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Ferroelectric RAM is a random-access memory similar in construction to DRAM but using a ferroelectric layer instead of a dielectric layer to achieve non-volatility. FeRAM is one of a growing number of alternative non-volatile random-access memory technologies that offer the same functionality as flash memory. An FeRAM chip contains a thin film of ferroelectric material, often lead zirconate titanate, commonly referred to as PZT. The atoms in the PZT layer change polarity in an electric field, thereby producing a power-efficient binary switch. However, the most important aspect of the PZT is that it is not affected by power disruption or magnetic interference, making FeRAM a reliable nonvolatile memory.
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In physics, photon-induced electric field poling is a phenomenon whereby a pattern of local electric field orientations can be encoded in a suitable ferroelectric material, such as perovskite. The resulting encoded material is conceptually similar to the pattern of magnetic field orientations within the magnetic domains of a ferromagnet, and thus may be considered as a possible technology for computer storage media. The encoded regions are optically active and thus may be "read out" optically.
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An optical modulator is an optical device which is used to modulate a beam of light with a perturbation device. It is a kind of transmitter to convert information to optical binary signal through optical fiber or transmission medium of optical frequency in fiber optic communication. There are several methods to manipulate this device depending on the parameter of a light beam like amplitude modulator (majority), phase modulator, polarization modulator etc. The easiest way to obtain modulation is modulation of intensity of a light by the current driving the light source. This sort of modulation is called direct modulation, as opposed to the external modulation performed by a light modulator. For this reason, light modulators are called external light modulators. According to manipulation of the properties of material modulators are divided into two groups, absorptive modulators and refractive modulators. Absorption coefficient can be manipulated by Franz-Keldysh effect, Quantum-Confined Stark Effect, excitonic absorption, or changes of free carrier concentration. Usually, if several such effects appear together, the modulator is called electro-absorptive modulator. Refractive modulators most often make use of electro-optic effect, other modulators are made with acousto-optic effect, magneto-optic effect such as Faraday and Cotton-Mouton effects. The other case of modulators is spatial light modulator (SLM) which is modified two dimensional distribution of amplitude & phase of an optical wave.
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Kenji Uchino is an American electronics engineer, physicist, academic, inventor and industry executive. He is currently a professor of Electrical Engineering at Pennsylvania State University, where he also directs the International Center for Actuators and Transducers at Materials Research Institute. He is the former associate director at The US Office of Naval Research – Global Tokyo Office.
A solaristor is a compact two-terminal self-powered phototransistor. The two-in-one transistor plus solar cell achieves the high-low current modulation by a memresistive effect in the flow of photogenerated carriers. The term was coined by Dr Amador Perez-Tomas working in collaboration with other ICN2 researchers in 2018 when they demonstrated the concept in a ferroelectric-oxide/organic bulk heterojunction solar cell.
References
- 1 2 3 4 5 Land, Cecil (2004). "Photoferroelectric imaging". McGraw-Hill Concise Encyclopedia of Science and Technology (5 ed.). New York: McGraw-Hill.
- ↑ Cecil E. Land (8 April 1981). Photoferroelectric Image Storage in PLZT Ceramics (PDF) (Report). Sandia National Labs. p. 1. Retrieved 4 April 2024.
PFE image storage devices are extremely sinple and easy to fabricate.
- ↑ D. Dimos and R. W. Schwartz (24 October 1991). "Electrooptic Properties of PZT Thin Films for Image Storage Applications". Mat. Res. Soc. Symp. Proc. Vol. 243. Materials Research Society. p. 73. doi:10.1557/PROC-243-73.
Transparent ferroelectric ceramics based on PLZT solid solutions, have been shown to exhibit a combination of properties, such as large electrooptic coefficients, high (intrinsic and extrinsic) photosensitivities, and nonvolatile memory, that make them suitable for optical information storage and processing applications.
- 1 2 3 Haertling, Gene H. (17 July 1986). "PLZT electrooptic materials and applications—a review 🔍". Ferroelectrics. 75 (1): 41, 43. doi:10.1080/00150198708008208 . Retrieved 7 April 2024.
- ↑ ICMAB-Institute de Sciencia de Materials de Barcelona (20 January 2021). "Storing information with light". Phys.org. Retrieved 1 April 2024.