Polymeric Thin Films for Electro-Optic Modulator and High Density Optical Memory Applications

1995 ◽  
Vol 392 ◽  
Author(s):  
Larry R. Dalton ◽  
Aaron W. Harper ◽  
Zhiyong Liang ◽  
Jingsong Zhu ◽  
Uzi Efron ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Optical Waveguides ◽  
Optical Memory ◽  
High Density ◽  
Hole Burning ◽  
Spectral Hole Burning ◽  
Polymeric Thin Films ◽  
Buried Channel ◽  
Electro Optic ◽  
Memory Applications

AbstractChromophores capable of undergoing conformational changes when exposed to ultraviolet or visible light have been synthesized with functional groups permitting attachment to polymer matrices. One class of such chromophores, containing reactive functionalities at both ends of the chromophore, are referred to as double-end crosslinkable (DEC) chromophores. These chromophores are used in the synthesis of hardened nonlinear optically active lattices and in the fabrication of buried channel nonlinear optical waveguides by photoprocessing; development of such waveguides represents a critical step in the production of polymeric electro-optic modulators. Such chromophores are also crucial to the phenomena of laser-assisted poling (also known as photochemically-induced poling). Finally, these chromophores are attached to the surface of polystyrene beads permitting the realization of room temperature spectral hole burning exploiting morphology-dependent resonances. Such resonances provide the basis of wavelength coding for the development of high density optical memories.

Spectral hole-burning holography in optical memory systems

1993 ◽  
Author(s):  
Eric S. Maniloff ◽  
Stefan B. Altner ◽  
Stefan Bernet ◽  
Felix R. Graf ◽  
Alois Renn ◽  
...  
Keyword(s):  
Optical Memory ◽  
Memory Systems ◽  
Hole Burning ◽  
Spectral Hole Burning ◽  
Spectral Hole

scholarly journals The Role of Graphene Monolayers in Enhancing the Yield of Bacteriorhodopsin Photostates for Optical Memory Applications

2021 ◽  
Vol 11 (20) ◽  
pp. 9698
Author(s):  
Roma Patel ◽  
Gregory Salamone ◽  
Isaac Macwan
Keyword(s):  
Conformational Changes ◽  
Optical Memory ◽  
Single Layer ◽  
Md Simulations ◽  
Memory Storage ◽  
Single Layer Graphene ◽  
Salt Bridges ◽  
Retinal Chromophore ◽  
Memory Applications ◽  
Van Der Waals Energies

Bacteriorhodopsin (bR) is a photoactive protein that has gained increasing importance as a tool for optical memory storage due to its remarkable photochemical and thermal stability. The two stable photostates (bR and Q) obtained during the bR photocycle are appropriate to designate the binary bit 0 and 1, respectively. Such devices, however, have limited success due to a low quantum yield of the Q state. Many studies have used genetic and chemical modification as optimization strategies to increase the yield of the Q state. Nonetheless, this compromises the overall photochemical stability of bR. This paper introduces a unique way of stabilizing the conformations of bacteriorhodopsin and, thereby, the bR and Q photostates through adsorption onto graphene. All-atom molecular dynamics (MD) simulations with NAMD and CHARMM force fields have been used here to understand the interactive events at the interface of the retinal chromophore within bR and a single-layer graphene sheet. Based on the stable RMSD (~4.5 Å), secondary structure, interactive van der Waals energies (~3000 kcal/mol) and electrostatic energies (~2000 kcal/mol), it is found that the adsorption of bR onto graphene can stabilize its photochemical behavior. Furthermore, the optimal adsorption distance for bR is found to be ~4.25 Å from the surface of graphene, which is regulated by a number of interfacial water molecules and their hydrogen bonds. The conformations of the key amino acids around the retinal chromophore that are responsible for the proton transport are also found to be dependent on the adsorption of bR onto graphene. The quantity and lifetime of the salt bridges also indicate that more salt bridges were formed in the absence of graphene, whereas more were broken in the presence of it due to conformational changes. Finally, the analysis on the retinal dihedrals (C11 = C12-C13 = C14, C12-C13 = C14-C15, C13 = C14-C15 = NZ and C14-C15 = NZ-CE) show that bacteriorhodopsin in the presence of graphene exhibits increased stability and larger dihedral energy values.

FEMTOSECOND SPECTRAL HOLE-BURNING IN GaAs/AlGaAs MULTIPLE QUANTUM WELLS

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-511-C5-515 ◽  
Author(s):  
J. L. OUDAR ◽  
J. DUBARD ◽  
F. ALEXANDRE ◽  
D. HULIN ◽  
A. MIGUS ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Hole Burning ◽  
Spectral Hole Burning ◽  
Multiple Quantum ◽  
Spectral Hole

Investigation of the V4+-Centre in 6H- and 4H-SIC by the Method of Spectral-Hole Burning

1998 ◽  
Vol 512 ◽  
Author(s):  
C. Hecht ◽  
R. Kummer ◽  
A. Winnacker
Keyword(s):  
Electronic Properties ◽  
Room Temperature ◽  
Hole Burning ◽  
Band Offset ◽  
Spectral Hole Burning ◽  
Type Ii ◽  
Thermally Stable ◽  
Spectral Hole

ABSTRACTIn the context of spectral-hole burning experiments in 4H- and 6H-SiC doped with vanadium the energy positions of the V4+/5+ level in both polytypes were determined in order to resolve discrepancies in literature. From these numbers the band offset of 6H/4H-SiC is calculated by using the Langer-Heinrich rule, and found to be of staggered type II. Furthermore the experiments show that thermally stable electronic traps exist in both polytypes at room temperature and considerably above, which may result in longtime transient shifts of electronic properties.

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