The Mathies Group biophysical research is focused on the use of resonance Raman and time resolved optical spectroscopy to elucidate the structure and reaction dynamics of energy and information transducing photoactive proteins and chemical systems. Extensive work on the photochemistry of the visual pigment rhodopsin has established the structure of the primary photoproduct using time-resolved vibrational spectroscopy, demonstrated that the primary cis-to-trans photoisomerization in vision is complete in only 200 fs, and analyzed the nonstationary state or wavepacket evolution that defines the excited state isomerization mechanism. His recent development of femtosecond stimulated Raman spectroscopy provides a revolutionary new way to study the structural dynamics of photochemical and photophysical processes with complete high resolution Raman vibrational spectra and <50 fs time resolution.