Santa Clara, CA--Coherent has unveiled a complete carrier-envelope-phase (CEP)-stabilized ultrafast amplifier system, which it calls the only such system designed, built, and supported by a single manufacturer.
Seeded by the Coherent Micra CEP oscillator, the Legend Elite CEP amplifier delivers a sub-35 fs pulse duration with a repetition rate of 1 kHz. The CEP-stabilized system is currently available with up to 4 W of average power and 4 mJ per pulse; more configurations will be released in the near future. The final carrier-envelope-offset stability depends on the operating environment, with a typical laboratory performance better than 200 mrad.
f-2f interferometer detects offset
Carrier envelope phase stabilization 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 stabilization requires low-noise system components and a low-noise operating environment. Coherent says that its Verdi is currently the only oscillator pump to provide sufficiently low noise for CEP operation, and thus Coherent is the only laser manufacturer capable of providing a complete off-the-shelf CEP-stabilized system.
Principal applications are attosecond physics, coherent X-ray generation, and other experiments relying on highly nonlinear optical processes.