载频调制大剪切电子散斑干涉系统

大剪切电子散斑干涉技术不需要引入参考光，具有条纹质量好等特点。提出将干涉场的载频调制技术引入到大剪切电子散斑干涉中，可形成具有载频调制功能的新的电子散斑干涉系统。该系统具有对测量环境的隔振振动要求低，能方便定量求解物体的变形场等优点。首先讨论大剪切载频的调制机理，然后利用中心加载、周边固定的圆盘进行典型实验，设计了可用计算机控制且可对参考物进行精确偏转的步进电机系统，进而实现了对电子散斑干涉场的自动控制调制。最后，利用傅里叶变换法对调制条纹进行解调，解调出变形场的相位，并通过相位与位移的转换计算，得到精确的物体变形场。实验结果证明，该系统能够调制电子散斑干涉场，求解物体的位移场。

Large-shearing electronic speckle pattern interference system with carrier-frequency modulation technique

Large-shearing electronic speckle pattern interferometry(LSESPI) offers many advantages such as good fringe quality and no reference beam needed.The fringe pattern obtained by the LSESPI is easy to be observed.The new electronic speckle pattern interferometer is formed by introducing carrier-frequency modulation for interference fields to LSESPI.The new system does not have strict requirement for environment on isolating vibration.The displacement fields could be quantitatively measured with the system.The principle of carrier-frequency modulation of LSESPI is discussed.A typical experiment is implemented with a central-loaded and peripheral-clamped plate.And a step motor system controlled by a computer is designed.With the step motor system the reference object can be rotated accurately so that the electronic speckle pattern can be modulated automatically.At last,Fourier transform is used to demodulate the modulated fringes and obtain the phase of deformed field,then acquire the precision deformation of the object by the transformation calculation of the phase and displacement.The experimental results indicate that the interference field of the speckle pattern can be modulated and the displacement of the object can be measured accurately by this system.