A grating distributed in a volume is a high-resolution spectral filter. The pass band for such a grating at optical wavelengths is about 0.1 nm for centimeter-thick holograms. By recording multiple gratings it is possible to modulate independently the spectrum of pulsed lasers. This project applies this process to generate very high bandwidth optical signals and pulsed images.

Optical and electrooptical modulation of Bragg gratings in GaAs and L:NbO₃ is being used to create pulse shapers. These pulse shapers act as optical signal generators that can create arbitrary time domain fields.

Optical communications bandwidths are limited by electrical modulation bandwidths. Higher communications bandwidths are achieved using multiplexing schemes to encode parallel electrical signals onto serial or spectrally distributed channels. This project uses distributed Bragg optical pulse shapers and interferometric receivers to encode and decode time domain and coherence domain signals on optical carriers at modulation bandwidths approaching 1 THz.