  Laser cooling of molecules employing broadband optical pumping involves a
timescale separation between laser excitation and spontaneous emission. Here,
we optimize the optical pumping step using shaped laser pulses. We derive two
optimization functionals to drive population into those excited state levels
that have the largest spontaneous emission rates to the target state. We show
that, when using optimal control, laser cooling of molecules works even if the
Franck-Condon map governing the transitions is preferential to heating rather
than cooling. Our optimization functional is also applicable to the laser
cooling of other degrees of freedom provided the cooling cycle consists of
coherent excitation and dissipative deexcitation steps whose timescales are
separated.

Quantum Physics;Atomic Physics