Light capturing sheet, light capturing rod, light receiving device using light capturing sheet or light capturing rod, light emitting device using light capturing sheet or light capturing rod, and optical-fiber amplifier using light capturing sheet or light capturing rod

摘要

A light capturing sheet includes a light transmitting sheet and a plurality of optical coupling structures disposed therein. The optical coupling structures each include a first light-transmitting layer, a second light-transmitting layer, a third light-transmitting layer interposed therebetween, and a diffraction grating. Refractive indices of the first and second light-transmitting layers are lower than a refractive index of the light transmitting sheet, and a refractive index of the third light-transmitting layer is higher than the refractive indices of the first and second light-transmitting layers. The optical coupling structures are arranged in first and second directions in a plane parallel to principal surfaces of the light transmitting sheet, and in a third direction not parallel thereto.

主权项

1. A light capturing sheet comprising:
a light transmitting sheet having first and second principal surfaces; and a plurality of optical coupling structures that are disposed within the light transmitting sheet and that are distant from the first and second principal surfaces by first and second distances or more, respectively, wherein the plurality of optical coupling structures each include a first light-transmitting layer, a second light-transmitting layer, and a third light-transmitting layer interposed between the first light-transmitting layer and the second light-transmitting layer, wherein a refractive index of each of the first and second light-transmitting layers is lower than a refractive index of the light transmitting sheet, wherein a refractive index of the third light-transmitting layer is higher than the refractive index of each of the first and second light-transmitting layers, wherein the plurality of optical coupling structures each have a diffraction grating that is parallel to the first and second principal surfaces of the light transmitting sheet, wherein the plurality of optical coupling structures are three-dimensionally arranged within the light transmitting sheet in first and second directions, which are different from each other in a plane parallel to the first and second principal surfaces, and in a third direction that is not parallel to the first and second directions, wherein a plurality of the optical coupling structures arranged in the first and second directions in the plane constitute a first group of optical coupling structures, wherein a plurality of the optical coupling structures arranged in the first and second directions in another plane parallel to the plane constitute a second group of optical coupling structures, wherein the first group of optical coupling structures and the second group of optical coupling structures are adjacent to each other in the third direction, wherein each optical coupling structure constituting the first group of optical coupling structures and each optical coupling structure constituting the second group of optical coupling structures do not overlap with each other in the third direction, and wherein the third light-transmitting layer in a first optical coupling structure included in the first group of optical coupling structures and the third light-transmitting layer in a second optical coupling structure included in the second group of optical coupling structures and adjacent to the first optical coupling structure are connected to each other by a connection portion composed of a material identical to the third light-transmitting layer.