Photodiode max. Output power?
In active configuration, the diode is shorted, so the voltage it produces is 0.  In this case, you are measuring its short-circuit current.  There is therefore no issue of "max voltage".

In passive configuration, you apply a reverse voltage across the diode.  Received light makes the diode leak more, and you measure this leakage current.  In that case, you decide what voltage to hold the diode at.  The reverse leakage current is usually quite insensitive to the reverse voltage over a reasonable range.