The Experts below are selected from a list of 34566 Experts worldwide ranked by ideXlab platform
K J Weingarten - One of the best experts on this subject based on the ideXlab platform.
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1.55 μm InAs/GaAs quantum dots and high repetition rate quantum dot SESAM mode-locked laser
Scientific Reports, 2012Co-Authors: Z.y. Zhang, Andreas E. H. Oehler, Mario Mangold, S. Kurmulis, T. Süedmeyer, K. J. Zhou, Bojan Resan, Ulrich Keller, Q. Wang, K J WeingartenAbstract:High pulse repetition rate (≥ 10 GHz) diode-pumped solid-state lasers, modelocked using semiconductor saturable absorber mirrors (SESAMs) are emerging as an enabling technology for high data rate coherent communication systems owing to their low noise and pulse-to-pulse optical phase-coherence. Quantum dot (QD) based SESAMs offer potential advantages to such laser systems in terms of reduced saturation fluence, broader bandwidth, and wavelength flexibility. Here, we describe the development of an epitaxial process for the realization of high optical quality 1.55 µm In(Ga)As QDs on GaAs substrates, their incorporation into a SESAM, and the realization of the first 10 GHz repetition rate QD-SESAM modelocked laser at 1.55 µm, exhibiting ∼2 ps pulse width from an Er-doped glass oscillator (ERGO). With a high areal dot density and strong light emission, this QD structure is a very promising candidate for many other applications, such as laser diodes, optical amplifiers, non-linear and photonic crystal based devices.
Mitsuo Namiki - One of the best experts on this subject based on the ideXlab platform.
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nutraceutical functions of Sesame a review
Critical Reviews in Food Science and Nutrition, 2007Co-Authors: Mitsuo NamikiAbstract:The results of recent food chemical and nutraceutical studies on the traditionally well-known health value of Sesame are described, including some aspects of the utilization of Sesame. The highly antioxidative activity of Sesame oil was clarified and found to involve newly discovered lignans. The antiaging effect of Sesame was elucidated to be due to the strong vitamin E activity caused by a novel synergistic effect of Sesame lignans with tocopherols resulting from the inhibition of metabolic decomposition of tocopherols by Sesame lignans. The specific inhibitory action of Sesame lignans on Δ5 desaturase in polyunsaturated fatty acid synthesis was found in studies on the microbial production of polyunsaturated fatty acids. This effect of Sesame lignans was extended to various effects on fatty acid metabolism involving lowering fatty acid concentration in liver and serum due to acceleration of fatty acid oxidation and suppression of fatty acid synthesis, and the controlling influence on the ratio of n-6/n-...
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the chemistry and physiological functions of Sesame
Food Reviews International, 1995Co-Authors: Mitsuo NamikiAbstract:Abstract Some historical facts on and botanical descriptions of Sesame are given. Some flavor studies of raw and roasted Sesame seeds and oils are described. Composition and some usages are also briefly reported. Sesame has long been regarded in the Orient as a health food which increases energy and prevents aging. Sesame oil has been known empirically as a cooking oil which is highly resistant to oxidative deterioration in comparison with other edible oils. Until recently there were no scientific studies to elucidate these interesting aspects of Sesame seed and oil, but the author and members of his group initiated studies on the chemical elucidation of antioxidative principles of Sesame seed and oil, and extensively investigated the antiaging effect of Sesame. Presence of various new antioxidative lignan phenol compounds in Sesame seed and oil is described. Sesaminol has been identified as a new antioxidative principle in raw Sesame salad oil. The mechanism of the superior antioxidative activity of roas...
Oleg Okhotnikov - One of the best experts on this subject based on the ideXlab platform.
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Evolution and stability of pulse regimes in sesam-mode-locked femtosecond fiber lasers
CLEO Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference, 2009Co-Authors: Olga Shtyrina, Mikhail Fedoruk, Sergey Turitsyn, Robert Herda, Oleg OkhotnikovAbstract:One of the key technologies exploited in femtosecond lasers is the application of semiconductor saturable absorber mirrors (SESAMs). The SESAM technology is based on bandgap engineering and epitaxial growth and has many advantages compared to other methods. From the laser design view point it is important to know how SESAM parameters affect properties of steady-state pulses and overall laser system performance. We have performed here a massive optimization of the laser system including total gain, cavity dispersion, saturable absorber recovery time and saturation energy.
