Merge branch 'master' of https://code.df.uba.ar/nnunez/pyliaf

pyLIAF/utils/trap_values.py

+# reference: https://www1.udel.edu/atom/CaII.html
+# TODO: typing annotations. Use ARTIQ's?
+from scipy.constants import c, pi, hbar
+from ..common_values import nm, MHz
+
+_all_transitions_keywds = ['SP', 'DP', 'SP32', 'D32P32', 'D52P32']
+_all_decays = {'SP': 135.53*MHz, 'DP': 9.45*MHz, 'SP32': 139.23*MHz,
+               'DP32': 0.9834*MHz ,'D52P32': 8.752*MHz}
+_all_waveln = {'SP': 396.959*nm, 'DP': 866.452*nm, 'SP32': 393.478*nm,
+               'DP32': 850.036*nm ,'D52P32': 854.444*nm}
+_all_branchratio = {'SP': 0.93481,'DP': 0.06519,'SP32': 0.93465,
+                    'DP32': 0.006602,'D52P32': 0.05875}
+
+__doc__ = """Docstring for trap_value module
+
+   Transition    | Keyword | Alt Keyword
+S_{1/2}->P_{1/2} | SP      | Doppler
+D_{3/2}->P_{1/2} | DP      | Repump
+S_{1/2}->P_{3/2} | SP32    |
+D_{3/2}->P_{3/2} | DP32    |
+D_{5/2}->P_{3/2} | D52P32  | Quench
+
+Possible extraction values:
+\t decay
+\t linewidth
+\t wavelength
+\t frequency
+\t branching_ratio
+
+Example: trap_values.frequency("DP32") returns frequency of transition D_{3/2}->P_{3/2}
+"""
+
+def help():
+    print(__doc__)
+
+def _preproc_names(fun_name):
+    """Decorator function to allow alt-keywords for transitions dict"""
+    def changename(transition):
+        outname = transition
+        if outname == 'Doppler':
+            outname = 'SP'
+        elif outname == 'Repump':
+            outname = 'DP'
+        elif outname == 'Quench':
+            outname = 'D52P32'
+        elif outname not in _all_transitions_keywds:
+            raise KeyError("No es una transicion valida")
+        return fun_name(outname)
+    return changename
+
+@_preproc_names
+def decay(transition):
+    """Returns decay rate of transition"""
+    # OBS: This is the value corresponding to 2*pi*\omega_{transition}
+    return _all_decays[transition]
+
+@_preproc_names
+def wavelength(transition):
+    """Returns wavelength of transition"""
+    return _all_waveln[transition]
+
+@_preproc_names
+def frequency(transition):
+    """Returns frequency of transition"""
+    return c/_all_waveln[transition]
+
+@_preproc_names
+def branching_ratio(transition):
+    """Returns branching ratio of transition"""
+    return _all_branchratio[transition]
+
+def sat_from_power(powers, laser_diameter, transition):
+    """Return Saturation parameter from laser power"""
+    # Reference: https://www.quantenbit.physik.uni-mainz.de/files/2015/11/pub_phd_Poschinger2011.pdf
+    # Eq. (2.22)
+    # And then using the formula for intensity: I = 2*Power/area
+
+    # Aparentemente hay un error en la cuenta, ejemplo:
+    # Transicion doppler con un haz de ancho 40um y potencia de 250uW:
+    #
+    # trap_values.sat_from_power(250e-6, 40e-6, "SP")   --->  1375864.87...
+    #
+    # deberia dar del orden de 1 o algo asi
+
+    intensity = 8*powers/(pi*(laser_diameter**2))
+    prefactor = (12*pi*c*c)/(hbar*(decay(transition)/(2*pi))*(frequency(transition)**3))
+    return prefactor*intensity
+