查看更多>>摘要：In this paper, we firstly review the optical circular motion with optical optimistic density in Heisenberg space. We define new quasi optical potential electromagnetic energy of quasi normal magnetic biharmonic fields. Moreover, we design the new characterization of uniformly optical electroosmotic phase and optical parallel transportation in cold plasma. Also, we collect new physical geometric designs for a optical optimistic density of normal magnetic biharmonic fields in Heisenberg space. Finally, we construct optical potential electromagnetic energy with respect to its electric field and sonic crystals.
查看更多>>摘要：In the domain of contrast enhancement, contrast as well as detail retention are critical for human visualization and onward processing by any other computer based application. Contrast enhancement of an image with naturalness and preserved details is a challenge. In this paper, we propose a method using an edge-preserving smoothing operator approach, based on the weighted least squares (WLS) optimization. The detail and base layers are extracted using the WLS and median filters respectively. Base layer is a smooth layer of the image that contains large scale intensity changes and the detail layer captures the smaller scale details in the image. The layers are enhanced with a fine tuning between the rate of enhancement of the base and detail layers. It is vital to manage the level of enhancement in both the extracted layers as any mistune in the rate of enhancement may lead to severe distortion and addition of artifacts. Color correction is applied to the image to provide a higher-resolution improved image. The simulation results over 680 images from different datasets, show that the proposed method outperforms the existing methods in terms of qualitative and quantitative parameters.
查看更多>>摘要：In this study, we study optical hasimoto map corresponds to under the quasi-frame for timelike curves in 3D Minkowski space. We investigate the relationship of this transformation with some flow equations, which are known examples for nonlinear optical systems. Here, we first obtain the q-Hasimoto map as equivalent of the Hasimoto map in the q-frame for timelike space curve in 3D Minkowski Space. Then, we examine the effect on the q-Hasimoto map of the some flow equations such as vortex filament equation, Heisenberg antiferromagnetic flow. Finally, we present comments on some of the physical consequences of these effects that we have examined.
查看更多>>摘要：For KDP crystal, linear and nonlinear optics as the important physical features are susceptible to be influenced by impurities, and the metallic element of sodium as a common impurity ion is practically impossible to remove. Hence, the dependences of linear and nonlinear optical properties on Na+ are necessary, and fully studied for as-grown KDP crystals by rapid growth technique. The UV-VIS-NIR spectrums indicate that the transmittance ranging from 200 to 800 nm, especially in the ultraviolet region, decrease with the increase of sodium concentration, while the corresponding refractive index presents a trend of increase. By Z-scan method, the characteristics of nonlinear absorption and nonlinear refraction demonstrate that the electron-cloud distortion of H2PO4- group play a major part in generating this nonlinear effect under picosecond laser pulses. Moreover, a more pronounced nonlinear response can be induced by the concentration of Na+ ions, implying that this variation is mainly attributable to the distortion of crystal lattice and electronic structure, originating from the substituting effect of sodium positive ions. All results are extremely useful to the growth and application as nonlinear optical devices for KDP crystal.
查看更多>>摘要：We report on the performance of an acousto-optically Q-switched Yb:NaY(WO4)2 crystal laser operating at 1015-1019 nm. Stable Q-switched laser action was demonstrated at pulse repetition frequencies (PRFs) ranging from 50 to 2 kHz, generating a pulsed output power of 2.19 W at 50 kHz, with optical-to-optical and slope efficiencies being respectively 40% and 60%. While Qswitched at the lower limit of PRF of 2 kHz, the laser was capable of producing 185.0 mu J of pulse energy, the pulse duration and peak power were 10.5 ns and 17.62 kW, respectively.
查看更多>>摘要：Reducing the noise level of fiber optic gyroscope (FOG) has been paid much attention. The relative intensity noise (RIN) of the light source is a dominant noise source and different methods have been used to reduce the RIN. However, the performance of the RIN suppression methods suffering from parameter variation is rarely discussed. In this paper, we introduced a method that uses the period LMS (PLMS) adaptive filter in the FOG system with noise subtraction implementation to ensure the sensor's performance in varying environment. By analyzing the sampled detector signals in the system, the parameters in the system are determined based on the convergence requirement and noise performance of PLMS. Simulations as well as experiments of a FOG system with the PLMS algorithm implemented in the signal processing board are used to verify the feasibility of the method. The performance comparison between the PLMS filter and the predetermined Wiener filter in different temperature is tested and analyzed, which reveals the variability of the system parameters and verifies the necessity and ability of the introduced method to adapt to the varying environment.
