[Laser] PGP RX PIN photodiode wiring

[F1AVYopto at aol.com]

Hello all.
I am now testing many prototypes  with various types of photodiodes and FETs.
On the basic schematic the diode  in fitted in reverse from FET gate to 
ground (anode to the ground).
The  photodiode is in reversed bias mode from the gate leakage.
I did some test  with the photodiodes cathode to the ground.
In this way the photodiode is  biased by the gate leakage in the conductive 
+U / +I sector.
The drain  current goes up with the photocurrent when, with the classic 
schematic, the  drain current goes down with the photocurrent.
The saturation light level  seems rather the same with both diode directions.
With very small light  signal, in dark condition, it seems to me the S/N is a 
little bit better with  the direct way (may be 1 or 2 dB...).
Is there somebody who can confirm this  observation?
Photodiode in reverse mode is known to be noisier than  photodiode in 
photovoltaic mode but what about the beginning of the conductive  sector?
73 Yves.