Emission of picosecond electromagnetic pulses from optically excited superconducting bridges

Abstract
In this paper we examine the origin of the emission of picosecond electromagnetic pulses from currentbiased superconducting bridges after optical excitation with femtosecond laser pulses. The peak frequency and the amplitude of the THz pulses are quantitatively correlated to the optically measured quasiparticle dynamics. We find that reflection and absorption within the superconductor fundamentally limit the ratio of the transmitted field amplitude to the generated signal to 103.