POLARIZED WHITE LIGHT DEVICES USING NON-POLAR OR SEMIPOLAR GALLIUM CONTAINING MATERIALS AND TRANSPARENT PHOSPHORS
A light emitting device includes a substrate having a surface region and a light emitting diode overlying the surface region. The light emitting diode is fabricated on a semipolar or nonpolar GaN containing substrate and emits electromagnetic radiation of a first wavelength. The diode includes a quantum well region characterized by an electron wave function and a hole wave function. The electron wave function and the hole wave function are substantially overlapped within a predetermined spatial region of the quantum well region. The device has a transparent phosphor overlying the light emitting diode. The phosphor is excited by the substantially polarized emission to emit electromagnetic radiation of a second wavelength.
1 . A packaged light emitting device comprising:
a substrate member having a surface region;
at least one light emitting diode overlying the surface region, the at least one light emitting diode being fabricated on a substrate characterized by a semipolar or nonpolar GaN orientation, the at least one light diode emitting electromagnetic radiation of a first wavelength;
a luminescent material characterized by a first refractive index being excited by emission from the at least one light emitting diode to emit electromagnetic radiation of a second wavelength; and
a dispersion medium characterized by a second refractive index containing the luminescent material;
wherein the second refractive index is about the same as the first refractive index; and
wherein at least one side of the at least one light emitting diode is in direct contact with the dispersion medium.
2 . The packaged light emitting device of claim 1 , wherein the dispersion medium comprises a scattering free medium for radiation of the first wavelength and for the radiation of the second wavelength.
3 . The packaged light emitting device of claim 1 , wherein the dispersion medium comprises silicone.
4 . The packaged light emitting device of claim 1 , further comprising a second dispersion medium encapsulating the first dispersion medium.
5 . The packaged light emitting device of claim 1 , further comprising a submount, wherein the at least one light emitting diode is mounted to the submount and the submount is mounted to the surface region.
6 . The packaged light emitting device of claim 1 , wherein the at least one light emitting diode has a top side, a bottom side, and three sides connecting the top side and the bottom side.