The design of a wide scan angle matched hexagonal ridged waveguide (HRWG) antenna array element is presented for Ka-band satellite downlink in low Earth orbit non-terrestrial network applications. The antenna achieves...
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ISBN:
(纸本)9798350385892;9782874870774
The design of a wide scan angle matched hexagonal ridged waveguide (HRWG) antenna array element is presented for Ka-band satellite downlink in low Earth orbit non-terrestrial network applications. The antenna achieves a very low active reflection coefficient (ARC) of less than -18 dB across a large bandwidth from 17.3 to 20.2 GHz with a +/- 50 degrees scan range. The aperture of the HRWG was designed to limit the variations in ARC when scanning, minimizing load pulling of integrated active devices as demonstrated with a modeled power amplifier in a co-simulation.
We design and characterize asymmetric Bragg gratings in waveguides which possess multiple reflected wavelengths. We experimentally demonstrate devices with two independent stopbands, then use finite-difference time do...
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ISBN:
(纸本)9781557529688
We design and characterize asymmetric Bragg gratings in waveguides which possess multiple reflected wavelengths. We experimentally demonstrate devices with two independent stopbands, then use finite-difference time domain software to characterize more complex grating designs.
In this paper, the building blocks for a smart glass connector platform are presented. The connector is meant to connect optical fibers, which cannot be connected using conventional connector or splicing technology, e...
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ISBN:
(纸本)9781510669307;9781510669291
In this paper, the building blocks for a smart glass connector platform are presented. The connector is meant to connect optical fibers, which cannot be connected using conventional connector or splicing technology, e.g. optical sensing fibers embedded in composite structures for structural health monitoring purposes. We are setting up a technology platform using aluminosilicate glass substrates as interposer between 2 optical fibers that need to be connected. Using femtosecond laser technology, this interposer can be equipped with basic building blocks such as low-loss intermediate single mode waveguides, couplers and Bragg grating sensors. To this end, femtosecond laser-written waveguides are inscribed in aluminosilicate glass (Xensation (R) Cover float glass) and the laser parameters are optimized. waveguides with estimated propagation losses of 0.65 dB/cm are obtained and are subsequently used to make couplers in glass. These couplers can be tuned in coupling ratio between 87:13 and 15:85 by varying the coupling length from 1 to 4.5 mm at a pitch of 17 mu m. In addition, fs-laser written Bragg gratings were manufactured, with the goal to add monitoring capabilities to the interposer. These were realized by modulating the fs-laser pulse train and as such a reflectivity up to 5.9% was achieved in the C-band for 23 mm long Bragg gratings. When properly designed, these can be made compatible with standard read out equipment for fiber Bragg gratings (FBGs).
The fundamental problem of efficiently outcoupling high-k waves from hyperbolic metamaterials is approached with an in-plane configuration, and enhanced with adiabatic tapering. This strategy may allow for better effi...
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ISBN:
(纸本)9781557529688
The fundamental problem of efficiently outcoupling high-k waves from hyperbolic metamaterials is approached with an in-plane configuration, and enhanced with adiabatic tapering. This strategy may allow for better efficiency of Purcell enhanced quantum sources.
This study introduces a tunable optical system based on liquid crystal gratings, designed for the infrared (IR) spectrum. The system is designed to be compact, occupying only a few square millimeters, and presents a m...
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ISBN:
(纸本)9798350361810;9798350361803
This study introduces a tunable optical system based on liquid crystal gratings, designed for the infrared (IR) spectrum. The system is designed to be compact, occupying only a few square millimeters, and presents a multilayer configuration featuring a grating between two stacked BK7 glass substrates. An external voltage, applied to the system, activates a secondary pathway configured as a Mach-Zehnder interferometer (MZI) by directing the light through the upper glass layer into two optical channels on the upper system's surface. Light is then redirected back into the internal waveguide via the top glass layer before finally reaching the system output. The results of the finite-difference time-domain (FDTD) simulations confirm the optical coupling of an incoming out-of-plane light beam into the MZI's bottom arm via the liquid crystal tilted grating structure. These findings provide a promising foundation for the development of a versatile, compact, and programmable Mach-Zehnder interferometer, all features suitable for applications in optical communication systems and optical biosensing.
We present general conditions for lossless propagation in near-infrared hyperbolic metamaterial (HMM) waveguides with lateral confinement. We conclude that HMMs based on noble metals, rather than transparent conductin...
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ISBN:
(纸本)9781557529688
We present general conditions for lossless propagation in near-infrared hyperbolic metamaterial (HMM) waveguides with lateral confinement. We conclude that HMMs based on noble metals, rather than transparent conducting oxides, offer greatest promise for low-loss propagation.
We present the design of a novel orthomode transducer, OMT, suitable for scaling up to Terahertz frequencies. The current design aims for the frequency band 270-380 GHz. The OMT combines waveguide components made with...
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ISBN:
(纸本)9789463968102;9798350360257
We present the design of a novel orthomode transducer, OMT, suitable for scaling up to Terahertz frequencies. The current design aims for the frequency band 270-380 GHz. The OMT combines waveguide components made with conventional milling with substrate-based parts fabricated using microfabrication techniques. This allows critical dimensions of the OMT conventionally to be mechanically machined parts being replaced by photolithographically defined and microfabricated structures. The paper provides details on the OMT layout, simulations, fabrication and tests. The two fabricated and tested prototype OMTs show similar performance providing better than 30 dB cross-pol suppression. The OMTs also demonstrated broadband performance with an operational band of 260-385 GHz corresponding to a 38,8% fractional bandwidth. With the microfabricated polarization splitting junction and relatively simple waveguide circuitry, the OMT has very good potential to be scaled up to higher frequencies, probably up to 1.5 THz.
Integrable optical isolators, play a crucial role in fortifying the overall performance of Photonic Integrated Circuits (PICs). In this paper, we propose a device functioning in Transverse Magneto-OpticKerr Effect (TM...
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Integrable optical isolators, play a crucial role in fortifying the overall performance of Photonic Integrated Circuits (PICs). In this paper, we propose a device functioning in Transverse Magneto-OpticKerr Effect (TMOKE) configuration, where a magneto-optic material is sandwiched in between parallel dielectric slab waveguides. The coupled optical modes hosted by such a geometry undergo an electromagnetic profile transformation that can be exploited to confine the input mode in one waveguide during forward propagation and in the other during backward propagation. Together with a ring resonator, such a system can provide a 20dB isolation ratio with negligible insertion losses.
We report recent developments in Bragg soliton dynamics on an ultra-silicon-rich nitride chip, including gap soliton-based tunable slow light and pure quartic Bragg solitons. (c) 2024 The Author(s)
ISBN:
(纸本)9781510678804;9781510678811
We report recent developments in Bragg soliton dynamics on an ultra-silicon-rich nitride chip, including gap soliton-based tunable slow light and pure quartic Bragg solitons. (c) 2024 The Author(s)
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