Spatial scan of light intensity by retinal rod cells

The optimization of coupling efficiency of light emerging from the tip of a tapered single mode fiber within a live retinal rod cell of adult frog Xenopus laevis is studied. Results show a Gaussian profile of the intensity distribution of light emitted from a single mode fibre. The capability of scanning the spatial intensity distribution of light field emerging from the tip of a fiber allows direct estimation of the coupling efficiency of light with retinal rods, which is highly relevant for precise characterisation of the cell response to optical stimulation in various biological tasks.