Newport LDC-3706 Series, User Manual

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December 2019 18 LDC-3706 Series Laser Controller
Photodiode Connections : Many laser diode modules contain an internal photodiode that monitors
the back-facet emission of the laser. Usually, this photodiode is internally connected to either the
laser anode or cathode. The photodiode and laser connections of the LDC-3706 Laser Controller are
electrically isolated from ground and each other. So, if a 4-pin connection is made (no common
connections) no additional jumpers are required. Figure 2.1 shows the recommended connections
and shielding for 3-pin lasers (where the common connection is internal to the device). A 4-pin laser
should be connected with the same shielding as shown in Figure 2.1. It is recommended that the
laser and photodiode remain isolated when possible.