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Extinction ratio

About: Extinction ratio is a research topic. Over the lifetime, 8541 publications have been published within this topic receiving 111908 citations.


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TL;DR: This paper analyzes the data suppression characteristic of the SOA using a large signal model and estimates the bit error rate degradation in the presence of an unsuppressed downstream bit pattern in an upstream signal.
Abstract: This paper describes a method for realizing the efficient utilization of wavelength resources in wavelength-division multiplexing networks with centralized light sources. Using a deeply saturated semiconductor optical amplifier (SOA) modulator located in a remote node (RN), we erase the data on a downstream signal with a low extinction ratio and modulate it with new data to generate an upstream signal. Thus, we use only one wavelength for bidirectional transmission between a center node and an RN, without placing lasers at the RN. In this paper, we analyze the data suppression characteristic of the SOA using a large signal model. We also estimate the bit error rate degradation in the presence of an unsuppressed downstream bit pattern in an upstream signal. We then report experimental results that confirm the basic characteristics of the wavelength channel data rewriter, which we constructed using a linear amplifier and an SOA. Finally, we provide the results of a data transmission experiment that we undertook using the data rewriter.

159 citations

Journal ArticleDOI
Zhaoning Yu1, Paru Deshpande1, Wei Wu1, Jian Wang1, Stephen Y. Chou1 
TL;DR: In this article, a reflective polarizer consisting of two layers of 190 nm period metal gratings was fabricated using nano-imprint lithography, and measurements with a He-Ne laser (wavelength=632.8 nm) showed that at normal incidence, this polarizer reflects light polarized perpendicular to the grating lines with a reflectance of 54%, but strongly absorbs parallel-polarized light (transverse electric polarization) with only 0.25%.
Abstract: A reflective polarizer consisting of two layers of 190 nm period metal gratings was fabricated using nanoimprint lithography. Measurements with a He–Ne laser (wavelength=632.8 nm) showed that at normal incidence, this polarizer reflects light polarized perpendicular to the grating lines (transverse magnetic polarization) with a reflectance of 54%, but strongly absorbs parallel-polarized light (transverse electric polarization) with a reflectance of only 0.25%. The enhanced polarization extinction ratio of over 200 at this wavelength is possibly related to the resonance between the two layers of metal gratings. This polarizer is thin, compact, and is suited for integrated optical systems.

158 citations

Journal ArticleDOI
TL;DR: In this article, a Si photonic wire waveguide was used for constructing various optical devices that are extremely small because the waveguides can be bent with extremely small curvatures of less than a few micrometers of bending radius.
Abstract: Si photonic wire waveguides are attractive for constructing various optical devices that are extremely small because the waveguides can be bent with extremely small curvatures of less than a few micrometers of bending radius. We have fabricated optical directional couplers with the waveguides and demonstrated their fundamental characteristics. Their coupling length was extremely short, several micrometers, because of strong optical coupling between the waveguide cores. We have also demonstrated wavelength-demultiplexing functions for these devices with a long coupled waveguide. Optical outputs from a device with a 100-mum-long coupled waveguide changed reciprocally with a 20-nm wavelength spacing between the parallel and cross ports. We also demonstrated the operation of ultrasmall optical add-drop multiplexers (OADMs) with Bragg grating reflectors made up of the waveguides. The dropping wavelength bandwidth of the OADMs was less than 0.7 nm, and these dropping wavelengths could be precisely designed by adjusting the grating period. Using the Si photonic wire waveguide, we have also demonstrated thermo-optic switches. Metal thin-film heaters were evaporated onto the branch of a Mach-Zehnder interferometer that incorporated the waveguide to achieve switching operations by thermo-optic effects. In these switching operations, we observed more than 30 dB of extinction ratio, less than 90 mW of switching power, and less than 100 mus of switching speed

156 citations

Journal ArticleDOI
Kaiming Zhou1, George Simpson1, Xianfeng Chen1, Lin Zhang1, Ian Bennion1 
TL;DR: In this paper, a near-ideal in-fiber polarizer implemented by use of 45° tilted fiber Bragg grating structures that are UV inscribed in hydrogenated Ge-doped fiber was reported.
Abstract: We report a near-ideal in-fiber polarizer implemented by use of 45° tilted fiber Bragg grating structures that are UV inscribed in hydrogenated Ge-doped fiber. We demonstrate a polarization-extinction ratio of 33?dB over a 100-nm operation range near 1550?nm. We further show an achievement of 99.5% degree of polarization for unpolarized light with these gratings. We also theoretically investigate tilted grating structures based on the Green's function calculation, therein revealing the unique polarization characteristics, which are in excellent agreement with experimental data.

154 citations

Journal ArticleDOI
TL;DR: Finite-difference time-domain simulation indicates that the proposed device can provide large extinction ratio with low insertion loss for the TE mode, and a very compact and broadband TE-pass polarizer can be implemented.
Abstract: Hybrid plasmonic waveguides consisting of a metal plane separated from a high-index medium by a low-index spacer have recently attracted much interest. Here we show that, by suitably choosing the dimensions and material properties of the hybrid waveguide, a very compact and broadband TE-pass polarizer can be implemented. Finite-difference time-domain simulation indicates that the proposed device can provide large extinction ratio with low insertion loss for the TE mode.

151 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023187
2022429
2021371
2020449
2019468
2018441