A light guide comprises two or more straight light guide sections and one or
more
light coupling elements between sections to transport light from one section to
another section. By having at least two TIR (totally internally reflecting) surfaces
aligned with the light guiding direction of one of the light guiding sections,
a light coupling element of the invention transports light from one light guide
section to another with little or no light loss and little or no increase of etendue.