Time-domain optical data storage by photon echo

R Krishna Mohan, Ulf Elman, Ming Tian +2 more

Jin Y. Choi, John F. Walkup, Thomas F. Krile +1 more

Time-domain optical data storage using photon echoes has received increasing attention in recent years. A particularly attractive feature of a time domain memory is the ability to store many bits of information in a very small spot and thereby increase the data storage density. In time domain memory based on photon echoes, the Fourier transform of the input data is written into the inhomogeneous linewidth.

В. А. Зуйков, I. I. Popov, Tatiana G. Mitrofanova +1 more

Yong R. Kim

The photon echo is unique among nonlinear optical effects in that it involves interference and diffraction in both space and time domain. This intrinsic spatio-temporal property offers multitude of interesting and useful applications in optical storage and processing of temporally as well as spatially encoded data. In this paper we consider the possibility of using stimulated photon echo (SPE) to implement all-optical associative memory of spatial data.

В. В. Самарцев, В. А. Зуйков, L. A. Nefedev

Masaharu Mitsunaga

The photon-echo memory[1], or the time-domain optical data storage, resembles the hole-burning memory [2] in that the inhomogeneous absorption line of a material is employed as a storage medium and the information is stored in it as a frequency-dependent absorption change with the resolution determined by the homogeneous width. Having the common memory capacity N given by the inhomogeneous-to-homogeneous width ratio, both types of memories share common problems like low-temperature operation, spectral diffusion and so on. Although a storage medium is common, storage techniques are definitely different for the two memories. The photon-echo memory utilizes the temporal interference effect between a reference pulse and a data pulse and their interference pattern is stored as a population grating in the frequency domain. In this sense this is a time-domain analog of holography where the spatial interference pattern between a reference beam and a data beam is stored in a medium as a population grating in the real space. Like the spatially diffracted beam from the read beam gives the information stored in the hologram, the “temporally diffracted pulse", or the photon echo, after the read pulse can give the information stored in the inhomogeneous distribution.