- If you like modern optics, including coherent and squeezed states, beam transfer
matrices, polarization optics, as well as periodic systems,
- If you are interested in entanglement problems, particularly
- If you are interested in entropy problems and Feynman's rest of the
universe, click here, and
- Poincaré and Einstein? click here,
- Poincaré sphere for polarization optics and the Poincaré symmetry
for Einstein's relativity.