摘要 |
An optical waveguide body includes a first layer of optically transmissive material and a second layer of optically transmissive material in contact with the first layer. At least one of the first and second layers is tapered and the first layer has a first index of refraction and the second layer has a second index of refraction less than the first index of refraction and the first and second indices of refraction are both greater than about 1.0. |