Light collecting and emitting apparatus, method, and applications

1A light guide apparatus includes a light guide layer having a top surface and a bottom surface, and a transversely oriented side-end surface that forms an output aperture of the light guide, characterized by an index of refraction, n, and further characterized by a length dimension in an intended light propagation direction towards the output aperture, where the intended light propagation direction is a z-axis direction of a Cartesian coordinate system; and a plurality of light injection elements disposed in the form of at least one linear strip in at least one of the top and bottom surfaces of the light guide layer, wherein some of the plurality of light injection elements are disposed on one lateral side of the strip and some other of the plurality of light injection elements are disposed on an opposing lateral side of the strip, further wherein each light injection element is disposed outwardly at a rotation angle Δz about the y-axis.