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Diffstat (limited to 'faraday/susceptibility_problem.m')
| -rw-r--r-- | faraday/susceptibility_problem.m | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/faraday/susceptibility_problem.m b/faraday/susceptibility_problem.m new file mode 100644 index 0000000..56808e9 --- /dev/null +++ b/faraday/susceptibility_problem.m @@ -0,0 +1,99 @@ +function [xi_linear, xi_left, xi_right]=susceptibility_problem(detuning_freq, Ep, psi_el, B_field, theta, phi) +% calculates transmission if light polarizations vs B field in the cell +% for given laser probe and B fields array +% Probe field defined by field strength (Ep) and ellipticity angle (pse_el) +% Magnetic field defined by magnitude (B_field) and angles theta and phi. +% +% Note: it is expensive to recalculate atom property for each given B_field strength +% so run as many calculation for constant magnetic field as possible + +t0 = clock (); % we will use this latter to calculate elapsed time + + +% load useful functions; +useful_functions; + +% some physical constants +useful_constants; + +basis_transformation; % load subroutines + + +% load atom energy levels and decay description +rb87_D1_line; + + +B_str=num2str(B_field(1),"%g"); +% the child file to which calculated matrices are written +cfile='L0m.cache/L0m_and_polarizability_calculated_for_B='; +cfile=strcat(cfile,B_str,'.mat'); + +need_update=true; +[s, err, msg] = stat (cfile); +if(err) + %file does not exist + need_update=true; +else + need_update=false; +endif; +if ( !need_update) + % matrices already calculated and up to date, all we need to load them + load(cfile); + else + % calculate E_field independent properties of the atom + % to be used as sub matrix templates for Liouville operator matrix + [L0m, polarizability_m]=L0_and_polarization_submatrices( ... + Nlevels, ... + H0, g_decay, g_dephasing, dipole_elements ... + ); + save(cfile, 'L0m', 'polarizability_m'); + endif + +global atom_properties; +atom_properties.L0m=L0m; +atom_properties.polarizability_m=polarizability_m; +atom_properties.dipole_elements=dipole_elements; + +%light_positive_freq = [wp]; +E_field_drive = [0 ]; +E_field_probe = [Ep ]; +E_field_zero = [0 ]; +E_field_lab_pos_freq.linear = E_field_zero + (1.00000+0.00000i)*E_field_probe + (1.00000+0.00000i)*E_field_drive; + +% we define light as linearly polarized +% where phi is angle between light polarization and axis x +% only sign of modulation frequency is important now +% we define actual frequency later on +[E_field_lab_pos_freq.x, E_field_lab_pos_freq.y] = rotXpolarization(phi, E_field_lab_pos_freq.linear); +% we add required ellipticity +E_field_lab_pos_freq.x*=exp(I*psi_el); +E_field_lab_pos_freq.y*=exp(-I*psi_el); +E_field_lab_pos_freq.z=E_field_zero; + +E_field_pos_freq=xyz_lin2atomic_axis_polarization(theta, E_field_lab_pos_freq); + + +wp0=w_pf1-w_sf2; %Fg=2 -> Fe=1 +wp=wp0+detuning_freq; +light_positive_freq=[ wp]; +% we calculate dc and negative frequencies as well as amplitudes +[modulation_freq, E_field] = ... + light_positive_frequencies_and_amplitudes2full_set_of_modulation_frequencies_and_amlitudes(... + light_positive_freq, E_field_pos_freq); +freq_index=freq2index(wp,modulation_freq); + +atom_field_problem.E_field = E_field; +atom_field_problem.modulation_freq = modulation_freq; +atom_field_problem.freq_index = freq_index; + +problems_cell_array=atom_field_problem; + +[xi_linear, xi_left, xi_right]=susceptibility_steady_state_at_freq( problems_cell_array); + + +elapsed_time = etime (clock (), t0) +return + +endfunction + +% vim: ts=2:sw=2:fdm=indent |