In the early nineteenth century, People paid attention to the phenomenon that the biaxial crystal could produce conical
refraction. A bunch of solid quasi-monochromatic beam can be considered as the light source, when the laser propagates
through the biaxial crystal, the "funnel-shaped" hollow cone laser can generate inside the biaxial crystal or outside. This
paper is based on this point to study the hollow cone laser that produced by biaxial crystal.
In this paper, the ring size of the conical refraction can change with incident angle from refractive indices ellipsoid of
biaxial crystal. Through computer simulation, the characteristics biaxial crystal produce conical refraction can be
analyzed. When laser propagate through the biaxial crystal, the phenomenon of absorption and dispersion is appeared,
and it will affect on the transmission quality.
According to the absorption and dispersion properties of conical refraction, the spatial coherence decrease when laser
propagates through the biaxial crystal. The beam propagation direction will change with refractive index, which will
cause the change of optical path length. In addition, the experiments and theoretical study can achieve the same results.
This paper also discuses the hollow cone laser can be applied to optical switching, radar scanner, copier, scanner and
other applications.
The water pollution has become more and more serious with the industrial progress and social development, so it become a worldwide leading environmental management problem to human survival and personal health, therefore, countries are looking for the best solution. Generally speaking, in this paper the work has the following main achievements and innovation:
(1) Developed a new plasma device--Plasma Water Bed.
(2) At atmospheric pressure condition, use oxygen, nitrogen, argon and helium as work gas respectively, use fiber spectrometer to atmospheric pressure plasma discharge the emission spectrum of measurement, due to the different work gas producing active particle is different, so can understand discharge, different particle activity, in the treatment of wastewater, has the different degradation effects.
(3) Methyl violet solution treatment by plasma water bed. Using plasma drafting make active particles and waste leachate role, observe the decolorization, measurement of ammonia nitrogen removal.
Dynamic weighing is a process that it reckons the weight of vehicles according to measuring the tires which are moving.
It makes use of sensors and some others auxiliary apparatus to measure the appearance of a certain vehicle and tires, then
calculates the weight and the speed of vehicles. Finally it can note and read this information.
To analyze the dynamic weighing system at home and abroad, it can be easily discovered that these are based on the
sensors of electricity. The disadvantages of those sensors are very obvious. For example, when vehicles are dynamic
weighed, the speed and accuracy can not be ensured at the same time.
Dynamic weighing system is designed in the research of papers. Linear CCD can be used as Sensor to be applied in the
mold of weighing. This paper describes the dynamic weighing system, analyses the dynamic of the system, and also
investigates the modules of the dynamic weighing system.
With the rapid development of power industry, the number of SF6 electrical equipment are increasing, it has gradually
replaced the traditional insulating oil material as insulation and arc media in the high-voltage electrical equipment. Pure
SF6 gas has excellent insulating properties and arc characteristics; however, under the effect of the strong arc, SF6 gas
will decompose and generate toxic substances, then corroding electrical equipment, thereby affecting the insulation and
arc ability of electrical equipment. If excessive levels of impurities in the gas that will seriously affect the mechanical
properties, breaking performance and electrical performance of electrical equipment, it will cause many serious
consequences, even threaten the safe operation of the grid.
This paper main analyzes the basic properties of SF6 gas and the basic situation of decomposition in the discharge
conditions, in order to simulate the actual high-voltage electrical equipment, designed and produced a simulation device
that can simulate the decomposition of SF6 gas under a high voltage discharge, and using fourier transform infrared
spectroscopy to analyze the sample that produced by the simulation device. The result show that the main discharge
decomposition product is SO2F2 (sulfuryl fluoride), the substance can react with water and generate corrosive H2SO4(sulfuric acid) and HF (hydrogen fluoride), also found that the increase in the number with the discharge, SO2F2concentration levels are on the rise. Therefore, the material can be used as one of the main characteristic gases to
determine the SF6 electrical equipment failure, and to monitor their concentration levels.
Intelligent video surveillance system study in this paper is constituted by CCD cameras, infrared pyroelectric sensor,
stepping motor and the computer. And make In-depth study for portable intelligent monitoring system from two aspects
of hardware and software. compare and analyse between CCD image sensor and CMOS image sensor, key research on
the CCD various' characteristics and performance indicators; investigate for the infrared pyroelectric sensor structure,
characteristics, put forward further method to improve pyroelectric sensor performance, response degree. On software,
according to the calculation of moving object detection, through controll the step motor, can tracking video real-time or
finish videoing,video Real-time. Intelligent video surveillance system use infrared pyroelectric sensor as access switches,
make sure the foolproof of monitoring site safety system.
The detection of inside surface of the hollow reactor uses the industrial fiber endoscope mostly. In order to obtain the
large view angle, industrial endoscope generally uses the ultra wide fisheye lenses, which have the larger image
distortion, and the smaller depth focus. Industrial endoscope uses optical look system. It is inconvenience for the
observer. Even if use the TV image transmission system, it is also hard to get high quality images for the limit of like a
bouquet of processing by preaching.
The hollow reactor inside surface rapidly detection system based on the photoelectric detecting technique is composed
by optical detection system, control system, the transmission system, image transmission system, image acquisition,
display and data processing system. It can detect four holes and eight surface at the same time, and the testing time only
50-60 seconds. It can save the real condition of the inside surface of hollow reactor in the form of the bitmap. It can
screen the bitmap stored according to the set of parameters, find out the problem bitmaps and supply for the techniques
to identify and confirm.
