TI's Precision Method for Laser Diode Emission Control app note shows a way to use the very small current generated from a photo diode to control the drive strength of a LED/Laser Diode. I want to build this circuit using the integrated photodiode in the laser module. My problem is that in a typical laser diode 3 pin package, I have access to the photo diode's anode but not the cathode. The cathode is tied to the laser diode's anode which is tied to VCC. Below, pin 2 will be tied to VCC, pin 1 to the PNP like Figure 2 of the app note.
How do I connect pin 3 to the opamp so that I can amplify the small current into a precision voltage?