Genas_system Eugeniy Mikhailov and Simon Rochester License GPL. Solving 4 level atom in 0->1 configuration, with field propagation along spatial axis Z no Doppler broadening Fields: light field, default circularly polarized rf field along x static B-field along z M=0 upper state sublevel can be shifted independently We are solving dE/dz+(1/c)*dE/dt=i*eta*rho_ji, where j level is higher then i. Note that E is actually a Rabi frequency of electromagnetic field not the EM field in xmds terms it looks like dE_dz = i*eta*rhoji - 1/c*L[E], here we moved t dependence to Fourier space VERY IMPORTANT: all Rabi frequency should be given in [1/s], if you want to normalize it to something else look drho/dt equation. No need to renormalizes eta as long as its express through i the upper level decay rate in the same units as Rabi frequency. z Ex Ey r11 r22 r33 r12 r13 r14 r23 r24 r34 r44 rf 200 200 density_matrix E_field rfField Lt E_field density_matrix E_field Ex_re_out Ex_im_out Ey_re_out Ey_im_out density_matrix r11_out r22_out r33_out r44_out r12_re_out r12_im_out r13_re_out r13_im_out r14_re_out r14_im_out r23_re_out r23_im_out r24_re_out r24_im_out r34_re_out r34_im_out