Methods and apparatus for modulating a particle pulse include a succession of Hermite-Gaussian optical modes that effectively construct a three-dimensional optical trap in the particle pulse's rest frame. Optical incidence angles between the propagation of the particle pulse and the optical pulse are tuned for improved compression. Particles pulses that can be modulated by these methods and apparatus include charged particles and particles with non-zero polarizability in the Rayleigh regime. Exact solutions to Maxwell's equations for first-order Hermite-Gaussian beams demonstrate single-electron pulse compression factors of more than 100 in both longitudinal and transverse dimensions. The methods and apparatus are useful in ultrafast electron imaging for both single- and multi-electron pulse compression, and as a means of circumventing temporal distortions in magnetic lenses when focusing ultra-short electron pulses.