| 摘要 |
An arrangement for testing a reflecting surface of a solid body, especially a relatively complex reflecting surface such as that of a grazing hyperboloid, for deviations of its actual shape from its ideal shape includes a laser source and a positive cylindrical lens interposed between the laser source and the reflecting surface to be tested. The lens optically modifies the laser beam in such a manner as to propagate between the lens and the reflecting surface substantially normal to the reflecting surface and to be reflected from the latter for propagation back to and through the lens toward the laser source as a return laser beam having a wave front indicative of the actual shape of the reflecting surface and any aberrations of the lens. The arrangement further includes an interferometer that forms an interference pattern between the original and return laser beams, and a circuitry for evaluating the interference pattern. The evaluating circuitry subtracts first and second reference signals respectively representative of the ideal shape of the reflecting surface and of the influence of the lens aberrations on the interference pattern from an initial signal representative of the sensed interference pattern.
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