Double Light Path Research Articles

4D surface shape measurement system with high spectral resolution and great depth accuracy.

A 4D surface shape measurement system that combines spectral detection and 3D surface morphology measurements is proposed, which can realize high spectral resolution and great depth accuracy (HSDA system). A starring hyperspectral imager system based on a grating generates precise spectral data, while a structured light stereovision system reconstructs target morphology as a 3D point cloud. The systems are coupled using a double light path module, which realize point-to-point correspondence of the systems' image planes. The spectral and 3D coordinate data are fused and transformed into a 4D data set. The HSDA system has excellent performance with a spectral resolution of 3 nm and depth accuracy of 27.5 μm. A range of 4D imaging experiments are presented to demonstrate the capabilities and versatility of the HSDA system, which show that it can be used in broad range of application areas, such as fluorescence detection, face anti-spoofing, physical health state assessment and green plant growth condition monitoring.

Reanalysis of the Michelson’s interferometric experiment in relation to the two swimmers problem

Theoretical basis of Michelson’s interferometer experiment is reanalyzed. Initially we reanalyzed the illustrative model, represented by two swimmers race traversing a river which revealed that the correct transversal trajectory is not an isosceles triangle, but a right triangle and the race ends in a tie. Also, in the interferometer device, the transversal double light path, considering the ether presence and classical geometrical optics together with Huygens principle of light, we found to be too a right triangle instead isosceles one considered by Michelson, which thus is an error. But this new path necessitates zero-time difference, for which fringes displacements are not expected, unlike Michelson’s analysis. So, we found that the light’s double travel times don’t depend on the interferometer arms directions and so the expected by Michelson fringes displacements, must not appear. The above findings are applicable to other similar experiments with ray double travel, including light, lasers, masers, γ-rays, etc. We demonstrated that Michelson’s experiment correct interpretation does not confirm the relativity of the light speed. Consequently, Michelson’s experiment should not be considered negative concerning the presence of ether which must remain the bearer of the E-M phenomena. Consequently, the Special Relativity Theory (SRT) must be reconsidered, based on Lorentz electromagnetic theory from 1895 and the quanta entanglement and E-M field can be physically explained by the ether presence.

Research on the signal of 4He pump magnetometer sensor using ECDL laser

One of the most important factors determines specifications of 4He optically pumped magnetometer is the quality of resonance signal given by sensor probe. This paper introduces a laser 4He optically pumped magnetometer using an ECDL laser. An external cavity length tuning system of ECDL laser based on the double light path atom saturated absorption spectrum method with a 4He cell is build up to ensure that an effective 1083.207 nm laser light source is provided for the magnetometer probe. It is designed a double path photoelectric detector to get the absorption peak signal by the difference technology. Because signal in accordance with Lorentz linear features, a detection method combined with first and second derivative of signal curve is proposed. Join a modulation signal whose form is dc component add sinusoidal component, the system make ECDL laser give a stable output wavelength around 1083.207 nm. With the laser light, a resonance signal with better quality than the 4He optically pumped magnetometer probe using the gas discharge lamp light source is given.

On the leakage flow around gas bubbles in slug flow in a microchannel

The leakage flow is that liquid does not push gas bubbles and leaks through the channel corners. This leakage flow was confirmed by tracking particles moving in the liquid film with a double light path method and was quantified by tracking the gas–liquid interface movement. The results show that leakage flow varies during bubble formation process. The average net leakage flow Qnet‐leak in a bubble formation cycle at T‐junction can be as large as 62.4% of the feeding liquid flow rate, depending on the liquid properties. Qnet‐leak for regular flow at main channel is much smaller, ranging from about 0 to 30% of the feeding liquid flow rate. The difference between the two leakage flows would lead to an increase in liquid slug length after generation. Finally, the effects of parameters such as phase flow rates, surface tension, and viscosity were investigated. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3964–3972, 2015

Experimental Study for Improving the Measurement Accuracy of Optical Fiber Sensor

This paper puts forward a double light path deep feedback integrated control compensation plan which is based on the current situation of the reflective intensity modulated fiber optic sensor compensation method. This scheme combines the deep feedback automation control technique with dual light path receiving and common-mode inhibition technique. The probe is designed to coaxial three-layer fiber structure. By experimental verification, this scheme effectively improves light intensity modulation fiber-optic sensor's measuring precision and stability and the error after compensation is less than 0.5%. The effect is Significant.

