Coherent control of nonlinear processes

• Grant number: 06/00836-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2006
• End date: February 28, 2007
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Sérgio Carlos Zilio
• Grantee: Ismael Andre Heisler
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

This activity project describes a research proposal at a postdoctoral level. The main objective of this work is the implementation, at the IFSC Photonics Group, of coherent control techniques that use high energy ultrashort pulses, a topic that is totally incipient in our country and is at the frontier of chemical physics knowledge. This work consists of the application of techniques that allow the manipulation of the amplitude or/and phase of the ultrashort pulse’s spectral composition, shaping these, with the objective to control, effectively, nonlinear processes in many different materials. Our interest is mainly in organic molecules, focusing on of Y-shaped chromophores and diazocompounds. Presently, the group is beginning the work with coherent control using a deformable mirror and a Ti:Sapphire oscillator. However, the energy of the pulses generated by the oscillator is in the nJ/ pulse range, which is insufficient for most of the frontier applications, especially on the control of chemical reactions. To improve our possibilities, we have to implement a amplification system to increase the pulse energy to the mJ/pulse level. Depending on the control form to be implemented, we will use the deformable mirror, which has already been used in the results presented by the IFSC photonics group, or a liquid crystal shaper, that will expands considerably the experimental possibilities.