Optical limiting properties of derivatized carbothiacyanine dyes

摘要

The nonlinear optical absorption of a rang eof dialikyl-carbothacyanine dyes has bene measured using intensity dependent transmission measurements of the absorption cross-section at 532 nm. The ground and effective excited state absorption cross-section for each of the dyes has been determined. It was observed that with increasing bridge conjugation length between the carbothiacyanine end groups, the absorption cross section of ground state decreases slightly while the absorption cross-section of the excited state increases leading to an overall increase in the absorption cross-section ratio by an order of magnitude from 0.3 to 5.29. The absorption cross-section ratio tracks linearly with the difference ions of the dyes also affect the nonlinear absorption significnalty. These organic materials exhibit good potential for optical limiting applications.