scholarly journals Comparative Study of Nano-Slot Silicon Waveguides Covered by Dye Doped and Undoped Polymer Cladding

2018 ◽  
Vol 9 (1) ◽  
pp. 89 ◽  
Author(s):  
Siegfried Bondarenko ◽  
Claus Villringer ◽  
Patrick Steglich
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Structural Parameters ◽  
Polymer System ◽  
Silicon On Insulator ◽  
Slot Waveguide ◽  
Optical Modulators ◽  
Optical Polymer ◽  
Waveguide Design ◽  
Cladding Material

Nonlinear optical dyes doped in optical polymer matrices are widely used for electro-optical devices. Linear optical properties change with dye concentration, which leads to a change in modal properties, especially in nano-structured integrated waveguides such as silicon slot-waveguides. Here, we investigate the influence of a nonlinear optical dye on the performance of a silicon-organic hybrid slot-waveguide. A simulation study of the modal and optical confinement properties is carried out and dependence of the structural parameters of the slot-waveguide and the organic cladding material is taken into account. As cladding material, a guest-host polymer system is employed comprising the nonlinear optical dye Disperse Red 1 (DR1) doped in a poly[methyl methacrylate] (PMMA) matrix. The refractive indices of doped and undoped PMMA were deduced from ellipsometric data. We present a guideline for an optimized slot-waveguide design for the fabrication in silicon-on-insulator technology giving rise to scalable, high-performance integrated electro-optical modulators.

scholarly journals Silicon-on-Insulator Slot-waveguide Design Trade-offs

2015 ◽  
Author(s):  
Patrick Steglich ◽  
Claus Villringer ◽  
Silvio Dümecke ◽  
Yazmin Padilla Michel ◽  
Mauro Casalboni ◽  
...  
Keyword(s):  
Silicon On Insulator ◽  
Slot Waveguide ◽  
Trade Offs ◽  
Waveguide Design

scholarly journals Elevating silicon into a high performance nonlinear optical platform through the integration of 2D graphene oxide thin films

2021 ◽  
Author(s):  
David Moss
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Kerr Nonlinearity ◽  
Photonic Devices ◽  
Silicon On Insulator ◽  
Layer By Layer ◽  
Large Area ◽  
Precise Control ◽  
Highly Nonlinear ◽  
Coating Method

Abstract Layered two-dimensional (2D) GO films are integrated with silicon-on-insulator (SOI) nanowire waveguides to experimentally demonstrate an enhanced Kerr nonlinearity, observed through self-phase modulation (SPM). The GO films are integrated with SOI nanowires using a large-area, transfer-free, layer-by-layer coating method that yields precise control of the film thickness. The film placement and coating length are controlled by opening windows in the silica cladding of the SOI nanowires. Owing to the strong mode overlap between the SOI nanowires and the highly nonlinear GO films, the Kerr nonlinearity of the hybrid waveguides is significantly enhanced. Detailed SPM measurements using picosecond optical pulses show significant spectral broadening enhancement for SOI nanowires coated with 2.2-mm-long films of 1 − 3 layers of GO, and 0.4-mm-long films with 5 − 20 layers of GO. By fitting the experimental results with theory, the dependence of GO’s n2 on layer number and pulse energy is obtained, showing interesting physical insights and trends of the layered GO films from 2D monolayers to quasi bulk-like behavior. Finally, we show that by coating SOI nanowires with GO films the effective nonlinear parameter of SOI nanowires is increased 16 fold, with the effective nonlinear figure of merit (FOM) increasing by about 20 times to FOM > 5. These results reveal the strong potential of using layered GO films to improve the Kerr nonlinear optical performance of silicon photonic devices.

Photoconductivity in an Epoxy-Based Photocrosslinkable Nonlinear Optical Polymer

1992 ◽  
Vol 247 ◽  
Author(s):  
Lian Li ◽  
R. J. Jeng ◽  
J. Y. Lee ◽  
Y. Yang ◽  
J. Kumar ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Nonlinear Optical ◽  
Carrier Transport ◽  
Polymer System ◽  
Optical Excitation ◽  
Diglycidyl Ether ◽  
Charge Carrier Transport ◽  
Optical Polymer ◽  
Nlo Chromophores ◽  
Nonlinear Optical Polymer

ABSTRACTPhotoconductivity measurements on an epoxy-based photocrosslinkable second-order nonlinear optical (NLO) polymer - DGENC - NAC ( diglycidyl ether of nitrocatechol / nitroaniline prepolymer functionalized with cinnamoyl groups) are presented. Without introducing any sensitizer or charge carrier transport agents, large photoconductivity was obtained in this polymer system. Optical excitation of the NLO chromophores leads to photocarrier generation and it is conjectured that these NLO chromophores also play a role in the carrier transport. This polymer is one of the candidate materials for photorefraction.

