1. Spin Optics Laboratory, Saint Petersburg State University, Petergof, 198504 St. Petersburg, Russia
2. Experimentelle Physik 2a, Technische Universität Dortmund, D-44221 Dortmund, Germany
3. Photonics Department, Saint Petersburg State University, Petergof, 198504 St. Petersburg, Russia
4. Department of Solid State, Saint Petersburg State University, Petergof, 198504 St. Petersburg, Russia