Phosphor based light sources having a non-planar long pass reflector
A light source includes an LED that emits excitation light, an optically transparent body, a phosphor material positioned to receive the excitation light and disposed on or in the optically transparent body, the phosphor material emitting visible light when illuminated with the excitation light, and a non-planar flexible multilayer reflector that reflects the excitation light and transmits visible light. The non-planar polymeric multilayer reflector is positioned to reflect LED light onto the phosphor material.
1. A light source, comprising:
an LED that emits excitation light;
an optically transparent body;
a phosphor material positioned to receive the excitation light and disposed on or in the optically transparent body, the phosphor material emitting visible light when illuminated with the excitation light; and
a non-planar flexible multilayer reflector that reflects the excitation light and transmits visible light, the non-planar flexible multilayer reflector being positioned to reflect LED light onto the phosphor material.
2. The light source according to claim 1 , wherein the non-planar flexible multilayer reflector comprises polymeric material.
3. The light source according to claim 1 , wherein the non-planar flexible multilayer reflector comprises alternating layers of a first and second thermoplastic polymer and wherein at least some of the layers are birefringent.
4. The light source according to claim 1 , wherein the phosphor material is uniformly disposed on or in the optically transparent body.
5. The light source according to claim 1 , wherein the phosphor material is non-uniformly disposed on or in the optically transparent body.
6. The light source according to claim 1 , wherein the phosphor material is disposed within the optically transparent body adjacent the LED and the optically transparent body has a second region spaced away from the LED where phosphor material is not present.
7. The light source according to claim 1 , wherein the phosphor material is disposed within the optically transparent body and spaced away from the LED.
8. The light source according to claim 1 , wherein the phosphor material is disposed on the optically transparent body and the phosphor material has a first thickness or first density that is greater at a first angle normal to the excitation light than a second thickness or second density at a second angle non-normal to the excitation light.
9. The light source according to claim 1 , wherein the phosphor material is disposed on the optically transparent body and the non-planar flexible multilayer reflector is disposed on the phosphor material.