Measurement and self-stabilization of carrier-envelope phase drift by use of an optical parametric amplifier

Abstract

Summary form only given. We show that severe technical problems associated with the practical implementation of the active carrier-envelope phase (CEP) control at kHz repetition rates can be readily obviated by employing unique properties of parametric amplification. We prove that the self-stabilization of the CEP is achieved in an OPA seeded with a white light that is derived from the pump pulse. The mechanism enabling this regime relies on a combination of three principal effects: 1) The pulse-to-pulse fluctuation of CEP (although not the CEP value itself), is inherited by the white-light continuum pulse from the input laser pulse. This fact is widely utilized in the CEP drift measurement based on the generation of octave-spanning spectra and creating a spectral overlap with the second-harmonic (SH) radiation. 2) In a similar way, in a seeded optical parametric amplifier, the CEP fluctuation is passed from the seed wave onto the amplified signal. This is a characteristic feature of white-light seeded OPAs only, since the CEP value of the signal wave is random in an OPA seeded by superfluorescence. 3) The phases of all three pulses taking part in a parametric interaction are linked, which can be described by a simplified phase equation. The phase properties of different white-light seeded OPAs are summarized. We believe that this work provides a new insight into the experimental capabilities of various OPA systems and opens attractive possibilities of their use in the applications of nonlinear optics with demands for sub-fringe resolution.