The easiest way to run this example is to open Ysplitter_tutorial.py in the FDTD Solutions script editor and press run.
You can open Ysplitter_tutorial.html in your browser to see the code annotations and images.
This requires FDTD Solutions 2019a R6 which includes a Python interpreter and the lumopt module. See:
https://kx.lumerical.com/t/how-can-i-run-inverse-design-examples-with-fdtd-2019a-r3/28158

If you have Jupyter notebooks installed, you can try the ipynb version. For this you will need to include:

<FDTD Solutions install folder>/api/python

in your Python path so it can find lumapi and lumopt modules.
