scholarly journals Photonic-plasmonic mode coupling in nanopillar Ge-on-Si PIN photodiodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lion Augel ◽  
Jon Schlipf ◽  
Sergej Bullert ◽  
Sebastian Bürzele ◽  
Jörg Schulze ◽  
...  
Keyword(s):  
Mode Coupling ◽  
Incident Light ◽  
Photonic Devices ◽  
Group Iv ◽  
Metallic Films ◽  
Starting Point ◽  
Close Proximity ◽  
Simulation And Experiment ◽  
Pin Photodiodes ◽  
Leaky Waveguide

AbstractIncorporating group IV photonic nanostructures within active top-illuminated photonic devices often requires light-transmissive contact schemes. In this context, plasmonic nanoapertures in metallic films can not only be realized using CMOS compatible metals and processes, they can also serve to influence the wavelength-dependent device responsivities. Here, we investigate crescent-shaped nanoapertures in close proximity to Ge-on-Si PIN nanopillar photodetectors both in simulation and experiment. In our geometries, the absorption within the devices is mainly shaped by the absorption characteristics of the vertical semiconductor nanopillar structures (leaky waveguide modes). The plasmonic resonances can be used to influence how incident light couples into the leaky modes within the nanopillars. Our results can serve as a starting point to selectively tune our device geometries for applications in spectroscopy or refractive index sensing.

scholarly journals Photonic-Plasmonic Mode Coupling in Nanopillar Ge-On-Si Pin Photodiodes

2020 ◽  
Author(s):  
Lion Augel ◽  
Jon Schlipf ◽  
Sergej Bullert ◽  
Sebastian Bürzele ◽  
Jörg Schulze ◽  
...  
Keyword(s):  
Mode Coupling ◽  
Incident Light ◽  
Photonic Devices ◽  
Group Iv ◽  
Metallic Films ◽  
Starting Point ◽  
Close Proximity ◽  
Simulation And Experiment ◽  
Pin Photodiodes ◽  
Leaky Waveguide

Abstract Incorporating group IV photonic nanostructures within active top-illuminated photonic devices often requires light-transmissive contact schemes. In this context, plasmonic nanoapertures in metallic films can not only be realized using CMOS compatible metals and processes, they can also serve to influence the wavelength-dependent device responsivities. Here, we investigate crescent-shaped nanoapertures in close proximity to Ge-on-Si PIN nanopillar photodetectors both in simulation and experiment. In our geometries, the absorption within the devices is mainly shaped by the absorption characteristics of the vertical semiconductor nanopillar structures (leaky waveguide modes). The plasmonic resonances can be used to influence how incident light couples into the leaky modes within the nanopillars. Our results can serve as a starting point to selectively tune our device geometries for applications in spectroscopy or refractive index sensing.

Properties of Nanostructured Resonant Leaky-Mode Photonic Devices

2008 ◽  
Vol 55 ◽  
pp. 101-107
Author(s):  
Robert Magnusson ◽  
Mehrdad Shokooh-Saremi
Keyword(s):  
Incident Light ◽  
Stop Band ◽  
Resonance Field ◽  
Photonic Devices ◽  
Leaky Mode ◽  
Guided Mode ◽  
Wave Effects ◽  
Guided Mode Resonance ◽  
Bandstop Filters ◽  
Leaky Waveguide

In this paper, we review the basic properties of resonant leaky mode elements implemented with periodic waveguide layers and consider their applicability in photonic devices and systems. Leaky waveguide modes can be exited when an incident light beam is coupled into the waveguide structure through an inscribed periodicity under phase-matching conditions. This results in generation of a guided-mode resonance field response in the spectrum. Device operation can be explained in terms of the photonic band structure and associated leaky-wave effects near the second stop band. Resonant devices such as bandpass/bandstop filters, polarizers, wideband reflectors, biosensors, tunable filters, and display pixels can be designed using this operational principle.

scholarly journals Controlling wave fronts with tunable disordered non-Hermitian multilayers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Denis V. Novitsky ◽  
Dmitry Lyakhov ◽  
Dominik Michels ◽  
Dmitrii Redka ◽  
Alexander A. Pavlov ◽  
...  
Keyword(s):  
Incident Light ◽  
Passage Time ◽  
Photonic Devices ◽  
Gain Saturation ◽  
Wave Fronts ◽  
Optical Effects ◽  
Front Shape ◽  
Optical Applications ◽  
Increasing Demand ◽  
First Time

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.

scholarly journals Numerical Investigation of a Designed-Inlet Optofluidic Beam Splitter for Split-Angle and Transmission Improvement

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1200
Author(s):  
Ting-Yuan Lin ◽  
Chih-Yang Wu
Keyword(s):  
Beam Splitter ◽  
Incident Light ◽  
Transmission Efficiency ◽  
Main Channel ◽  
Calcium Chloride Solution ◽  
Deionized Water ◽  
Flow Rate Ratio ◽  
Horizontal Line ◽  
Simulation And Experiment ◽  
Side Walls

