scholarly journals All-optical control of cardiac excitation: combined high-resolution optogenetic actuation and optical mapping

2016 ◽  
Vol 594 (9) ◽  
pp. 2503-2510 ◽  
Author(s):  
Emilia Entcheva ◽  
Gil Bub
Keyword(s):  
High Resolution ◽  
Optical Mapping ◽  
Optical Control ◽  
All Optical ◽  
Cardiac Excitation

Ultrafast Switching Dynamics

2017 ◽  
Author(s):  
Olle Eriksson ◽  
Anders Bergman ◽  
Lars Bergqvist ◽  
Johan Hellsvik
Keyword(s):  
Lower Energy ◽  
Research Field ◽  
Optical Control ◽  
Magnetic Memory ◽  
Magnetic Media ◽  
Switching Dynamics ◽  
All Optical ◽  
Ultrafast Switching ◽  
Stored Information ◽  
Intense Research

The time-integrated amount of data and stored information, is doubled roughly every eighteen months, and since the majority of the worlds information is stored in magnetic media, the possibility to write and retrieve information in a magnetic material at ever greater speed and with lower energy consumption, has obvious benefits for our society. Hence the seemingly simple switching of a magnetic unit, a bit, is a crucial process which defines how efficiently information can be stored and retrieved from a magnetic memory. Of particular interest here are the concepts of ultrafast magnetism and all-optical control of magnetism which have in recent decades become the basis for an intense research field. The motivation is natural; the mechanisms behind these phenomena are far from trivial and the technological implications are huge.

scholarly journals Optofluidic Platform Based on Liquid Crystals in X-Cut Lithium Niobate: Thresholdless All-Optical Response

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 908
Author(s):  
Fabrizio Ciciulla ◽  
Annamaria Zaltron ◽  
Riccardo Zamboni ◽  
Cinzia Sada ◽  
Francesco Simoni ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Light Intensity ◽  
Lithium Niobate ◽  
Photovoltaic Effect ◽  
Optical Control ◽  
Crystal Layer ◽  
Liquid Crystal Layer ◽  
Threshold Behaviour ◽  
All Optical

In this study, we present a new configuration of the recently reported optofluidic platform exploiting liquid crystals reorientation in lithium niobate channels. In order to avoid the threshold behaviour observed in the optical control of the device, we propose microchannels realized in a x-cut crystal closed by a z-cut crystal on the top. In this way, the light-induced photovoltaic field is not uniform inside the liquid crystal layer and therefore the conditions for a thresholdless reorientation are realized. We performed simulations of the photovoltaic effect based on the well assessed model for Lithium Niobate, showing that not uniform orientation and value of the field should be expected inside the microchannel. In agreement with the re-orientational properties of nematic liquid crystals, experimental data confirm the expected thresholdless behaviour. The observed liquid crystal response exhibits two different regimes and the response time shows an unusual dependence on light intensity, both features indicating the presence of additional photo-induced fields appearing above a light intensity of 107 W/m2.

scholarly journals Functional THz emitters based on Pancharatnam-Berry phase nonlinear metasurfaces

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cormac McDonnell ◽  
Junhong Deng ◽  
Symeon Sideris ◽  
Tal Ellenbogen ◽  
Guixin Li
Keyword(s):  
Amino Acids ◽  
Linear Polarization ◽  
Berry Phase ◽  
Science And Technology ◽  
Optical Control ◽  
Biomedical Science ◽  
Spin States ◽  
Single Cycle ◽  
All Optical ◽  
Thz Waves

AbstractRecent advances in the science and technology of THz waves show promise for a wide variety of important applications in material inspection, imaging, and biomedical science amongst others. However, this promise is impeded by the lack of sufficiently functional THz emitters. Here, we introduce broadband THz emitters based on Pancharatnam-Berry phase nonlinear metasurfaces, which exhibit unique optical functionalities. Using these new emitters, we experimentally demonstrate tunable linear polarization of broadband single cycle THz pulses, the splitting of spin states and THz frequencies in the spatial domain, and the generation of few-cycle pulses with temporal polarization dispersion. Finally, we apply the ability of spin control of THz waves to demonstrate circular dichroism spectroscopy of amino acids. Altogether, we achieve nanoscale and all-optical control over the phase and polarization states of the emitted THz waves.

