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1.
J Strength Cond Res ; 37(4): e289-e296, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36165976

RESUMEN

ABSTRACT: Ferioli, D, Conte, D, Rucco, D, Alcaraz, PE, Vaquera, A, Romagnoli, M, and Rampinini, E. Physical demands of elite male and female 3×3 international basketball matches. J Strength Cond Res 37(4): e289-e296, 2023-This study aimed to (1) characterize the physical demands of 3 × 3 basketball games during live playing time and ball possession and (2) assess the differences in physical demands between male and female players. Following an observational design, video footage from 27 games of the International Basketball Federation 3 × 3 World Cup 2019 were analyzed from 104 international 3 × 3 basketball players ( n = 52 male and n = 52 female players) resulting in a total of 216 (104 male and 112 female) individual game samples. Manual frame-by-frame time-motion analyses determined the relative frequency (n·min -1 ) and duration (%) for several physical demands at different intensities, according to sex, during the live playing time and in ball possession phases. Linear mixed models for repeated measures and effect size (ES) analyses revealed small non-significant differences in the intermittent profile of 3 × 3 basketball games according to sex (total movements per minute, male = 39.3 (38.6-40.1); female = 40.2 (39.5-41.0), estimated marginal means with 95% confidence intervals). Female competitions had significantly greater number of low-intensity activities (LIA, small ES) and high-intensity activities (HIA, small ES) performed per minute over longer games ( small ES), whereas male players had more recovery activities ( small ES). During ball possession, male players spent a larger amount of time performing LIA ( small ES) than female players, who displayed both the greatest number of HIA and the highest percentage of playing time performed at high intensity ( small ES). Overall, these findings suggest that basketball coaches should design sex-specific training sessions based on the specific match demands.


Asunto(s)
Rendimiento Atlético , Baloncesto , Humanos , Masculino , Femenino , Movimiento , Movimiento (Física) , Frecuencia Cardíaca
2.
Biol Sport ; 40(2): 377-387, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37077781

RESUMEN

Despite the increased popularity and number of international competitions for 3 × 3 basketball, the precise physical demands of this sport are not well described. Therefore, this study aimed to quantify the physical demands of 3 × 3 basketball games according to game outcome and competition phase. Following an observational design, video footage from 27 games were analysed from 104 international 3 × 3 basketball players (n = 52 male and n = 52 female players) belonging to 26 national teams (n = 13 male and n = 13 female teams) during the 2019 FIBA 3 × 3 World Cup. Manual frame-by-frame time-motion analyses were conducted to determine the relative frequency (n · min-1) and duration (% of live playing time) for several physical demand variables to make comparisons according to game outcome (win vs. loss) and competition phase (group games vs. finals games). Linear mixed models for repeated measures and effect size analyses revealed non-significant, trivial-small differences in physical demands between games that were won and lost. Regarding competition phase, male players completed more high-intensity activity (sprinting, high-intensity specific movements, and jumping) but spent a greater proportion of playing time jumping and performing recovery activities (standing/ walking) during finals games than group games (P < 0.05, small), while female players performed more low-intensity activity (jogging and low-intensity specific movements) during group games than finals games (P < 0.05, small). These findings indicate that the physical capabilities of male and female 3 × 3 basketball players may not be the determining factor for team success in games and players can mostly maintain activity outputs across phases of tournament play conducted at the highest international standard.

3.
Nano Lett ; 19(11): 7632-7644, 2019 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-31536362

RESUMEN

We present a micrometer-scale, on-chip integrated, plasmonic enhanced graphene photodetector (GPD) for telecom wavelengths operating at zero dark current. The GPD is designed to directly generate a photovoltage by the photothermoelectric effect. It is made of chemical vapor deposited single layer graphene, and has an external responsivity ∼12.2 V/W with a 3 dB bandwidth ∼42 GHz. We utilize Au split-gates to electrostatically create a p-n-junction and simultaneously guide a surface plasmon polariton gap-mode. This increases the light-graphene interaction and optical absorption and results in an increased electronic temperature and steeper temperature gradient across the GPD channel. This paves the way to compact, on-chip integrated, power-efficient graphene based photodetectors for receivers in tele- and datacom modules.

