Techniques and Results for a Study of Relativistic Birefringence using Particle-in-Cell Simulations*

Unique plasma behaviors emerge when electrons in a plasma are driven to relativistic velocities by an intense laser pulse (>10¹⁸ W/cm²). Two effects in this regime, Relativistic Transparency and Relativistic Birefringence, have been proposed for possible use in plasma-based optics. Experimental efforts at the Scarlet Laser Facility explored these effects along with a complementary simulation campaign using a novel particle-in-cell pump-probe (two laser) methodology. In this work, we present techniques developed to analyze Relativistic Birefringence using particle-in-cell simulations as well as preliminary results from the simulation campaign.