Measuring Voltages on the Submicron Scale V. Dierolf and V.Gopalan DMR-0349632, 602986

1. Measuring Voltages on the Submicron ScaleV. Dierolf and V.Gopalan DMR-0349632, 602986 How can you measure voltages and electric fields on length scales smaller than electrical leads and how can you them inside of a material ? You need a small probe that is located inside the material and has a small size. For this purpose, the PIs have developed the concept of “Designer Defects” that are intentionally introduced into the material and are of atomic scale. They demonstrated the feasibility of the method for ferroelectric domain walls regions in LiNbO3. In these regions the direction of the electrical polarizations changes from up to down. Using a confocal microscope they were able to measure the electric fields with about 500nm resolution Domain walls in LiNbO3 150 3 100 2 Electric Field Change (kV/cm) 50 1 2 3 1 0 Parts of this research has been carried out by two undergraduate students from Lehigh and Penn State Universities in collaboration with University of Bonn, where they worked in Summer 2005.

2. Lehigh Valley Opto CampV. Dierolf and V.Gopalan DMR-0349632, 602986 In the last three years, six Opto Camps have been organized for the summer by the Center for Optical Technologies. Several of these camps for young highschool students have been dedicated for girls exclusively. The PIs offered a tuturial and hands-on experiments on optical microscopy with high spatial resolution. By measuring, the features of their hair and the detailed structure of a Music-CD the girls and boys learned about how it is possible to measure things that the eye cannot see. Prof. Dierolf explaining the basics of near field optical microscopy to Lehigh Valley high school students