Abstract

Advances in ultrafast laser technology led to the generation of optical pulses that comprise less than 3 optical cycles within their FWHM directly from mode-locked lasers.¹ Further progress in femtosecond oscillator technology² are expected to yield shorter pulses in the near future. As the pulse duration approaches the optical oscillation period, a parameter that has not received attention previously, namely the phase of the electric field at pulse center, ψ gains rapidly increasing significance. This becomes apparent by comparing the electric field evolution in two pulses having identical envelopes but different carrier phases, as shown in Fig. 1.

© 1996 Optical Society of America