Photonic Hilbert transformers based on laterally apodized integrated waveguide Bragg gratings on a SOI wafer.

We experimentally demonstrate high-performance integer and fractional-order photonic Hilbert transformers based on laterally apodized Bragg gratings in a silicon-on-insulator technology platform. The sub-millimeter-long gratings have been fabricated using single-etch electron beam lithography, and the resulting HT devices offer operation bandwidths approaching the THz range, with time-bandwidth products between 10 and 20.

Experimental demonstration of sub-picosecond optical pulse shaping in silicon based on discrete space-to-time mapping.

We experimentally demonstrate on-chip optical pulse shaping based on discrete space-to-time mapping in cascaded co-directional couplers. The demonstrated shapers validate a recent design methodology that exploits the direct relationship between the discrete complex spatial apodization profile of a structure of cascaded couplers and the time-domain impulse response of the device. In this design, the amplitude and phase of the apodization profile can be controlled through the coupling strength of each coupler and the relative time delay between the waveguides connecting consecutive couplers, respectively.

Optical pulse shaping based on discrete space-to-time mapping in cascaded co-directional couplers.

We propose and numerically validate a new design concept for on-chip optical pulse shaping based on discrete space-to-time mapping in cascaded co-directional couplers. We show that under weak-coupling conditions, the amplitude and phase of the discrete complex apodization profile of the device can be directly mapped into its temporal impulse response. In this scheme, the amplitude and phase of the apodization profile can be controlled by tuning the coupling strength and relative time delay between the couplers, respectively.