Publication Date


Document Type


First Advisor

Spangler, Charles W.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Chemistry


Optical phase conjugation; Nonlinear optics


In the design of new materials with enhanced optical nonlinearities, considerable attention has been paid to the structural identity of NLO-active chromophores. For both second and third order materials, the effective conjugation length relationship for β and γ has been studied by several groups, and it has been predicted that hyperpolarizabilities will level off as a function of the number of repeat units. However, much less attention has been paid to the overall effect of polar mesomerically interactive substituent groups on γ, although donor(D) and acceptor(A) identity and pairings have been well studied for 3. In this paper we will review substituent group and conjugation length effects on 3 and y, focusing on the relationship of D-D, A-A, and D-A pairings on γ in a series of diphenyl polyenes. Substituent group enhancement of γ follows the order D-A > A-A > D-D, thus confirming theoretical predictions of the influence of charge transfer on γ as well as β.


Includes bibliographical references (pages 79-81)


viii, 81 pages




Northern Illinois University

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