Scattering at a Superluminal Arbitrarily Decelerating Interface

We present a general analytical solution to the electromagnetic scattering problem at an arbitrarily decelerating interface in the superluminal regime, employing the same methodology of its already addressed counterpart, the subluminal regime. We demonstrate that the solutions in both regimes exhibit similar forms while elucidating their differences. Furthermore, our analysis reveals that arbitrary chirping also occurs in the superluminal regime, albeit constrained. This work constitutes a notable progression in the development of accelerated space-time engineered modulation crystals, offering substantial potential for integration into microwave and optical devices that depend on chirp-based functionalities.