We show a new scheme of nonperturbative pair production by high energy
photons (ω≳m) in a strong external field is achievable at the
next high intensity laser experiments. The pair momentum is boosted and for
ω≳1.2m the pair yield is increased when the external field is
formed by two laser pulses converging at a small angle. These characteristics
are nonperturbative in origin and related to the presence of magnetic field in
addition to electric field. By enhancing the signal over perturbative
backgrounds, these features allow the employment of above-threshold photons
ω>2m, which further increases the pair yield. We note the close relation
of this photon-pair conversion mechanism to spontaneous pair creation,
recommending it as an accessible stepping stone experiment using
state-of-the-art or soon-to-be laser technology.Comment: 5 pages, 2 figures, revtex forma