The Experts below are selected from a list of 111837 Experts worldwide ranked by ideXlab platform
Giorgio Santarelli - One of the best experts on this subject based on the ideXlab platform.
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an agile laser with ultra Low Frequency Noise and high sweep linearity
Optics Express, 2010Co-Authors: Haifeng Jiang, A Clairon, Fabien Kefelian, P Lemonde, Giorgio SantarelliAbstract:We report on a fiber-stabilized agile laser with ultra-Low Frequency Noise. The Frequency Noise power spectral density is comparable to that of an ultra-stable cavity stabilized laser at Fourier frequencies higher than 30 Hz. When it is chirped at a constant rate of ~ 40 MHz/s, the max non-linearity Frequency error is about 50 Hz peak-to-peak over more than 600 MHz tuning range. The Rayleigh backscattering is found to be a significant Frequency Noise source dependent on fiber length, chirping rate and the power imbalance of the interferometer arms. We analyze this effect both theoretically and experimentally and put forward techniques to reduce this Noise contribution.
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an agile laser with ultra Low Frequency Noise and high sweep linearity
Optics Express, 2010Co-Authors: Haifeng Jiang, A Clairon, Fabien Kefelian, P Lemonde, Giorgio SantarelliAbstract:We report on a fiber-stabilized agile laser with ultra-Low Frequency Noise. The Frequency Noise power spectral density is comparable to that of an ultra-stable cavity stabilized laser at Fourier frequencies higher than 30 Hz. When it is chirped at a constant rate of approximately 40 MHz/s, the max non-linearity Frequency error is about 50 Hz peak-to-peak over more than 600 MHz tuning range. The Rayleigh backscattering is found to be a significant Frequency Noise source dependent on fiber length, chirping rate and the power imbalance of the interferometer arms. We analyze this effect both theoretically and experimentally and put forward techniques to reduce this Noise contribution.
Jamal M Deen - One of the best experts on this subject based on the ideXlab platform.
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Low Frequency Noise in bilayer mos2 transistor
ACS Nano, 2014Co-Authors: Xuejun Xie, Jamal M Deen, Deblina Sarkar, Wei Liu, Jiahao Kang, Ognian Marinov, Kaustav BanerjeeAbstract:Low-Frequency Noise is a significant limitation on the performance of nanoscale electronic devices. This limitation is especially important for devices based on two-dimensional (2D) materials such as graphene and transition metal dichalcogenides (TMDs), which have atomically thin bodies and, hence, are severely affected by surface contaminants. Here, we investigate the Low-Frequency Noise of transistors based on molybdenum disulfide (MoS2), which is a typical example of TMD. The Noise measurements performed on bilayer MoS2 channel transistors show a Noise peak in the gate-voltage dependence data, which has also been reported for graphene. To understand the peak, a trap decay-time based model is developed by revisiting the carrier number fluctuation model. Our analysis reveals that the peak originates from the fact that the decay time of the traps for a 2D device channel is governed by the van der Waals bonds between the 2D material and the surroundings. Our model is generic to all 2D materials and can be ...
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Low Frequency Noise behavior of polysilicon emitter bipolar junction transistors a review
SPIE's First International Symposium on Fluctuations and Noise, 2003Co-Authors: Jamal M Deen, F PascalAbstract:For many analog integrated circuit applications, the polysilicon emitter bipolar junction transistor (PE-BJT) is still the preferred choice because of its higher operational Frequency and Lower Noise performance characteristics compared to MOS transistors of similar active areas and at similar biasing currents. In this paper, we begin by motivating the reader with reasons why bipolar transistors are still of great interest for analog integrated circuits. This motivation includes a comparison between BJT and the MOSFET using a simple small-signal equivalent circuit to derive important parameters that can be used to compare these two technologies. An extensive review of the popular theories used to explain Low Frequency Noise results is presented. However, in almost all instances, these theories have not been fully tested. The effects of different processing technologies and conditions on the Noise performance of PE-BJTs is reviewed and a summary of some of the key technological steps and device parameters and their effects on Noise is discussed. The effects of temperature and emitter geometries scaling is reviewed. It is shown that dispersion of the Low Frequency Noise in ultra-small geometries is a serious issue since the rate of increase of the Noise dispersion is faster than the Noise itself as the emitter geometry is scaled to smaller values. Finally, some ideas for future research on PE-BJTs, some of which are also applicable to SiGe heteorjunction bipolar transistors and MOSFETs, are presented after the conclusions.
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modeling the variation of the Low Frequency Noise in polysilicon emitter bipolar junction transistors
IEEE Electron Device Letters, 2001Co-Authors: M Sanden, Jamal M Deen, O Marinov, Mikael OstlingAbstract:The variation of the Low-Frequency Noise in polysilicon emitter bipolar junction transistors (BJTs) was investigated as a function of emitter area (A/sub E/). For individual BJTs with submicron-sized A/sub E/, the Low-Frequency Noise strongly deviated from a 1/f-dependence. The averaged Noise varied as 1/f, with a magnitude proportional to A/sub E//sup -1/, while the variation in the Noise level was found to vary as A/sub E//sup -1.5/. A new expression that takes into account this deviation is proposed for SPICE modeling of the Low-Frequency Noise. The traps responsible for the Noise were located at the thin SiO/sub 2/ interface between the polysilicon and monosilicon emitter. The traps' energy level, areal concentration and capture cross-section were estimated to 0.31 eV, 6/spl times/10/sup 8/ cm/sup -2/ and 2/spl times/10/sup -19/ cm/sup 2/, respectively.