scholarly journals Sequentially Timed All-optical Mapping Photography

2017 ◽  
Vol 37 (145) ◽  
pp. 26-31
Author(s):  
Keiichi NAKAGAWA ◽  
Takakazu SUZUKI ◽  
Fumihiko KANNARI
Keyword(s):  
Optical Mapping ◽  
All Optical

scholarly journals Anisotropic Conduction Properties in Canine Atria Analyzed by High-Resolution Optical Mapping

Circulation ◽  
2002 ◽  
Vol 105 (17) ◽  
pp. 2092-2098 ◽  
Author(s):  
Takahiro Koura ◽  
Motoki Hara ◽  
Susumu Takeuchi ◽  
Kenichi Ota ◽  
Yasumasa Okada ◽  
...  
Keyword(s):  
High Resolution ◽  
Optical Mapping ◽  
Anisotropic Conduction ◽  
Conduction Properties

scholarly journals Isolated superfused rats atrial model for the investigation of atrial fibrillation mechanisms and treatment

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
S Glatstein ◽  
M Ghiringhelli ◽  
L Maizels ◽  
E Heller ◽  
E Maor ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
High Resolution ◽  
Sinus Rhythm ◽  
Optical Mapping ◽  
Ex Vivo ◽  
Anatomical Landmarks ◽  
Ex Vivo Model ◽  
Electrophysiological Properties ◽  
Custom Made ◽  
Isolated Atria

Abstract Background One of the major barriers to an improved mechanistic understanding of atrial fibrillation (AF), and thus in the pipeline of drug development, has been a lack of appropriate tissue models, especially in small animals. Aim We propose an advanced anatomical ex-vivo model based on rat atria for acute assessment of AF susceptibility. This novel model could yield a better understanding of arrhythmia mechanisms as well as the development of potential therapeutic strategies for the prevention or termination of atrial arrhythmias. Methods Wistar rats atria (N=25) were isolated, flattened and pinned to a custom-made silicon plate. Atria were superfused with an oxygenized Tyrode's solution. Tissues were then loaded with a voltage-sensitive dye and mapped using a high-resolution optical mapping system. AF was induced with 1uM carbamylcholine (N=23) coupled with pacing maneuvers and treated with 30uM Vernakalant (N=10) or 10uM Flecainide (N=10). Finally, the feasibility of a new ablation technique (electroporation) was evaluated. Results Optical mapping results suggested that the superfusion procedure led to a fast atrial recovery. Sinus activity was conserved for all atria for a long period. All the anatomical landmarks were clearly visualized. The acquired optical signals were analyzed during sinus rhythm and pacing, which allowed the creation of detailed activation maps and measurements of action potential duration (APD) and conduction velocity (CV) at different pacing rates. The resulting APD restitution curves revealed electrical excitation at high pacing rates (cycle length between 50ms and 300ms) with a relatively flattened curve. AF was successfully induced and optically mapping confirmed the presence of reentrant activity. AF was successfully treated using Vernacalant and Flecainide. Finally, we demonstrated the feasibility of a new ablation approach (electroporation) for creation of a continuous linear lesion serving as a functional block. Conclusion The isolated superfused atria model, coupled with voltage-sensitive dyes, can be utilized for long-term high-resolution functional imaging of the atria during sinus rhythm, pacing and arrhythmogenic activity. This allows the study of the atrial electrophysiological properties, the mechanisms involved in AF initiation, perpetuation, and termination as well as the study of drug and new ablation modalities. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Research Council (ERC) Spontaneous activation of isolated atria

scholarly journals Localized All-Optical Control of Single Semiconductor Quantum Dots through Plasmon Polariton-Induced Screening

2018 ◽  
Vol 6 (15) ◽  
pp. 1800345
Author(s):  
Matt Seaton ◽  
Alex Krasnok ◽  
Allan S. Bracker ◽  
Andrea Alù ◽  
Yanwen Wu
Keyword(s):  
Quantum Dots ◽  
Semiconductor Quantum Dots ◽  
Optical Control ◽  
All Optical ◽  
Plasmon Polariton

scholarly journals All-optical control of lead halide perovskite microlasers

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nan Zhang ◽  
Yubin Fan ◽  
Kaiyang Wang ◽  
Zhiyuan Gu ◽  
Yuhan Wang ◽  
...  
Keyword(s):  
Optical Control ◽  
All Optical ◽  
Halide Perovskite ◽  
Lead Halide
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