偏光状態が指定どおりに時間変化するフェムト秒パルスの発生

抄録

We demonstrate the generation of femtosecond pulses with targeted time-dependent polarization. In order to shape desired pulses, we feed back analyzed results from a homemade polarization characterization system. The characterization of momentary polarization is based on the Fourier transform analyses of dual-channel spectral interferometry. The genetic algorithm (GA) is employed to find optimum modulation parameters for the pulse shaper. We successfully shape femtosecond pulses whose ellipticity increases at a constant rate. With the target rate of 3.44×10^-3 fs^-1, we achieve pulses with the rate of 3.24×10^-3 fs^-1 at the 150 th generation of GA. The relative error between the shaped pulse and the target pulse is less than 6% over the main part of the pulse. This shows that our shaping technique is capable of shaping femtosecond pulses with desired timedependent polarization. Time-dependent polarization pulses have many potential applications as discussed in the text.