The Experts below are selected from a list of 19536 Experts worldwide ranked by ideXlab platform
Connie J Changhasnain - One of the best experts on this subject based on the ideXlab platform.
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novel chirp enhanced tunable fast light of ultra short pulses in semiconductor Optical Amplifiers
Optical Fiber Communication Conference, 2008Co-Authors: Bala Pesala, A V Uskov, Forrest G Sedgwick, Connie J ChanghasnainAbstract:Large tunable advance and delay are demonstrated by varying the sign and magnitude of the linear chirp of 440 fs pulses using ultrafast nonlinearities in semiconductor Optical Amplifiers, for the first time.
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chirp enhanced fast light in semiconductor Optical Amplifiers
Optics Express, 2007Co-Authors: Forrest G Sedgwick, Bala Pesala, A V Uskov, Connie J ChanghasnainAbstract:We present a novel scheme to increase the THz-bandwidth fast light effect in semiconductor Optical Amplifiers and increase the number of advanced pulses. By introducing a linear chirp to the input pulses before the SOA and recompressing at the output with an opposite chirp, the advance-bandwidth product reached 3.5 at room temperature, 1.55 µm wavelength. This is the largest number reported, to the best of our knowledge, for a semiconductor slow/fast light device.
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polarization dependence of thz bandwidth fast light in semiconductor Optical Amplifiers
International Nano-Optoelectronics Workshop, 2007Co-Authors: Bala Pesala, A V Uskov, Forrest G Sedgwick, Connie J ChanghasnainAbstract:Polarization dependence of fast light in semiconductor Optical Amplifiers is studied. For a 630 fs pulse propagating through the SOA, an advance of 2.7 pulses is achieved for TE polarisation while TM polarisation gives an advance of 2.3 pulses.
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experimental demonstration of slow and superluminal light in semiconductor Optical Amplifiers
Optics Express, 2006Co-Authors: Bala Pesala, Zhangyuan Chen, A V Uskov, Connie J ChanghasnainAbstract:Tunable delays in semiconductor Optical Amplifiers are achieved via four wave mixing between a strong pump beam and a modulated probe beam. The delay of the probe beam can be controlled both electrically, by changing the SOA bias, and Optically, by varying the pump power or the pump-probe detuning. For sinusoidal modulated signal at 0.5 GHz, a tunable delay of 1.6 ns is achieved. This corresponds to a RF phase change of 1.6 pi. For 1.3 ns Optical pulses propagating through the SOA a delay of 0.59 ns is achieved corresponding to a delay-bandwidth product exceeding 0.45. For both the cases, slow light and superluminal light are observed as the pump-probe detuning is varied.
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slow and superluminal light based on four wave mixing in semiconductor Optical Amplifiers
Quantum Electronics and Laser Science Conference, 2006Co-Authors: Bala Pesala, Zhangyuan Chen, A V Uskov, Connie J ChanghasnainAbstract:Both Optically and electrically controllable slow and superluminal light are demonstrated via four-wave mixing in semiconductor Optical Amplifiers. Tunable delays up to 1.2 ns are achieved for 0.5 GHz, corresponding to a RF phase change of 1.2 p.
A V Uskov - One of the best experts on this subject based on the ideXlab platform.
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novel chirp enhanced tunable fast light of ultra short pulses in semiconductor Optical Amplifiers
Optical Fiber Communication Conference, 2008Co-Authors: Bala Pesala, A V Uskov, Forrest G Sedgwick, Connie J ChanghasnainAbstract:Large tunable advance and delay are demonstrated by varying the sign and magnitude of the linear chirp of 440 fs pulses using ultrafast nonlinearities in semiconductor Optical Amplifiers, for the first time.
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chirp enhanced fast light in semiconductor Optical Amplifiers
Optics Express, 2007Co-Authors: Forrest G Sedgwick, Bala Pesala, A V Uskov, Connie J ChanghasnainAbstract:We present a novel scheme to increase the THz-bandwidth fast light effect in semiconductor Optical Amplifiers and increase the number of advanced pulses. By introducing a linear chirp to the input pulses before the SOA and recompressing at the output with an opposite chirp, the advance-bandwidth product reached 3.5 at room temperature, 1.55 µm wavelength. This is the largest number reported, to the best of our knowledge, for a semiconductor slow/fast light device.
