scholarly journals Investigation of Side Wall Roughness Effect on Optical Losses in a Multimode Si3N4 Waveguide Formed on a Quartz Substrate

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 104
Author(s):  
Anastasia Yakuhina ◽  
Alexey Kadochkin ◽  
Vyacheslav Svetukhin ◽  
Dmitry Gorelov ◽  
Sergey Generalov ◽  
...  
Keyword(s):  
Optical Waveguides ◽  
Quartz Substrate ◽  
Side Wall ◽  
Wall Roughness ◽  
Roughness Parameters ◽  
Optical Losses ◽  
Waveguide Width ◽  
Integration Density ◽  
Frequency Domain Reflectometry ◽  
Multimode Operation

This article presents the results of the study of the influence of the most significant parameters of the side wall roughness of an ultra-thin silicon nitride lightguide layer of multimode integrated optical waveguides with widths of 3 and 8 microns. The choice of the waveguide width was made due to the need to provide multimode operation for telecommunication wavelengths, which is necessary to ensure high integration density. Scattering in waveguide structures was measured by optical frequency domain reflectometry (OFDR) of a backscattering reflectometer. The finite difference time domain method (FDTD) was used to study the effect of roughness parameters on optical losses in fabricated waveguides, the roughness parameters that most strongly affect optical scattering were determined, and methods of its significant reduction were specified. The prospects for implementing such structures on a quartz substrate are justified.

scholarly journals Reflectometry Study of the Pyroelectric Effect on Proton-Exchange Channel Waveguides in Lithium Niobate

2021 ◽  
Vol 11 (21) ◽  
pp. 9853
Author(s):  
Roman Ponomarev ◽  
Yuri Konstantinov ◽  
Maxim Belokrylov ◽  
Ivan Lobach ◽  
Denis Shevtsov
Keyword(s):  
Lithium Niobate ◽  
Optical Waveguides ◽  
Lithium Niobate Crystal ◽  
Proton Exchange ◽  
Optical Losses ◽  
Pyroelectric Effect ◽  
Optical Frequency Domain Reflectometry ◽  
Exchange Channel ◽  
Frequency Domain Reflectometry ◽  
Channel Waveguides

This work is devoted to the study of the pyroelectric effect on the properties of optical waveguides formed in a lithium niobate crystal by proton exchange. In the present work, we studied the cessation effect of the radiation channeling during thermocycling of Y-splitters samples. We examined the spectral dependence of optical losses on the wavelength using an optical spectrum analyzer. The results demonstrate that in the range of 1530–1570 nm, all wavelengths are suppressed equally. The optical frequency domain reflectometry shows that the increase of optical losses is observed along the entire waveguide, but not only at the Y-splitting point, as supposed earlier.

The Dependence of Demolding Characteristics on Side Wall Roughness of Mold in Thermal Imprint

2008 ◽  
Vol 128 (8) ◽  
pp. 325-330 ◽  
Author(s):  
Hiroaki Kawata ◽  
Junya Ishihara ◽  
Masayo Kayama ◽  
Masaaki Yasuda ◽  
Yoshihiko Hirai
Keyword(s):  
Side Wall ◽  
Wall Roughness

Side-wall roughness of deep trenches in 1D and 2D periodic silicon structures fabricated by photoelectrochemical etching

2011 ◽  
Vol 8 (6) ◽  
pp. 1936-1940 ◽  
Author(s):  
E. V. Astrova ◽  
G. V. Fedulova ◽  
Yu. A. Zharova ◽  
E. V. Gushchina
Keyword(s):  
Side Wall ◽  
Wall Roughness ◽  
Photoelectrochemical Etching ◽  
Silicon Structures

Measurements and Evaluation of Internal Wall Surface Roughness of Small Diameter Pipes for High Pressure Natural Gas Systems

2014 ◽  
Author(s):  
C. Hartloper ◽  
K. K. Botros ◽  
J. Geerligs ◽  
H. Golshan ◽  
K. Jensen
Keyword(s):  
Surface Roughness ◽  
Pipe Wall ◽  
Large Diameter ◽  
Roughness Parameter ◽  
Small Diameter ◽  
Wall Roughness ◽  
Roughness Parameters ◽  
Internal Wall ◽  
Effective Roughness ◽  
Pipe Size

