Figure 4. Rapid waveform reconfiguration using a silicon modulator.

(a) An optical image of a rapidly reconfigurable AWG chip fabricated in a CMOS manufacturing foundry. The AWG chip consists of an eight-channel silicon pulse shaper and a silicon free-carrier depletion effect based intensity modulator embedded in the 8th channel of the shaper. The replica generation rings are not shown in the optical image. The inset is a scanning electron microscope picture of a tuneable delay line. (b) Experimental set-up. PC, polarization controller; PD, photodetector; PG, pattern generator. (c) Amplitude control of individual pulses through resonance mismatching between the replica generation and recombination rings. ch1, channel 1. (d) Two consecutive RF bursts show rapid amplitude modulation of the last pulse in the waveforms through a synchronously driven silicon intensity modulator.