scholarly journals Cm-Level Photonic-Crystal-Like Subwavelength Waveguide Platform with High Integration Density

2019 ◽  
Vol 9 (16) ◽  
pp. 3410 ◽  
Author(s):  
Xiangxin Huang ◽  
Gengxin Chen ◽  
Wen Zhou ◽  
Xuguang Huang
Keyword(s):  
Photonic Crystal ◽  
Large Scale ◽  
Propagation Loss ◽  
Photonic Integration ◽  
Passive Components ◽  
Power Splitter ◽  
Excess Loss ◽  
Integration Density ◽  
Metal Waveguide ◽  
Future Work

In this paper, the cm-level photonic-crystal-like subwavelength waveguide platform is developed and analyzed by using the finite-difference time-domain method. The configuration can be considered as a hybrid waveguide combining with the advantages of a metal-dielectric-metal waveguide and a photonic crystal waveguide. The symmetric and high reflection effect of metallic sidewall and the effect of the photonic crystal structure on the light-guiding mechanism and integration characteristics of the waveguide are systematically investigated. The results reveal that the cm-level photonic-crystal-like waveguide platform provides subwavelength confinement and very low propagation loss with the isolation more than 30 dB, which are promising for high-density photonic integration. The tradeoff between integration density and propagation loss is optimized. In addition, a T-shaped power splitter based on the waveguide platform is proposed. The excess loss of the T-shaped power splitter is less than 0.4 dB. A set of passive components can be exploited on the proposed cm-level photonic-crystal-like subwavelength waveguide platform in future work to constitute the large-scale integrated photonic systems.

scholarly journals Low-Loss and Broadband Silicon Photonic 3-dB Power Splitter with Enhanced Coupling of Shallow-Etched Rib Waveguides

2020 ◽  
Vol 10 (13) ◽  
pp. 4507
Author(s):  
Vinh Huu Nguyen ◽  
In Ki Kim ◽  
Tae Joon Seok
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Low Loss ◽  
Critical Dimensions ◽  
Power Splitter ◽  
Excess Loss ◽  
Silicon Photonic ◽  
Essential Components ◽  
Rib Waveguides ◽  
Power Splitters

A silicon photonic 3-dB power splitter is one of the essential components to demonstrate large-scale silicon photonic integrated circuits (PICs), and can be utilized to implement modulators, 1 × 2 switches, and 1 × N power splitters for various PIC applications. In this paper, we reported the design and experimental demonstration of low-loss and broadband silicon photonic 3-dB power splitters. The power splitter was realized by adiabatically tapered rib waveguides with 60-nm shallow etches. The shallow-etched rib waveguides offered strong coupling and relaxed critical dimensions (a taper tip width of 200 nm and gap spacing of 300 nm). The fabricated device exhibited an excess loss as low as 0.06 dB at a 1550-nm wavelength and a broad operating wavelength range from 1470 nm to 1570 nm. The relaxed critical dimensions (≥200 nm) make the power splitter compatible with standard fabrication processes of existing silicon photonics foundries.

scholarly journals Polarization-Independent Circulator Based on Composite Rod of Ferrite and Plasma in Photonic Crystal Structure

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 381
Author(s):  
Mi Lin ◽  
Lixin Fu ◽  
Shakeel Ahmed ◽  
Qiong Wang ◽  
Yaoxian Zheng ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Large Scale ◽  
Optimization Method ◽  
Coupling Condition ◽  
High Isolation ◽  
Optimum Parameters ◽  
Composite Rod ◽  
Polarized Waves ◽  
Two Dimensional Photonic Crystal ◽  
Polarization Independent

We propose a type of polarization-independent circulator based on a composite rod of ferrite and plasma materials in a two-dimensional photonic crystal (PhC) slab. Only one composite rod was set at the center of the structure to provide circulation for both TE- and TM-polarized waves. Additionally, to improve the performance of the circulator, three additional rods were inserted to improve the coupling condition between the center magneto-optical microcavity and the corresponding waveguides. Finite element method was used to calculate the characteristics of the structure and the Nelder–Mead optimization method was employed to obtain the optimum parameters. The results show that a low insertion loss (~0.22 dB) and high isolation (~14 dB) can be achieved in our structure for waves of both TE and TM polarizations. The idea presented here may be useful for designing compact polarization devices in large-scale integrated photonic circuits.

