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
Tilted Wave Interferometry(TWI)is a measurement technique for fast and flexible interferometric testing of aspheres and freeform surfaces.The first version of the tilted wave principle was implemented in a Twyman-Gree...Tilted Wave Interferometry(TWI)is a measurement technique for fast and flexible interferometric testing of aspheres and freeform surfaces.The first version of the tilted wave principle was implemented in a Twyman-Green type setup with separate reference arm,which is intrinsically susceptible to environmentally induced phase disturbances.In this contribution we present the TWI in a new robust common-path(Fizeau)configuration.The implementation of the Tilted Wave Fizeau Interferometer requires a new approach in illumination,calibration and evaluation.Measurements of two aspheres and a freeform surface show the flexibility and also the increased stability in both phase raw data and surface measurements,which leads to a reduced repeatability up to a factor of three.The novel configuration significantly relaxes the tolerances of the imaging optics used in the interferometer.We demonstrate this using simulations on calibration measurements,where we see an improvement of one order of magnitude compared to the classical Twyman-Green TWI approach and the capability to compensate higher order error contributions on the used optics.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Tilted Wave Interferometry(TWI)is a measurement technique for fast and flexible interferometric testing of aspheres and freeform surfaces.The first version of the tilted wave principle was implemented in a Twyman-Green type setup with separate reference arm,which is intrinsically susceptible to environmentally induced phase disturbances.In this contribution we present the TWI in a new robust common-path(Fizeau)configuration.The implementation of the Tilted Wave Fizeau Interferometer requires a new approach in illumination,calibration and evaluation.Measurements of two aspheres and a freeform surface show the flexibility and also the increased stability in both phase raw data and surface measurements,which leads to a reduced repeatability up to a factor of three.The novel configuration significantly relaxes the tolerances of the imaging optics used in the interferometer.We demonstrate this using simulations on calibration measurements,where we see an improvement of one order of magnitude compared to the classical Twyman-Green TWI approach and the capability to compensate higher order error contributions on the used optics.
