I am using labsphere LCS 100, 2 inch integrated sphere to measure the brightness where I get the brightness value in Lumens. Now how can I convert that into cd/m2 value. what is the value of solid angle and apex angle should I take?
I am using ocean optics USB2000+RAD spectroradiometer, it first measure intensity peak position, later i have to use absolute irradiance measurement (which itself in the spectrosuite software which i used) to convert the received intensity into lumen or Cd/m2 (lumen=cd/m2 only if sterdian is = 1).
After calculating the lumen (or cd/m2) value, you can divide it with current density (in A/m2), it gives current efficiency in Cd/A.
then it is similar to power efficiency (lumens/watt), instead of J you have to use P(V*i).
you have to check in your software where it helps to find absolute irradiance measurement,
Thanks for your answer. But I am actually a little bit confused about the steradian value I have to consider. Can you help me in this matter. How can I know what is the steradian value I have to use.
measuring in an integrating sphere luminous flux in lumens is the right way for correct power efficiency. Here you just need to divide by the power supplied to your OLED.
Brightness, needed for calculation of current efficiency, is measured in forward direction and cannot be calculated from total light output measured in the integrating sphere without knowing angular dependence of emission.
Assuming lambertian emission Pi is the factor between luminous flux and luminous intensity. Dividing this by the driving current of your OLED gives you current efficiency in cd/A.
i have not used integrating sphere, what i am using is a cosine corrector coupled into fiber. In general, the steradian has default value of 1.0 in it, at this angle lumen = candela.
Hello, have a look at the attached publication. With the explainations given here it should be easily possible for you to calculate all of your figures of merit.