Interferometric Measurement of Holographic Lenslets

A holographic optical element can either be characterized by the wave aberrations or by the point spread function or alternatively by the modulation transfer function. Here we propose the measurement of the wave aberrations with the help of a Twyman-Green interferometer adapted to the requirements for testing holographic optical elements. The evaluation of the interferograms is done with the phase-shifting technique. The resulting wave aberrations are expressed by Zernike coefficients. In addition to this evaluation, the point spread function and the modulation transfer function are calculated from the wave aberrations. The set-up, the evaluation method and also exemplary results of a tested holographic optical element are presented.