The vibrational spectrum (650-1750 cm(-1)) of the lumi-rhodopsin (lumi) intermediate formed in the microsecond time regime of the room-temperature rhodopsin (Rh-RT) photoreaction is measured for the first time using picosecond time-resolved coherent anti-Stokes Raman spectroscopy (PTR/CARS). The vibrational spectrum of lumi is recorded 2.5 mu s after the 3-ps, 500-nm excitation of Rh-RT. Complementary to Fourier transform infrared spectra recorded at Rh sample temperatures low enough to freeze lumi, these PTR/CARS results provide the first detailed view of the vibrational degrees of freedom of room-temperature lumi (lumi(RT)) through the identification of 21 bands. The exceptionally low intensity (compared to those observed in batho(RT)) of the hydrogen out-of-plane (HOOP) bands, the moderate intensity and absolute positions of C-C stretching bands, and the presence of high-intensity C=C stretching bands suggest that lumi(RT) contains an almost planar (nontwisting), all-trans retinal geometry. Independently, the 944-cm(-1) position of the most intense HOOP band implies that a resonance coupling exists between the out-of-plane retinal vibrations and at least one group among the amino acids comprising the retinal binding pocket. The formation of lumi(RT), monitored via PTR/CARS spectra recorded on the nanosecond time scale, can be associated with the decay of the blue-shifted intermediate (BSIRT) formed in equilibrium with the batho(RT) intermediate. PTR/CARS spectra measured at a 210-ns delay contain distinct vibrational features attributable to BSIRT, Which suggest that the all-trans retinal in both BSIRT and lumi(RT) is strongly coupled to part of the retinal binding pocket. With regard to the energy storage/transduction mechanism in Rh-RT, these results support the hypothesis that during the formation of lumi(RT), the majority of the photon energy absorbed by Rh-RT transfers to the apoprotein opsin.