Existence of strong optical coupling among seven identical human foveal cones

[摘要] Optical waveguide properties of human photoreceptors play important roles in vision. When two optical waveguides are close enough, the exchange or coupling of power between adjacent optical waveguides is a well-known phenomenon. In this paper, we study seven identical human foveal cones arranged in a hexagonal pattern, i.e. six at the vertex of hexagon and one at the center. Each foveal cone consists of the outer fiber and inner segment section. Based on the beam propagation method (BPM), we systematically investigate the light propagation and optical coupling among seven foveal cones. The coupling behaviour depends on the incident wavelength, length of cone and the inter-cone distance. When given certain length and inter-cone distance, most of light is coupled into the neighbouring six cones for the wavelength of 0.4-0.45 μm. While for the wavelength of 0.54–0.63 μm most of light remains in the central cone. So strong optical coupling exists among seven foveal cones and the strength of coupling depends on wavelength significantly. The wavelength dependence of optical coupling may reveal a novel mechanism for color sensation and color vision in the retina.

[学科分类] 眼科学