Accession Number:

ADA334824

Title:

Ultrafast Spatiotemporal Coupling in Nonlinear Dispersive Media

Descriptive Note:

Final rept.

Corporate Author:

AIR FORCE RESEARCH LAB BOLLING AFB DC

Personal Author(s):

Report Date:

1997-01-01

Pagination or Media Count:

199.0

Abstract:

In this thesis the results of a systematic investigation into the behavior of ultrashort optical pulses propagating in dispersive media with a Kerr nonlinearity and intensity-dependent refractive index are presented. The effect of the nonlinear index is to couple the spatial and temporal behaviors of the optical field together in a process known as spatiotemporal coupling. In the first chapter, a review of the previous work done in describing spatiotemporal coupling is presented as well as a discussion of its relevance to the remaining chapters. Optical wave propagation in general is described by Maxwells equations. In the second chapter Maxwells equations are used to derive the various forms of the nonlinear Schrodinger equation NSE which describe optical wave propagation in the presence of a Kerr nonlinearity. The different forms of the NSE account for different propagation geometries and conditions. The numerical model based on the NSE which is used to derive many of the results in the remainder of the thesis is also described. In chapter three, the numerical model is employed to give a thorough description of the dynamics of the pulse behavior in the presence of spatiotemporal coupling. An explanation of enhanced beam-broadening in self-defocusing media and localized pulse compression in normally dispersive self-focusing media are presented. The remaining two chapters describe experimental conditions under which spatiotemporal coupling may become important. In chapter four, the model is used to describe a means to exploit the ultrafast Kerr nonlinearity to achieve pulse compression with spatial phase modulation. In the fifth and final chapter, the influence of spatiotemporal coupling on Z-scan measurement of the nonlinear refractive index is discussed.

Subject Categories:

  • Optics
  • Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE