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101.
WANG Baoguang ZHU Mengzhou 《Chinese Journal of Lasers》1997,6(4):366-371
ANewDevelopmentofaSingleModeLaserInterferometerWANGBaoguangZHUMengzhou(DepartmentofPrecisionInstrumentEngineering,TianjinUniv... 相似文献
102.
Plane-parallel biaxial plates as polarization interferometers. Knowing the refractive indices and the directions of the rays inside a birefringent crystal, it is possible to calculate the positions of the images formed, when a non-parallel light beam incides on it.We part from general expressions for images in plane-parallel plates of any type of medium and we use vectorial expressions for the incident and refractive rays and waves in both interfaces.From them, we obtained the interference patterns which are observed when the plate is placed between two crossed polarizers. This experimental device constitutes a polarization interferometer. In order to find the shape of the interference patterns, we superposed the wave's fronts emerging from the images determining, in this way, the phase difference curves of phase constant on a screen. 相似文献
103.
We propose a sinusoidal wavelength-scanning interferometer for measuring thickness and surface profile of a thin film. The interference signal contains phase modulation amplitude Z and phase $aL which are related to the positions and profiles of the reflecting surfaces, respectively. By reducing the difference between the detected signal and the estimated signal using the multidimensional nonlinear least-squares algorithm, we estimate values of Z and $aL. Experimental results show that the front and rear surfaces of a silica glass plate of 20 $mUm-thickness could be measured with an error less than 10 nm. 相似文献
104.
A configuration of reversal shear interferometer suitable for measurement of spatial coherence of high average power, large cross-section laser beam has been discussed. Ghost-less beam splitters in which unwanted multiple reflections from the surfaces have been suppressed by total internal reflection are used for beam splitting and re-combination. Advantages and drawbacks of this configuration have been discussed. 相似文献
105.
A novel precision wavemeter is presented with a resolution of better than 0·01 nm. A Sagnac interferometer with two diffraction gratings forms the basis of the instrument. Using spatial heterodyning techniques and a CCD camera/frame grabber data acquisition system allows fast computer control and power spectrum analysis. The mode structure and mode hopping characteristics of a typical laser diode were examined as a function of diode injection current. 相似文献
106.
We propose a photothermal phase-modulating laser diode interferometer equipped with a high-speed feedback control system. The CCD camera’s shutter-function raises the modulating frequency, which in turn elicits a higher feedback response, thus enabling us to eliminate nearly all external disturbance. With the recent application of a system purpose-built for discriminating between numerous fringe sequences, we have also reduced processing time. 相似文献
107.
An all-optical regeneration scheme for DQPSK and QPSK signals using phase-sensitive amplifiers (PSAs) is studied and its effectiveness is investigated through numerical simulations. By leveraging the ability of PSAs to provide phase and amplitude regenerative amplification, we show significant simultaneous suppression of both phase and amplitude noises of (D)QPSK signals under optimized conditions. The reduction in the phase noise variance of a noise-corrupted DQPSK signal obtained by one such regenerative amplification can be as large as ∼5.5 folds, showing its good potential for distributed optical regeneration of (D)QPSK signals. 相似文献
108.
109.
本文分析了右旋偏振波穿透高密度等离子体的条件,给出了理论根据及原理性实验的结果。实验证实,当ω_(ce)≈2ω时,右旋偏振波(哨波模)可以穿透很高密度的等离子体(ω_(pe)~2>>ω~2),并可能成为克服“再入”时“黑障”的一个途径。 相似文献
110.
A new method is proposed for reconstructing wavefront from discretely sampled interferogram data obtained by a digital lateral shearing interferometer. Assumptions applied in the conventional methods are not used and reconstruction error caused by the difference between the amount of shear and the sampling interval can be removed. System error and the influence of the discrete sampling, which limit accuracy of the tested results of the lateral shearing interferometer, are analyzed. 相似文献