.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "auto_examples/core/YbOH.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code. .. rst-class:: sphx-glr-example-title .. _sphx_glr_auto_examples_core_YbOH.py: Optical pumping in 171YbOH -------------------------- Beyond diatomic molecules, recent years have seen major advances in the direct laser cooling and control of polyatomic species. A particularly relevant case is ytterbium monohydroxide (YbOH), whose odd isotopologues :math:`^{173}\text{YbOH}` and :math:`^{171}\text{YbOH}` are of great interest as sensitive probes for nuclear properties and tests of fundamental symmetries. Motivated by these applications, optical cycling in these isotopologues has recently been demonstrated for the first time. In this tutorial, we will model the optical cycling process in 171YbOH to highlight the key mechanisms that enable photon scattering in such polyatomic systems. .. GENERATED FROM PYTHON SOURCE LINES 20-22 Import and function definition ------------------------------ .. GENERATED FROM PYTHON SOURCE LINES 22-33 .. code-block:: Python from MoleCool import System, np, plt, save_object, open_object from MoleCool.spectra import multiindex_filter as filt from MoleCool.tools import gaussian import os.path def fun(system): t_cut = (system.lasers[-1].r_k[0]-3e-3)/system.v0[0] Nscatt = np.where(system.t>t_cut, system.Nscattrate[0], 0) Nscatt = np.interp(system.t_plt, system.t, Nscatt, right=0, left=0) return {'Nscatt':Nscatt} .. GENERATED FROM PYTHON SOURCE LINES 34-36 Level system initialization --------------------------- .. GENERATED FROM PYTHON SOURCE LINES 36-48 .. code-block:: Python if __name__ == '__main__': if not os.path.isfile("YbOH.pkl"): system = System(load_constants='171YbOH') system.levels.add_electronicstate('X','gs') system.levels.add_electronicstate('A','exs') system.levels.X.load_states(v=[0,1]) system.levels.A.load_states(v=[0]) system.levels.X.add_lossstate() .. GENERATED FROM PYTHON SOURCE LINES 49-54 Since we added a loss state which includes a vibrational state with the vibrational quantum number which is by 1 greater than the maximum ``v``. So, we deliberately must add another vibrational level in the pandas.DataFrame ``system.levels.vibrbranch`` and ``system.levels.wavelengths`` for the loading to be working. .. GENERATED FROM PYTHON SOURCE LINES 54-60 .. code-block:: Python :dedent: 1 system.levels.vibrbranch.loc[('X',2),:] = 1 - system.levels.vibrbranch.sum() system.levels.wavelengths.loc[('X',2),:] = 700 # system.levels.print_properties() .. GENERATED FROM PYTHON SOURCE LINES 61-64 Transition spectrum ------------------- Let's have a look how the transition spectrum looks like: .. GENERATED FROM PYTHON SOURCE LINES 64-74 .. code-block:: Python :dedent: 1 system.levels.plot_transition_spectrum( wavelengths = [float(system.levels.wavelengths.loc[('X',0)])*1e-9], subplot_sep = 2000, N_points = 1000, relative_to_wavelengths = True, # QuNrs = [['G','F'],['F']], # formatting for legend legend = False, ) .. GENERATED FROM PYTHON SOURCE LINES 75-78 .. image:: /_figures/core/YbOH_fig1.svg :alt: Demo plot :align: center .. GENERATED FROM PYTHON SOURCE LINES 80-82 Initial population and velocity ------------------------------- .. GENERATED FROM PYTHON SOURCE LINES 82-95 .. code-block:: Python :dedent: 1 