The main aim of this paper is to analyze the propagation and attenuation in PIR fibers. The thermal change of these
parameters for different mode structures will be done due to propagation of high optical power witch cases fiber
heating.
Rapidly vanishing polar ice may be supplemented with extensive artificial ice in order to alleviate effects of global warming. Here we consider methods for creating such artificial ice by introducing synthetic polymer rafts or films to the supercooled topmost water layer near ice sheet borders in northern Arctic seas. Such films will have three major effects. They will reflect incoming solar radiation, reducing ice melting, ocean absorption of solar energy, and net heating rates. The films will also provide additional sites for nucleation of ice crystals. Finally, by decreasing wave amplitudes in their immediate vicinity, polymer films will allow ice crystals to aggregate into larger ice structures.
The main idea of proposed method is based on the novel possibility to create a precise point action of explosion series which produces the diffraction grating. In practice this process could be achieved by bombarding the ocean with explosive material in vicinity of tsunami region from the earth or from airplane. The tsunami velocity could be decreased and the wave front could be disturbed. In this paper the relevant calculations were performed for this overall process to be optimized.
The proposed method offers one possibility to restore climate in order to avoid overheating. The method to create a
supplemental icy cover is considered in the paper. We investigate theoretically the creation of artificial rafts in the border
of water-ice area in the north seas. Firstly, such artificial rafts or films can be used as additional mirror for san energy.
Secondly, these rafts can decrease local water vibration for the ice to form easily in north regions. And finally, these rafts can be treated as crystallization centers in the supercooled water.
There are the results for the 3 groups of fiber-optical sensors. First is the fiber-optical sensor with changed sensitive heads on the base on porous polymer with clamped activated dye. Vibration method for fiber-optical sensors provides more convenient output measurements of resonant frequency changes, in comparison with the first device. The self-focusing of the living sells into optical wave-guides in laser road in water will be considered as a new touch method for environment remote sensing.
In this paper we analyzed and calculated the deformation based on noon symmetrical temperature distributions in the
cross section of optical fiber. Deformation distortion causes the micro vibrations of the optical fibers under periodical
thermal excitation applied to one side of cylindrical surface. Calculations were made to optimize the exposure and to
minimize energy, needed for realization of this class of sensors based on vibrations. The same effect can play negative
role for the fiber-optic communication's systems. The main feature in presented work from the similar theoretical
considerations is the analysis of the non-symmetrical heating azimuthally with appropriate deformations.
T. Tulaikova, B. Goryunov, E. Vinogradov, S. Sivergin, S. Kireeva, K. Veksler, M. Koldunov, S. Dolotov, A. Nemeruk, M. Simakova, P. Dorojkin, A. Michtchenko, N. Minhuey-Mendez
The main subject of presented work is the development of the family of fiber-optic chemical sensors for admixtures detection in air or in water. The experimental results are presented in details for the sensors for NH3, H2S and RSH with the appropriate models for operation in gas and liquid media. These sensors could be used for remote control of the common pollutions in environment, or for the measurements of the admixtures in different processes in industry. The production of these sensors for the detection and measurement of the concentrations of toxic gases yields rather simple and inexpensive tools for laboratory and industrial use.
In presented paper the analytical method of the complex analysis for PIR fiber-optic depending on number of optical modes was applied with numeral estimations. In this paper the consideration of polycrystalline-fiber materials (ArBrCl) for the wavelengths 4-20mm were performed with real appropriate numeral estimations. The physical nature of imaginary part of refractive indexes was assumed as the total sum of material scattering with material absorption. The simple equations were received and used for calculations of the imaginary parts of these main functions as well as for the set of mode's attenuations (am) from the imaginary parts of propagation constants. Using designed in given paper algorithm, the analysis of the operation of surrounding water was organized for effective desirable absorption of the set of optical cladding's modes.
KEYWORDS: Robots, Control systems, Fiber optics, Electromagnetism, Optical fibers, Power supplies, Control systems design, Visualization, Motion controllers, Light emitting diodes
The control systems of the miniature robots are suggested for their motion over internal surfaces inside of the small diameter tubes. The mechanical system, information-measuring sensor and control systems are considered. Three versions of the mechanical systems are suggested: electromagnetic, triad wheels and conversion of rotation motion to translation one. The electromagnetic mechanism use push pull tipe method for translation motion realization. Developed schemes in the modules design of control systems were checked experimentally on the robot’s prototypes. Some of the results of the computer simulation illustrate the multilink robot control motion along the internal diameters of the tubes. This work was fulfilled under financial support of the Russian Found of Fundamental researches N 01-01-00913 and in frames of Federal Multi Purpose Scientific and Technical Program of Ministry of Industry, Science and Technologies: “Researches and Developments on priority directions of science and technology”, “Knowledgeable basic investigations” block, “Basic investigations at the field of physics sciences” part Mechanics.
A convenient method for exact recognitions of the curved shape and amplitudes of vibrated micro cantilevers is presented. The method includes the analysis based on preliminary introduction of the formulas for the shapes of deviated cantilevers to get the intensity distribution R(ξ) of the optical pattern of image. The feature of this method is the possibility to get high accuracy for MEMS orientation.
