To enable tunable temporal engineering in optical communications and processing systems, we integrate RF and wavelength control of mode excitation angle in a multimode waveguide. Dynamic tunability of dispersion is de...
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ISBN:
(纸本)9781943580422
To enable tunable temporal engineering in optical communications and processing systems, we integrate RF and wavelength control of mode excitation angle in a multimode waveguide. Dynamic tunability of dispersion is demonstrated over 1.27 ns and 40 nm of optical bandwidth.
Within this work, a novel millimeter-wave design platform is introduced, utilizing conventional microfabrication techniques to produce fully monolithic miniaturized 3D ridged half-mode waveguides. These structures off...
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ISBN:
(纸本)9781538650677
Within this work, a novel millimeter-wave design platform is introduced, utilizing conventional microfabrication techniques to produce fully monolithic miniaturized 3D ridged half-mode waveguides. These structures offer substantial die real estate reduction compared to previously reported wafer-level waveguides, while also offering the opportunity for improvements in integration and fabrication yield. The microfabrication process flow is outlined, and a fabricated prototype is measured. A ridged half-mode waveguide is designed and fabricated with cutoff frequency of 58 GHz, for operation within E-band. The measured results show attenuation loss as low as 0.3 dB/mm, while achieving 63% miniaturization over standard rectangular monolithic 3D waveguide previously reported. Independent from the carrier substrate performance, the proposed air-filled monolithic ridged half-mode waveguide demonstrates potential to provide enhanced integration technology suitable for millimeter-wave communication.
The optical mode properties of an anisotropic nano-layered aluminum-doped zinc oxide rectangular waveguides at the epsilon-near-zero spectral point are numerically investigated. The finite element method is used for a...
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ISBN:
(数字)9781510615380
ISBN:
(纸本)9781510615380
The optical mode properties of an anisotropic nano-layered aluminum-doped zinc oxide rectangular waveguides at the epsilon-near-zero spectral point are numerically investigated. The finite element method is used for a numerical study of the optical resonance frequencies for a square Al:ZnO/ZnO waveguide (1 mu m width/height). Optical permittivity for multilayered Al:ZnO/ZnO is described using an effective medium approximation Our numerical finite element method calculations predict a significant spectral shift, a modified free spectral range, and an asymmetric electric field distribution for lower order optical modes. Those modes have resonance wavelengths at the epsilon-near-zero point (similar to 1800 nm). We show that the resonant frequency for the lower order TE11 mode increases dramatically compared to the non-doped zinc-oxide waveguides, while the higher order modes (e.g, TE21) remain almost at the same frequency. This results in less than a 5% difference in resonance frequencies for these two modes for Al:ZnO/ZnO square waveguide.
We observe the propagation of an exciton-polariton wave in a WSe2 nanometric slab. We directly visualize with unprecedented spatio-temporal resolution (50 nm, <70 fs) a strikingly slow polaritonic wave with a veloc...
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ISBN:
(纸本)9781943580422
We observe the propagation of an exciton-polariton wave in a WSe2 nanometric slab. We directly visualize with unprecedented spatio-temporal resolution (50 nm, <70 fs) a strikingly slow polaritonic wave with a velocity of similar to 0.017c.
We demonstrate a high effective nonlinearity in high refractive-index-contrast gallium nitride waveguides by performing four-wave mixing characterization. The intrinsic material nonlinearity (n2) of gallium nitride is...
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ISBN:
(纸本)9781943580422
We demonstrate a high effective nonlinearity in high refractive-index-contrast gallium nitride waveguides by performing four-wave mixing characterization. The intrinsic material nonlinearity (n2) of gallium nitride is extracted at telecom wavelengths.
While microwaves have many features and advantages, problems may occur, including non-heating, partial overheating, and fire due to damaged magnetrons caused by reflected waves, when they are used without a proper und...
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While microwaves have many features and advantages, problems may occur, including non-heating, partial overheating, and fire due to damaged magnetrons caused by reflected waves, when they are used without a proper understanding of the permittivity of the object to be heated, the electromagnetic field distribution, the matching between the chamber and the waveguide, and the reflected electromagnetic waves. Simulation was performed using the Ansys HFSS tool. Conditions for the uniform electromagnetic field were derived using the distance from the waveguides to the ceramic material as well as the microwave energy intensity as major parameters.
