Energy conversion: two interphases

Hi Tom! I have a theoretical question. I sketched the situation in the attached plot. With my data, I am able to reproduce the sketched situation, which was expected.
Where we expect double signals is where I have the confusion
My doubt is:
What is really happening there? the P rays convert at the converter 1 and then the S converted rays just ignore the shallowest converted? Would be the deeper interface (lithosphere 1 in the sketch) the only one that generate mode conversion? Or are there conversions in the deeper converter and then also in the shallowest one?
Thanks in advance!

Hi Qian, with two or more interfaces it is of course more complicated. Apart from the single conversions you will get a mixture of multiply converted (and reflected) waves. There will be conversions at every interface. The dipping adds more complexities, probably you will see a signal on the T transverse component.