4.
Opt Express ; 27(15): 20145-20155, 2019 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-31510114

RESUMEN

We report on a C-band double layer graphene electro-absorption modulator on a passive SOI platform showing 29GHz 3dB-bandwith and NRZ eye-diagrams extinction ratios ranging from 1.7 dB at 10 Gb/s to 1.3 dB at 50 Gb/s. Such high modulation speed is achieved thanks to the quality of the CVD pre-patterned single crystal growth and transfer on wafer method that permitted the integration of high-quality scalable graphene and low contact resistance. By demonstrating this high-speed CVD graphene EAM modulator integrated on Si photonics and the scalable approach, we are confident that graphene can satisfy the main requirements to be a competitive technology for photonics.

5.
J Strength Cond Res ; 32(10): 2846-2852, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25226325

RESUMEN

Romagnoli, M, Alis, R, Sanchis-Gomar, F, Lippi, G, and Arduini, A. An 18-minute submaximal exercise test to assess cardiac fitness in response to aerobic training. J Strength Cond Res 32(10): 2846-2852, 2018-We aimed to evaluate the utility of a submaximal heart rate recovery (HRR) test to monitor changes in cardiac fitness after aerobic training. Twenty healthy subjects were assigned to a control (n = 10) or a training (n = 10) group. Subjects in the training group performed 8 weeks of bicycle training, followed by 8 weeks of detraining. Heart rate recovery was assessed after exercises at 65% and 80% HRmax. The HRR test was performed at weeks 0 (W0), 4 (W4), 8 (W8), and 16 (W16) in the training group and at W0 and W8 in the control group. Heart rate recovery indices changed in response to training and detraining. Absolute HRR at 60, 120, and 180 seconds after exercise increased at both exercise intensities at W8 of training (p < 0.01, W8 vs. W0) and returned to the pretraining level after detraining (p > 0.05, W16 vs. W0). Time constants of fast HRR recovery (<1 minute) changed with training (p < 0.05-0.01, W8 vs. W0) and detraining (p > 0.05, W16 vs. W0) but only at 65% HRmax. At the end of the 3-minute recovery period, the predicted heart rate (HR) value (A0) and the HR recovered (Amax) from the monoexponential analysis changed with training (p < 0.05-0.01, W8 vs. W0) and detraining (p > 0.05, W16 vs. W0). We conclude that this novel submaximal HRR test is highly sensitive for monitoring cardiac fitness during training and detraining in healthy people. Because this test is simple, inexpensive, and the data are reliable and easy to analyze, we hope that it may be of interest to the sports science community.


Asunto(s)
Capacidad Cardiovascular , Prueba de Esfuerzo , Ejercicio Físico/fisiología , Adulto , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Acondicionamiento Físico Humano
6.
Appl Opt ; 56(31): 8811-8815, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29091696

RESUMEN

An innovative and effective architecture for lidar systems is presented and experimentally demonstrated. The proposed scheme can also be easily exploited for optical communications. In particular, the system includes an innovative lidar software-defined architecture based on optically coherent detection, overcoming current drawbacks of time of flight incoherent systems. The experiments demonstrate the ability to perform long range detection resorting to the waveform compression on the continuous wave approach, obtaining a range resolution of 15 cm with a sensitivity of -95 dBm. Beside the bulk implementation, the system has been also implemented in a photonic integrated circuit using complementary metal-oxide-semiconductor-compatible silicon on insulator technology with an extremely reduced footprint of 1.5 mm×3.5 mm. The testing of the integrated device confirms the effectiveness of this proof-of-concept realization.

7.
Opt Lett ; 41(24): 5688-5691, 2016 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-27973490

RESUMEN

We report on an experimental prototype of a low-cost silicon photonic reconfigurable optical add/drop multiplexer (ROADM). The device is able to operate with up to 12 wavelength division multiplexing channels. In order to control the polarization of the multi-wavelength signal at the input of the device, an integrated polarization controller is investigated as an alternative to the polarization diversity device architecture. The integrated ROADM is equipped with optical switches for the selection of the path direction and variable optical attenuators for optical power control. We demonstrate the polarization insensitive routing of 10 Gb/s channels between two ROADM nodes with error-free transmission.

