Carrier-envelope phase of single-cycle pulses generated through two-color laser filamentation

Abstract

Carrier-envelope phase (CEP) of the single-cycle pulses generated through two-color filamentation has been investigated. It has been found that the phase of high frequency components of the generated pulses changes continuously and linearly with the relative phase between the two-color input pulses, whereas the phase of the low frequency components takes only two discrete values. To our knowledge, such behavior of the phase has never been discussed before. The transition of the phase behavior has been clearly observed by using frequencyresolved optical gating capable of CEP determination.