Nonlinear multiphoton processes in organic and polymeric materials

TLDR

Multiphoton spectroscopy has been studied for decades, yet widespread applications are limited by the low absorption cross sections of most materials. This article surveys recent photonic applications of multiphoton processes, including upconversion lasing, optical power limiting, laser scanning microscopy, 3D data storage, and photodynamic therapy. The review highlights how these applications exploit two‑photon absorption and related nonlinear effects in organic and polymeric materials. The emergence of multifunctional organic materials with large multiphoton absorption cross sections has enabled these novel photonic and biophotonic applications.

Abstract

For several decades there has been extensive research in the area of multiphoton spectroscopy. However, multiphoton processes have not found widespread applications due to the relatively low multiphoton absorption cross sections of most materials. A new generation of multifunctional organic materials with large multiphoton absorption cross sections has opened up a number of unique applications in photonics and biophotonics. Two-photon pumped upconversion lasing, multiphoton absorption-induced optical power limiting, multiphoton laser scanning microscopy, and two-photon three-dimensional optical data storage are some of the recent photonic applications of multiphoton processes highlighted in this article. Two-photon photodynamic therapy is another promising application to biophotonics which is also discussed here.