@misc{indiciae0fe0a706a3bf,
  title = {3 x 3 matrix for unitary optical systems.},
  author = {S T Tang and H S Kwok},
  year = {2001},
  doi = {10.1364/josaa.18.002138},
  url = {https://pubmed.ncbi.nlm.nih.gov/11551046/},
  note = {Source identifier: 11551046}
}