DURIP 99 - Instrumentation for Characterization of Two-Photon and Excited-State Properties of Conjugated Molecules
Abstract
This report summarizes the status of the apparati which have been created or augmented by equipment purchased under the titled DURIP grant. Initial progress made using these systems in studies of two-photon absorption and optical limiting is also reported. Two new measurement systems have been set up and are operational. These systems are: (1) nanosecond transient absorption spectroscopy, and (2) femtosecond time resolved absorption spectroscopy. The transient spectroscopy systems provide a capability for monitoring the time evolution of transient species over the time scale of approximately equal 100 fs to milliseconds, by following absorption bands in the range of approximately equal 300 to 1000 nm. Initial results obtained using the new systems described above are presented. (1) The optical limiting properties of a new charge transfer complex (bis-(dibutylamino)stilbene:(2,4,7-trinit-9-ylidene)malononitrile; BDAS:TNFDM) are reported. This complex shows a sizeable nonlinear response at 600nm which is dependent on solvent polarity, with the strongest response in toluene solution. (2) the solvent dependence of the nonlinear transmission response of BDAS, which is dominated by two-photon induced excited state absorption (TPESA), is reported. Very large nonlinear absorption coefficients are observed in polar solvents like acetonitrile, alcohols and acetone, up to a factor of 10 larger than that in toluene. This indicates that optimization of the environment can be important for TPESA chromophores like BDAS.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 31, 2000
- Accession Number
- ADA385782
Entities
People
- Joseph W Perry
Organizations
- University of Arizona