Patent ID: 7701982

Claim:
An apparatus for stabilizing a carrier-envelope phase (CEP) of a laser pulse generated by a mode locked pulsed laser based on a direct locking method, the apparatus comprising: a laser oscillator including the mode locked pulsed laser generating the laser pulse; an interferometer generating laser pulses having first and second frequency components from the laser pulse generated by the mode locked pulsed laser to generate first and second interference signals that substantially correspond to each other in a time domain and a space domain; a detector receiving the first and second interference signals to output third and fourth interference signals by inverting a phase of the second interference signal; and a double feedback circuit controlling the laser oscillator so that the carrier-envelope phase (CEP) of the laser pulse generated by the mode locked pulsed laser has substantially a constant value with respect to time using a carrier-envelope phase (CEP) signal obtained from the third and fourth interference signals.