Photoconducting Charge Mobility, and Nonlinear Optical Properties of DNA
Abstract
This report results from a contract tasking Angers University as follows: The studies will be performed on thin films obtained by the spinning technique from DNA solutions. For the rotational and charge mobility measurements the films will be deposited on ITO coated glass substrates with an over deposited aluminium electrode. 1. Electro-optic Kerr effect. Experiments will be done at 632 nm using the variable frequency AC power supply. This will allow to determine the Kerr constant and its frequency dependence, assessing eventual resonance enhancements. 2. Phase conjugation measurements. Using a 20 ps pulsed laser the optical Kerr susceptibility and its temporal response will be measured. These experiments will allow to determine the contributions to the Kerr susceptibility coming from rotational mobility and/or charge transport. The experiments will be performed at 1064 nm and 532 nm. The second wavelength will allow to measure also enhancement of cubic susceptibility due to eventual multiphoton excitations. 3. Dynamic holography to measure the charge mobility. This technique, based on the study of the kinetics of grating inscription and decay permits to have information on the charge mobility. For doing that a 20 ps pulsed laser beam of 1064 nm wavelength will be used to write the grating in a two beam coupling geometry. The grating will be read with a cw laser at 632 nm. The film will be sensitized with photosensitive molecules like TNF or its derivative and C60 or its derivative. The response times obtained by fitting the write and decay curves will be obtained and from them the charge mobility. The experiments will be done changing the grating period and applying DC electric field to drive generated charges.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 21, 2007
- Accession Number
- ADA524662
Entities
People
- Francois Kajzar