(3)System Setup Instruction
Figure 2. System diagram with controller’s on-board photodiode Figure 3. System diagram with modulator’s internal photodiode
Depending on the different systems, the controller can be connected to the system as shown in Figure 2 or Figure 3. Here are the setup steps:
Step2. Controller’s output connection
⚫Connect controller’s OUT pin to modulator’s DC Bias pin
⚫Connect controller’s GND pin to modulator’s Ground pin
Setp1. Setup controller’s feedback input
Note: User should only choose one of the feedback method between controller’s on-board photodiode or modulator’s internal photodiode.
a) Using controller’s on-board photodiode as feedback input:
Choose an appropriate optical coupler to ensure the controller’s feedback optical power is within the range indicated in the Product Operating
Information table. For example, if the laser output power is 10dBm and the modulator’s insertion loss is 5dB, then the maximum optical output of the
modulator is about 5dBm. In this situation, user can choose a 1:99 coupler and the 1% port output power is about -15dBm, which is within the range
of controller’s input range. Then user can connect the 1% port to controller’s on-board photodiode as feedback input and the 99% port is the system’s
output.
b) Using modulator’s internal photodiode as feedback input:
⚫Connect modulator’s PD-C(Photodiode Cathode)pin to controller’s Ca pin.
⚫Connect modulator’s PD-A(Photodiode Anode)pin to controller’s An pin.
Step3. Controller’s power connection
⚫Note:V+ connect to +15V DC supply, V- connect to -15V DC supply
⚫Controller can be turned on after the RF source and laser output is stable.
⚫After the controller is turned on, if the LED is lighted, that means the controller
starts to work.