Patent ID: 7293876

Claim:
A light source unit comprising: a light emitting unit that includes a substrate having an incident side and an emission side opposed to each other; and a light propagating unit that propagates light from the light emitting unit, the light propagating unit being formed of a transparent member, and being arranged to propagate evanescent light from the substrate in the light emitting unit, and the light propagating unit including a transparent substrate having an incident plane on a side of the light emitting unit, the incident plane having a fine structure including thin protrusions for propagating evanescent light, wherein a semiconductor layer is provided on the incident side of the substrate for supplying light via the substrate to the light propagating unit, a micro prism array is provided on an emission side of the transparent substrate, and a gap is provided between the thin protrusions and the emission side of the substrate, and a length of the gap is equal to or smaller than a wavelength of the emitted light.