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polarization dependence of thz bandwidth fast light in semiconductor Optical Amplifiers
International Nano-Optoelectronics Workshop, 2007Co-Authors: Bala Pesala, A V Uskov, Forrest G Sedgwick, Connie J ChanghasnainAbstract:Polarization dependence of fast light in semiconductor Optical Amplifiers is studied. For a 630 fs pulse propagating through the SOA, an advance of 2.7 pulses is achieved for TE polarisation while TM polarisation gives an advance of 2.3 pulses.
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experimental demonstration of slow and superluminal light in semiconductor Optical Amplifiers
Optics Express, 2006Co-Authors: Bala Pesala, Zhangyuan Chen, A V Uskov, Connie J ChanghasnainAbstract:Tunable delays in semiconductor Optical Amplifiers are achieved via four wave mixing between a strong pump beam and a modulated probe beam. The delay of the probe beam can be controlled both electrically, by changing the SOA bias, and Optically, by varying the pump power or the pump-probe detuning. For sinusoidal modulated signal at 0.5 GHz, a tunable delay of 1.6 ns is achieved. This corresponds to a RF phase change of 1.6 pi. For 1.3 ns Optical pulses propagating through the SOA a delay of 0.59 ns is achieved corresponding to a delay-bandwidth product exceeding 0.45. For both the cases, slow light and superluminal light are observed as the pump-probe detuning is varied.
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slow and superluminal light based on four wave mixing in semiconductor Optical Amplifiers
Quantum Electronics and Laser Science Conference, 2006Co-Authors: Bala Pesala, Zhangyuan Chen, A V Uskov, Connie J ChanghasnainAbstract:Both Optically and electrically controllable slow and superluminal light are demonstrated via four-wave mixing in semiconductor Optical Amplifiers. Tunable delays up to 1.2 ns are achieved for 0.5 GHz, corresponding to a RF phase change of 1.2 p.
Jesper Mork - One of the best experts on this subject based on the ideXlab platform.
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theory of slow light semiconductor Optical Amplifiers
Optics Letters, 2020Co-Authors: Marco Saldutti, Mariangela Gioannini, Thorsten S Rasmussen, Jesper MorkAbstract:We have developed an efficient framework for analyzing the reflection and transmission properties of semiconductor photonic crystal Optical Amplifiers. Specifically, we have investigated the use of slow light to enhance the gain of short integrated Amplifiers. We find that the expected enhancement in transmission is limited by distributed feedback induced by the material gain itself. Such back-scattering is further enhanced by the refractive index variation associated with the linewidth enhancement factor. The inclusion of this effect reveals that for a given material gain, devices with smaller linewidth enhancement factor may offer better performance.
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microwave phase shifter with controllable power response based on slow and fast light effects in semiconductor Optical Amplifiers
Optics Letters, 2009Co-Authors: Weiqi Xue, J Capmany, Salvador Sales, Jesper MorkAbstract:We suggest and experimentally demonstrate a method for increasing the tunable rf phase shift of semiconductor waveguides while at the same time enabling control of the rf power. This method is based on the use of slow- and fast-light effects in a cascade of semiconductor Optical Amplifiers combined with the use of spectral filtering to enhance the role of refractive index dynamics. A continuously tunable phase shift of ~240° at a microwave frequency of 19 GHz is demonstrated in a cascade of two semiconductor Optical Amplifiers, while maintaining an rf power change of less than 1.6 dB. The technique is scalable to more Amplifiers and should allow realization of an rf phase shift of 360°.
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demonstration of tunable microwave photonic notch filters using slow and fast light effects in semiconductor Optical Amplifiers
Optical Fiber Communication Conference, 2009Co-Authors: Weiqi Xue, Jesper Mork, Salvador Sales, J CapmanyAbstract:We introduce a novel scheme based on slow and fast light effects in semiconductor Optical Amplifiers, to implement a microwave photonic notch filter with ∼100% fractional tuning range at a microwave frequency of 30 GHz.
