Upconversion expands laser's reach
N. Deepak Kumar and Bruce Reinhardt state University of New York at Buffalo, and Polymer Branch, Air Force Research Laboratory
Until the late 1980s, multiphoton processes in organic and polymeric materials were only of academic interest due to their relatively low-multiphoton-absorption cross sections. However, a new generation of highly efficient organic materials with large multiphoton absorption cross sections has enabled a variety of novel applications in photonics and biophotonics.