Generation of ultrashort optical pulses by efficient 10-GHz-order electrooptic deflector

摘要

We have experimentally demonstrated ultrashort optical pulse generation from a continuous wave (CW) laser using an external electrooptic deflector (EOD). Highly efficient EOD operating at 16.25 GHz has been realized with periodically domain-inverted LiTaO_3 crystal. The shape of domain inversion region has been theoretically designed in consideration of the velocity mismatching between the modulation microwave and the light so as to realize spatially linearly-varying phase shift. The deflected CW Ar laser beam passed the Fourier transform lens, and then optical pulses were picked out at a repetition rate of 32.5 GHz through a narrow slit, which was placed at the focal point of the lens. The pulses were observed by streak camera (Hamamatsu: C5948) and the achieved shortest pulse width was estimated to be 0.9 ± 0.1 ps.