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chirp dependence of filter assisted slow and fast light effects in semiconductor Optical Amplifiers
Slow and Fast Light (2008) paper JMB12, 2008Co-Authors: Weiqi Xue, Yaohui Chen, Filip Ohman, Salvador Sales, Jesper MorkAbstract:We demonstrate that the initial Optical phase difference between the carrier and sidebands will strongly influence the final RF phase shift induced by filter assisted slow and fast light effects in semiconductor Optical Amplifiers.
G. Guekos - One of the best experts on this subject based on the ideXlab platform.
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cross polarization modulation in semiconductor Optical Amplifiers
IEEE Photonics Technology Letters, 1999Co-Authors: H Soto, D Erasme, G. GuekosAbstract:The polarization sensitivity of semiconductor Optical Amplifiers can be assessed in terms of gain or in terms of induced phase shift. Although the former aspect has received a lot of attention, the latter is rarely mentioned in the literature. Nevertheless, this birefringence leading to a rotation of the lightwave polarization at the output of the device may give rise to some interesting or unwanted effects. An Optical control of the birefringence can be applied to wavelength conversion, signal regeneration, all-Optical switching or gating. In this letter, the variation of the birefringence with input polarization and input power is measured.
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Four-wave mixing in semiconductor Optical Amplifiers: a practical tool for wavelength conversion
IEEE Journal of Selected Topics in Quantum Electronics, 1997Co-Authors: A. D'ottavi, F. Girardin, L. Graziani, Faustino Martelli, Paolo Spano, Antonio Mecozzi, S. Scotti, R. Dall'ara, J. Eckner, G. GuekosAbstract:Four-wave mixing in semiconductor Optical Amplifiers is used to produce wavelength conversion. We report an extended study on the dependence of efficiency and noise on device length, pump power, operation wavelength and conversion interval. The use of longer active regions is a good way to obtain performance as good as requested by the most advanced telecommunication systems.
K E Stubkjaer - One of the best experts on this subject based on the ideXlab platform.
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all Optical wavelength conversion at bit rates above 10 gb s using semiconductor Optical Amplifiers
IEEE Journal of Selected Topics in Quantum Electronics, 1997Co-Authors: C Joergensen, K E Stubkjaer, S L Danielsen, M Schilling, K Daub, P Doussiere, F Pommerau, P B Hansen, H N Poulsen, A KlochAbstract:This work assesses the prospects for high-speed all-Optical wavelength conversion using the simple Optical interaction with the gain in semiconductor Optical Amplifiers (SOAs) via the interband carrier recombination. Operation and design guidelines for conversion speeds above 10 Gb/s are described and the various tradeoffs are discussed. Experiments at bit rates up to 40 Gb/s are presented for both cross-gain modulation (XGM) and cross-phase modulation (XPM) in SOAs demonstrating the high-speed capability of these techniques.
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all Optical wavelength conversion by semiconductor Optical Amplifiers
Journal of Lightwave Technology, 1996Co-Authors: T Durhuus, B Mikkelsen, C Joergensen, Lykke S Danielsen, K E StubkjaerAbstract:Following a brief introduction to the applications for wavelength conversion and the different available conversion techniques, the paper gives an in depth analysis of cross gain and cross phase wavelength conversion in semiconductor Optical Amplifiers. The influence of saturation filtering on the bandwidth of the converters is explained and conditions for conversion at 20 Gb/s or more are identified. The cross gain modulation scheme shows extinction ratio degradation for conversion to longer wavelengths. This can be overcome using cross phase modulation in semiconductor Optical Amplifiers that are integrated into interferometric structures. The first results for monolithic integrated interferometric wavelength converters are reviewed, and the quality of the converted signals is demonstrated by transmission of 10 Gb/s converted signals over 60 km of nondispersion shifted single mode fiber.