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Low Frequency Noise in polysilicon emitter bipolar junction transistors
Journal of Applied Physics, 1995Co-Authors: Jamal M Deen, J.j. Ilowski, Ping YangAbstract:This paper describes experimental results on Low Frequency Noise in several types of polysilicon‐emitter NPN bipolar junction transistors. The experimental data were modelled using a combination of 1/f Noise, generation‐recombination Noise (g‐r), and shot Noise, and good agreement between model calculations and experimental measurements were obtained. Observed differences in the experimental Low Frequency Noise spectra of devices with similar geometry and under similar biasing conditions could be explained by the differences in the generation‐recombination (g‐r) Noise contributions. Experiments were performed on devices with emitter areas varying from 1.6 to 144 μm2, and it was found that the magnitude of the flicker Noise contribution KF varied inversely with emitter area AE or emitter perimeter PE. The fact that KF∼A−1E or KF∼P−1E is explained by the observation that AE∼PE within fabrication errors/tolerances. Using a set of 3.2 μm2 BJTs with pronounced g‐r Noise, input current Noise was measured at dif...
Haifeng Jiang - One of the best experts on this subject based on the ideXlab platform.
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an agile laser with ultra Low Frequency Noise and high sweep linearity
Optics Express, 2010Co-Authors: Haifeng Jiang, A Clairon, Fabien Kefelian, P Lemonde, Giorgio SantarelliAbstract:We report on a fiber-stabilized agile laser with ultra-Low Frequency Noise. The Frequency Noise power spectral density is comparable to that of an ultra-stable cavity stabilized laser at Fourier frequencies higher than 30 Hz. When it is chirped at a constant rate of ~ 40 MHz/s, the max non-linearity Frequency error is about 50 Hz peak-to-peak over more than 600 MHz tuning range. The Rayleigh backscattering is found to be a significant Frequency Noise source dependent on fiber length, chirping rate and the power imbalance of the interferometer arms. We analyze this effect both theoretically and experimentally and put forward techniques to reduce this Noise contribution.
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an agile laser with ultra Low Frequency Noise and high sweep linearity
Optics Express, 2010Co-Authors: Haifeng Jiang, A Clairon, Fabien Kefelian, P Lemonde, Giorgio SantarelliAbstract:We report on a fiber-stabilized agile laser with ultra-Low Frequency Noise. The Frequency Noise power spectral density is comparable to that of an ultra-stable cavity stabilized laser at Fourier frequencies higher than 30 Hz. When it is chirped at a constant rate of approximately 40 MHz/s, the max non-linearity Frequency error is about 50 Hz peak-to-peak over more than 600 MHz tuning range. The Rayleigh backscattering is found to be a significant Frequency Noise source dependent on fiber length, chirping rate and the power imbalance of the interferometer arms. We analyze this effect both theoretically and experimentally and put forward techniques to reduce this Noise contribution.
R Wordenweber - One of the best experts on this subject based on the ideXlab platform.
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Low Frequency Noise reduction in yba2cu3o7 δ superconducting quantum interference devices by antidots
Applied Physics Letters, 2000Co-Authors: P Selders, R WordenweberAbstract:It is demonstrated that the Low-Frequency Noise due to vortex motion in high-temperature superconducting quantum interference devices (SQUIDs) in ambient magnetic fields can strongly be reduced by a simple arrangement of antidots patterned into the SQUID. Sputter-deposited YBa2Cu3O7−δ radio-Frequency SQUIDs (rf-SQUIDs) with step edge junctions are characterized before and after patterning of antidots in the vicinity of the Josephson junction. No deterioration of the rf-SQUIDs due to the introduction of the antidots can be detected. In contrary, the onset of the increase of the Low-Frequency Noise in an applied magnetic field is shifted from 10 μT for the bare SQUID to 40 (field cooled) and 18 μT (zero-field cooled) for the rf-SQUIDs with antidots. The reduction of Low-Frequency Noise in ambient field is explained by trapping of vortices by the antidots. The comparison of zero-field and field-cooled experiments demonstrates that flux penetrating the washer does not affect the Low-Frequency Noise as long as...
A Vertiatchikh - One of the best experts on this subject based on the ideXlab platform.
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Low Frequency Noise parameters in an algan gan heterostructure with 33 and 75 al mole fraction
International Journal of High Speed Electronics and Systems, 2004Co-Authors: S A Vitusevich, S V Danylyuk, N Klein, M V Petrychuk, A Vertiatchikh, A Belyaev, L F EastmanAbstract:Transport and Low Frequency Noise properties of undoped AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with 33% and 75% Al mole fractions in the ohmic and nonlinear regimes of applied voltages are studied. In contrast to the Low Al mole fraction, the Noise properties of 75% content structures are not affected by passivation. At small voltages both kinds of structures demonstrate about the same level of 1/f excess Noise. Deviations from conventional flicker Noise were observed at high applied voltages. Additionally, differences in Noise behaviour between the two structures were revealed. In the 75% content structures, a Noise level suppression was registered in the non-linear regime, which is important for the development of Low Noise oscillator circuits.
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excess Low Frequency Noise in algan gan based high electron mobility transistors
Applied Physics Letters, 2002Co-Authors: S A Vitusevich, S V Danylyuk, N Klein, M V Petrychuk, V N Sokolov, V A Kochelap, Alexander Belyaev, V Tilak, J A Smart, A VertiatchikhAbstract:The Low-Frequency 1/f Noise characteristics of AlGaN/GaN high-electron-mobility transistors with gate length scaled down to 150 nm grown on sapphire by metalorganic chemical vapor deposition have been studied. Certain features of the 1/f Noise have been revealed in these short-gate transistors. The Low-Frequency Noise spectra show drastically different behavior depending on the gate voltage VG in the range of Low (VGt⩽VG⩽0) and high (VG
