Precisely size-controlled fabrication of germanium pyramid array as an effective light-trapping material for photonic devices

2021 ◽  
Vol 127 (12) ◽  
Author(s):  
Sabriye Acikgoz ◽  
Hasan Yungevis
Author(s):  
Xiaoxin Wang ◽  
Andrew Wong ◽  
Stephanie Malek ◽  
Xiaobai Yu ◽  
Jing Kong ◽  
...  

MRS Advances ◽  
2019 ◽  
Vol 4 (51-52) ◽  
pp. 2759-2769
Author(s):  
Seokhyoung Kim

ABSTRACTSemiconductor nanowires (NWs) have widely been studied as an ideal platform for developing electronic, photovoltaic, photonic devices and biological probes in the nanoscale. The ability to synthesize high-quality NWs of various materials with a precise control in shape, doping and crystal structure is the key to the growth of NW-based technologies. In the past decade, there has been growing interest in controllably creating NW heterojunctions and periodically-modulated superlattices (SLs) because it is expected to bring new functionalities that are not present in uniform NWs. In particular, the interaction of NW SLs with light has been one of the central interests because the diameter and modulation length scale are on the same order as the wavelength of light in the optical regime. Also, degenerately-doped semiconductor NWs exhibit localized surface plasmon resonances (LSPRs), which comprises unexpected long-range interactions when the plasmon resonators are regularly placed in NW SLs. In this review, I will summarize the recent progress in photonics research of NW SLs. The topics discussed include preparation and types of NW SLs, light-trapping and light-emission properties, and plasmonic optical- and thermal-transport properties.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hwan-Seop Yeo ◽  
Kwanjae Lee ◽  
Young Chul Sim ◽  
Seoung-Hwan Park ◽  
Yong-Hoon Cho

Abstract Optical polarization is an indispensable component in photonic applications, the orthogonality of which extends the degree of freedom of information, and strongly polarized and highly efficient small-size emitters are essential for compact polarization-based devices. We propose a group III-nitride quantum wire for a highly-efficient, strongly-polarized emitter, the polarization anisotropy of which stems solely from its one-dimensionality. We fabricated a site-selective and size-controlled single quantum wire using the geometrical shape of a three-dimensional structure under a self-limited growth mechanism. We present a strong and robust optical polarization anisotropy at room temperature emerging from a group III-nitride single quantum wire. Based on polarization-resolved spectroscopy and strain-included 6-band k·p calculations, the strong anisotropy is mainly attributed to the anisotropic strain distribution caused by the one-dimensionality, and its robustness to temperature is associated with an asymmetric quantum confinement effect.


2018 ◽  
Vol 124 (5) ◽  
pp. 053101
Author(s):  
Zhi Liu ◽  
Jietao Liu ◽  
Buwen Cheng ◽  
Jun Zheng ◽  
Chuanbo Li ◽  
...  

Author(s):  
Zahra Heydari ◽  
Ibrahim Zarkesh ◽  
Mohammad-Hossein Ghanian ◽  
Mahdokht H. Aghdaei ◽  
Svetlana Kotova ◽  
...  
Keyword(s):  

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 210
Author(s):  
Da Teng ◽  
Kai Wang

The waveguiding of terahertz surface plasmons by a GaAs strip-loaded graphene waveguide is investigated based on the effective-index method and the finite element method. Modal properties of the effective mode index, modal loss, and cut-off characteristics of higher order modes are investigated. By modulating the Fermi level, the modal properties of the fundamental mode could be adjusted. The accuracy of the effective-index method is verified by a comparison between the analytical results and numerical simulations. Besides the modal properties, the crosstalk between the adjacent waveguides, which determines the device integration density, is studied. The findings show that the effective-index method is highly valid for analyzing dielectric-loaded graphene plasmon waveguides in the terahertz region and may have potential applications in subwavelength tunable integrated photonic devices.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Denis V. Novitsky ◽  
Dmitry Lyakhov ◽  
Dominik Michels ◽  
Dmitrii Redka ◽  
Alexander A. Pavlov ◽  
...  

AbstractUnique and flexible properties of non-Hermitian photonic systems attract ever-increasing attention via delivering a whole bunch of novel optical effects and allowing for efficient tuning light-matter interactions on nano- and microscales. Together with an increasing demand for the fast and spatially compact methods of light governing, this peculiar approach paves a broad avenue to novel optical applications. Here, unifying the approaches of disordered metamaterials and non-Hermitian photonics, we propose a conceptually new and simple architecture driven by disordered loss-gain multilayers and, therefore, providing a powerful tool to control both the passage time and the wave-front shape of incident light with different switching times. For the first time we show the possibility to switch on and off kink formation by changing the level of disorder in the case of adiabatically raising wave fronts. At the same time, we deliver flexible tuning of the output intensity by using the nonlinear effect of loss and gain saturation. Since the disorder strength in our system can be conveniently controlled with the power of the external pump, our approach can be considered as a basis for different active photonic devices.


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