p [0:0.5] "OPTICS_0.005_-0.02/FeSi.oc" u 1:2 t "OPTICS_0.005_-0.02/FeSi.oc u 1:2" w l lw 2, "OPTICS_0.005/FeSi.oc" u 1:2 t "OPTICS_0.005/FeSi.oc u 1:2" w l lw 2