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Calculating Flux for non-lambertian emitter

  1. Apr 21, 2013 #1
    Hey everyone!

    I am struggling with the following problem:
    I am calculating the ratio of photons emitted to electrons generated in an LED. Due to the architecture the device shows a strong cavity effect and as such the emission profile is not lambertian but very "flat".
    Unfortunately I can not use an integrating sphere with my apparatus. So I tried to measure the luminance (cd/m^2) for angles from the surface normal down to 80°. Indeed this measurements show a strong deviation from the lambertian cosine law.

    Now I need to calculate the luminous flux (for an lambertian this is [itex]\Phi=\pi L[\latex]) but I am not sure how to properly do so for my case (though this seems like very basic optics).

    The main confusion stems from the inclusion of the solid angle. I do not know how to properly discretize the solid angle element to somehow "sum up" over the half sphere I effectively measure (that is the luminance shows no dependence on the azimuth).

    I am very thankful for every tip!

    Have a nice sunday!
  2. jcsd
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