The default roughness parameter values used in industry to determine the pressure loss through small diameter pipeline systems are much higher than the values employed in typical large diameter gas transmission and lateral systems. It is uncertain whether these higher roughness values are due to higher topological roughness of the internal wall of the small diameter pipes or if they are a result of other factors. Measurements were taken on 17 small diameter pipe samples in order to evaluate the pipe-wall roughness parameter. A model to calculate the effective roughness parameter, which takes into account pressure losses due to the measured roughness as well as internal welds and scaling, has been developed. The effective roughness parameter of these samples is found to range from 20.4μm to 62.9μm, an increase of 11.0μm to 23.3μm over the measured pipe-wall roughness parameter. This range of effective roughness parameters agrees well with the default range of 35μm to 65μm used in industry, as well as the literature quoted range for clean pipe of 40μm to 100μm. The measured roughness parameter on average increases with increasing nominal pipe size, a result that may be a characteristic of the extrusion or hot-rolling processes used to manufacture small diameter pipes. Additionally, there is a large variation in the measured roughness parameters of pipe samples of the same nominal pipe size, indicating that surface roughness can vary depending on the manufacturing source of these pipes.

Influence of Ribbon Structure Rough Wall on the Microscale Poiseuille Flow

2005 ◽  
Vol 127 (6) ◽  
pp. 1140-1145 ◽  
Author(s):  
Haoli Wang ◽  
Yuan Wang ◽  
Jiazhong Zhang
Keyword(s):  
Harmonic Functions ◽  
Wave Number ◽  
Fundamental Wave ◽  
Wall Roughness ◽  
Parallel Plates ◽  
Roughness Parameters ◽  
Regular Perturbation ◽  
Roughness Model ◽  
Ribbon Structure ◽  
Flow Resistances

The regular perturbation method is introduced to investigate the influence of two-dimensional roughness on laminar flow in microchannels between two parallel plates. By superimposing a series of harmonic functions with identical dimensional amplitude as well as the same fundamental wave number, the wall roughness functions are obtained and the relative roughness can be determined as the maximal value of the product between the normalized roughness functions and a small parameter. Through modifying the fundamental wave number, the dimensionless roughness spacing is changed. Under this roughness model, the equations with respect to the disturbance stream function are obtained and analyzed numerically. The numerical results show that flowing in microchannels are more complex than that in macrochannels; there exist apparent fluctuations with streamlines and clear vortex structures in microchannels; the flow resistances are about 5–80% higher than the theoretical value under different wall-roughness parameters. Furthermore, analysis shows that the effect of roughness on the flow pattern is distinct from that on the friction factor.

Side wall roughness in ultradeep X-ray lithography

2002 ◽  
Vol 9 (1-2) ◽  
pp. 130-132 ◽  
Author(s):  
N. Moldovan ◽  
D. C. Mancini ◽  
R. Divan ◽  
O. V. Makarova ◽  
A. Peele ◽  
...  
Keyword(s):  
Side Wall ◽  
Wall Roughness ◽  
X Ray

Thin Film Epitaxial Oxide Optical Waveguides

1995 ◽  
Vol 392 ◽  
Author(s):  
D. K. Fork ◽  
F. Armani-Leplingard ◽  
J. J. Kingston ◽  
G. B. Anderson
Keyword(s):  
Thin Film ◽  
Optical Waveguides ◽  
Computational Models ◽  
Comparative Anatomy ◽  
Residual Effects ◽  
Light Sources ◽  
Optical Losses ◽  
Rapid Improvement ◽  
Waveguide Loss ◽  
Epitaxial Oxide

AbstractOne of the most challenging applications of ferroelectric thin films is the formation of technologically practical optical waveguideing devices, particularly in the context of a dynamically changing environment where competing light sources and optical materials simultaneously undergo rapid improvement. In order to assess the prospects of this technology, a fundamental understanding of waveguide loss is being pieced together. This includes the relative contributions of surface scattering, and grain boundary scattering to optical losses. With computational models, it is possible to predict the surface losses from measured topographic data. This tool provides a method to probe the residual effects of grain boundaries, defects and impurities on optical losses. A comparative anatomy of various thin film structures and their loss characteristics will be provided in the context of these experiments.

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