Light-emitting device, illumination device, and vehicle headlamp
A headlamp includes a light-emitting section which emits fluorescence upon receiving excitation light from a laser element. Energy intensity distribution of the excitation light, which is received by the light-emitting section, is a top-hat distribution.
1. A light-emitting device, comprising:
a first optical member which transmits excitation light emitted from an excitation light source and has an exit surface through which the excitation light goes out;
a second optical member which receives the excitation light which has come out through the exit surface; and
a light-emitting section
the second optical member controlling a spot size of the excitation light and directing the excitation light of the controlled spot size to the light-emitting section,
the light-emitting section emitting fluorescence upon receiving the excitation light which has come out of the second optical member,
the exit surface and a spot of the excitation light on a light irradiation surface of the light-emitting section being optically conjugate with each other,
the first optical member being a multimode fiber, and
the multimode fiber converting an energy intensity distribution of the excitation light, which has been emitted from the excitation light source, into a top-hat distribution.
2. The light-emitting device of claim 1 , wherein:
a region of the exit surface through which the excitation light passes has at least one linear edge.
3. The light-emitting device of claim 1 , wherein:
the exit surface is a planar surface.
4. An illumination device comprising a light-emitting device of claim 1 .
5. A vehicle headlamp comprising an illumination device of claim 4 .