Insulating oil is widely used in transformer and other large high-voltage electrical equipment.Its main functions are
insulation, cooling and arc extinction. When the transformer runs, it may emit heat or discharge, which generate gas,
micro water and trace metals in transformer oil. This will not only reduce the insulation capacity of insulating oil,and
will greatly reduce the ability of its extinction, causing the transformers or other oil-filled electrical equipment appearing
Internal latent malfunction, which would affect the operation of equipment.
In this Paper, we simulate the transformer discharge effect to discharge in transformer oil. Then we use spectral theory
and photo-spectroscopy technology to measure and analyse the oil sample, combining with IR absorption peaks of main
fault characteristic gases, and qualitatively analyse CO, CO2, CH4, C2H6, C2H4, C2H2, H2 in gas mixture. The results show that the Fourier transform infrared spectroscopy can be very effective for analysing gases in transformer oil, which
can quickly detect possible problems in the equipment.
Cooperative effect radiation loss of optical pump solid laser was investigated deeply. Using Maxwell-Bloch equation the
characteristic and cause of coherent spontaneous were discussed .By laser rate equation, the expression of upper energy
level lifetime shortening due to the cooperative effect radiation was given. The influence of cooperative effect for laser
threshold and the loss were analyzed. Through the experiment, the relation of coherent spontaneous radiation intensity
and direction with reversal population and the power of optical pump was obtained.
Based on the theory of the conical refraction, the hollow conical laser will appear at the internal of the biaxial crystal
when laser traveling along one of the axis of the biaxial crystal. The hollow conical laser is different from the solid laser;
all of its energy is disturbing on the cone that is similarly the funnel. The study of the produce and control of the hollow
conical laser will provide the theoretical and technique basis for its application. In this paper, Based on the matter
equation of anisotropies and the propagation law of light in the biaxial crystal, the production of the conical laser was
theoretically analyzed and calculated in detail, and the cone angle equation of the hollow conical refraction was obtained,
which provided the control and modulation of hollow conical laser with theoretical bases. The cone angle of the conical
laser was adjusted by changing the convergence angle of the incidence laser; the all-beam, large-angle and dynamic
laser scan was realized by controlling emergent conical laser with varifocal system.
In this paper the theoretical analysis of the conical laser traveling in atmosphere is presented. Under the circumstances that conical angle of laser is invariable and conical laser travels along horizontal, vertical and slant routes, the basic equation of intensity attenuation of the conical laser is obtained and the time curve of transmissivity vs. transmission distance is given. The researches lay the theoretical and technical foundations for the conical laser application to laser guidance and laser radar.
In this paper the performance of Hartmann-Shack wave-front sensor in the aberration measurements of human eyes is investigated and the accuracy and repeatability of measurements are presented qualitatively and quantitatively.
The laser blood sampling is the last idea. The idea is based on focus laser beam to pierce the finger skin, and then we can get and analyze the blood sampling. Because there is not contact the method can wholly avoid the contact infection. In the paper, the core light source is a compact no water-cooled Er-doped YAG solid laser, researched and developed by ourselves. The erbium laser output wavelength is 2.94?m, which is accordance with water' s absorption peak. The water' s absorption in tissues is particularly great, so the erbium laser is suitable. Simultaneously we design the laser alignment system, the laser shaping system and the focal setting system. Depend on the theoretical analysis and experiments, we research and develop a medical blood—sampling instrument of laser, with the good application prospect.
According to refraction law and total reflection law, the transmission characteristic of laser beam in solid and hollow cone is studied, on this case, the laser fiber refraction coupler which reflect laser with internal cone of hollow cone lens is made, and coupling and transmission of high-repetition-rate spike pulse laser which peak power is MW in fiber are realized, the coupling efficiency get to 80%.
In this paper, the pulse Nd:YAG laser pumped with wide-pulse of ms level output Q-modulating serial pulse through high frequency electrooptical Q-modulation. Compared with ordinary pulse laser pumped with pulse of µs level, it can output over ten times higher single high energy. Based on this, the frequency of pulse laser can be doubled more efficiently.
Radial and longitudinal distribution characteristics of temperature of Nd:YAG laser rod pumped by semiconductor laser line-array are analyzed in this paper. Thermal effect of laser rod, the relation between thermal stress birefringence of laser rod and light pumping power, and the relation between thermolens focal length and pumping power density and repetition frequency of light pumping are studied.
A high power Q-CW array LD pumped Nd: YAG laser was successfully developed by building the model that Q-CW array LD pumped Nd: YAG laser. Using laser rate equation, the geometry formed by the pumping beam meeting laser beam in the resonant cavity was calculated out. In the experiment, two Q-CW array LDs were used. The average output power is 60w and the duty cycle is 20% each. The two Q-CW array LDs were placed along side ofNd: YAG bar at the angle 90°. The pumping beam enters Nd: YAG rod radial so as to fills in the whole medium uniformly, which not only decreases the threshold but increases the slope efficiency. By setting a pair of ? /4 wave plates in cavity steady single mode output can be obtained. Its average output power is 12w, the pulse width is 10-12ns, and the pulse frequency can be variable from 500Hz to 1000Hz.
In this paper, the theories of CW- laser and pulse laser were analyzed. A novel wide pulse laser is provided. Its pulse width is 1-6ms , the wave length is 1.064 µ m, the energy is 2-6 J. Using high repetition frequency electro-optical Q-switching at a repetition of 1000-5000Hz, it can obtain a series ofshort pulse, whose width is 30-50ns. The pumping of power of the wide pulse laser is decided by IV ? t, where the ? t is the width of electric —pulse. By adjusting ? t, the output power and pulse width can be adjusted . The wide pulse laser can be widely used for machining and therapy.
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