We describe a new approach to develop a high-speed, high-density random access cache memory. This new technique

ABSTRACT We describe a new approach to develop a high-speed, high-density random access cache memory. This new techniqueis based on a novel approach using, in essence, a hybrid of the time domain stimulated echo (SE) concept and the frequencydomain scheme. It has been demonstrated that the rare-earth doped crystals, can at low temperatures store large amounts of information for up to 24 hours using SE. The basic approach we have developed is the partitioning of the absorption frequency domain into smaller bins, so that each frequency bin stores a smaller portion of information independently. Thebins are distinguishable by their different absorption frequencies and they are accessed by changing the laser frequency (color).However, information is still stored and retrieved using the time-domain pulse sequency used in SE. Specifically, with the laser frequency set at the particular absorption of a frequency bin, the laser is externally modulated by an acousto-optic modulator to produce amplitude modulated pulses representing the digital data, the write pulse, and the read pulse, during thewrite and retrieve operation, respectively. The advantages of this approach are that memory can be stored in space, time, andfrequency domain, allowing us to tailor a flexible memory architecture to match those of the computational processor.