Calculate optical power output of LEDs

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
1 reply · 4K views
Sophie MC
Messages
1
Reaction score
0
Hi guys,

I have to calculate de optical power output of a set of LEDs. For that I used a photodiode to measure the photocurrent at each wavelength and then calculate the optical power at each wavelength using the following formula:

R (A/W) = I/P,

where R is the responsivity of the photodiode at each wavelength,
I is the photocurrent measure with the photodiode at each wavelength and
P is the optical power output at each wavelength that I want to measure.

I have de responsivity curve of my photodiode and I have measure the photocurrent. However when calculating de optical power output I obtain very small values.

For example, for a LED with typical 17000 mlm (from datasheet), I only obtain 0,027 mW (summation of all wavelegths) of optical power. I think that this is a very small value comparing with the value in lumens (17000 mlm).

Can any on help with this? Am I right? Am I wrong? Is this the right way of calculate optical power?

Thank you so much
 
Engineering news on Phys.org
We would have to see your raw data and your methods to comment.

Are you using a sum where an integral is needed?