  The notions of acceleration gradient and deflection gradient are generalized
to phasor quantities (complex-valued functions) in the context of dielectric
laser acceleration (DLA). It is shown that the electromagnetic forces imparted
on a near-resonant particle traversing a unit cell of a grating-type DLA can be
conveniently described by generalized acceleration and deflection gradients.
A~simple formulation of the Panofsky-Wenzel theorem in terms of the generalized
gradients is given. It is shown that all particle transfer properties of a DLA
unit cell can be derived from a single, complex-valued function, the
generalized acceleration gradient.