Large-scale integration of wavelength-addressable all-optical memories on a photonic crystal chip

2014 ◽  
Vol 8 (6) ◽  
pp. 474-481 ◽  
Author(s):  
Eiichi Kuramochi ◽  
Kengo Nozaki ◽  
Akihiko Shinya ◽  
Koji Takeda ◽  
Tomonari Sato ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Large Scale ◽  
Optical Memories ◽  
All Optical ◽  
Large Scale Integration ◽  
Scale Integration

Flexibility Effects in a Single Link Robotic Manipulator

1993 ◽  
Author(s):  
C. Nataraj
Keyword(s):  
Large Scale ◽  
Robotic Manipulator ◽  
Flexible Beam ◽  
Rotating Speed ◽  
Weighted Residuals ◽  
Individual Interaction ◽  
Single Link ◽  
Rigid Mass ◽  
The Individual ◽  
Future Work

Abstract A single link robotic manipulator is modeled as a rotating flexible beam with a rigid mass at the tip and accurate energy expressions are derived. The resulting partial differential equations are solved using an approximate method of weighted residuals. From the solutions, coupling between axial and flexural deformations and the interactions with rigid body motions are rigorously analyzed. The emphasis in the current paper is not on an exhaustive analysis of existing systems but it is rather intended to compare and highlight the various flexibility effects in a relatively simple system. Hence, a nondimensional parametric analysis is performed to determine the effect of several parameters (including the rotating speed) on the errors and the individual interaction effects are discussed. Comparison with previous work in the field shows important phenomena often ignored or buried in large scale numerical analyses. Future work including application to multi-link robots is outlined.

Research and industrialisation of Hermetia illucens L. in China

2020 ◽  
Vol 6 (1) ◽  
pp. 5-12
Author(s):  
J.B. Zhang ◽  
J.K. Tomberlin ◽  
M.M. Cai ◽  
X.P. Xiao ◽  
L.Y. Zheng ◽  
...  
Keyword(s):  
Large Scale ◽  
Organic Waste ◽  
Animal Feed ◽  
Egg Laying ◽  
Breeding Method ◽  
Hermetia Illucens ◽  
Cold Temperatures ◽  
The Usa ◽  
The Government ◽  
Future Work

The larvae of the black soldier fly (BSF), Hermetia illucens L., are commonly associated with decaying organic wastes. Over the past 15 years, investigators in China have conducted extensive research exploring the use of BSF larvae to recycle organic materials as a means to protect the environment, while producing products of value, such as protein and bioenergy. Initial efforts were based on a BSF strain from the USA. However, since then, H. illucens strains from specimens collected in Hubei and Guangdong Provinces have been established and used as models to explore the use of this species in sustainable agriculture. China has played an instrumental role in developing an in-door breeding method using a quartz-iodine lamp rather than depend on natural sunlight. This discovery has allowed the establishment of in-door BSF colonies in regions throughout the world where abiotic conditions (i.e. cold temperatures) are preventative. Researchers in China paved the way for using microbes as a means to enhance BSF production including, enhancing BSF egg-laying as well as waste reduction. Furthermore, bacteria from BSF gut or waste can be cultured and used to promote BSF growth, shorten conversion time, and enhanced conversion efficacy. Recent efforts have demonstrated BSF larvae can degrade antibiotics as well as suppress noxious odours in livestock manure. Due to the efforts of research on BSF in China, numerous companies that recycle organic waste at a large scale (>20 tonnes waste digested/day), have been established. Resulting products include insect powder, and live BSFL that can be used as animal feed ingredients for livestock (e.g. eels and frogs), while protecting the environment. Future work will decipher the mechanisms regulating BSF larval conversion of organic waste so that the system can be optimised. However, efforts are still needed at the government level to establish quality assurance standards if this process is truly to become established as an industry in China.

scholarly journals Long Low-Loss-Litium Niobate on Insulator Waveguides with Sub-Nanometer Surface Roughness

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 910 ◽  
Author(s):  
Rongbo Wu ◽  
Min Wang ◽  
Jian Xu ◽  
Jia Qi ◽  
Wei Chu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Integrated Circuits ◽  
Large Scale ◽  
Photonic Integrated Circuits ◽  
Surface Patterning ◽  
Propagation Loss ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Low Loss ◽  
Atomic Force

In this paper, we develop a technique for realizing multi-centimeter-long lithium niobate on insulator (LNOI) waveguides with a propagation loss as low as 0.027 dB/cm. Our technique relies on patterning a chromium thin film coated on the top surface of LNOI into a hard mask with a femtosecond laser followed by chemo-mechanical polishing for structuring the LNOI into the waveguides. The surface roughness on the waveguides was determined with an atomic force microscope to be 0.452 nm. The approach is compatible with other surface patterning technologies, such as optical and electron beam lithographies or laser direct writing, enabling high-throughput manufacturing of large-scale LNOI-based photonic integrated circuits.

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