Silicon-Based All-Dielectric Metasurface on an Iron Garnet Film for Efficient Magneto-Optical Light Modulation in Near IR Range

All-dielectric nanostructures provide a unique low-loss platform for efficiently increasing light-matter interaction via excitation of the localized or propagating optical modes. Here, we report on the transverse magneto-optical Kerr effect enhancement in an all-dielectric metasurface based on a two-dimensional array of Si nanodisks on a cerium substituted dysprosium iron garnet thin film. We observed up to 15% light intensity modulation under TM modes excitation. The observed magneto-optical effect is nearly independent of the rotation of the light incidence plane with respect to the metasurface. Being compatible with conventional semiconductor technology, our structure holds promise for device applications, such as light modulators, magnetic and chemical sensors.

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Observation of strong excitonic magneto-chiral anisotropy in twisted bilayer van der Waals crystals

Nature Communications ◽

10.1038/s41467-021-22412-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Shoufeng Lan ◽

Xiaoze Liu ◽

Siqi Wang ◽

Hanyu Zhu ◽

Yawen Liu ◽

...

Keyword(s):

Time Reversal ◽

Room Temperature ◽

Photochemical Reactions ◽

Full Width ◽

Half Maximum ◽

A Value ◽

Device Applications ◽

Spectral Splitting ◽

Iron Garnet ◽

Spontaneous Magnetic Moment

AbstractThe interplay between chirality and magnetism generates a distinct physical process, the magneto-chiral effect, which enables one to develop functionalities that cannot be achieved solely by any of the two. Such a process is universal with the breaking of parity-inversion and time-reversal symmetry simultaneously. However, the magneto-chiral effect observed so far is weak when the matter responds to photons, electrons, or phonons. Here we report the first observation of strong magneto-chiral response to excitons in a twisted bilayer tungsten disulfide with the amplitude of excitonic magneto-chiral (ExMCh) anisotropy reaches a value of ~4%. We further found the ExMCh anisotropy features with a spectral splitting of ~7 nm, precisely the full-width at half maximum of the excitonic chirality spectrum. Without an externally applied strong magnetic field, the observed ExMCh effect with a spontaneous magnetic moment from the ferromagnetic substrate of thulium iron garnet at room temperature is favorable for device applications. The unique ExMCh processes provide a new pathway to actively control magneto-chiral applications in photochemical reactions, asymmetric synthesis, and drug delivery.

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Photovoltaic Characterization of Trapping in Porous Silicon

MRS Proceedings ◽

10.1557/proc-358-587 ◽

1994 ◽

Vol 358 ◽

Cited By ~ 1

Author(s):

D. W. Boeringer ◽

R. Tsu

Keyword(s):

Porous Silicon ◽

Photovoltaic Effect ◽

Light Spot ◽

Dangling Bond ◽

Photogenerated Electrons ◽

Device Applications ◽

Photovoltaic Characterization ◽

P Type ◽

Silicon Based ◽

Position Sensitive Detectors

ABSTRACTWe report the first observation of the lateral photovoltaic effect in porous silicon. Contacts placed on either side of a porous silicon region develop a voltage up to several millivolts if the sample is asymmetrically illuminated. If the light spot is closer to one contact, the voltage will have one polarity; if it is closer to the other contact, the polarity will be opposite. In the case of n-type, the contact nearest the light spot is positive; for p-type, the contact nearest the light spot is negative In the region between the contacts, the photovoltage varies almost linearly with the position of the light spot, over a distance 4.5 cm across. The origin of our lateral photoeffect may be explained by the trapping of photoexcited carriers by a pair of dangling bond centers in porous silicon. In the case of p-type, the photogenerated electrons are trapped by the dangling bond states while holes diffuse away in the substrate. The situation for n-type is opposite; holes are trapped by the dangling bond states while electrons diffuse away in the substrate. This differs from the conventional lateral photoeffect, which arises under the nonuniform illumination of a junction between two layers of differing conductivities. Hamamatsu sells silicon-based position-sensitive detectors with a resolution down to 0.1 µm. The possibility of using this lateral photoeffect to characterize these dangling bond states in porous silicon as well as several possible device applications will be discussed.

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Technological Prospects for Germanium Silicide Epitaxy

MRS Proceedings ◽

10.1557/proc-126-111 ◽

1988 ◽

Vol 126 ◽

Cited By ~ 8

Author(s):

John C. Bean

Keyword(s):

Heterojunction Bipolar Transistors ◽

Bipolar Transistors ◽

Band Alignment ◽

Growth Mechanisms ◽

Electrical And Optical Properties ◽

Optical Detectors ◽

Germanium Silicide ◽

Device Applications ◽

Silicon Based ◽

Induced Defects

ABSTRACTThis paper describes preliminary device work on GexSi1−x, based devices and examines progress towards the realization of a silicon based heterostructure technology. Target areas for further work are identified including: An enhanced understanding of metastable-growth processes; The need for defect confinement in discommensurate epitaxy; Elimination of manufacturing barriers caused by particulate induced defects in MBE and low growth rates in low temperature CVD.Over the last five years, studies of GexSi1−x have yielded an understanding of crystal growth mechanisms and information on electrical and optical properties such as bandstructure and heterojunction band alignment. These in turn lead to a number of preliminary device applications including optical detectors, modulation doped transistors and heterojunction bipolar transistors. In this paper, I will try to answer the question posed by the symposium organizers: In the germanium silicide system, has our understanding and experience reached the point that we have the basis for a technology, and if not, where must further work be done?