system.levels.X.set_init_pops({'v=0':1/1.11,'v=1':0.11/1.11}) # system.levels.X.set_init_pops({'v=0,G=1,F1=1':1/1.11*6/24, # 'v=1,G=1,F1=1':0.11/1.11*6/24}) system.set_v0( # v0 = [170,0,0], v0 = np.linspace(80,400,100), direction = 'x', ) system.t_plt = np.linspace(0,0.2e-3,800) .. GENERATED FROM PYTHON SOURCE LINES 96-98 Calculation routine ------------------- .. GENERATED FROM PYTHON SOURCE LINES 98-155 .. code-block:: Python :dedent: 1 colors = dict(ro='C0', rc='C1', nopump='k') D_exp = dict(ro=0.48+0.17*np.array([+1,-1]), rc=7.4+1.3*np.array([+1,-1])) labels = dict(rc='rc pumping',ro='ro pumping',nopump='no pumping') x_pump = 5e-3 x_probe = 17e-3 P_pump = 10e-3 for P, F1_pump, label in zip([1e-8,P_pump,P_pump], [0,0,1], ['nopump','rc','ro']): del system.lasers[:] #pump system.lasers.add( lamb = system.levels.wavelengths.loc[('X',0),('A',0)]*1e-9, P = P, FWHM = 5e-3, k = [0,0,1], r_k = [x_pump,0,0], freq_shift = 1e6*(filt(system.levels.A.freq, dict(F1=F1_pump)).mean() - filt(system.levels.X.freq, dict(G=1,F1=1)).mean()), ) #probe system.lasers.add( lamb = system.levels.wavelengths.loc[('X',1),('A',0)]*1e-9, P = 0.1e-3, w = 1e-3, k = [0,0,1], r_k = [x_probe,0,0], freq_shift = 1e6*(filt(system.levels.A.freq, dict(F1=0)).mean() - filt(system.levels.X.freq, dict(G=1,F1=1)).mean()), ) # system.lasers.plot_I_2D(ax='z',limits=([0,17e-3],[-7e-3,7e-3])) # # system.lasers[-1].I # system.draw_levels(QuNrs_sep=['v']) #%% system.multiprocessing.update({ 'processes' : 2, # 'maxtasksperchild' : None, # 'show_progressbar' : True, 'savetofile' : False }) system.calc_rateeqs( # t_int=10e-6, t_int = x_probe/80, magn_remixing = True, magn_strength = 7, trajectory = True, position_dep = True, max_step = 1e-6, verbose = False, return_fun = fun, ) save_object(system, 'YbOH_'+label) .. GENERATED FROM PYTHON SOURCE LINES 156-158 Loading data and plotting ------------------------- .. GENERATED FROM PYTHON SOURCE LINES 158-196 .. code-block:: Python :dedent: 1 plt.figure() unit_x = 1e6 lifs_arr = dict() for label in ['nopump','ro','rc']: system = open_object('YbOH_'+label) LIFs_i = system.results.vals['Nscatt']*gaussian(system.v0[:,0],a=1,x0=180,std=40)[:,None]*1e-3 LIFs = LIFs_i.sum(axis=0) if label == 'rc': plt.plot(system.t_plt*unit_x, 2.2 * LIFs_i[::(LIFs_i.shape[0]//25),:].T, c='grey', alpha=0.3) # for i, ls in enumerate(['-','--']): plt.plot(system.t_plt*unit_x, LIFs, ls=dict(rc='-',ro='-',nopump='--')[label], label=labels[label], c=colors[label], ) lifs_arr[label] = LIFs if label in ['ro','rc']: lif_pump = lifs_arr[label].max() lif_nopump = lifs_arr['nopump'].max() D = (lif_pump - lif_nopump)/lif_nopump lif_pump_exp = (D_exp[label]+1)*lif_nopump plt.axhspan(*lif_pump_exp, alpha=0.25, color=colors[label]) print(f'Max ({label})',lif_pump/lif_nopump) print(f'D ({label})',D) plt.xlim(left=0.9*x_probe/system.v0.max()*unit_x) plt.xlabel('Time (us)') plt.ylabel('Photon scattering rate (kHz)') plt.legend() .. GENERATED FROM PYTHON SOURCE LINES 197-200 .. image:: /_figures/core/YbOH_fig2.svg :alt: Demo plot :align: center .. _sphx_glr_download_auto_examples_core_YbOH.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: YbOH.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: YbOH.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: YbOH.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_