The laser inscription of waveguides into the volume of crystalline silicon is presented. By using sub-ps laser pulses at a wavelength of 1552 nm highly localized light guiding structures with an average diameter rangi...
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ISBN:
(数字)9781510615243
ISBN:
(纸本)9781510615243
The laser inscription of waveguides into the volume of crystalline silicon is presented. By using sub-ps laser pulses at a wavelength of 1552 nm highly localized light guiding structures with an average diameter ranging from 1 - 3 mu m are achieved. The generated waveguides are characterized in terms of mode field distribution, damping losses and permanent refractive index modification. First investigations indicate an induced increase of the refractive index in the order of 10(-3) to 10(-2). Depending on the applied laser pulse energy single-mode to multimode like propagation behavior can be observed. At optimized processing parameters, the damping losses can be estimated below 3 dB/mm.
We present that the nonlinear optical conversion efficiency in LNOI ridge/rib waveguides can be improved by considering the lateral leakage at the second harmonic wavelength, enabling an improved nonlinear optical con...
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ISBN:
(纸本)9781943580576
We present that the nonlinear optical conversion efficiency in LNOI ridge/rib waveguides can be improved by considering the lateral leakage at the second harmonic wavelength, enabling an improved nonlinear optical conversion efficiency of ～780% W~(-1)cm~(-2).
Semiconductor organometallic halide (CH3NH3PbX3, X= Cl, Br, I) perovskites (MHP) have emerged as a very high promising material for optoelectronics. Their large absorption coefficients, high electronic mobilities, exc...
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ISBN:
(纸本)9781538666050
Semiconductor organometallic halide (CH3NH3PbX3, X= Cl, Br, I) perovskites (MHP) have emerged as a very high promising material for optoelectronics. Their large absorption coefficients, high electronic mobilities, excellent quantum yield of emission at room temperature and tunable band-gap with the composition resulted in a new generation of photovoltaics and electronic devices. In this work, HPVK materials are successfully incorporated on a nanocellulose (NC) substrate with the intention to exploit the interesting properties of HPVK materials to construct wearable devices. In particular, a bilayer Poly(methyl methacrylate) / HPVK deposited on NC resulted in a suitable waveguide to demonstrate amplification of the spontaneous emission (ASE) with a threshold as low as 3 - 4 nJ. Moreover, when a photodetector system is integrated within the waveguide, the device provides a photocurrent useful to monitor the light/ ASE propagated/ generated along the structure. This approximation paves the road of new wearable systems with a broad range of applications.
Polymer optical sensors have attracted significant scientific interest due to the advantages of flexibility and lowcost mass-production possibilities. A main challenge in integration of all-polymer systems is interfac...
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ISBN:
(数字)9781510615564
ISBN:
(纸本)9781510615564
Polymer optical sensors have attracted significant scientific interest due to the advantages of flexibility and lowcost mass-production possibilities. A main challenge in integration of all-polymer systems is interfacing sensor parts to light sources and detectors. Coupling strategies such as end-facet coupling, 45 degrees mirrors coupler and gratings coupler have been investigated. However, facet polishing is complicated for large flexible foils, while 45 degrees mirrors often require a metal reflection layer. Thus grating couplers have the biggest potential and are compatible with roll-to-roll processes. Polymers have higher thermo-optic-coefficients and thermal-expansion-coefficients compared to inorganic materials, making them very sensitive to temperature changes. Consequently, polymer grating couplers show a shift of the coupling angle with temperature and thus a decay of efficiency. We therefore present a temperature characterization of all-polymer based grating couplers on waveguides based sensors. Cost-effective manufacturing methods, including hot-embossing and spin-coating, were used for the fabrication of waveguides and gratings on PMMA foils. Single mode waveguides were realized by modifying the dimensions of their cross-section. Gratings with a period of 560 nm were subsequently bonded on the waveguides for input coupling. Thermal response was characterized by monitoring the coupling angle at different temperatures. Temperature dependences of the incident angle at two main peaks of 0.0027 degrees/K and 0.0054 degrees/K were determined respectively at the wavelength of 852 nm and a linear response over the evaluated range between 298 K and 323 K was observed, which opens up possible applications for on-chip temperature monitoring and thermal compensation when integrated with polymer sensors.
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