NB 2: The photophysics

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NB 2 The photophysics
Is hidden in s
(So we havent done much yet)
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EINSTEIN COEFFICIENT
of transitions / second
Radiation density of photons/unit freq.
of molecules
degeneracy
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Stimulated emission
Spontaneous emission
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Stimulated emission
Spontaneous emission
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YAG laser
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Boltzman
Planck
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Oscillator strength
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Oscillator strength
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Other interactions
Magnetic interaction of B with charge 1/137 of
electric interaction of E (fine structure
constant e2/hc 1/137.036) ? Magnetic dipole
10-4 10-5 compared to electric dipole
Spatial variation Operators qx2, qxy,
etc. (?103 times the size of an atom) ?
Electric quadrupole 10-6 compared to electric
dipole
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Lifetimes
Einstein coefficients are rate constants
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Heisenberg may have been here
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Contributions to excited state lifetime

• Natural lifetime
• Pressure broadening
• Saturaion broadening
• Doppler broadening

NB f(v) in a gas is Gaussian ?Doppler line
shape is Gausian
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electrons
Nuclei
(depends on coordinates of electrons and
nuclei And on time)
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NB Resonant frequency
NB 1 I f ? e0 and µ becomes permanent
dipole NB 2 ?if as beat frequency NB
3 compare to nuclear vibrations
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Compare 1015 s-1 to IR
Nuclear motion is 2 orders of Magnitude slower
than Electronic motion
Born-Oppenheimer approximation
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Robert Oppenheimer
Max Born (1882-1970) pq qp h/2pi
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Max Delbrück Walter Elsasser Friedrich
Hund Pascual Jordan Maria Goeppert-Mayer Lothar
Wolfgang Nordheim J. Robert Oppenheimer Victor
Weisskopf. Enrico Fermi Werner Heisenberg Gerhard
Herzberg Friedrich Hund Pascual Jordan Wolfgang
Pauli Léon Rosenfeld Edward Teller Eugene Wigner
Max Born (1882-1970) pq qp h/2pi
NB 1933 Heisenberg SchrodingerDirac
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The Russell-Einstein ManifestoIssued in London,
9 July 1955                                    
                                                  
                                                  
                                               
                                                  
             Bertrand Russell and Albert
Einstein
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There lies before us, if we choose, continual progress in happiness, knowledge, and wisdom. Shall we, instead, choose death, because we cannot forget our quarrels? We appeal as human beings to human beings Remember your humanity, and forget the rest. If you can do so, the way lies open to a new Paradise if you cannot, there lies before you the risk of universal death. Resolution WE invite this Congress, and through it the scientists of the world and the general public, to subscribe to the following resolution "In view of the fact that in any future world war nuclear weapons will certainly be employed, and that such weapons threaten the continued existence of mankind, we urge the governments of the world to realize, and to acknowledge publicly, that their purpose cannot be furthered by a world war, and we urge them, consequently, to find peaceful means for the settlement of all matters of dispute between them."   Max Born Percy W. Bridgman Albert Einstein Leopold Infeld Frederic Joliot-Curie Herman J. Muller Linus Pauling Cecil F. Powell Joseph Rotblat Bertrand Russell Hideki Yukawa

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There lies before us, if we choose, continual progress in happiness, knowledge, and wisdom. Shall we, instead, choose death, because we cannot forget our quarrels? We appeal as human beings to human beings Remember your humanity, and forget the rest. If you can do so, the way lies open to a new Paradise if you cannot, there lies before you the risk of universal death. Resolution WE invite this Congress, and through it the scientists of the world and the general public, to subscribe to the following resolution "In view of the fact that in any future world war nuclear weapons will certainly be employed, and that such weapons threaten the continued existence of mankind, we urge the governments of the world to realize, and to acknowledge publicly, that their purpose cannot be furthered by a world war, and we urge them, consequently, to find peaceful means for the settlement of all matters of dispute between them."   Max Born (physics 1954) Percy W. Bridgman (physics 1946) Albert Einstein (physics 1921) Leopold Infeld Frederic Joliot-Curie (physics 1935) Herman J. Muller (physiology or medicine 1946) Linus Pauling (chemistry 1954, peace 1962) Cecil F. Powell (physics 1950) Joseph Rotblat (peace 1995) Bertrand Russell (literature 1950) Hideki Yukawa (physics 1949)

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Joseph Rotblat Nobel Peace prize 1995
(together with Pugwash conferences) Russel-Einste
in Manifesto, 1995 Above all, rememebr your
humanity
It's the psychology of war,' said Joseph Rotblat.
'Once we enter war, our moral values are thrown
overboard. We are encouraged to kill people.
Even people who in the past had been friends
became, in our minds, our mortal enemies.'
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Robert Oppenheimer
Max Born (1882-1970) pq qp h/2pi
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Orthogonal (no overlap)
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Mx is odd
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verboten
allowed
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One more parameter.
a ß up down ? ? ½ -½
SPIN
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Pauli principle
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If we can separate space and spin (no spin-orbit
coupling)