Dear Bilal,
you can change the modulator setting through component properties as attached. I think, although when you change the amplitude of the electrical input the power still constant. As we know the MZM modulator has man modes of operation including quadrature point, null point and maximum point and there is a specific setting for each operation. I attached you here a file I got it from this forum includes different modulator setting.
I use the markers in the visualizers to measure the pulse width.
Hope this help
Thanks