A terahertz-wave generator based on optical parametric oscillator principle, detection based on combination of Fizeau wedged interferometer and an electro-optical crystal ZnTe has been studied. The analytical solution...A terahertz-wave generator based on optical parametric oscillator principle, detection based on combination of Fizeau wedged interferometer and an electro-optical crystal ZnTe has been studied. The analytical solution based on the basic principle of operation of solid wedge Fizeau interferometer has been realized. The mathematical calculations for THz frequency and intensity measurement dependent on wedge angle and fringe spacing have been considered. The efficiency of THz wave detection depends upon optimized wedge angle has been also realized. The feasibility of detection of THz waves＇ frequency and intensity by solid Fizeau interferometer （THz-waves＇ range of 1 - 3 THz） has been studied. By optimization of other parameters like thickness of Fizeau film, refractive index, material of Fizeau film, we can proceed towards the design of Fizeau interferometer for required research plans as it is a simple and inexpensive interferometer.展开更多
The interferogram of multiple-beam Fizeau fringe technique plays an important role to investigate the optical properties of fiber because this interferogram provides us with useful information which can used to determ...The interferogram of multiple-beam Fizeau fringe technique plays an important role to investigate the optical properties of fiber because this interferogram provides us with useful information which can used to determine the dispersion curve of the fiber sample. A common problem in any interferogram analysis is the accuracy in locating fringe centers (fringe skeleton). There are a lot of computer-aided algorithms, which depend on the interferogram types, used to fringe skeleton extraction of various digital interferogram. In this paper, as far as I know, a novel algorithm for fringe skeleton extraction of double bright fringe of multiple-beam Fizeau fringe is presented. The proposed algorithm based on using the different order of Fourier transform and the derivative-sign binary image. Also the proposed algorithm has been successfully tested by using a computer simulation fringe and an experimental pattern. The results are compared with the original interferogram and shown a good agreement.展开更多
In this study,we present a dual-Fizeau-interferometer-based high-speed and wide-range fiber-optic Fabry-Perot(F-P)demodulation system.We employ two Fizeau interferometers with air cavity thickness satisfying the quadr...In this study,we present a dual-Fizeau-interferometer-based high-speed and wide-range fiber-optic Fabry-Perot(F-P)demodulation system.We employ two Fizeau interferometers with air cavity thickness satisfying the quadrature requirement to increase the demodulation speed and broaden the demodulation range in order to address the issues of the existing fiber F-P demodulation system's sluggish demodulation rate and limited range.In order to investigate the demodulation properties of the dual-Fizeau-interferometer-based demodulation system,we derive and create a theoretical model of the system.The theoretical model,which primarily consists of the structural design of the interferometer and the study of the center wavelength of the light sources and their bandwidth selection,is used to construct the optical structure of the demodulation system.According to the calculation results,the demodulated signal exhibits the best contrast ratio when the two light sources'respective center wavelengths are 780nm and 850nm,and their bandwidths are 28nm and 30 nm.Finally,we finish evaluating the demodulation system's demodulation performance,parameter calibration,and assembly debugging.The test results demonstrate the constant operation of the demodulation system,an update rate of 100kHz,a demodulation range of 4.74μm,and a cavity length resolution of approximately 5 nm.Additionally,the system can perform high speed demodulation thanks to the light emitting diode's(LED's)nanosecond level switching speed and the usage of a single point detector.展开更多
文摘A terahertz-wave generator based on optical parametric oscillator principle, detection based on combination of Fizeau wedged interferometer and an electro-optical crystal ZnTe has been studied. The analytical solution based on the basic principle of operation of solid wedge Fizeau interferometer has been realized. The mathematical calculations for THz frequency and intensity measurement dependent on wedge angle and fringe spacing have been considered. The efficiency of THz wave detection depends upon optimized wedge angle has been also realized. The feasibility of detection of THz waves＇ frequency and intensity by solid Fizeau interferometer （THz-waves＇ range of 1 - 3 THz） has been studied. By optimization of other parameters like thickness of Fizeau film, refractive index, material of Fizeau film, we can proceed towards the design of Fizeau interferometer for required research plans as it is a simple and inexpensive interferometer.
文摘The interferogram of multiple-beam Fizeau fringe technique plays an important role to investigate the optical properties of fiber because this interferogram provides us with useful information which can used to determine the dispersion curve of the fiber sample. A common problem in any interferogram analysis is the accuracy in locating fringe centers (fringe skeleton). There are a lot of computer-aided algorithms, which depend on the interferogram types, used to fringe skeleton extraction of various digital interferogram. In this paper, as far as I know, a novel algorithm for fringe skeleton extraction of double bright fringe of multiple-beam Fizeau fringe is presented. The proposed algorithm based on using the different order of Fourier transform and the derivative-sign binary image. Also the proposed algorithm has been successfully tested by using a computer simulation fringe and an experimental pattern. The results are compared with the original interferogram and shown a good agreement.
文摘In this study,we present a dual-Fizeau-interferometer-based high-speed and wide-range fiber-optic Fabry-Perot(F-P)demodulation system.We employ two Fizeau interferometers with air cavity thickness satisfying the quadrature requirement to increase the demodulation speed and broaden the demodulation range in order to address the issues of the existing fiber F-P demodulation system's sluggish demodulation rate and limited range.In order to investigate the demodulation properties of the dual-Fizeau-interferometer-based demodulation system,we derive and create a theoretical model of the system.The theoretical model,which primarily consists of the structural design of the interferometer and the study of the center wavelength of the light sources and their bandwidth selection,is used to construct the optical structure of the demodulation system.According to the calculation results,the demodulated signal exhibits the best contrast ratio when the two light sources'respective center wavelengths are 780nm and 850nm,and their bandwidths are 28nm and 30 nm.Finally,we finish evaluating the demodulation system's demodulation performance,parameter calibration,and assembly debugging.The test results demonstrate the constant operation of the demodulation system,an update rate of 100kHz,a demodulation range of 4.74μm,and a cavity length resolution of approximately 5 nm.Additionally,the system can perform high speed demodulation thanks to the light emitting diode's(LED's)nanosecond level switching speed and the usage of a single point detector.
