Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Japanese Journal of Applied Physics

Stimulated Electronic Transition Concept for an Erasable Optical Memory

Sacharia Albin, James D. Satira, David L. Livingston

Published Feb 1, 1992• 42 citations
Publisher

Abstract

A new concept for an erasable optical memory is demonstrated using stimulated electronic transition (SET). Large bandgap semiconductors are suitable materials for the SET medium. We have investigated the properties of MgS:Eu, Sm and SrS:Eu, Sm as possible media for the SET process. Quantum storage is achieved in the form of charges in deep levels in the medium and stimulated radiative recombination is used as the reading process. Unlike magneto-optic (M-O) and phase change (PC) processes, optical writing, reading and erasing are achieved without localized heating. The SET process will have an inherently faster data transfer rate and a higher storage density, and the medium will be more durable than the M-O and PC media. A possible application of the SET process in neural networks is also discussed.

DOI
10.1143/jjap.31.715

Related papers

Erasable optical memory using stimulated electronic transition concept

Sacharia Albin, James D. Satira, Linwood Watkins +1 more

Mass storage optical memory for use aboard unmanned orbital space platforms are currently under development by NASA. These storage systems with large information capacities, high data transfer rates, and high mean time between failures are needed. An optical system using stimulated electronic transition (SET) concept would be ideal for this application. For a single reading and writing beam system, the estimated storage capacity of 66 Gbits per disk, and a data transfer rate of 186 Mbits per second can be achieved. There are several oxide and sulfide materials that can be doped with rare earth elements to produce SET for optical storage. Unlike magneto-optic and phase change processes, the SET concept does not involve localized heating which produces material fatigue. Since electronic transitions are the only processes involved in SET storage, the disk will have an infinite lifetime.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 1, 1990•1 citation

Erbium-Based Photonic Flip-Flop Memories: Model and Experimental Validation

Luca Potì

Operating principle for a flip-flop memory cell based on erbium-doped devices is presented. A complete model for memory dynamics is introduced taking into account, at the same time, for memory writing, reading, and erasing. Simple equations are found relating writing, spontaneous and stimulated erasing times to device physical parameters, signals wavelength and power. In principle, for example, increasing writing and erasing energies at the appropriate wavelength it is possible to dramatically reduce transition times. Extinction ratio (ER) is also determined as a function of host medium, and signals properties. An optimization technique is proposed for erasing signal design in order to guarantee maximum ER. Numerical example are provided for Er and Er-Yb doped fibers whose doping ion density is rho = 1.1413middot1024ions/m3, and 2.0 middot1025ions/m3, respectively. Finally, an experimental demonstration giving an Er higher than 5 and 16 dB for the two fibers, respectively, is provided and discussed.

IEEE Journal of Quantum Electronics•Mar 12, 2008•6 citations

Optical memory effect in Si:Er

M. Forcales, T. Gregorkiewicz

In spite of a small and indirect bandgap, silicon features properties that are potentially very attractive for optical applications. The unsurpassed level of impurity control leads to suppression of nonradiative recombination paths and provides for a very long minority carrier lifetime. Up to the present, observation of an optical memory effect has not been reported for crystalline silicon (c-Si). In contrast, it has been observed in GaAs and GaN. In this study, we have used c-Si doped with erbium (Er) ions, since the trivalent Er3+ ion emits at a wavelength of 1.54 μm that is suitable for telecommunication applications. In a two-color experiment, utilizing a Nd:YAG pulse excitation as a writing beam and a free-electron laser (FEL) as a reading beam, we revealed that Si exhibits optical memory and afterglow effects at low temperatures T<50 K. Both effects are, in fact, manifestations of the properties of Si itself, conveniently revealed by the optical dopant. Detailed investigations of the FEL-induced emission at 1.54 μm show that this excitation mechanism is governed by the release of a single type of charge carrier. This implies that hole and electron capture events necessary for the Er excitation could, in principle, be separated in time. Therefore it appears possible to combine optical and electrical write/read procedures for the reported memory effect.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jun 30, 2003•0 citations

Random-access stimulated-echo optical cache memory

Ravinder Kachru, Yu Bai, Xiao A. Shen +1 more

We describe a new approach to develop a high-speed, high-density random access cache memory. This new technique is based on a novel approach using, in essence, a hybrid of the time domain stimulated echo (SE) concept and the frequency domain 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. The bins 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 the write and retrieve operation, respectively. The advantages of this approach are that memory can be stored in space, time, and frequency domain, allowing us to tailor a flexible memory architecture to match those of the computational processor.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 1, 1992•2 citations

Stimulated Electronic Transition Concept for an Erasable Optical Memory : Future Technology

Sacharia Albin, James D. Satira, David L. Livingston +1 more

JJAP series•Mar 31, 1992•0 citations

Photon echoes retrieved from semiconductor spins: access to basis for long-term optical memories

