Please realize that to someone who DOES understand photodiodes and how they are used, this argument is complete nonsense:When asking for advice on a technical forum, do some research and thinking before responding, otherwise people will assume that you are an idiot and and a waste of time.
For the case of a photodiode, I need to have a beam of light directed at my diode, which means the light and the diode should be stationary
I don't know if I'm not asking my question properly or not.
And how is this different for a camera?
Would it help if I pointed out that a CMOS camera sensor is, in essence, an array of photodiodes?
The camera will focus on whatever it is pointed at.A lot like a photodiode with optics.
Sadly, the OFS uses laser light backscattering and a photodiode, which the OP has most emphatically rejected.