Abstract:
A retro-focus Michelson type shearing speckle interferometry imaging system was proposed to extend the field of view (FOV) for a speckle shearing interferometer. The retro-focus imaging system includes negative lens group and television lens. Analysis of the optical setup was taken out and the simulation was demonstrated by ZEMAX software. The phase shifting unit was a plane mirror attached with a piezo, the non-uniform phase difference caused by the tilted mirror was discussed. The equal-step Carre algorithm was used to calculate the phase map so that the non-uniform phase error was avoided. The experiment results of center loaded metal plane show this method can achieve large FOV detection system. A 70°FOV imaging system can be implemented by using three plano-concave lenses with -75mm focus length and the FOV can be adjusted by changing the focus length and number of lenses.