Electromagnetic waves propagation in time-varying dielectric media and in a de Sitter spacetime

In this work we investigate the propagation of electromagnetic waves in a homogenous dielectric linear medium with time-varying electric permittivity modulated exponentially at constant rate and de Sitter spacetime. We demonstrate that classical quantum dynamics for both cases are equivalent can be mapped into damped harmonic oscillators which generated by similar Hamiltonians. By making use Lewis Riesenfeld invariant theory together Fock states solve time-dependent Schrödinger equation problem evaluate some important properties quantized light, such as coherent states, expectation values amplitude momentum each mode, their variances corresponding uncertainty principle.