  To be useful for most scientific and medical applications, compact particle
accelerators will require much higher average current than enabled by current
architectures. For this purpose, we propose a photonic crystal architecture for
a dielectric laser accelerator, referred to as a multi-input multi-output
silicon accelerator (MIMOSA), that enables simultaneous acceleration of
multiple electron beams, increasing the total electron throughput by at least
one order of magnitude. To achieve this, we show that the photonic crystal must
support a mode at the $\Gamma$ point in reciprocal space, with a normalized
frequency equal to the normalized speed of the phase matched electron. We show
that the figure of merit of the MIMOSA can be inferred from the eigenmodes of
the corresponding infinitely periodic structure, which provides a powerful
approach to design such devices. Additionally, we extend the MIMOSA
architecture to electron deflectors and other electron manipulation
functionalities. These additional functionalities, combined with the increased
electron throughput of these devices, permit all-optical on-chip manipulation
of electron beams in a fully integrated architecture compatible with current
fabrication technologies, which opens the way to unconventional electron beam
shaping, imaging, and radiation generation.
