  A class of strictly localized states which can be made arbitrarily close to
single photons is constructed, and expressions for central properties are
provided. It is demonstrated that single photon states can be well approximated
by these states down to localization scales on the order of a few pulse cycles.
The results readily generalize to states close to $n$-photons. We also provide
upper and lower bounds for the fidelity between a given single photon and any
state strictly localized to a given volume. These results constitute the limit
of photon localization, complementary to the weak-localization limit (I.
Bialynicki-Birula, Phys. Rev. Lett. 80, 5247 (1998)).
