Multiphoton absorption excited upconversion luminescence in optical fiber

TL;DR

This paper reports the experimental observation of a new nonlinear upconversion luminescence effect in optical fibers, driven by multiphoton absorption of femtosecond IR pulses, with insights into defect roles and numerical validation.

Contribution

It introduces a novel nonlinear upconversion luminescence mechanism in optical fibers induced by multiphoton absorption, with direct estimation of photon involvement and defect influence.

Findings

Demonstration of multiphoton absorption induced upconversion luminescence in fibers

Quantitative estimation of photon number involved in the process

Comparison of experimental results with numerical pulse propagation simulations

Abstract

We experimentally demonstrate a novel nonlinear effect in optical fibers: upconversion luminescence generation excited by multiphoton absorption of femtosecond infrared pulses. We directly estimate the average number of photons involved in the up-conversion process, by varying the wavelength of the pump source. We highlight the role of non-bridging oxygen hole centers and oxygen deficient center defects, and directly compare the intensity of side-scattered luminescence with numerical simulations of pulse propagation.