MAGNETOOPTICAL TRAP FOR SODIUM ATOMS OPERATING ON THE D-1 LINE

We report on the observation of magneto-optical trapping of sodium ato ms in the 3S(1/2) --> 3P(1/2) transition (D-1 line). There are four co mbinations of atomic transitions within the D-1 line which produce tra pping: two of them are achieved with the usual orthogonal circular pol arizations used in the trap operating on the D-2 line, while the other two are just observed with reversed polarizations. The need of revers ing the polarizations is attributed to the negative Zeeman shift of th e lower hyperfine levels of the D-1 transition in alkalis. We have con fined 10(5) to 10(7) atoms, depending on the atomic transitions involv ed.