  The invention of laser immediately enabled us to detect nonlinearities of
photon interaction in matter, as manifested for example by Franken et al.'s
detection of second harmonic generation and the excitation of the Brillouin
forward scattering process. With the recent advancement in high power high
energy laser and the examples of the nonlinearity study of laser-matter
interaction by virtue of properly arranging laser and detectors, we envision
the possibility of probing nonlinearities of photon interaction in vacuum over
substantial spacetime scales compared with the microscopic scale provided by
high energy accelerators. The hithertofore never detected Euler-Heisenberg
nonlinearities in quantum electrodynamics (QED) in vacuum should come within
our reach of detection using intense laser fields. Also our method should put
us in a position with a far greater sensitivity of probing possible light-mass
fields that have been postulated. With the availability of a large number of
coherent photons our suggested measurement methods include the phase sensitive
(contrast) imaging that avoids the pedestal noise and the scheme of second
harmonic detection of photon nonlinearities in vacuum over a long
co-propagating distance incurring resonance excitation. These methods carve out
a substantial swath of new experimental parameter regimes of the exploration of
photon nonlinearities in vacuum covering the force range from the electron mass
scale to below neV.
