1,115 research outputs found

    Ultra-short of pico and femtosecond soliton laser pulse using microring resonator for cancer cells treatment

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    A system of microring resonators (MRRs) incorporating with an add/drop filter system is presented in which ultra-short single and multi temporal and spatial optical soliton pulses can be simulated and used to thermalbased killing of abnormal cells, tumor and cancer, applicable in nanomedical treatments. This proposed system uses chaotic signals generated by a bright soliton pulse within a nonlinear MRRs system. Interaction between gold nanoparticles and ultra-short femtosecond and picosecond laser pulses holds great interest in laser nanomedicine. By using the appropriate soliton input power and MRRs parameters, required spatial and temporal signals are generated spreading over the spectrum. Results obtained show that smallest single temporal and spatial soliton pulse with FWHM = 712 fs and FWHM = 17.5 pm could be generated respectively. The add/drop filter system is used to generate high capacity ultra-short soliton pulses in the range of nanometer/second and picometer/second

    Half-panda ring resonator used to generate 100 MHZ repetition rate femtosecond soliton

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    Interferometric measurement techniques have been employed in research and industry for investigations into propagation behavior aspects of the optical solitons within semiconductor lasers. The half-PANDA ring resonator system introduced in this paper consists of an add/drop multiplex connected to a microring resonator on the right side, where the output powers can be controlled by specific parameters. The collision of dark and bright solitons occurs inside the system in which femtosecond (fs) optical solitons with 100 MHz repetition rate form the through and drop port outputs of the system. A trapping force is produced via the add port signals that constitute the input powers; thus the femtosecond optical soliton are generated and controlled within the half-PANDA ring resonator. The results of the soliton signals are obtained based on the iterative method technique in which a number of experimental and practical parameters are employed. These circumstances allow for manipulation of the trapping bandwidth by means of system parameter alterations. The input powers of the dark and bright solitons are 5.12 mW and 4 mW respectively. The full width at half maximum (FWHM) of the through and drop port output signals are 35 and 76 femtoseconds respectively correspond to 0.76 and 1.56 terahertz (THz) in frequency domain, where the repetition rate of the solitons is 100 MHz

    Modification of classical electron transport due to collisions between electrons and fast ions

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    A Fokker-Planck model for the interaction of fast ions with the thermal electrons in a quasi-neutral plasma is developed. When the fast ion population has a net flux (i.e. the distribution of the fast ions is anisotropic in velocity space) the electron distribution function is significantly perturbed from Maxwellian by collisions with the fast ions, even if the fast ion density is orders of magnitude smaller than the electron density. The Fokker-Planck model is used to derive classical electron transport equations (a generalized Ohm's law and a heat flow equation) that include the effects of the electron-fast ion collisions. It is found that these collisions result in a current term in the transport equations which can be significant even when total current is zero. The new transport equations are analyzed in the context of a number of scenarios including α\alpha particle heating in ICF and MIF plasmas and ion beam heating of dense plasmas

    Interleukin 6, interleukin 1&#946, estradiol and testosterone concentrations in serum and follicular fluid of females with stimulated and non-stimulated ovaries

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    The ovarian physiology is regulated by some complex factors such as hormones and growth factors. The hormones and growth factors are synthesized by follicular and ovarian cells during follicular maturation stage and cytokines are synthesized by the immune system. Interaction between immune and endocrine systems modulates ovarian function through the secretion of regulatory soluble factors, especially cytokines. There is a close contact between corona-cumulus-oocyte complex with follicular fluid which affects the quality and degree of oocyte maturation. The objectives of this study were to determine the levels of interleukin-6 (IL-6), interleukin 1β, estradiol and testosterone concentration in serum and follicular fluid of women with stimulated and non-stimulated ovaries. A total of 41 women, 27 in stimulated and 14 non-stimulated cycles, undergoing intra cytoplasmic sperm injection (ICSI) treatment were included in this study. Follicular fluid and serum samples from all cases were collected at the time of oocyte retrieval and concentration of testosterone, estradiol, interleukin 6 and interleukin 1β were measured. The results show that serum concentration of testosterone was significantly higher in non stimulated cases. Also, the serum and follicular fluid concentrations of interleukin 6 and interleukin 1β in stimulated cases were significantly higher than non stimulated group. There was an important negative correlation between the level of testosterone in patient's serum and IL-6 and IL-1β levels of follicular fluid. In conclusion, according to these results, it seems that the levels of testosterone and IL-6 and IL-1β in patient's serum and follicular fluid are a good factor for prediction of maturity of oocytes.Key words: Oocyte maturation, follicular fluid, interleukin 6, interleukin 1β, testosterone, estradiol

    The analysis of phase, dispersion and group delay in InGaAsP/InP microring resonator

