copy psr to faraday

1 files changed, 161 insertions, 0 deletions

diff --git a/faraday/psr_vs_detuning.m b/faraday/psr_vs_detuning.m
new file mode 100644
index 0000000..acf7d43
--- /dev/null
+++ b/faraday/psr_vs_detuning.m
@@ -0,0 +1,161 @@
+function [psr_rad]=psr_vs_detuning(detuning_freq, Ep, psi_el, B_field, theta, phi) 
+% calculates psr in rad  vs detunings of the probe field 
+% for given laser probe and B field.
+% 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;
+%four_levels_with_polarization;
+%four_levels;
+%three_levels;
+%two_levels;
+
+% load EM field description
+%field_description;
+
+%Nfreq=length(modulation_freq);
+
+
+
+%tune probe frequency
+detuning_p=0;
+%detuning_p_min=-B_field*gmg*4; % span  +/-4 Zeeman splitting
+%detuning_freq=zeros(1,N_detun_steps+1);
+N_detun_steps=length(detuning_freq);
+kappa_p      =zeros(1,N_detun_steps+1);
+kappa_m      =zeros(1,N_detun_steps+1);
+%detun_step=(detuning_p_max-detuning_p_min)/N_detun_steps;
+
+fprintf (stderr, "calculating atom properties\n");
+fflush (stderr);
+pfile='atomic_B_field.mat'; % the parent file where B_field is stored. This is the parameter for calculated L0_and_polarization_submatrices 
+cfile='L0m_and_polarizability_calculated.mat'; % the child  file to which calculated matrices are  written 
+need_update=false;
+[s, err_p, msg] = stat (pfile); 
+if(err_p)
+		%file does not exist
+		need_update=true;
+	else
+		B_field_cur=B_field;
+		load (pfile); % loading old B_field value
+		if (B_field ~= B_field_cur)
+			% old and current B field are different
+			B_field=B_field_cur;
+			need_update=true;
+		else
+			need_update=false;
+		endif
+endif
+
+[s, err, msg] = stat (cfile); 
+if(err) 
+	%file does not exist
+	need_update=true; 
+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(pfile, 'B_field');
+		save(cfile, 'L0m', 'polarizability_m');
+	endif
+elapsed_time = etime (clock (), t0);
+fprintf (stderr, "elapsed time so far is %.3f sec\n",elapsed_time);
+fflush (stderr);
+
+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; 
+%E_field_lab_pos_freq.right  = E_field_zero + (0.00000+0.00000i)*E_field_probe  + (0.00000+0.00000i)*E_field_drive;
+%E_field_lab_pos_freq.left   = E_field_zero + (0.00000+0.00000i)*E_field_probe  + (0.00000+0.00000i)*E_field_drive;
+
+% phi is angle between linear polarization and axis x
+%phi=pi*2/8;
+% theta is angle between lab z axis (light propagation direction) and magnetic field axis (z')
+%theta=0;
+% psi_el is the ellipticity parameter (phase difference between left and right polarization)
+%psi_el=-30/180*pi;
+
+% 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);
+
+
+fprintf (stderr, "tuning laser in forloop to set conditions vs detuning\n");
+fflush (stderr);
+for detuning_p_cntr=1:length(detuning_freq);
+	wp0=w_pf1-w_sf2;  %Fg=2 -> Fe=1
+	%wd=w_pf1-w_hpf_ground;
+	%detuning_p=detuning_p_min+detun_step*(detuning_p_cntr-1);
+	detuning_p=detuning_freq(detuning_p_cntr);
+	wp=wp0+detuning_p;
+	light_positive_freq=[ wp];
+	% we calculate dc and negative frequiencies 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{detuning_p_cntr}=atom_field_problem;
+
+
+	%kappa_p(detuning_p_cntr)=susceptibility_steady_state_at_freq( atom_field_problem);
+	%detuning_freq(detuning_p_cntr)=detuning_p;
+endfor
+
+save '/tmp/problem_definition.mat' problems_cell_array atom_properties  detuning_freq ;
+fprintf (stderr, "now really hard calculations begin\n");
+fflush (stderr);
+% once we define all problems the main job is done here
+[xi_linear, xi_left, xi_right]=parcellfun(2, @susceptibility_steady_state_at_freq, problems_cell_array);
+%[xi_linear, xi_left, xi_right]=cellfun( @susceptibility_steady_state_at_freq, problems_cell_array);
+
+%save '/tmp/relative_transmission_vs_detuning.mat' detuning_freq relative_transmission_vs_detuning;
+save '/tmp/xi_vs_detuning.mat' detuning_freq xi_linear xi_left xi_right  E_field_pos_freq E_field_probe B_field psi_el;
+
+psr_rad=output_psr_results_vs_detuning;
+
+elapsed_time = etime (clock (), t0)
+return
+
+% vim: ts=2:sw=2:fdm=indent