Lukas Langer, S. V. Poltavtsev, I. A. Yugova +6 more

The possibility to store optical information is important for classical and quantum communication. Atoms or ions as well as color centers in crystals offer suitable two-level systems for absorbing incoming photons. To obtain a reliable transfer of coherence, strong enough light-matter interaction is required, which may enforce use of ensembles of absorbers, but has the disadvantage of unavoidable inhomogeneities leading to fast dephasing. This obstacle can be overcome by echo techniques that allow recovery of the information as long as the coherence is preserved. Albeit semiconductor quantum structures appear appealing for information storage due to the large oscillator strength of optical transitions, inhomogeneity typically is even more pronounced for them and most importantly the optical coherence is limited to nanoseconds or shorter. Here we show that by transferring the information to electron spins the storage times for the optical coherence can be extended by orders of magnitude up to the spin relaxation time. From the spin reservoir it can be retrieved on purpose by inducing a stimulated photon echo. We demonstrate this for an n-doped CdTe/(Cd,Mg)Te quantum well for which the storage time thereby could be increased by more than three orders of magnitude from the picosecond-range up to tens of nanoseconds.

arXiv:1401.3377•Jan 14, 2014•0 citations
A new concept for an erasable optical memory is demonstrated using stimulated electronic transition (SET). Large bandgap semiconductors are suitable materials for the SET medium. We have investigated the properties of MgS:Eu, Sm and SrS:Eu, Sm as possible media for the SET process. Quantum storage is achieved in the form of charges in deep levels in the medium and stimulated radiative recombination is used as the reading process. Unlike magneto-optic (M-O) and phase change (PC) processes, optical writing, reading and erasing are achieved without localized heating. The SET process will have an inherently faster data transfer rate and a higher storage density, and the medium will be more durable than the M-O and PC media. A possible application of the SET process in neural networks is also discussed.
Mass storage optical memory for use aboard unmanned orbital space platforms are currently under development by NASA. These storage systems with large information capacities, high data transfer rates, and high mean time between failures are needed. An optical system using stimulated electronic transition (SET) concept would be ideal for this application. For a single reading and writing beam system, the estimated storage capacity of 66 Gbits per disk, and a data transfer rate of 186 Mbits per second can be achieved. There are several oxide and sulfide materials that can be doped with rare earth elements to produce SET for optical storage. Unlike magneto-optic and phase change processes, the SET concept does not involve localized heating which produces material fatigue. Since electronic transitions are the only processes involved in SET storage, the disk will have an infinite lifetime.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Operating principle for a flip-flop memory cell based on erbium-doped devices is presented. A complete model for memory dynamics is introduced taking into account, at the same time, for memory writing, reading, and erasing. Simple equations are found relating writing, spontaneous and stimulated erasing times to device physical parameters, signals wavelength and power. In principle, for example, increasing writing and erasing energies at the appropriate wavelength it is possible to dramatically reduce transition times. Extinction ratio (ER) is also determined as a function of host medium, and signals properties. An optimization technique is proposed for erasing signal design in order to guarantee maximum ER. Numerical example are provided for Er and Er-Yb doped fibers whose doping ion density is rho = 1.1413middot1024ions/m3, and 2.0 middot1025ions/m3, respectively. Finally, an experimental demonstration giving an Er higher than 5 and 16 dB for the two fibers, respectively, is provided and discussed.
In spite of a small and indirect bandgap, silicon features properties that are potentially very attractive for optical applications. The unsurpassed level of impurity control leads to suppression of nonradiative recombination paths and provides for a very long minority carrier lifetime. Up to the present, observation of an optical memory effect has not been reported for crystalline silicon (c-Si). In contrast, it has been observed in GaAs and GaN. In this study, we have used c-Si doped with erbium (Er) ions, since the trivalent Er3+ ion emits at a wavelength of 1.54 μm that is suitable for telecommunication applications. In a two-color experiment, utilizing a Nd:YAG pulse excitation as a writing beam and a free-electron laser (FEL) as a reading beam, we revealed that Si exhibits optical memory and afterglow effects at low temperatures T<50 K. Both effects are, in fact, manifestations of the properties of Si itself, conveniently revealed by the optical dopant. Detailed investigations of the FEL-induced emission at 1.54 μm show that this excitation mechanism is governed by the release of a single type of charge carrier. This implies that hole and electron capture events necessary for the Er excitation could, in principle, be separated in time. Therefore it appears possible to combine optical and electrical write/read procedures for the reported memory effect.
We describe a new approach to develop a high-speed, high-density random access cache memory. This new technique is based on a novel approach using, in essence, a hybrid of the time domain stimulated echo (SE) concept and the frequency domain 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. The bins 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 the write and retrieve operation, respectively. The advantages of this approach are that memory can be stored in space, time, and frequency domain, allowing us to tailor a flexible memory architecture to match those of the computational processor.
The possibility to store optical information is important for classical and quantum communication. Atoms or ions as well as color centers in crystals offer suitable two-level systems for absorbing incoming photons. To obtain a reliable transfer of coherence, strong enough light-matter interaction is required, which may enforce use of ensembles of absorbers, but has the disadvantage of unavoidable inhomogeneities leading to fast dephasing. This obstacle can be overcome by echo techniques that allow recovery of the information as long as the coherence is preserved. Albeit semiconductor quantum structures appear appealing for information storage due to the large oscillator strength of optical transitions, inhomogeneity typically is even more pronounced for them and most importantly the optical coherence is limited to nanoseconds or shorter. Here we show that by transferring the information to electron spins the storage times for the optical coherence can be extended by orders of magnitude up to the spin relaxation time. From the spin reservoir it can be retrieved on purpose by inducing a stimulated photon echo. We demonstrate this for an n-doped CdTe/(Cd,Mg)Te quantum well for which the storage time thereby could be increased by more than three orders of magnitude from the picosecond-range up to tens of nanoseconds.