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An ultrashort pulse laser system with precisely controlled output-timing and carrier-envelope phase (CEP) is reported.
Recently developed technology Ofl CEP control of a mode-locked laser not only introduced an optical frequency comh
in frequency domain hut also gave us a way to generate optical pulses whose oscillating electric field is under a fixed
phase relation with the intensity shape. Fortunately, recent advances on optical physics have also showed that sonic types
of light-matter interactions become sensitive to the field shape when the pulse approaches a few cycles in duration and
has a high peak intensity. Owing to those advances, field-controlled ultrashort pulse generation, based on
suh-femtosecond resolution timing-control and sub-radian CEP control of femtosecond lasers, becomes an attractive
challenge. Our final goal is to realize a shaped electric field within optical-cycle time scale br researches on light-matter
interaction and other future application.
CEP control Ofl a mode-locked Ti:sapphire laser is the first step of such a laser system. Trade-off between the
accuracy and robustness of the control, and the monitoring technique of CEP br amplilication, will he discussed.
Amplification of a CEP-controlled pulse, which is necessary for most of time-domain application, is successfully
performed by the CEP monitoring technique. Our chirped-pulse amplifier, that includes a grating-based
stretcher/compressor, has a potential to achieve higher-energy amplification of a fixed CEP pulse. Multichannel phase
control of spectrally divided ultrashort pulses is applied to dynamic control of pulse-timing and CEP of amplifled pulses.
Related results on short-pulse, sub-l3fs, generation by a chirped-pulse Ti:sapphire amplifier, and multicolor
phase-coherent pulse sources will be also discussed briefly, showing our on-going efforts to approach the final goal.
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