8.
Platelets ; 27(2): 117-22, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26023745

RESUMEN

It is now well known that hemostasis is directly involved in the benefits induced by physical activity. It has recently been shown that the baseline mean platelet volume (MPV) may be a predictor of endurance performance. We aimed to explore whether platelet parameters are associated with VO2max as well as running duration and speed in a short-duration exhaustive exercise test. Thirty healthy male subjects (10 sedentary and 20 trained) performed an incremental running test until exhaustion. MPV, platelet distribution width (PDW), platelet (Plt) count, and plateletcrit (Pct) were determined before exercise, immediately after exercise and after 30' recovery. Training status did not produce any difference in the baseline levels or in the post-exercise increases found in all the parameters tested. VO2max, test duration, and running speed were not correlated with any baseline parameter. Although MPV was found to be a predictor of endurance performance in long-duration exercise, the results of the present study are consistent with the hypothesis that MPV may not be a significant marker of performance in short-duration exhaustive exercise. Likewise, more research is needed to ascertain whether platelet activation is a reliable performance predictor in other exercise settings.


Asunto(s)
Plaquetas/fisiología , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Carrera/fisiología , Capacidad Vital/fisiología , Adulto , Atletas , Plaquetas/citología , Ejercicio Físico , Humanos , Masculino , Volúmen Plaquetario Medio , Activación Plaquetaria , Recuento de Plaquetas , Conducta Sedentaria
9.
Opt Express ; 23(15): 19261-71, 2015 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-26367587

RESUMEN

Adiabatic polarization splitter-rotators are investigated exploiting continuous symmetry breaking thereby achieving significant device size and losses reduction in a single mask fabrication process for both SOI channel and ridge waveguides. A crosstalk lower than -25 dB is expected over 300nm bandwidth, making the device suitable for full grid CWDM and diplexer/triplexer FTTH applications at 1310, 1490 and 1550nm.

10.
Opt Express ; 23(5): 6478-90, 2015 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-25836866

RESUMEN

In this paper we report on an electro-refractive modulator based on single or double-layer graphene on top of silicon waveguides. The graphene layers are biased to the transparency condition in order to achieve phase modulation with negligible amplitude modulation. By means of a detailed study of both the electrical and optical properties of graphene and silicon, as well as through optimization of the geometrical parameters, we show that the proposed devices may theoretically outperform existing modulators both in terms of V(π)L and of insertion losses. The overall figures of merit of the proposed devices are as low as 8.5 and 2dB∙V for the single and double layer cases, respectively.

11.
Scand J Clin Lab Invest ; 74(3): 192-8, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24484196

RESUMEN

Short, middle, and long-term exercise, as well as the relative intensity of the physical effort, may influence a broad array of laboratory results, and it is thereby of pivotal importance to appropriately differentiate the 'physiologic' from the 'pathological' effects of exercise. Therefore, the values of some biomarkers in physically active subjects may be cautiously interpreted since the results may fall outside the conventional reference ranges. It has been demonstrated that middle and long-term endurance and/or strenuous exercise triggers transient elevations of muscular and cardiac biomarkers. However, no data have been published about the effect of short-term maximal exercise test on the most useful muscular, hepatic and cardiovascular biomarkers. The aim of the present study was to assess the baseline concentrations of muscular, hepatic, and cardiovascular makers between trained and untrained subjects, along with changes induced by maximal exercise test. We measured C reactive protein (CRP), procalcitonin (PCT), gamma glutamyltransferase (GGT), creatine kinase-MB isoenzyme (CK-MB), Hs-TnT, NT-proBNP, CK, LDH, AST, and ALT in serum samples of physically active (trained) and physically inactive (sedentary) male collected before, immediately after a maximal exercise test and after a 30-min recovery period. Trained subjects tend to have significantly raised base concentrations of CK, CK-MB, ALT, and LDH compared to sedentary individuals, and this can be clearly interpreted as a mild injury of skeletal muscle. A single maximal exercise was also effective to transiently increase the concentrations of NT-proBNP, but not those of Hs-TnT, thus suggesting that the cardiac involvement is mostly benign in nature.


