Polarisation effects in reflection of ultrashort single-cycle pulses from semiconductors and metals

A model, capable of providing an analytic solution, is proposed for describ ing the reflection and refraction of polarised ultrashort single-cycle puls es (i.e. pulses with durations as short as one or several oscillations of t he field) with an asymmetric nonsinusoidal envelope on the surfaces of disp ersive and conducting media. The fields excited by single-cycle pulses in t hese media are represented by novel transient solutions of the Maxwell equa tions, obtained directly in the time domain without separation of variables and without Fourier expansions. This approach yields simple formulas for t he reflection coefficients of s- and p-polarised single-cycle pulses with L aguerre envelopes, incident at arbitrary angles. The Fresnel, Snell, and Br ewster formulas are generalised. It is shown that the reflection coefficien ts and the angles of refraction of a single-cycle pulse depend on the chara cteristic duration of the envelope of such a pulse and on the relaxation ti me of the field in the investigated medium.