Detection of the upper edge of exciton multiplets in the antenna complexes LH1 and LH2 of bacterial photosynthesis, by optical reflection

The second-lowest state in exciton multiplets on the ring aggregate of bacteriochlorophylls in LH1 and LH2 has a transition dipole parallel to the ring plane, absorbing light strongly. The highest state has that perpendicular to the plane, but has not been detected, since its oscillator strength is much smaller than the former’s. Let us prepare an aggregate of LH1s or LH2s so as for their ring planes to be parallel to a surface. The more slantingly is the surface shone by light polarized within the plane of incidence, the more strongly the latter reflects the light, compared with the former.