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Ultra-fast fibre laser systems based on SESAM technology: New horizons and applications
New Journal of Physics, 2004Co-Authors: Oleg Okhotnikov, Anatoly Grudinin, Markus PessaAbstract:A promising route to manufacturing portable (sub-)picosecond fibre lasers is to use a semiconductor saturable absorber mirror (SESAM). With SESAMs, the mode-locked regime can be achieved for different values of cavity dispersion for a broad spectrum ranging from 0.8 to 1.6 μm. The fibre lasers, characterized by a high efficiency and reliability and a small footprint, are very attractive for applications traditionally occupied by solid-state lasers. The broad fluorescence spectrum makes different fibre gain media attractive for tuneable and ultra-short-pulse sources. In this paper, we discuss recent advances in ultra-fast fibre lasers. We study the fundamental properties and technical challenges of mode-locked fibre lasers operating in the 0.9–1.6 μm range, and the methods to achieve high peak-powers from all-fibre devices. The key component is the SESAM, notably, a dilute nitride SESAM. The SESAM supplies a strong mechanism for picosecond pulse generation that is entirely self-starting for a wide range of cavity dispersion and ensures stability against Q-switched mode-locking. In particular, compact mode-locked lasers stabilized by near-resonant SESAMs can be realized in a short fibre cavity free from any dispersion compensator. An appropriate dispersion delay line at the output of the master source may be used for pulse clean-up. The high-quality pulses obtained can then be compressed using traditional methods, when the pulse first undergoes spectral enrichment via self-phase modulation in an auxiliary fibre and then gets compressed in a grating pair. The fibre laser is capable of efficient wavelength conversion via second harmonic generation in non-linear crystals. Using a periodically poled LiNbO3 crystal for frequency doubling, we produce sub-100 fs pulses at 0.8 μm with a 50% conversion efficiency.
Haiyang Zhang - One of the best experts on this subject based on the ideXlab platform.
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identification and testing of reference genes for Sesame gene expression analysis by quantitative real time pcr
Planta, 2013Co-Authors: Hongmei Miao, Ruihong Zhao, Tide Zhang, Haiyang ZhangAbstract:Sesame (Sesamum indicum L.) is an ancient and important oilseed crop. However, few Sesame reference genes have been selected for quantitative real-time PCR until now. Screening and validating reference genes is a requisite for gene expression normalization in Sesame functional genomics research. In this study, ten candidate reference genes, i.e., SiACT, SiUBQ6, SiTUB, Si18S rRNA, SiEF1α, SiCYP, SiHistone, SiDNAJ, SiAPT and SiGAPDH, were chosen and examined systematically in 32 Sesame samples. Three qRT-PCR analysis methods, i.e., geNorm, NormFinder and BestKeeper, were evaluated systematically. Results indicated that all ten candidate reference genes could be used as reference genes in Sesame. SiUBQ6 and SiAPT were the optimal reference genes for Sesame plant development; SiTUB was suitable for Sesame vegetative tissue development, SiDNAJ for pathogen treatment, SiHistone for abiotic stress, SiUBQ6 for bud development and SiACT for seed germination. As for hormone treatment and seed development, SiHistone, SiCYP, SiDNAJ or SiUBQ6, as well as SiACT, SiDNAJ, SiTUB or SiAPT, could be used as reference gene, respectively. To illustrate the suitability of these reference genes, we analyzed the expression variation of three functional Sesame genes of SiSS, SiLEA and SiGH in different organs using the optimal qRT-PCR system for the first time. The stability levels of optimal and worst reference genes screened for seed development, anther sterility and plant development were validated in the qRT-PCR normalization. Our results provided a reference gene application guideline for Sesame gene expression characterization using qRT-PCR system.
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development and validation of genic ssr markers in Sesame by rna seq
BMC Genomics, 2012Co-Authors: Haiyang Zhang, Hongmei Miao, Tide Zhang, Cuiying WangAbstract:Background Sesame (Sesamum indicum L.) is one of the most important oil crops; however, a lack of useful molecular markers hinders current genetic research. We performed transcriptome sequencing of samples from different Sesame growth and developmental stages, and mining of genic-SSR markers to identify valuable markers for Sesame molecular genetics research.
Stefano Veronesi - One of the best experts on this subject based on the ideXlab platform.
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GaSb-based SESAM mode-locked Tm:YAG ceramic laser at 2 µm
Optics Express, 2015Co-Authors: Alexander Gluth, Antti Härkönen, Günter Steinmeyer, Jonna Paajaste, Xavier Mateos, Valentin Petrov, Yicheng Wang, Soile Suomalainen, Mircea Guina, Stefano VeronesiAbstract:Tunable and mode-locked laser operation near 2 µm based on different Tm-doped YAG ceramics, 4 at.% and 10 at.%, is demonstrated. Several designs of GaSb-based surface-quantum-well SESAMs are characterized and studied as saturable absorbers for mode-locking. Best mode-locking performance was achieved using an antireflection-coated near-surface quantum-well SESAM, resulting in a pulse duration of ~3 ps and ~150 mW average output power at 89 MHz. All mode-locked Tm:YAG ceramic lasers operated at 2012 nm, with over 133 nm demonstrated tuning for continuous-wave operation.
