Spectral memory & other applications of spatial-spectral holography

Optical devices have been slower to mature than those based purely on electronics. Yet optical interactions offer a number of unique capabilities expected to support entirely new classes of devices-devices offering unprecedented performance in communications, computing, and data storage applications. In the present work, optical devices based on the interaction of light with frequency-selective recording materials are discussed. A frequency-selective recording material has the capability of supporting multiple independent recording channels. Each channel is addressed by light within a specific narrow band of optical frequencies. In some materials, operative at cryogenic temperatures, millions of distinct spectral channels are available. Through the mechanism of persistent spectral hole-burning, light can be employed to transiently or even permanently modify the absorptive or dispersive properties of the recording material within a selected channel. Such modifications provide a means of recording multiple bits of optical information within single spatial locations. Spectral multiplexing of information has clear potential in information storage systems. Less obviously, the ability to spectrally encode information provides an enabling basis for ultrahigh speed, content-controlled, all-optical switching devices operable at data speeds up to the Terabit/sec level.