Asunto(s)
Ejercicio Físico , Resistencia Física , Esfuerzo Físico , Adulto , Aspartato Aminotransferasas/sangre , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Calcitonina/sangre , Péptido Relacionado con Gen de Calcitonina , Forma MB de la Creatina-Quinasa/sangre , Prueba de Esfuerzo , Corazón/fisiología , Humanos , L-Lactato Deshidrogenasa/sangre , Hígado/fisiología , Masculino , Músculo Esquelético/fisiología , Péptido Natriurético Encefálico/sangre , Fragmentos de Péptidos/sangre , Precursores de Proteínas/sangre , Valores de Referencia , Conducta Sedentaria , Troponina/sangre , gamma-Glutamiltransferasa/sangre
12.
Hemoglobin ; 38(3): 165-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24601859

RESUMEN

Studies dealing with rheological red blood cell (RBC) behavior in sickle cell trait carriers are scarce. Moreover, the association with α-thalassemia (α-thal), which also modifies erythrocyte behavior, has not always been taken into account. We analyzed erythrocyte deformability by means of a shear stress diffractometer, along with hematological and biochemical parameters (glucose and plasma lipids), given their possible influence on erythrocyte deformability, in 14 sickle cell trait carriers and 23 healthy controls. Nine patients were also α-thal carriers and five were not. Among the thalassemia carriers, eight were heterozygous and one was homozygous. When compared with controls, sickle cell trait carriers showed no differences for any of the biochemical parameters analyzed (p > 0.05), but significantly lower hemoglobin (Hb) (p = 0.003), mean corpuscular volume (MCV) and mean corpuscular Hb (MCH) (p < 0.001) levels, although no differences in erythrocyte deformability were observed at any of the shear stresses tested (p > 0.05). When comparing sickle cell trait carriers, with and without α-thal, no differences in erythrocyte deformability were observed (p > 0.05), in spite of the former showing lower MCV and MCH (p < 0.05) levels. Carriers of α-thal had lower Hb S [ß6(A3)Glu → Val; HBB: c.20A > T] levels (p = 0.013) than non carriers. The existence of a compensating mechanism seems reasonable because, despite presenting lower erythrocyte indices, which could worsen erythrocyte deformability, this rheological property improves when the percentage of Hb S is lower.


Asunto(s)
Deformación Eritrocítica , Eritrocitos/metabolismo , Rasgo Drepanocítico/metabolismo , Talasemia alfa/metabolismo , Adulto , Sustitución de Aminoácidos , Índices de Eritrocitos , Eritrocitos/patología , Femenino , Hemoglobina Falciforme/genética , Hemoglobina Falciforme/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Mutación Missense , Rasgo Drepanocítico/genética , Rasgo Drepanocítico/patología , Talasemia alfa/genética , Talasemia alfa/patología
13.
J Sci Med Sport ; 27(2): 105-112, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37957039

RESUMEN

OBJECTIVES: We tested whether mental fatigue (MF), induced by a cognitively-demanding task, would impair repeated sprint ability (RSA) and repeated jump ability (RJA) performance, and whether physical fatigue and MF would impair psychomotor vigilance. DESIGN: Randomized within-participant design. METHODS: After establishing baseline peak countermovement jump (CMJ), 18 male participants performed 12 maximal 20-m (10-m linear + 10-m directional) repeated sprints (RSA random test) followed by 12 maximal repeated CMJs (RJA test) subsequent to 30-min Stroop task (MF) or a documentary (Control). Peak and mean running time and height, percent decrement score (Sdec), blood lactate, heart rate and RPE were measured for CMJ, RSA, and RJA tests. MF (M-VAS) and psychomotor vigilance [psychomotor vigilance test (PVT)] were measured at baseline, after each condition, and after the RSA/RJA tests. RESULTS: Compared to Control, the Stroop task elevated MF (p = .001), RPE ratings (all p < .031), and mean and Sdec performance in directional (but not linear) RSA (all p < .032) and RJA tests (all p < .034). PVT score worsened after Stroop task (p = .011) but not Control, declined after RSA/RJA tests in both conditions (all p < .023) and was lower in the MF condition (p = .029). No condition differences were noted for peak (CMJ, RSA and RJA tests) performance, blood lactate, and heart rate. CONCLUSIONS: MF impairs directional RSA, and RJA performance. This impairment was linked with increased RPE and without physiological changes. The progressive impairment in PVT score suggests a cumulatively negative effect of mental and physical fatigue on psychomotor vigilance.


