Abstract

In a dispersive medium, phase and group velocity are different, inducing a slippage of the carrier frequency wave inside the envelope. This slippage is usually of no concern for long pulses but for ultra-short pulses, which contain few optical cycles, physical phenomena can strongly depend on the electric field and not only on its envelope [1]. It is, in this case, of prime importance to control the Carrier-Envelope Phase (CEP). Due to environmental effects, which are linked to variations of parameters of the system induced mainly by perturbations (vibrations, thermal drift…), laser systems emitting ultra-short pulses do not generate a train of pulses with the same value of the CEP. Different techniques already exist to stabilize the CEP of the amplified pulses of a CPA laser system seeded by a CEP stabilized mode locked oscillator. They are mainly based on a slow feedback loop containing a f-2f interferometer [2]. These techniques can be split into two categories. In the first one, the correction is made by modifying parameters inside the cavity of the mode-locked oscillator [3]. In the second one, the corrections are made outside the mode-locked oscillator [4-7].

© 2011 Optical Society of America