Abstract

Subpicosecond electrical pulses were recently generated by photoconductively shorting a charged copianar transmission line with 80~fs laser pulses.¹ The 20-mm long transmission line was composed of three 5-μΓη wide lines separated by 10 pm, lithographically fabricated on an ion-implanted siiicon-on-sapphire (SOS) wafer. The ph.QtQCQo.ciu.ctwe shcctim, qc slidlco, contact ccettv od of excitation seems to be well matched to the propagating mode of the transmission line in that shorter pulses were obtained and they broadened less with propagation than their counterparts generated via photoconductive gaps. The optically sampled voltage pulses are shown in Fig. 1. Figure 1(a) is the generated pulse, sampled by a photoconductive gap 50 pm away from the generating beam spot. After 8-mm propagation the puise broadened and reshaped as shown in Fig. 1(b).

© 1986 Optical Society of America