The beam splitter is one of the important elements in optical waveguide circuits. To improve the performance of an optofluidic beam splitter, a microchannel including a two-stage main channel with divergent side walls and two pairs of inlet channels is proposed. Besides, the height of the inlets injected with cladding fluid is set to be less than the height of other parts of the microchannel. When we inject calcium chloride solution (cladding fluid) and deionized water (core fluid) into the inlet channels, the gradient refractive index (GRIN) developed in fluids flowing through the microchannel split the incident light beam into two beams with a larger split angle. Moreover, the designed inlets yield a GRIN distribution which increases the light collected around the middle horizontal line on the objective plane, and so enhances the transmission efficiency of the device. To demonstrate the performance of the proposed beam splitter, we use polydimethylsiloxane to fabricate the microchannel. The results obtained by simulation and experiment are compared to show the effectiveness of the device and the validity of numerical simulation. The influence of the microchannel geometry and the flow rate ratio on the performance of the proposed beam splitter is investigated.

Process Modeling, Optimization and Characterization of Silicon Optical Waveguides by Anisotropic Wet Etching

2011 ◽  
Vol 403-408 ◽  
pp. 4295-4299
Author(s):  
H. Hazura ◽  
A.R. Hanim ◽  
B. Mardiana ◽  
Sahbudin Shaari ◽  
P.S. Menon
Keyword(s):  
Optical Waveguide ◽  
Optical Waveguides ◽  
Photonic Devices ◽  
Wet Etching ◽  
Fabrication Process ◽  
Etching Time ◽  
Optical Modulators ◽  
Silicon Waveguide ◽  
Simulation And Experiment ◽  
Silicon Based

We present a detailed fabrication process of silicon optical waveguide with a depth of 4μm via simulation and experiment. An anisotropic wet etching using Potassium Hydroxide (KOH) solutions was selected to study the influence of major fabrication parameters such as etch rate, oxidation time and development time to the fabrication performance. The fabrication of the silicon waveguide with the orientation of was modeled using ATHENA from 2D Silvaco software and was later compared with the actual fabricated device. Etching time of 4 minutes was required to etch the Si to the depth of 4μm to obtain a perfectly trapeizoidal optical waveguide structure. Our results show that the simulation model is trustworthy to predict the performance of the practical anisotropic wet etching fabrication process. The silicon-based waveguide components are targeted to be employed in realizing future photonic devices such as optical modulators.

ASPHERO5 – Simulation and Analysis of Aspherical Polishing Process

2007 ◽  
Vol 364-366 ◽  
pp. 488-492 ◽  
Author(s):  
Rainer Boerret ◽  
Andreas Kelm ◽  
Helge Thiess ◽  
Volkmar Giggel
Keyword(s):  
Surface Quality ◽  
Removal Rate ◽  
Limiting Factors ◽  
Polishing Process ◽  
Power Spectral ◽  
Starting Point ◽  
German Research ◽  
First Results ◽  
Simulation And Experiment

ASPHERO5 is a funded German research project (project prime: Schneider OpticalMachines) with the goal of economic fabrication of high precision aspheres. The research is concentrated on the classical process chain consisting of grinding and polishing. The characterization of the incoming and outgoing surface quality is one issue to characterize the improvements. The variation of the local removal rate related to local curvature is one of the limiting factors of the polishing process. In this paper we report on first results characterizing the surface quality with a PSD (Power Spectral Density) algorithm and analyzing the local removal rates for the polishing step. In our research, two types of aspheres with 30 and 60 mm diameter were polished with a spinning tool process. The final deviation between simulation and experiment was less than 10 percent. That’s the starting point for further investigations within the project.

Epitaxial Growth of Metallic Layers by Solid Phase Interdiffusion : Study of the Ni/GaAs and Ni/AlAs Systems

1989 ◽  
Vol 160 ◽  
Author(s):  
Roland Guerin ◽  
S. Deputier ◽  
J. Caulet ◽  
M. Minier ◽  
A. Poudoulec ◽  
...  
Keyword(s):  
Solid State ◽  
Metal Film ◽  
Ternary Phase ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Metallic Films ◽  
Ternary Phase Diagrams ◽  
Starting Point ◽  
Semiconductor Contact

