The Microstructural Response of a Multilayer Thin Film to Local Laser Heating

ABSTRACTThe microstructures associated with pulsed-laser heating of multilayer thin films used for phase-change optical data storage are studied in three related films. Two employ the multilayer structure SiOx/TeGeSn/SiOx where the chalcogenide layer is either amorphous or crystalline. The third uses the same trilayer structure with a crystalline chalcogenide layer but with an additional layer of aluminum. Pulsed-laser melting of micron-sized spots leads to solidification in the non-aluminized specimens with a morphology dependent on the preexisting structure of the chalcogenide layer and to amorphization in the aluminized film. Heat-flow modelling shows that the maximum temperature reached is lower and the cooling rate through the glass-forming temperature range higher in the aluminized structure. Discussion centers on the thermal and optical properties of the different films and the impact of the pre-existing chalcogenide structure on the subsequent phase transformations.

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Influences of Central Units and Terminal Chains on the Banana-Shaped Liquid Crystals

Crystals ◽

10.3390/cryst10100857 ◽

2020 ◽

Vol 10 (10) ◽

pp. 857

Author(s):

Tang Xin Ting ◽

Mohd Sani Sarjadi ◽

Md Lutfor Rahman

Keyword(s):

Liquid Crystals ◽

Data Storage ◽

Smart Materials ◽

Optical Data Storage ◽

Optical Data ◽

Display Devices ◽

Functionalized Materials ◽

Potential Applications ◽

The Impact ◽

Photoisomerization Process

Azo-functionalized materials are one of the appealing groups of the functionalized materials owing to their photoswitching behaviour and have been explored for various potential applications viz., optical data storage, sensor, display devices, nonlinear materials and molecular switches. Recently, azo-functionalized bent-core liquid crystals (BCLCs) have gained significant attention because they have dual properties of BCLCs and azobenzene, which enables to generate new multifaceted functional and smart materials. In this report, the recently synthesized azobenzene containing bent-core mesogens and its subclass, the so-called hockey stick and V-shaped molecules are summarized. The mesomorphic behaviour of reported BCLCs affected by the type of central core unit, the nature, number and position of the lateral substituents and the type and length of the terminal chain are discussed. The photoisomerization process of these photoresponsive BCLCs in solid, solution and mesophase, as well as the impact of light on the chemical and electrical properties of them, are discussed.

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Advances in the Growth of SrS Thin Films by Pulsed Laser Deposition

MRS Proceedings ◽

10.1557/proc-508-295 ◽

1998 ◽

Vol 508 ◽

Cited By ~ 2

Author(s):

A. Piqué ◽

R. C. Y. Auyeung ◽

D. B. Chrisey ◽

B. Justus ◽

A. Huston ◽

...

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Data Storage ◽

Pulsed Laser ◽

Optical Data Storage ◽

Laser Deposition ◽

Optical Data ◽

Glass Substrates ◽

Deposition Parameters ◽

Background Gas

AbstractHigh quality luminescent thin films of strontium sulfide (SrS) doped with rare earths have been grown using Pulsed Laser Deposition (PLD). SrS films ranging in thicknesses from 0.05 to 2 µm. were deposited on MgO (001) and glass substrates. Deposition parameters such as growth temperature and H2S background gas pressure were varied and their effect on the structure, morphology and luminescence of the films was evaluated. The PLD grown films all showed texture and were highly oriented when deposited on MgO substrates as determined by their XRD spectra. Optical microscopy, SEM and AFM analysis were used to study the films' surface morphology. The thermally and optically stimulated luminescence properties of these films were evaluated as well. The data indicates that these materials may be useful for optical data storage applications.

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Femtosecond pulsed laser induced shape change of metallic nanoparticles and its application to optical data storage

Pacific International Conference on Applications of Lasers and Optics ◽

10.2351/1.5056980 ◽

2006 ◽

Author(s):

James W. M. Chon ◽

Craig Bullen ◽

Min Gu

Keyword(s):

Data Storage ◽

Metallic Nanoparticles ◽

Shape Change ◽

Pulsed Laser ◽

Optical Data Storage ◽

Optical Data ◽

Femtosecond Pulsed Laser

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Structural and optical properties of amorphous Si–Ge–Te thin films prepared by combinatorial sputtering

Scientific Reports ◽

10.1038/s41598-021-91138-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

C. Mihai ◽

F. Sava ◽

I. D. Simandan ◽

A. C. Galca ◽

I. Burducea ◽

...

Keyword(s):

Optical Properties ◽

Data Storage ◽

Optical Sensors ◽

Material Selection ◽

Functional Materials ◽

Stability Study ◽

Optical Data Storage ◽

Optical Data ◽

Structural And Optical Properties ◽

Topological Constraint

AbstractThe lack of order in amorphous chalcogenides offers them novel properties but also adds increased challenges in the discovery and design of advanced functional materials. The amorphous compositions in the Si–Ge–Te system are of interest for many applications such as optical data storage, optical sensors and Ovonic threshold switches. But an extended exploration of this system is still missing. In this study, magnetron co-sputtering is used for the combinatorial synthesis of thin film libraries, outside the glass formation domain. Compositional, structural and optical properties are investigated and discussed in the framework of topological constraint theory. The materials in the library are classified as stressed-rigid amorphous networks. The bandgap is heavily influenced by the Te content while the near-IR refractive index dependence on Ge concentration shows a minimum, which could be exploited in applications. A transition from a disordered to a more ordered amorphous network at 60 at% Te, is observed. The thermal stability study shows that the formed crystalline phases are dictated by the concentration of Ge and Te. New amorphous compositions in the Si–Ge–Te system were found and their properties explored, thus enabling an informed and rapid material selection and design for applications.

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Optical Isomerization and Photo-Patternable Properties of GeO2/Ormosils Organic-Inorganic Composite Films Doped with Azobenzene

Coatings ◽

10.3390/coatings11070818 ◽

2021 ◽

Vol 11 (7) ◽

pp. 818

Author(s):

Xuehua Zhang ◽

Qian Wang ◽

Shun Liu ◽

Wei Zhang ◽

Fangren Hu ◽

...

Keyword(s):

Optical Waveguide ◽

Data Storage ◽

Optical Switching ◽

Sol Gel ◽

Composite Films ◽

Optical Data Storage ◽

Optical Data ◽

Single Chip ◽

Coating Method ◽

Inorganic Composite

GeO2/organically modified silane (ormosils) organic-inorganic composite films containing azobenzene were prepared by combining sol-gel technology and spin coating method. Optical waveguide properties including the refractive index and thickness of the composite films were characterized by using a prism coupling instrument. Surface morphology and photochemical properties of the composite films were investigated by atomic force microscope and Fourier transform infrared spectrometer. Results indicate that the composite films have smooth and neat surface, and excellent optical waveguide performance. Photo-isomerization properties of the composite films were studied by using a UV–Vis spectrophotometer. Optical switching performance of the composite films was also studied under the alternating exposure of 365 nm ultraviolet light and 410 nm visible light. Finally, strip waveguides and microlens arrays were built in the composite films through a UV soft imprint technique. Based on the above results, we believe that the prepared composite films are promising candidates for micro-nano optics and photonic applications, which would allow directly integrating the optical data storage and optical switching devices onto a single chip.

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