Dielectric laser-driven accelerators (DLAs) based on grating structures are considered to be one of
the most promising technologies to reduce the size and cost of future particle accelerators. They
offer high accelerating gradients of up to several GV/m in combination with mature lithographic
techniques for structure fabrication. This paper numerically investigates the beam quality for acceleration of electrons in a realistic dual-grating DLA. In our simulations, we use beam parameters of the future Compact Linear Accelerator for Research and Applications facility to load an electron bunch into an optimized 100-period dual-grating structure where it interacts with a realistic laser pulse. The emittance, energy spread, and loaded accelerating gradient for modulated electrons are then analyzed in detail. Results from simulations show that an accelerating gradient of up to 1.13 6 0.15 GV/m with an extremely small emittance growth, 3.6%, can be expected.