AbstractAn ideal metal/III-V semiconductor contact should be made by stable and epitaxial metallic films. In principle, such a contact may be obtained by the solid state ΐnterdiffusion of a metal film with a III-V SC substrate. We studied the solid state interdiffusions in the Ni/GaAs and Ni/AlAs systems. Our starting point was the experimental determination of the Ni-Ga-As and Ni-Al-As ternary phase diagrams. The main steps of the interaction appear to be different in the two systems. During the Ni/GaAs one, three successive steps as a function of the annealing temperature are observed : first a mixture of a Ga-rich ternary phase (C phase) + NiAs, then C phase + NiAs + NiGa and at last the two binaries NiAs + NiGa where the reaction stops. In the case of the Ni/AlAs reactions, the three steps successively correspond to a mixture of NiAl + an As-rich ternary phase then NiAl + another As-rich ternary phase + NiAs and finally NiAl + NiAs. NiAs and NiAl are the key compounds in Ni/GaAs and Ni/AlAs reactions respectively and all the reaction compounds are either textured (pseudocubic NiAs and ternaries) or epitaxial (cubic binaries NiGa and NiAl).

scholarly journals Photothermal Optical Beam Steering Using Large Deformation Multi-Layer Thin Film Structures

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 428
Author(s):  
Harris J. Hall ◽  
Sean McDaniel ◽  
Piyush Shah ◽  
David Torres ◽  
Jose Figueroa ◽  
...  
Keyword(s):  
Large Deformation ◽  
Beam Steering ◽  
Incident Light ◽  
Optical Beam ◽  
Directional Control ◽  
Highly Sensitive ◽  
Simulation And Experiment ◽  
On Chip ◽  
Layer Thin Film ◽  
Tilt Response

Photothermal actuation of microstructures remains an active area of research for microsystems that demand electrically isolated, remote, on-chip manipulation. In this study, large-deformation structures constructed from thin films traditional to microsystems were explored through both simulation and experiment as a rudimentary means to both steer and shape an incident light beam through photothermal actuation. A series of unit step infrared laser exposures were applied at increasing power levels to both uniformly symmetric and deliberately asymmetric absorptive structures with the intent of characterizing the photothermal tilt response. The results indicate that a small angle (<4° at ~74 W/cm2) mechanical tilt can be instantiated through central placement of an infrared beam, although directional control appears highly sensitive to initial beam placement. Greater responsivity (up to ~9° mechanical tilt at ~54 W/cm2) and gross directional control was demonstrated with an asymmetrical absorptive design, although this response was accompanied by a large amount (~5–10°) of mechanical tilt burn-in and drift. Rigorous device cycling remains to be explored, but the results suggest that these structures, and those similar in construction, can be further matured to achieve controllable photoactuation suitable for optical beam control or other applications.

Couplings in GaAs/AlGaAs/Metal Photonic Waveguides with Metallic Variations

2012 ◽  
Vol 1396 ◽  
Author(s):  
Meng-Mu Shih
Keyword(s):  
Mode Coupling ◽  
Hybrid Structure ◽  
Wave Mode ◽  
Photonic Devices ◽  
Coupling Coefficients ◽  
Light Emitting ◽  
Photonic Waveguides ◽  
And Performance ◽  
Metal Gratings ◽  
Future Work

ABSTRACTTo have better light-emitting performance, semiconductor-metal periodic photonic waveguides can generate stable wavelengths. This work constructs a multi-parameter model to compute the backward-wave mode-coupling coefficients, which are important to the analysis and performance of photonic devices. For such a semiconductor-metal hybrid structure, a proper photonic technique needs to be utilized to solve this computational complexity.Numerical results demonstrate how the materials of metal gratings, the corrugation amplitudes of metal gratings, and the metallic aluminum mole fraction can affect the coupling coefficients. Further physical interpretation and discussion can support and explain the above results. The results can help engineers decide the values of parameters used in fabrication. Future work and applications will be proposed.

scholarly journals Patterned Photoalignment in Thin Films: Physics and Applications

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 84
Author(s):  
Vladimir Chigrinov ◽  
Aleksey Kudreyko ◽  
Qi Guo
Keyword(s):  
Liquid Crystals ◽  
Azo Dye ◽  
Rotational Diffusion ◽  
Incident Light ◽  
Polarized Light ◽  
Photonic Devices ◽  
Dye Molecules ◽  
Ferroelectric Liquid Crystals ◽  
Dependent Change ◽  
Alignment Process

Photoalignment of liquid crystals by using azo dye molecules is a commonly proposed alternative to traditional rubbing alignment methods. Photoalignment mechanism can be well described in terms of rotational diffusion of azo dye molecules exposed by ultraviolet polarized light. A specific feature of the irradiated light is the intensity dependent change of azimuthal anchoring of liquid crystals. While there are various mechanisms of azo dye photoalignment, photo-reorientation occurs when dye molecules orient themselves perpendicular to the polarization of incident light. In this review, we describe both recent achievements in applications of photoaligned liquid crystal cells and its simulation. A variety of display and photonic devices with azo dye aligned nematic and ferroelectric liquid crystals are presented: q-plates, optically rewritable flexible e-paper (monochromatic and color), and Dammann gratings. Some theoretical aspects of the alignment process and display simulation are also considered.

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