Microcavity effect on dye impregnated porous silicon samples S. Setzu, P. Solsona, S. Létant, R. Romestain and J. C. Vial Eur. Phys. J. AP, 7 1 (1999) 59-63 Published online: 15 July 1999 DOI: 10.1051/epjap:1999199