VIENNA, May 18, 2012 — The rainbow CEP4 is Femtolasers Produktions GmbH’s latest generation of carrier-envelope phase (CEP) stabilization-technique laser. Via a direct feed-forward approach, the CEP drift is corrected on-the-fly after the free-running, passively stable ultrafast oscillator. Zero phase slip (a train of pulses with identical waveform) is easy to achieve. The CEP4 is packaged in a compact and robust module available with the rainbow oscillator. The rainbow CEP4 generates ultrafast CEP stable few-cycle pulses, and CEP noise is reduced via an increased correction loop bandwidth. Applications include attoscience, ultrafast nano-optics, harmonic generation, and amplifier and optical parametric chirped-pulse amplifier seeding.