Abstract

Frequency-selective data storage (FSDS) offers a means of storing multiple data bits at single spatial locations. In one approach to FSDS (frequency-domain FSDS¹), distinct spectral storage cells are defined and are accessed by laser tuning. Operation with distinct spectral channels mandates that single-channel access times exceed the inverse channel width—a serious speed limit given the narrow channel widths Δv_h, necessary to fully utilize many storage materials. In another FSDS approach (time-domain FSDS²), distinct spectral channels are not used. Instead, data bits are encoded onto the temporal waveform of a data beam of maximum duration Δv_h⁻¹, and the Fourier transform of the data beam is recorded. Because individual bits are spectrally distributed, the speed limit of frequency-domain FSDS is circumvented. With time-domain FSDS, full material utilization requires that the data bandwidth span the available storage bandwidth—a requirement frequently impossible to satisfy.

© 1995 Optical Society of America