基于经验模态分解的SO2浓度检测信号处理方法

The fluorescent spectrometry is a common method to detect the concentration of SO2in the atmospheric monitoring.The detection system adopting double light paths can eliminate the noise jamming from the light source and light path.However,background noise produced by photoelectric converting device under the laser irradiation will also affect the accuracy of quantitative analysis.Empirical Mode Decomposition(EMD)filtering algorithm was used to reduce various kinds of noise existing in the detection,which could retain the useful original signal and reduce the noise effectively.The simulation results show that for the sulfur dioxide concentration detection system,using EMD denoising,the Signal Noise Ratio(SNR)increases to 204.273 6,and the Mmean Squared Error(MSE)is 0.007 0.Compared with the wavelet de-noising method,the effect of EMD detection is much better.Finally,the signal processed with the two signal methods were applied to the gas detection system.From the experimental data of the linear relationship,it can be concluded that the EMD method applied to the proposed concentration detection system is feasible.

A Reanalysis of the Theory of Interferometer Experiment Demonstrating that Michelson’s Analysis Contains an Error, Including the Boat Model Analysis, so Readmitting the Ether Presence

Theoretical basis of Michelson interferometer experiment is reanalyzed. Initially we reanalyzed the illustrative model, represented by a boat traversing a river which revealed that the correct transversal trajectory is not an isosceles triangle, but a right triangle. Also in the interferometer, the transversal double light path, considering the ether presence and classical theories of light, we found to be too a right triangle instead isosceles one considered by Michelson. But this new path necessitates zero time difference, for which fringes displacements are not expected, unlike Michelson’s analysis. So we found that the light’s double travel times don’t depend on the interferometer arms directions and so the expected by Michelson fringes displacements, must not appear. The above findings are applicable to other similar experiments with ray double travel, including light, lasers, masers, γ-rays, etc. We demonstrated that Michelson’s experiment correct interpretation does not confirm the relativity of the light speed. Consequently, Michelson’s experiment should not be considered negative concerning the presence of ether which must remain the bearer of the E-M phenomena. Consequently, the Special Relativity Theory (SRT) must be reconsidered, based on Lorentz electromagnetic theory from 1895 and the quanta entanglement and E-M field can be physically explained by the ether presence.

Simple method for simultaneous determination of the phase retardation and fast axis of a wave plate

A simple method for simultaneous determination of the phase retardation and fast axis of a wave plate is presented. In this method, double light path compare system is adopted to achieve better accuracy. In the main optical path, laser beam passes successively through a polarizer, a wave plate to be measured, an analyzer, and then is incident on a detector. In the reference optical path, another detector is used to monitor the fluctuation of the light source. With rotation of the wave plate, the maximum and minimum output light intensity, rotation angle of the wave plate are detected in the main light path; corresponding light intensity are simultaneously detected in the reference light path. Based on the light intensity and the rotation angle, the phase retardation and fast axis of the wave plate can be determined simultaneously. The main advantage of this method is its simplicity of apparatus, easy operation, low cost, and high accuracy. We believe that the method reported in this paper should be a useful approach to measure a wave plate without requiring any complex and expensive components.

Research on the Optical Fiber Gas Sensing System Based on the Gas Concentration Measurement

At present , the catalytic combustion type gas sensors is still used in our country which is the extensive use of underground coal mine gas detection instrument , this kind of sensor slow response, calibration cycle is short, and the apparatus for the selectivity of methane is poor. Thus it can be seen that develop a safe and reliable, selective, high sensitivity of gas concentration measurement system that for mine safety operation, the personal safety and environment protection has a very important social significance and economic significance. Optical fiber sensing monitoring system according to the gas absorption spectrum principle with double light path structure on the mine gas online monitoring the concentration of the gas, has avoid the explosion, dust and so on many special advantages.