By using stochastic theory, we analyze the non-Markovian temporal behavior in four types of photon echoes, including the two-pulse echo, stimulated echo, accumulated echo, and heterodyne-detected accumulated echo. In particular, the origin of the exp(- ${\mathit{ct}}^{3}$ ) dependence of the two-pulse echo in the limit of slow modulation is discussed in detail. It is also pointed out that, at the slow-modulation limit, the temporal behavior of the stimulated echo changes from exp(- ${\mathit{ct}}^{3}$ ) dependence to exp(- ${\mathit{ct}}^{2}$ ) dependence as the waiting time (the time interval between the second and the third excitation pulses) is varied.By using stochastic theory, we analyze the non-Markovian temporal behavior in four types of photon echoes, including the two-pulse echo, stimulated echo, accumulated echo, and heterodyne-detected accumulated echo. In particular, the origin of the exp(-${\mathit{ct}}^{3}$) dependence of the two-pulse echo in the limit of slow modulation is discussed in detail. It is also pointed out that, at the slow-modulation limit, the temporal behavior of the stimulated echo changes from exp(-${\mathit{ct}}^{3}$) dependence to exp(-${\mathit{ct}}^{2}$) dependence as the waiting time (the time interval between the second and the third excitation pulses) is varied.

Physical Review ADec 1, 199210 citations

Stimulated Photon Echo Induced by Broad-Bandwidth Pulses

Vladimir Finkelstein, P. R. Berman

Springer eBooksJan 1, 19890 citations

Pattern recognition by photon echoes

P. Talagala, M. K. Kim

We demonstrate, we believe for the first time, the capability of spatial pattern recognition by backward stimulated photon echo (BSPE) in a low temperature solid activated by rare earth ions. The BSPE experiment is done with three time-delayed input laser pulses. The first pulse (DATA) contains several characters in its beam profile, the second pulse (WRITE) is a plane wave, and the third (READ) has the search character. The echo pulse profile has peak intensity at the position of the search character. The experiment has a time scale of several tens of nanoseconds. Pattern recognition by BSPE is a result of the convolution/correlation property of holographic four-wave mixing geometry. In contrast to the photorefractive processes, however, the BSPE in rare earth-doped solids is a resonant coherent optical transient effect. By combining spatial and temporal holographic processes of BSPE, it would be possible to construct a high density, high speed optical processor of spatial and temporal data using BSPE.We demonstrate, we believe for the first time, the capability of spatial pattern recognition by backward stimulated photon echo (BSPE) in a low temperature solid activated by rare earth ions. The BSPE experiment is done with three time-delayed input laser pulses. The first pulse (DATA) contains several characters in its beam profile, the second pulse (WRITE) is a plane wave, and the third (READ) has the search character. The echo pulse profile has peak intensity at the position of the search character. The experiment has a time scale of several tens of nanoseconds. Pattern recognition by BSPE is a result of the convolution/correlation property of holographic four-wave mixing geometry. In contrast to the photorefractive processes, however, the BSPE in rare earth-doped solids is a resonant coherent optical transient effect. By combining spatial and temporal holographic processes of BSPE, it would be possible to construct a high density, high speed optical processor of spatial and temporal data using BSPE.

Annual Meeting Optical Society of AmericaJan 1, 19910 citations

Spectral programming of temporal pulse sequences using photon echoes

B. Luo, Ulf Elman, Stefan Kröll +1 more

Optical memories based on spectral hole burning (SHB) and stimulated photon echoes (SPE) are attracting much attention. Both approaches add an extra dimension for addressing (frequency and temporal dimension respectively) to the spatial dimensions. With these concepts the storage density can become 103 – 106 times higher than in conventional optical memories. In both approaches, the ratio of the inhomogeneous line width to the homogeneous line width of the ions activated in the storage process determines the improvement in storage density. Compared to the SHB approach, SPE has certain advantages including high R/W rate and ability to process the stored (spatial as well we temporal) information. Using SPE, the authors have experimentally realised the AND, OR and NOT logical operations [1,2]. Further all optical processing, such as temporal pattern recognition, can be done using SPE.Optical memories based on spectral hole burning (SHB) and stimulated photon echoes (SPE) are attracting much attention. Both approaches add an extra dimension for addressing (frequency and temporal dimension respectively) to the spatial dimensions. With these concepts the storage density can become 103 – 106 times higher than in conventional optical memories. In both approaches, the ratio of the inhomogeneous line width to the homogeneous line width of the ions activated in the storage process determines the improvement in storage density. Compared to the SHB approach, SPE has certain advantages including high R/W rate and ability to process the stored (spatial as well we temporal) information. Using SPE, the authors have experimentally realised the AND, OR and NOT logical operations [1,2]. Further all optical processing, such as temporal pattern recognition, can be done using SPE.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)Jan 1, 19960 citations

{\mathit{ct}}^{3}

) dependence of the two-pulse echo in the limit of slow modulation is discussed in detail. It is also pointed out that, at the slow-modulation limit, the temporal behavior of the stimulated echo changes from exp(-

{\mathit{ct}}^{3}

) dependence to exp(-

{\mathit{ct}}^{2}

) dependence as the waiting time (the time interval between the second and the third excitation pulses) is varied.