Analytical study of vertical external-cavity surface-emitting organic lasers H. Rabbani-Haghighi, S. Forget, A. Siove and S. Chénais Eur. Phys. J. Appl. Phys., 56 3 (2011) 34108 Published online: 23 November 2011 DOI: 10.1051/epjap/2011110123