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    The Vernier operation with signal flow graph (SFG) is a graphical approach for analyzing the intricate photonic circuits mathematically and quick calculation of optical transfer function. Analysis of a cascaded microring resonators (CMRR) made of InGaAsP/InP semiconductor is presented using the signal flow graph (SFG) method which enables modelling the transfer function of the passive CMRR. These passive filters are mostly characterized by their frequency response. The theoretical calculations of the system is performed by the Vernier effects analysis. Two MRRs with radius of 100 μm which are vertically coupled together are used to generate resonant peaks. Here, the phase, dispersion and group delay of the generated signals are analyzed

    Temporal soliton: generation and applications in optical communications

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    In general, the temporal and spectral shape of a short optical soliton pulse does not change during propagation in a nonlinear medium due to the Kerr effect which balances the chromatic dispersion. Microring resonators (MRRs) can be used to generate chaotic signals. The smaller MRR is used to form the stopping and filtering system. The employed optical material was InGaAsP/InP, which is suitable for use in the practical devices and systems. The tuning and manipulation of the bandwidth of the soliton signals is recommended to control the output signals. The MRRs can be applied to produce ultra-short pulses, where the medium has a nonlinear condition, thus, using of soliton laser becomes an interesting subject. Therefore, an ultra-short pulse in the scope of pico and femtoseconds soliton pulses can be utilized for many applications in engineering communications. In order to obtain smaller bandwidth of the optical soliton pulses, we propose integrating series of MRRs. In this study, 5 fs soliton pulse could be generated using a series of five MRRs. The soliton signals experience less loss during the propagation, where they are more stable compared to normal conventional laser pulses. Using the series of MRRs connected to an add/drop system, shorter soliton bandwidth and highly multi soliton pulses can be obtained. Therefore, generation of ultra-short multi picosecond (1.2 and 1.3 ps), could be performed, where the radius of the add/drop system has been selected to 50 and 300 μm respectively

    Dual-wavelength generation with terahertz spacing using GaAs–AlGaAs microring resonator waveguides

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    In this research, we present the demonstration of GaAs–AlGaAs waveguide resonators. Two microring resonators (MRRs) have the same radius of 6.36 μm are coupled and used to generate dual-wavelength with terahertz (THz) spacing. We have shown that such resonators can be used to generate ultra-wide free spectral range (FSR) pulses with THz spacing, providing THz photonics communication signals. A Gaussian laser beam with power of 1 W is used as input. The MRRs are modeled by using GaAs–AlGaAs with GaAs core having refractive index of 3.368 surrounded by AlGaAs (n = 3.135). The drop port outputs of the MRRs system contains a dual-wavelength generated within 33 nm wavelength range, having a linewidth of 1.48 (185.320 GHz) and FSR of 3.95 nm (500 GHz) which varies slightly along the wavelength. Results were generated using the time-domain travelling wave (TDTW) method and capable of modeling both active and passive photonic circuits

    Digital Binary Codes Transmission via TDMA Networks Communication System Using Dark and Bright Optical Soliton

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    In this study, new system of microring resonator forquantum cryptography in network communication is proposed.optical potential well can be generated and propagate via anonlinear modified add/drop interferometer systemincorporated with a beam splitter and a time division multipleaccess (TDMA) system wherein the quantum binary codes canbe generated, propagated and transmitted. A system known asoptical multiplexer can be used to increase the channel capacityand security of the signals, where the beam splitters generatehigh capacity of binary codes within the proposed system.Therefore, ring resonator system is used to form the opticalpotential wells. The multiplexed potential wells are formed andtransmit via an available link, where the logic codes can be sentout with different time, used for high capacity transmission ofthe secured data. In this work narrow pulses with FHHM of 9.57nm and 8 nm could be obtained from the drop and throughports of the add/drop interferometer system respectively. Theoutputs of different center wavelengths are combined and usedto generate multiple potential well signals, where the multiplesignals with FWHM and FSR of 0.8 nm and 5 nm could beobtained respectively. Digital codes can be generated andtransmitted via communication networks systems such as timedivision multiple access (TDMA) using dark and bright solitonpulses with FHHM and FSR of 0.54 nm and 4.71 nm

    Generation of Quantum Photon Information Using Extremely Narrow Optical Tweezers for Computer Network Communication

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    A system of microring resonator (MRR) is presentedto generate extremely narrow optical tweezers. An add/dropfilter system consisting of one centered ring and one smaller ringon the left side can be used to generate extremely narrow pulseof optical tweezers. Optical tweezers generated by the dark-Gaussian behavior propagate via the MRRs system, where theinput Gaussian pulse controls the output signal at the drop portof the system. Here the output optical tweezers can be connectedto a quantum signal processing system (receiver), where it can beused to generate high capacity quantum codes within series ofMRR’s and an add/drop filter. Detection of the encoded signalsknown as quantum bits can be done by the receiver unit system.Generated entangled photon pair propagates via an opticalcommunication link. Here, the result of optical tweezers with fullwidth at half maximum (FWHM) of 0.3 nm, 0.8 nm and 1.6 nm,1.3 nm are obtained at the through and drop ports of the systemrespectively. These results used to be transmitted through aquantum signal processor via an optical computer networkcommunication link
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