In this paper, a transient plasma is produced by focusing the 1064 nm radiation from a Q-switched Nd:YAG onto the one-yuan coin at room temperature in air at atmospheric pressure. Using the iterative Boltzmann algorithm, the plasma electron temperature of the one-yuan coin is calculated as 28144 K. Experiments show that the correlation coefficient increases from 0.197 to 0.997 as the number of iterations increases. Experimental results show that the laser induced one-yuan coin plasma meets the LTE model.
Mg doped ZnO (MZO) thin films were prepared by magnetron sputtering and laser induced breakdown spectroscopy (LIBS) were characterized by Q-switched nanosecond 1064nm Nd:YAG laser pulse. Element characteristic spectral lines from MZO thin films with Mg concentration of 0.1 at%, 0.26 at% and 0.49 at% are illustrated by LIBS system. The results show that Mg (I) emission lines are observed corresponding the relatively high excitation with increasing Mg doped concentration. It can be mainly interpreted as more crystallization planes produced by high Mg doping concentration radiate different atomic spectral lines. The results are in relative agreement with XDR patterns. We calculated the electron density of 8.08×1022 cm-3, 7.70×1022 cm-3 and 7.99×1022 cm-3 inferred by measuring the Starkbroadened line profile. The electron temperature of 21875.85 K, 42941.49K and 28985.51K was determined using the Boltzmann plot method through the acquired data.
Plasma produced by the radiation of a 1064 nm Nd:YAG laser focused onto a standard aluminum alloy E311 was studied spectroscopically. The electron density was inferred by measuring the Stark broadened line profile of Cu I 324.75 nm at a distance of 1.5 mm from the target surface with the laser irradiance of 3.27 GW/cm2. The electron temperature was determined using the Boltzmann plot method with eight neutral iron lines. At the same time, the validity of the assumption of local thermodynamic equilibrium was discussed in light of the results obtained.
A new strategy for images fusion is developed on the basis of block compressed sensing (BCS) and multiwavelet transform (MWT). Since the BCS with structured random matrix requires small memory space and enables fast computation, firstly, the images with large amounts of data can be compressively sampled into block images for fusion. Secondly, taking full advantages of multiwavelet such as symmetry, orthogonality, short support, and a higher number of vanishing moments, the compressive sampling of block images can be better described by MWT transform. Then the compressive measurements are fused with a linear weighting strategy based on MWT decomposition. And finally, the fused compressive samplings are reconstructed by the smoothed projection Landweber algorithm, with consideration of blocking artifacts. Experiment result shows that the validity of proposed method. Simultaneously, field test indicates that the compressive fusion can give similar resolution with traditional MWT fusion.
A compressive fusion of remote sensing images is presented based on the block compressed sensing (BCS) and non-subsampled contourlet transform (NSCT). Since the BCS requires small memory space and enables fast computation, firstly, the images with large amounts of data can be compressively sampled into block images with structured random matrix. Further, the compressive measurements are decomposed with NSCT and their coefficients are fused by a rule of linear weighting. And finally, the fused image is reconstructed by the gradient projection sparse reconstruction algorithm, together with consideration of blocking artifacts. The field test of remote sensing images fusion shows the validity of the proposed method.
In this paper, we present a new and simple method to produce larger height (with millimeter-sized) helical surface
compared with the other methods. During the process, a convenient method for the fabrication of the helical substrate
made of B270 glass by using a smart oven is presented. A Global 7107 Coordinate Measuring Machines (CMM) is used
for the detection of the glass helicoid. The experimental results proved to be in agreement with the theoretical prediction
within the uncertainty of the error and can satisfied our requirement. Moreover, this method seems easy and simple to
produce larger height helical surface compared with other ways mentioned in the literature.
We derive and calculate numerically laser linewidth by means of the laser rate equation in an extending diode laser
cavity provided by an end reflector. We found that narrow linewidth is closely connected with phase modulation and
frequency modulation. The numerical simulation shows the dominance of effect over another depends on inherent factors
such as the α coefficient, bandwidth of laser, length of external cavity, reflective coefficient etc.
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