  Stark deceleration enables the production of cold and dense molecular beams
with applications in trapping, collisional studies, and precision measurement.
Improving the efficiency of Stark deceleration, and hence the achievable
molecular densities, is central to unlock the full potential of such studies.
One of the chief limitations arises from the transverse focusing properties of
Stark decelerators. We introduce a new operation strategy that circumvents this
limit without any hardware modifications, and experimentally verify our results
for hydroxyl radicals. Notably, improved focusing results in significant gains
in molecule yield with increased operating voltage, formerly limited by
transverse-longitudinal coupling. At final velocities sufficiently small for
trapping, molecule flux improves by a factor of four, and potentially more with
increased voltage. The improvement is more significant for less readily
polarized species, thereby expanding the class of candidate molecules for Stark
deceleration.