查看更多>>摘要：The quest for improving the limits of trace elemental detection and reproducibility in LaserInduced Breakdown Spectroscopy (LIBS) resulted in the development of novel methodologies for sample excitation and plasma collection. Efficient plasma collection and coupling to the detector is of utmost importance in LIBS studies for meaningful and logical data interpretations. Unfortunately, limited attention is paid to such critical aspects in comparison with the plethora of publications in advanced data analysis. In view of this, we probe the role of the different optical schemes on the collected plasma signal strength from three standard samples (Cu, Cd, Pb) while retaining all other experimental conditions such as laser energy, detector gain, gate width, and gate delay same. In addition, the role of coupling modalities on the plasma signal strength, an area not studied in depth, is investigated and found that the direct coupling scheme always provides better signal strength and repeatability. Moreover, the role of spectrographs in the measured signal strength is also investigated in detail for all the said standard samples. A comparative study elucidates that single shot experiments with low excitation pulse energies of the order of a few mJ are sufficient as compared to multi-short pulse laser excitation to provide the required limit of detection of the samples of interest which in turn makes the technique practically non-destructive. The efficacy of the optimized system was manifested by investigating idealistic and real-life samples viz. standard meals and teeth to differentiate between the normal and carious states. Our results reveal that the developed strategies may be useful in designing a robust system for fast ultra-trace elemental detection.
查看更多>>摘要：In this work, we report the numerical and simulation studies on the coupling behaviors of siliconon-insulator (SOI) slotted photonic crystal cavity (SPhCC) and slotted photonic crystal waveguide (SPhCW). Coupled mode theory (CMT) based numerical calculations for a coupled structure consisting of SOI SPhCC and SPhCW have shown that the structure reaches a strong coupling when the Qc >= 2Qi in which Qi and Qc are the quality factors of the cavity alone and of the cavity when coupled with waveguide, respectively, then the transmission of the output signal is less than 0.25, and the build-up factor is of nanosecond. In the simulation scheme with Plane wave expansion (PWE) and Finite-difference time-domain (FDTD) methods, the slot confined PhC cavity mode, which lies deep below in the band-gap, has been excited properly from the side coupling SPhCW with the obtained transmission of around 0.22. Our study sheds light on the SOI SPhCC-SPhCW coupled structure, knowledge of which may enable its applications in integrated circuits, hybrid silicon platform and sensing.
查看更多>>摘要：This paper proposes a fiber optic magnetic field sensor based on the surface plasmon resonance effect. By filling the elliptical magnetic fluid medium layer in the optical fiber cladding, the structure increases the effective contact area between the magnetic medium and the fiber core, thereby improving the sensing performance, at the same time, the structural stability of the sensor is considered. Coating the metal silver film on the inner surface of the elliptical cavity can prevent the metal layer from being oxidized. In addition, compared with other metal materials, silver film can significantly improve the resolution of the output spectrum. The performance of the sensor was studied using the finite element method. The results show that the sensor can measure the commonly used low magnetic field in the range of 50-115 Oe, it also has the advantages of strong sensitivity about S = 2.02 nm/Oe, high resolution R = 4.9 x 10(-3) Oe and large Figure of Merit FOM = 0.024/Oe. Based on the characteristics of miniaturization, integration and high sensi-tivity, the sensor can be considered for the applications in military, medical, industrial production and other fields.
查看更多>>摘要：The movement of targets often lead to a noticeable motion blur in the local part of an image. Traditional methods mainly based on separating the blur part and performing Fourier transform are often affected by window effect due to the deviation of edge segmentation in the case of complex background and edge occlusion. Rather than applying a more sophisticated edge extraction algorithm, this paper presents a simple method which can guarantee the accuracy of PSF extraction and reduce the precision requirements in edge segmentation. The proposed method is based on Wigner distribution of image and can reduce the impact of local sampling and processing. With this method, the requirement of sampling interval can be reduced from the whole targets to the size of motion pixels. Besides, the application of Wigner distribution in Light Field can make it possible in the application of computational optical imaging.
NSTL
Elsevier