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Amorphous Silicon Based Waveguides And Light Modulators For Silicon Low-Cost Photonic Integrated Circuits

MRS Proceedings ◽

10.1557/proc-486-113 ◽

1997 ◽

Vol 486 ◽

Cited By ~ 1

Author(s):

G. Cocorullo ◽

F. G. Della Corte ◽

R. De Rosa ◽

I. Rendina ◽

A. Rubino ◽

...

Keyword(s):

Integrated Circuits ◽

Amorphous Silicon ◽

Low Cost ◽

Switching Frequency ◽

Fabrication Technology ◽

Low Loss ◽

Light Modulators ◽

Microelectronic Technology ◽

Infrared Wavelengths ◽

Silicon Based

AbstractThis paper reports about the fabrication and experimental test of an interferometric light intensity modulator integrated in a low loss (0.7 dB/cm), amorphous silicon based waveguide. It measures approximately 1 mm in length, while its cross section is 30-μm-wide and 3-μm-high. The device, which exploits the strong thermo-optic effect in thin film a-Si for its operation, is designed for application at the infrared wavelengths of 1.3 and 1.55 μm. The measured maximum operating on-off switching frequency of the device is 600 kHz. The very simple fabrication technology involves maximum process temperatures of 230 °C, and is therefore compatible with the standard microelectronic technology. This offers a new opportunity for the integration of optical and electronic functions on the same substrate.

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Technological Prospects for Germanium Silicide Epitaxy

MRS Proceedings ◽

10.1557/proc-116-479 ◽

1988 ◽

Vol 116 ◽

Cited By ~ 7

Author(s):

John C. Bean

Keyword(s):

Heterojunction Bipolar Transistors ◽

Bipolar Transistors ◽

Band Alignment ◽

Growth Mechanisms ◽

Electrical And Optical Properties ◽

Optical Detectors ◽

Germanium Silicide ◽

Device Applications ◽

Silicon Based ◽

Induced Defects

AbstractThis paper describes preliminary device work on GexSil−x based devices and examines progress towards the realization of a silicon based heterostructure technology. Target areas for further work are identified including: An enhanced understanding of metastable-growth processes; The need for defect confinement in discommensurate epitaxy; Elimination of manufacturing barriers caused by particulate induced defects in MBE and low growth rates in low temperature CVD.Over the last five years, studies of GexSi1−x have yielded an understanding of crystal growth mechanisms and information on electrical and optical properties such as bandstructure and heterojunction band alignment. These in turn lead to a number of preliminary device applications including optical detectors, modulation doped transistors and heterojunction bipolar transistors. In this paper, I will try to answer the question posed by the symposium organizers: In the germanium silicide system, has our understanding and experience reached the point that we have the basis for a technology, and if not, where must further work be done?

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Light–matter interaction of 2D materials: Physics and device applications

Chinese Physics B ◽

10.1088/1674-1056/26/3/036802 ◽

2017 ◽

Vol 26 (3) ◽

pp. 036802 ◽

Cited By ~ 11

Author(s):

Zi-Wei Li ◽

Yi-Han Hu ◽

Yu Li ◽

Zhe-Yu Fang

Keyword(s):

2D Materials ◽

Matter Interaction ◽

Device Applications ◽

Light Matter Interaction

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Observation of strong excitonic magneto-chiral anisotropy in twisted bilayer van der Waals crystals

10.21203/rs.3.rs-38525/v1 ◽

2020 ◽

Author(s):

Shoufeng Lan ◽

Xiaoze Liu ◽

Siqi Wang ◽

Hanyu Zhu ◽

Yawen Liu ◽

...

Keyword(s):

Time Reversal ◽

Room Temperature ◽

Photochemical Reactions ◽

Full Width ◽

Half Maximum ◽

A Value ◽

Device Applications ◽

Spectral Splitting ◽

Iron Garnet ◽

Spontaneous Magnetic Moment

Abstract The interplay between chirality and magnetism generates a distinct physical process, the magneto-chiral effect, which enables one to develop functionalities that cannot be achieved solely by any of the two. Such a process is universal with the breaking of parity-inversion and time-reversal symmetry simultaneously. However, the magneto-chiral effect observed so far is weak when the matter responds to photons, electrons, or phonons. Here we report the first observation of strong magneto-chiral response to excitons in a twisted bilayer tungsten disulfide with the amplitude of excitonic magneto-chiral (ExMCh) anisotropy reaches a value of ~4%. We further found the ExMCh anisotropy features with a spectral splitting of ~7 nm, precisely the full-width at half maximum of the excitonic chirality spectrum. Without an externally applied strong magnetic field, the observed ExMCh effect with a spontaneous magnetic moment from the ferromagnetic substrate of thulium iron garnet at room temperature is favorable for device applications. The unique ExMCh processes provide a new pathway to actively control magneto-chiral applications in photochemical reactions, asymmetric synthesis, and drug delivery.

Download Full-text