It’s written much more clearly in the paper. https://www.osapublishing.org/ao/fulltext.cfm?uri=ao-57-31-9341&id=399640 https://www.osapublishing.org/ao/fulltex

It’s written much more clearly in the paper. https://www.osapublishing.org/ao/fulltext.cfm?uri=ao-57-31-9341&id=399640 https://www.osapublishing.org/ao/fulltext.cfm?uri=ao-57-31-9...