Roughness measurements of nonlinear optical polymer films by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 22-23
Author(s):  
I. H. Musselman ◽  
R.-T. Chen ◽  
P. E. Russell
Keyword(s):  
Surface Roughness ◽  
Scanning Tunneling Microscopy ◽  
Nonlinear Optical ◽  
Polymer Surface ◽  
Light Extinction ◽  
Scanning Tunneling ◽  
Silicon Substrates ◽  
Tunneling Microscopy ◽  
Optical Polymer ◽  
Total Light

Scanning tunneling microscopy (STM) has been used to characterize the surface roughness of nonlinear optical (NLO) polymers. A review of STM of polymer surfaces is included in this volume. The NLO polymers are instrumental in the development of electrooptical waveguide devices, the most fundamental of which is the modulator. The most common modulator design is the Mach Zehnder interferometer, in which the input light is split into two legs and then recombined into a common output within the two dimensional waveguide. A π phase retardation, resulting in total light extinction at the output of the interferometer, can be achieved by changing the refractive index of one leg with respect to the other using the electrooptic effect. For best device performance, it is essential that the NLO polymer exhibit minimal surface roughness in order to reduce light scattering. Scanning tunneling microscopy, with its high lateral and vertical resolution, is capable of quantifying the NLO polymer surface roughness induced by processing. Results are presented below in which STM was used to measure the surface roughness of films produced by spin-coating NLO-active polymers onto silicon substrates.

Photoconductivity in a Photocrosslinkable Second Order Nonlinear Optical Polymer

1992 ◽  
Author(s):  
L. Li ◽  
J. Y. Lee ◽  
Y. Yang ◽  
J. Kumar ◽  
S. K. Tripathy
Keyword(s):  
Nonlinear Optical ◽  
Second Order ◽  
Optical Polymer ◽  
Nonlinear Optical Polymer

scholarly journals Exploring the Structure–Performance Relationship of Sulfonated Polysulfone Proton Exchange Membrane by a Combined Computational and Experimental Approach

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 959
Author(s):  
Cataldo Simari ◽  
Mario Prejanò ◽  
Ernestino Lufrano ◽  
Emilia Sicilia ◽  
Isabella Nicotera
Keyword(s):  
High Performance ◽  
Mechanical Stability ◽  
Structural Parameters ◽  
Hydration Number ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Water Dynamics ◽  
Mechanical Resistance ◽  
Theoretical Simulation ◽  
Sulfonated Polysulfone

Sulfonated Polysulfone (sPSU) is emerging as a concrete alternative to Nafion ionomer for the development of proton exchange electrolytic membranes for low cost, environmentally friendly and high-performance PEM fuel cells. This ionomer has recently gained great consideration since it can effectively combine large availability on the market, excellent film-forming ability and remarkable thermo-mechanical resistance with interesting proton conductive properties. Despite the great potential, however, the morphological architecture of hydrated sPSU is still unknown. In this study, computational and experimental advanced tools are combined to preliminary describe the relationship between the microstructure of highly sulfonated sPSU (DS = 80%) and its physico-chemical, mechanical and electrochemical features. Computer simulations allowed for describing the architecture and to estimate the structural parameters of the sPSU membrane. Molecular dynamics revealed an interconnected lamellar-like structure for hydrated sPSU, with ionic clusters of about 14–18 Å in diameter corresponding to the hydrophilic sulfonic-acid-containing phase. Water dynamics were investigated by 1H Pulsed Field Gradient (PFG) NMR spectroscopy in a wide temperature range (20–120 °C) and the self-diffusion coefficients data were analyzed by a “two-sites” model. It allows to estimate the hydration number in excellent agreement with the theoretical simulation (e.g., about 8 mol H2O/mol SO3− @ 80 °C). The PEM performance was assessed in terms of dimensional, thermo-mechanical and electrochemical properties by swelling tests, DMA and EIS, respectively. The peculiar microstructure of sPSU provides a wider thermo-mechanical stability in comparison to Nafion, but lower dimensional and conductive features. Nonetheless, the single H2/O2 fuel cell assembled with sPSU exhibited better features than any earlier published hydrocarbon ionomers, thus opening interesting perspectives toward the design and preparation of high-performing sPSU-based PEMs.

Research on CFD Simulation of the Cement Slurry Mixer

2012 ◽  
Vol 621 ◽  
pp. 196-199
Author(s):  
Shui Ping LI ◽  
Ya Li Yuan ◽  
Lu Gang Shi
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Cfd Simulation ◽  
Structural Parameters ◽  
Internal Flow ◽  
Simulation Method ◽  
Cement Slurry ◽  
Fluid Machinery ◽  
Computational Fluid Dynamics Cfd ◽  
Machinery Design

Numerical simulation method of the internal flow field of fluid machinery has become an important technology in the study of fluid machinery design. In order to obtain a high-performance cement slurry mixer, computational fluid dynamics (CFD) techniques are used to simulate the flow field in the mixer, and the simulation results are studied. According to the analysis results, the structural parameters of the mixer are modified. The results show the mixer under the revised parameters meet the design requirements well. So CFD analysis method can shorten design period and provide valuable theoretical guidance for the design of fluid machinery.

Coupled strip-slot waveguide design for dispersion compensation

2015 ◽  
Vol 47 (9) ◽  
pp. 3161-3169 ◽  
Author(s):  
Vidhi Mann ◽  
Nandam Ashok ◽  
Vipul Rastogi
Keyword(s):  
Dispersion Compensation ◽  
Slot Waveguide ◽  
Waveguide Design
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