Frequency-selective time-domain optical data storage by electromagnetically induced transparency in a rare-earth-doped solid

1997 ◽  
Vol 22 (24) ◽  
pp. 1849 ◽  
Author(s):  
B. S. Ham ◽  
M. S. Shahriar ◽  
M. K. Kim ◽  
P. R. Hemmer
Keyword(s):  
Rare Earth ◽  
Data Storage ◽  
Time Domain ◽  
Electromagnetically Induced Transparency ◽  
Optical Data Storage ◽  
Optical Data ◽  
Frequency Selective ◽  
Induced Transparency ◽  
Rare Earth Doped

Upconversion Luminescence Behaviour of Er3+/Yb3+ Doped MY2O4 (M=Ba, Ca, Sr) Phosphors

2018 ◽  
pp. 117-148
Author(s):  
Vikas Dubey ◽  
Neha Dubey ◽  
Ravi Shrivastava ◽  
Jagjeet KaurSaluja ◽  
Sudipta Som ◽  
...  
Keyword(s):  
Rare Earth ◽  
Data Storage ◽  
Upconversion Luminescence ◽  
Optical Transmittance ◽  
Optical Data Storage ◽  
Optical Data ◽  
High Optical Transmittance ◽  
Potential Applications ◽  
Rare Earth Doped ◽  
Upconversion Process

The upconversion (UC) of the rare earth doped MY2O4 (M=Ba, Sr, Ca) has been extensively investigated due to their potential applications in many fields, such as color display, high density memories, optical data storage, sensor and energy solar cell, etc. Many series of them, especially the Er3+, Yb3+ doped MY2O4 were studied in this chapter, due to the thermal and mechanical toughness, high optical transmittance from the ultraviolet to the infrared regions, and a low nonlinear refractive index compared to the other commercial laser glasses. The energy transfer (ET) mechanism of rare earth doped phosphor plays an important role in the upconversion process.

Spectral Data Storage Using Rare-Earth-Doped Crystals

MRS Bulletin ◽  
1999 ◽  
Vol 24 (9) ◽  
pp. 46-50 ◽  
Author(s):  
Eric S. Maniloff ◽  
Alan E. Johnson ◽  
Thomas W. Mossberg
Keyword(s):  
Rare Earth ◽  
Absorption Line ◽  
Data Storage ◽  
Optical Data Storage ◽  
Optical Data ◽  
Hole Burning ◽  
Spectral Hole Burning ◽  
Line Broadening ◽  
Spectral Hole ◽  
Rare Earth Doped

Conventional optical data-storage techniques, such as magneto-optic disks and CD-ROMs, record a single bit of information at each particular substrate location. In order to produce the gigabyte-class storage substrates demanded by today's computers using such conventional technologies, access to tens of billions of individual material locations is required. This brute-force approach to optical data storage has produced impressive results. However, there is increasing interest in methods for more efficiently accessing storage materials. One approach is to record multiple bits at a single storage-material location. This can be accomplished by multiplexing the bits spectrally, using differing optical frequencies to record data bits. It has been realized for over 20 years that when certain materials are cooled to appropriate temperatures, typically below 20 K, the possibility of spectrally multiplexing large numbers of bits in a single material location arises. Although this approach, known as spectral hole-burning, has been proposed as a data-storage mechanism, to date it has primarily been used as a tool to study material properties. Rare-earth-doped crystals have been demonstrated to have properties that lend themselves to a variety of different spectral hole-burning-based data-storage applications. In this article, we will review the principles of spectral hole-burning, discuss some specific material systems in which spectral hole-burning is of particular interest, and describe methods for producing high-capacity, high-data-rate spectral memories.Spectral hole-burning, and spectral memories based on spectral hole-burning, depend on a material property referred to as inhomogeneous absorption line broadening. Materials exhibiting this property contain active atoms or molecules that individually respond to (absorb) very specific frequencies of light, but the collective response of all of the material's active atoms or molecules covers a spectral region that is broad compared with the response of a particular active atom or molecule. Inhomogeneous absorption line broadening is caused by local variations in the structure of the host, which in turn lead to variations in the electronic levels of the active atoms or molecules. The absorption linewidth of an individual absorber is referred to as the homogeneous linewidth Γh, and the absorption width of a collection of inhomogeneously broadened absorption centers is referred to as the inhomogeneous linewidth Γi. Application of monochromatic light to such a material has the effect of exciting only a very small subset of active absorbing atoms—those residing in the illuminated spatial volume within a homogeneous width of the exciting light's specific frequency. If the frequency of the imposed light is shifted, a different subset of active absorbing atoms in the illuminated volume responds.

Ion-Assisted Deposition of Protective Overlayers for Magneto-Optic Alloys

1988 ◽  
Vol 128 ◽  
Author(s):  
Kenneth D. Cornett ◽  
Ursula J. Gibson ◽  
Anthony Taylor
Keyword(s):  
Rare Earth ◽  
Data Storage ◽  
Optical Data Storage ◽  
Optical Data ◽  
Iron Films ◽  
Transition Metal Alloys ◽  
Refractory Oxides ◽  
Porous Microstructure ◽  
Data Storage Materials ◽  
Magneto Optic

ABSTRACTRare-Earth Transition-Metal alloys such as Tb-Fe-Co are being studied and used as magneto-optic data storage materials. These materials are susceptible to oxidation by either oxygen or water vapor, particularly the rare earth component. Pitting corrosion is also a problem when protective overlayers have pinholes or a porous microstructure. Both degradation mechanisms are significant for application of this material to optical data storage. We have used ion assisted deposition (IAD) to produce protective overlayers of refractory oxides, such as Al2O2 and ZrO2. These layers were deposited both with and without IAD onto iron films and exposed to environments with controlled temperature and humidity. A scanning micro-reflectometer capable of detecting micrometer-sized pinholes was used to monitor the degradation of the iron layer with exposure time.

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