Coherent has launched its Legend Elite CEP ultrafast amplifier, which the company claims is the first and only complete CEP-stabilised ultrafast amplifier system designed, built and supported by a single manufacturer. Seeded by the Coherent Micra CEP oscillator, the new Legend Elite CEP delivers a sub-35fs pulse duration with a repetition rate of 1kHz. Legend Elite CEP is currently available up to 4W of average power and 4mJ per pulse, with more configurations to be released in the near future. The final carrier envelope offset (CEO) stability depends on the operating environment, with typical laboratory performance better than 200mrad.
Carrier envelope phase (CEP) stabilisation refers to fixing the temporal relationship between the overall ultrafast pulse envelope and the underlying electric field oscillations. In the Legend Elite CEP, the offset is detected by the well-established f-2f interferometer method, and this feedback signal is used to actively control the dispersion of the amplifier cavity by changing the relative angle of the dispersion compensation gratings. Successful CEP stabilisation requires low-noise system components and a low-noise operating environment. Since Coherent Verdi is currently the only oscillator pump to provide sufficiently low noise for CEP operation, Coherent is the only laser manufacturer capable of providing a complete off-the-shelf solution for this fast growing field of research.
Principal applications for the Legend Elite CEP are attosecond physics, coherent X-ray generation, and several other sophisticated experiments relying on highly non-linear optical processes.