THORLABS MX40G Series, Руководство пользователя

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MX40G, MX70G Series of E-O Converters Chapter 4: Operating Instructions
Rev. E, March 19, 2019 Page 19
In the Constant Ratio mode there is an option to select between the two available operating regions by selecting the Slope
field. Positive slope is the non-inverting operating point where increasing voltage on the MZM results in increasing optical
output power. Negative slope is the inverting operating point where increasing voltage on the MZM results in decreasing
optical output power.
Figure 30 Selecting Operating Point in Constant Ratio Mode
When switching to one of the Manual modes from a different bias mode, the Manual mode set point is automatically calculated
to keep the MZM at the same location on the transmission function. For example, in order to switch to Constant Ratio mode at
the Quadrature location, follow these steps:

Turn the bias on, and choose Quadrature mode.

Wait for the green indicator dot to stop blinking (indicating the bias is locked at quadrature).

Optional: For greater accuracy at this point, slowly reduce the dither tone amplitude to ~100 mV in order to remove
errors that can occur due to second order effects with a large dither tone. Make sure the green dot is not blinking.

Now change the bias mode to Manual and select Constant Ratio.

The instrument will calculate the ratio to keep the MZM biased at the Quadrature location.

From here, the ratio set point can be adjusted to further tune performance.
Select Positive Slope
Select Negative Slope
Tap here to Change Slope.