Light emitting device

1. A light emitting device, comprising:

a light emitting element configured to emit an excitation light; and

a fluorescent element including:

a semi-translucent film facing the light emitting element, and configured to transmit the excitation light;

a first luminescent film including a plurality of phosphors configured to absorb the excitation light transmitted through the semi-translucent film and to emit a visible light having a different wavelength than the excitation light; and

a reflection film disposed on an opposite side of the first luminescent film on which the semi-translucent film is disposed, configured to reflect the excitation light transmitted through the first luminescent film towards the first luminescent film.

2. The light emitting device of claim 1 , wherein the first luminescent film includes a transparent base material that is transparent for the excitation light, and the phosphors are dispersed in the transparent base material.

3. The light emitting device of claim 1 , wherein the fluorescent element further includes a second luminescent film, which emits a visible light having a wavelength different from the first luminescent film.

4. The light emitting device of claim 3 , wherein one of the first and second luminescent films, emitting the visible light having a shorter wavelength, has a larger refractive index than the other.

5. The light emitting device of claim 3 , wherein the fluorescent element further includes a transparent film that is transparent for the excitation light, between the first and second luminescent films.

6. The light emitting device of claim 5 , wherein the transparent film has a refractive index smaller than the refractive index of the first and second luminescent films at the wavelengths of the visible lights.

7. The light emitting device of claim 3 , wherein one of the first and second luminescent films at a near side of the reflection film emits the visible light having a shorter wavelength.

8. The light emitting device of claim 1 , wherein the phosphors includes a plurality of phosphor materials, which emit lights having different wavelengths from each other.

9. The light emitting device of claim 1 , wherein the reflection film has a reflectivity of about eighty % or more for the excitation light.

10. The light emitting device of claim 1 , wherein the reflection film comprises a metal film.

11. The light emitting device of claim 1 , wherein the reflection film comprises a multi-layer distributed Bragg reflector selectively reflecting the excitation light.

12. The light emitting device of claim 1 , wherein the semi-translucent film comprises a metal film or a dielectric multi-layer film.

13. The light emitting device of claim 1 , wherein the semi-translucent film has an opening through which the excitation light can directly enter the first luminescent film.

14. The light emitting device of claim 1 , wherein the light emitting element comprises a semiconductor light emitting element emitting a light having a spectrum with a peak wavelength of about 430 nm or less.

15. The light emitting device of claim 1 , wherein the light emitting element comprises an edge emitting type semiconductor laser diode.

16. The light emitting device of claim 1 , wherein the light emitting element comprises a surface emitting type semiconductor laser diode.

17. The light emitting device of claim 1 , wherein the light emitting element has an active layer of a nitride based compound semiconductor including at least one of aluminum, gallium, and indium.

18. The light emitting device of claim 1 , wherein the light emitting element has an active layer of an oxide semiconductor including at least one of magnesium and zinc.

19. The light emitting device of claim 3 , wherein the fluorescent element further includes a third luminescent film, which emits a visible light having a wavelength different from the first and second luminescent films.