Compact collinear staging of laser wakefield acceleration

The concept of arbitrarily structed laser (ASTRL) pulses, in which envelope properties of a laser pulse (e.g., focal position, spot size, centroid, OAM, polarization, and frequency shifts) can vary with axial slice and not just propogation distance, opens up new and interesting laser-plasma interactions. One application of ASTRL pulses is for addressing dephasing in LWFA-based linear colliders. To address dephasing, current designs employ many stages, each operating at a low plasma density, which limits the acceleration gradient and elongates both the individual stages and total collider length. In this work, we explore the possibility of using ASTRL pulses to create a compact, continuously staged bubble-regime LWFA in high-density plasma. By chaining together discrete pulses with controlled delays, powers, spot sizes, durations, polarizations, or focal positions, ASTRL pulses allow for the formation of a highly tunable flying focus that moves at the vacuum speed of light in plasma. In addition, the use of periodic density gaps mitigates distortion of the accelerating structure by dispelling depleted, red-shifted laser light. We present preliminary simulations using the OSIRIS-validated quasistatic particle-in-cell code QPAD for 800nm laser light at a plasma density of 3e18 cm^{-3}.