Optical gain and saturation in conjugated polymer waveguide structures

• Applicant: Dr. Martin Vehse
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2002 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5386718

The goal of the present research project is to study the mechanism of optical gain and saturation in pi-conjugated polymer waveguide structures. In these conjugated polymer structures, the formation and correlation of geminate carriers of opposite charge strongly influence the optical properties at small carrier densities. Furthermore, the Förster energy transfer is utilized to reduce self-absorption processes in conjugated polymer blends. By time integrated and time resolved optical gain spectroscopy, it should be examined how these processes influence the optical gain and threshold behaviour of the samples at carrier concentrations as high as necessary to achieve lasing. A further aspect of this project is to investigate the saturation of the optical gain in p-conjugated polymer structures. I intend to demonstrate the effects of structural disorder, dimensionality and nonradiative recombination processes, respectively. Additionally, the influence of the differential gain on the saturation behaviour will be examined. The strong correlation of optical gain and its saturation obviously suggest a common study of the questions mentioned above as proposed by this research project.

• DFG Programme: Research Fellowships