scholarly journals All-optical dynamic tuning of local excitonic emission of monolayer MoS2 by integration with Ge2Sb2Te5

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2351-2359
Author(s):  
Hao Ouyang ◽  
Haitao Chen ◽  
Yuxiang Tang ◽  
Jun Zhang ◽  
Chenxi Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Optical Networks ◽  
Dominant Role ◽  
Laser Pulses ◽  
Coulomb Interactions ◽  
Optical Modulators ◽  
Dynamic Tuning ◽  
All Optical ◽  
Excitonic Emission

AbstractStrong quantum confinement and coulomb interactions induce tightly bound quasiparticles such as excitons and trions in an atomically thin layer of transitional metal dichalcogenides (TMDs), which play a dominant role in determining their intriguing optoelectronic properties. Thus, controlling the excitonic properties is essential for the applications of TMD-based devices. Here, we demonstrate the all-optical tuning of the local excitonic emission from a monolayer MoS2 hybridized with phase-change material Ge2Sb2Te5 (GST) thin film. By applying pulsed laser with different power on the MoS2/GST heterostructure, the peak energies of the excitonic emission of MoS2 can be tuned up to 40 meV, and the exciton/trion intensity ratio can be tuned by at least one order of magnitude. Raman spectra and transient pump-probe measurements show that the tunability originated from the laser-induced phase change of the GST thin film with charge transferring from GST to the monolayer MoS2. The dynamic tuning of the excitonic emission was all done with localized laser pulses and could be scaled readily, which pave a new way of controlling the excitonic emission in TMDs. Our findings could be potentially used as all-optical modulators or switches in future optical networks.

The effect of an aluminum heat-sink layer on the laser-induced amorphization of SiOx/TeGeSn/SiOx phase-change recording films

1989 ◽  
Vol 47 ◽  
pp. 574-575
Author(s):  
Matthew R. Libera ◽  
Martin Chen
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Heat Sink ◽  
Multilayer Film ◽  
Glassy Phase ◽  
Film Structure ◽  
Glass Forming ◽  
Active Storage ◽  
Dielectric Layers ◽  
Amorphous States

Phase-change erasable optical storage is based on the ability to switch a micron-sized region of a thin film between the crystalline and amorphous states using a diffraction-limited laser as a heat source. A bit of information can be represented as an amorphous spot on a crystalline background, and the two states can be optically identified by their different reflectivities. In a typical multilayer thin-film structure the active (storage) layer is sandwiched between one or more dielectric layers. The dielectric layers provide physical containment and act as a heat sink. A viable phase-change medium must be able to quench to the glassy phase after melting, and this requires proper tailoring of the thermal properties of the multilayer film. The present research studies one particular multilayer structure and shows the effect of an additional aluminum layer on the glass-forming ability.

scholarly journals Signaling free localization of node failures in all-optical networks

2014 ◽  
Author(s):  
Janos Tapolcai ◽  
Lajos Ronyai ◽  
Eva Hosszu ◽  
Pin-Han Ho ◽  
Suresh Subramaniam
Keyword(s):  
Optical Networks ◽  
All Optical ◽  
Node Failures

Photonic crystal based on mott phase change material as all-optical bandgap switch and composite logic gate

2021 ◽  
Vol 113 ◽  
pp. 110855
Author(s):  
Lei Zhang ◽  
Yuanhe Sun ◽  
Zhenjiang Li ◽  
Lin Wang ◽  
Shuqi Cao ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Phase Change ◽  
Phase Change Material ◽  
Logic Gate ◽  
Optical Bandgap ◽  
All Optical ◽  
Mott Phase ◽  
Change Material

scholarly journals Dual-shot dynamics and ultimate frequency of all-optical magnetic recording on GdFeCo

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Sicong Wang ◽  
Chen Wei ◽  
Yuanhua Feng ◽  
Hongkun Cao ◽  
Wenzhe Li ◽  
...  
Keyword(s):  
Magnetization Reversal ◽  
Energy Efficient ◽  
High Speed ◽  
Data Transfer ◽  
Laser Pulses ◽  
Time Resolved ◽  
All Optical ◽  
Fs Laser ◽  
High Speed Data ◽  
Natural Way

AbstractAlthough photonics presents the fastest and most energy-efficient method of data transfer, magnetism still offers the cheapest and most natural way to store data. The ultrafast and energy-efficient optical control of magnetism is presently a missing technological link that prevents us from reaching the next evolution in information processing. The discovery of all-optical magnetization reversal in GdFeCo with the help of 100 fs laser pulses has further aroused intense interest in this compelling problem. Although the applicability of this approach to high-speed data processing depends vitally on the maximum repetition rate of the switching, the latter remains virtually unknown. Here we experimentally unveil the ultimate frequency of repetitive all-optical magnetization reversal through time-resolved studies of the dual-shot magnetization dynamics in Gd27Fe63.87Co9.13. Varying the intensities of the shots and the shot-to-shot separation, we reveal the conditions for ultrafast writing and the fastest possible restoration of magnetic bits. It is shown that although magnetic writing launched by the first shot is completed after 100 ps, a reliable rewriting of the bit by the second shot requires separating the shots by at least 300 ps. Using two shots partially overlapping in space and minimally separated by 300 ps, we demonstrate an approach for GHz magnetic writing that can be scaled down to sizes below the diffraction limit.

Electron Microscopy Study on Amorphous Ge-Sb-Te Thin Film for Phase Change Optical Recording

2003 ◽  
Vol 42 (Part 2, No. 10A) ◽  
pp. L1158-L1160 ◽  
Author(s):  
Muneyuki Naito ◽  
Manabu Ishimaru ◽  
Yoshihiko Hirotsu ◽  
Masaki Takashima
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Phase Change ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Optical Recording

scholarly journals Metal - Insulator Transition Driven by Vacancy Ordering in GeSbTe Phase Change Materials

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Valeria Bragaglia ◽  
Fabrizio Arciprete ◽  
Wei Zhang ◽  
Antonio Massimiliano Mio ◽  
Eugenio Zallo ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Random Access ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Reversible Transformation ◽  
Vacancy Ordering

Abstract Phase Change Materials (PCMs) are unique compounds employed in non-volatile random access memory thanks to the rapid and reversible transformation between the amorphous and crystalline state that display large differences in electrical and optical properties. In addition to the amorphous-to-crystalline transition, experimental results on polycrystalline GeSbTe alloys (GST) films evidenced a Metal-Insulator Transition (MIT) attributed to disorder in the crystalline phase. Here we report on a fundamental advance in the fabrication of GST with out-of-plane stacking of ordered vacancy layers by means of three distinct methods: Molecular Beam Epitaxy, thermal annealing and application of femtosecond laser pulses. We assess the degree of vacancy ordering and explicitly correlate it with the MIT. We further tune the ordering in a controlled fashion attaining a large range of resistivity. Employing ordered GST might allow the realization of cells with larger programming windows.

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