Asunto(s)
Rendimiento Atlético , Deportes de Equipo , Humanos , Masculino , Rendimiento Atlético/fisiología , Atletas , Fatiga Mental , Lactatos , Prueba de Esfuerzo
14.
Opt Express ; 21(5): 5391-400, 2013 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-23482110

RESUMEN

A new method for measuring waveguide propagation loss in silicon nanowires is presented. This method, based on the interplay between traveling ring modes and standing wave modes due to back-scattering from edge roughness, is accurate and can be used for on wafer measurement of test structures. Examples of loss measurements and fitting are reported.

15.
Opt Lett ; 38(5): 631-3, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23455247

RESUMEN

We discuss the existence of nonlinear modes sustained by graphene layers in dielectric waveguides. Taking advantage of the almost two dimensional nature of graphene, we introduce the nonlinear effect as a parameter in the continuity equations. We then apply our modeling to a simple slab waveguide to enlighten how graphene can be used to induce huge nonlinear phase shifts at easily accessible power levels.

16.
J Sci Med Sport ; 26(7): 375-385, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37301613

RESUMEN

OBJECTIVES: To evaluate the effects of brain endurance training (BET) on endurance and cognitive performance in road cyclists. DESIGN: Two independent randomized controlled pretest-posttest training studies. METHODS: In both studies cyclists trained five times/week for six weeks and completed either cognitive response inhibition tasks (Post-BET group) or listened to neutral sounds (control group) after each training session. In Study-1, 26 cyclists performed a time to exhaustion (TTE) test at 80 % peak power output (PPO), followed by a 30-min Stroop task, and a TTE test at 65 % PPO. In Study-2, 24 cyclists performed a 5-min time trial, followed by a 30-min Stroop task, 60-min submaximal incremental test, and a 20-min . Heart rate, lactate, rating of perceived exertion (RPE), Stroop reaction time and accuracy were also measured. RESULTS: During Study 1, Post-BET improved TTE at 80 % (p = 0.032) and 65 % PPO (p = 0.011) significantly more than control with lower RPE (all p < 0.043). In Study 2, 5-min TT performance did not differ between groups. During the 60-min submaximal incremental test, RPE was lower in the Post-BET group compared to the control group (p = 0.034) and 20-min TT performance improved significantly more in the Post-BET group than in the control group (all p < 0.031). No group differences were found in physiological measures. In both studies, Stroop reaction times improved significantly more in the Post-BET group than in the control group (all p < 0.033). CONCLUSIONS: These findings suggest that Post-BET may be used to improve the performance of road cyclists.


Asunto(s)
Entrenamiento Aeróbico , Humanos , Ácido Láctico , Frecuencia Cardíaca/fisiología , Cognición/fisiología , Encéfalo , Ciclismo/fisiología , Resistencia Física/fisiología , Consumo de Oxígeno/fisiología
17.
Int J Sports Physiol Perform ; 18(5): 465-473, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-36898388

RESUMEN

PURPOSE: Mental fatigue (MF) can impair physical performance in sport. We tested the hypothesis that cognitive load alone, and intermixed with standard resistance training, would induce MF, increase rating of perceived exertion (RPE), alter perception of weight lifting and training, and impair cycling time-trial performance. METHODS: This 2-part study employed a within-participant design. In part 1, after establishing leg-extension 1-repetition maximum (1RM), 16 participants lifted and briefly held weights at 20%, 40%, 60%, and 80% of 1RM. RPE and electromyography (EMG) were measured for each lift. During the testing sessions, participants completed cognitive tasks (MF condition) or watched neutral videos (control condition) for 90 minutes before lifting the weights. In part 2, they completed submaximal resistance training comprising 6 weight training exercises followed by a 20-minute cycling time trial. In the MF condition, they completed cognitive tasks before and between weight training exercises. In the control condition, they watched neutral videos. Mood (Brunel Mood Scale), workload (National Aeronautics and Space Administration Task Load Index), MF-visual analogue scale (MF-VAS), RPE, psychomotor vigilance, distance cycled, power output, heart rate, and blood lactate were measured. RESULTS: In part 1, the cognitive task increased lift-induced RPE (P = .011), increased MF-VAS (P = .002), and altered mood (P < .001) compared with control. EMG did not differ between conditions. In part 2, the cognitive tasks increased RPE (P < .001), MF-VAS (P < .001), and mental workload (P < .001), but reduced cycling time-trial power (P = .032) and distance (P = .023) compared with control. Heart rate and blood lactate did not differ between conditions. CONCLUSION: A state of MF induced by cognitive load, alone or intermixed with physical load, increased RPE during weight lifting and training and impaired subsequent cycling performance.


