  We show for the first time that it is possible to realize laser beam focusing
at the few-photon level in the four-wave-mixing process, and at the same time,
reducing the quantum uncertainty in width. The reduction in quantum uncertainty
results directly from the strong suppression of local intensity fluctuations.
This surprising effect of simultaneous focusing and reduction of width
uncertainty is enabled by multi-spatial-mode squeezing, and is not possible via
any classical optical approach or single-spatial-mode squeezing. Our results
open promising possibilities for quantum-enhanced imaging, bio-sensing and
metrology including measurements of nanometer displacement.
