Chapter 4 Operating Instructions; Control Loop Diagram; Amplifier Settings Page - THORLABS MX10C Series User Manual

MX10C, MX40C Series of Optical Transmitters
Chapter 4 Operating Instructions

4.1 Control Loop Diagram

The following diagram shows the control loops added to the block diagram. From this picture, the user can see how the power
monitors and VOA are used to provide stability and control to the whole system. It will be helpful to refer to this diagram to gain
a better understanding of the functionality of the unit as described in the upcoming sections of the manual. Note the MX40C
series does not have the external RF loopback.

4.2 Amplifier Settings Page

To get to the Amplifier Settings page, tap on the Amplifier monitor pane on the Home page. The Amplifier has a fixed gain that
it applies to a user input signal. The signal is then routed to the RF input port of the modulator via the front panel loop-back
cable.
There are two Modes for the amplifier: 1) Digital and 2) Analog, but both work with the same fixed gain. Analog mode simply
sets the output swing of the amplifier to maximum.
The default amplifier mode is Digital, in which case the output swing and crossing point can both be adjusted while the gain is
held constant. This digital mode is recommended for OOK (On-Off Keying) digital signals. The V
conveniently set the Max Output Swing to the optimum value to achieve high extinction modulation with the internal modulator.
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Figure 16 Selecting between Analog and Digital Amplifier Settings
Chapter 4: Operating Instructions
Tap here to change modes.
Select Analog mode to
provide maximum output
swing.
Select Digital mode to
enable adjustable
output swing.
Swing button is provided to
π
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