  We consider the structure of the operator product expansion (OPE) in
conformal field theory by employing the OPE block formalism. The OPE block
acted on the vacuum is promoted to an operator and its implications are
examined on a non-vacuum state. We demonstrate that the OPE block is dominated
by a light-ray operator in the Regge limit, which reproduces precisely the
Regge behavior of conformal blocks when used inside scalar four-point
functions. Motivated by this observation, we propose a new form of the OPE
block, called the light-ray channel OPE block that has a well-behaved expansion
dominated by a light-ray operator in the Regge limit. We also show that the two
OPE blocks have the same asymptotic form in the Regge limit and confirm the
assertion that the Regge limit of a pair of spacelike-separated operators in a
Minkowski patch is equivalent to the OPE limit of a pair of timelike-separated
operators associated with the original pair in a different Minkowski patch.
