Hello,
the OPT101 datasheet states that "If the light source is focused to a small area of the photodiode, nonlinearity occurs at lower radiant power". Is this due to an intrinsic electric phenomenon or this sentence is explaining that a large area photodiode signal will integrate a non homogenous irradiance all over its surface (with non linear effects)?
Also, will this phenomenon occur both in photoconductive and photovoltaic modes?
Let's assume we are detecting a collimated beam producing a homogenous spot whose size is constant but less than the photodiode area. Why will the OPT response suffer from non linearity with regards to beam intensity in this situation?
Is there a way to approximately quantify the non linearity due to this aspect?
Thanks and best regards,
DP