In this paper we analyzed and calculated the temperature distributions and deformation fields in the cross section of optical fiber under periodical photo thermal excitation applied to one side of cylindrical surface. This calculations were made to optimize the exposure and to minimize energy, needed for realization of this class of sensors. The main difference from other papers is the non-symmetrical heating for initiating vibrations.
Simple remote sensors are investigated on the basis on various variants of amalgamation of optical fibers with 'living sensitive element' as they apply to environmental processes. The living aquatic plant serves as the natural sensitive element of sensor of water pollution, but the tasks for technology are the reliable connection with 'living' sensor as well as the readout of pollution reaction with high efficiency. (Abstract only available)
An electromagnetic immune fiber-optic microvibrated sensor systems with cantilever-type sensing element are perspective for investigation of ground traffic monitoring, for earthquake forecasts, motor diagnostics, etc. An acceleration sensitivity of vibrated fiber tip will be analyzed and compared with another traditional approaches. The most of low-frequency accelerometers have been based on the seismic mass effect. But this different way of detecting of the movement of the seismic mass is by allowing it to produce of the micro stresses in the fiber body, which are detected by grating's spectrum immediately. This type sensor system was developed and realized in certain experiments to measure of the ground vibration excited by acoustic emission and mechanical interaction between the motor and the ground. But the whole potentials of high sensitivity of fiber-optic sensors with inner fiber gratings were not realized enough yet in experiments. (Abstract only available)
This paper presents a signal analysis method with the purpose of detecting frequency chande and acceleration amplitude of vibrating-type accelerometer's output. The method has potential application for newly developed oscillating micro accelerometers.
New waveguide effects are considered on the basis on various variants for self-focusing of the living cells of aquatic plant by laser beam irradiation. It is studying the process of forming of the 'living multi-mode fiber-optic' into the road of laser's beam in water with motion of green living cells. Analysis gives that the wide set of different profiles of the refractive index in this 'living optical fiber' could be easy produced depending the frequency of applied lasers. Optical waveguide approach gives high sensitivity in living layer readout and control, this waveguides could be apply to environmental processing or for a cell's studying, also different medical application could be realized according described mechanism.
Simple remote sensors are investigated on the basis on various variants of amalgamation of optical fibers with 'living sensitive element' as they apply to environmental processes. The theory of optical fiber with additional formed cladding is presented, but a profile of the refractive index in this layer lowers from the diffusion dictation. Analysis of a new mechanism for effective operation of such additional liquid cladding of optical fiber with long-period grating is considered.
Fiber-optic inner core gratings are considered together with the non-uniform Deformations is oscillated optical fiber. This is wide method of vibration registration as a result of appropriate deformations. Analysis was done for fiber cantilevers with the length 1-10 mm. Different cases were analyzed that correspond to transverse and longitudinal vibrations of the fiber tips or fragments with tow clamps. The pi-shifted Bragg-gratings are discussed to measure of vibrating amplitude in different real cases.
This subject is the class of high sensitive fiber optical vibrated sensors. It could be classified as a micromachining principle application to a fiber optics. The principle of operation is the resonance frequency change of the micromechanical vibrated fiber optical sections by depending on the environment. Bragg-gratings were considered to measure the amplitudes of vibrations of this small fiber cantilevers.
Composite optical fiber cantilever micromechanical vibrated sensor is considered. Usual quartz fiber is supplemented by crystal sapphire fiber part which have high Q-factor of mechanical oscillations. Sensitivity of the Bragg-gratings with yr-phase shift at the end of the fiber cantilever are discussed. Keywords: fiber, cantilever, mechanical vibrations, fiber grating.
Amplitude equations are obtained for the optical fiber cantilever than periodical force acts for excitation of vibrations. Two cases are considered which correspond to one or two clamped cantilever's ends. Fiber optical cantilevers from different fiber's materials are considered to get high sensitivity. Grating's type registration of the fiber cantilever vibrations are discussed.
The results of intracavity application of soft or apodized apertures (AA) with smooth transmission profiles decreasing from the center to the edges are presented. Photooxidation (PhO) AA, made of CaF2:Pr crystals were used. The approximately 3-4 mm diameter of PhO AA with bell-like transmission profiles as placed inside the 2.94 micrometers and 1.06 micrometers resonators of master oscillators. The tendency of the order of magnitude of 1.3 - 1.8 times increasing in output energy and diminishing in beam divergence in single-mode lasing as compared with hard-edge aperture have been observed in the experiment described.
This paper presents a novel application of UV laser radiation: fabrication of soft or apodized apertures (AA)I-3 with transmission profiles decreasing smoothly from the center to the edges for high-power single-pulse visible and near-IR lasers. Such units are used both outside and inside the cavity for beam shaping, for avoiding hard-edge Fresnel diffraction ripples in laser amplifiers, for increasing the second harmonic conversion efficiency, and for the brightness enhancement of master oscillators in single-mode lasing.
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