *

The recent development of the dye laser [1] 1 has opened up an important new field of applications for organic dyes. This has led to a renewed interest in the theory of nonradiative transitions in dyes and also to the synthesis of new highly fluores cent dyes. In this article we review briefly the relations between fluor· escence and molecular structure in the most important classes of laser dy...