Share Email Print
cover

Proceedings Paper

Interpretation of two photon absorption driven nonlinear absorption
Author(s): Daniel G. McLean; Richard L. Sutherland; Joy E Rogers; Jonathan E. Slagle; Mark C. Brant; Paul A. Fleitz
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Extensive measurements and modeling of several two photon absorbing materials are described. These are used to elucidate the relative significance of various relaxation and excitation processes that come into play in nonlinear transmission (NLT) and two photon absorption cross section measurements. A reliable measurement of the one photon absorption cross sections at energies 0.5 to ~1.7 eV below the fundamental transition are presented with Voigt function fits that enable the determination of the Gaussian and Lorentzian line widths. Both a numerical model and an analytical model are developed neither of which use any adjustable parameters in comparing calculated NLT results to data. Both models fit the data relatively well over the full range of the experiment. The analytical model captures the primary causes of the nonlinear absorption in the low intensity regime and demonstrates that the nonlinear transmittance can be estimated as a simple effective three-photon process. The numerical model calculates the spatial and time dependence of three state populations and all of the transitions between these states. This model improves the quality of the nonlinear transmission fit which is due to the inclusion of the ground state absorption. Additionally an observation of a strong, long lived transient which is quenched by oxygen suggests multiphoton ionization is happening at low intensities. Thus the full range of constraints applicable to all measurements of the two photon cross section are presented.

Paper Details

Date Published: 18 August 2005
PDF: 15 pages
Proc. SPIE 5934, Nonlinear Optical Transmission and Multiphoton Processes in Organics III, 593401 (18 August 2005); doi: 10.1117/12.618056
Show Author Affiliations
Daniel G. McLean, Air Force Research Lab (United States)
Science Applications International Corp. (United States)
Richard L. Sutherland, Air Force Research Lab (United States)
Science Applications International Corp. (United States)
Joy E Rogers, Air Force Research Lab (United States)
UES, Inc. (United States)
Jonathan E. Slagle, Air Force Research Lab (United States)
AT&T Government Solutions (United States)
Mark C. Brant, Air Force Research Lab (United States)
Science Applications International Corp. (United States)
Paul A. Fleitz, Air Force Research Lab (United States)


Published in SPIE Proceedings Vol. 5934:
Nonlinear Optical Transmission and Multiphoton Processes in Organics III
A. Todd Yeates, Editor(s)

© SPIE. Terms of Use
Back to Top