Asunto(s)
Entrenamiento de Fuerza , Levantamiento de Peso , Humanos , Levantamiento de Peso/fisiología , Fatiga Mental , Cognición , Lactatos , Esfuerzo Físico/fisiología
18.
ACS Photonics ; 10(5): 1446-1453, 2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37215326

RESUMEN

Starting from its classical domain of long distance links, optical communication is conquering new application areas down to chip-to-chip interconnections in response to the ever-increasing demand for higher bandwidth. The use of coherent modulation formats, typically employed in long-haul systems, is now debated to be extended to short links to increase the bandwidth density. Next-generation transceivers are targeting high bandwidth, high energy efficiency, compact footprint, and low cost. Integrated photonics is the only technology to reach this goal, and silicon photonics is expected to play the leading actor. However, silicon modulators have some limits, in terms of bandwidth and footprint. Graphene is an ideal material to be integrated with silicon photonics to meet the requirements of next generation transceivers. This material provides optimal properties: high mobility, fast carrier dynamics and ultrabroadband optical properties. Graphene photonics for direct detection systems based on binary modulation formats have been demonstrated so far, including electro-absorption modulators, phase modulators, and photodetectors. However, coherent modulation for increased data-rates has not yet been reported for graphene photonics yet. In this work, we present the first graphene photonics I/Q modulator based on four graphene on silicon electro-absorption modulators for advanced modulation formats and demonstrate quadrature phase shift keying (QPSK) modulation up to 40 Gb/s.

19.
Nat Commun ; 14(1): 6471, 2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37833246

RESUMEN

Optoelectronics is a valuable solution to scale up wireless links frequency to sub-THz in the next generation antenna systems and networks. Here, we propose a low-power consumption, small footprint building block for 6 G and 5 G new radio wireless transmission allowing broadband capacity (e.g., 10-100 Gb/s per link and beyond). We demonstrate a wireless datalink based on graphene, reaching setup limited sub-THz carrier frequency and multi-Gbit/s data rate. Our device consists of a graphene-based integrated optoelectronic mixer capable of mixing an optically generated reference oscillator approaching 100 GHz, with a baseband electrical signal. We report >96 GHz optoelectronic bandwidth and -44 dB upconversion efficiency with a footprint significantly smaller than those of state-of-the-art photonic transmitters (i.e., <0.1 mm2). These results are enabled by an integrated-photonic technology based on wafer-scale high-mobility graphene and pave the way towards the development of optoelectronics-based arrayed-antennas for millimeter-wave technology.

20.
Opt Express ; 20(21): 23144-55, 2012 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-23188279

RESUMEN

Graphene's conductivity at optical frequencies can be varied upon injection of carriers. In the present paper, this effect is used to modulate losses of an optical wave traveling inside a ring cavity. This way an optical modulator based on the critical-coupling concept first introduced by Yariv can be realized. Through numerical simulations, we show that a modulator featuring a bandwidth as large as 100 GHz can be designed with switching energy in the order of few fJ per bit. Also, we show that operations with driving voltages below 1.2 volt could be obtained, thus making the proposed modulator compatible with requirements of low-voltage CMOS technology.


Asunto(s)
Diseño Asistido por Computadora , Grafito/química , Semiconductores , Procesamiento de Señales Asistido por Computador/instrumentación , Telecomunicaciones/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo
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