Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

Dynamic Wavefront Sensor by Radial Shearing Interferometry Using Geometric Phase Lenses

Hyo Mi Park1, Daewook Kim2, Charlotte E. Guthery2 and Ki-Nam Joo1,a

1Dept. of Photonic Engineering, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju, 61452, South Korea

2Wyant College of Optical Sciences, University of Arizona, 1630 E. University Blvd, Tucson, Arizona 85721, USA


In this investigation, we propose a compact wavefront sensor, which consists of a geometric phase lens (GPL) pair to generate two radially-sheared wavefronts and a polarization pixelated camera (PCMOS) to simultaneously obtain four phase-shifted interferograms from a single image. An arbitrary wavefront is incident to the GPL pair, and two radially-sheared wavefronts are generated, and they are combined by the polarization array inside of the PCMOS, which can generate four phase-shifted interferograms at once. By using the spatial phase shifting technique, the phase map is simply calculated from the interferograms, and finally the original wavefront can be obtained by the wavefront reconstruction algorithm. Furthermore, the radial shearing ratio can be easily adjusted by changing the distance between two GPLs. In the experiments, the wavefront corresponding to the specific surface shape of a deformable mirror was measured, and the measurement result was compared with the counterpart of a commercial Shack-Hartmann wavefront sensor to verify the performance of the proposed sensor. As the result, the reconstructed wavefronts was the same as those of the Shack-Hartmann wavefront sensor, and even it was confirmed that the proposed sensor can reconstruct a wavefront with the higher resolution than the typical Shack-Hartmann wavefront sensor.

Keywords: Wavefront sensor, Radial shearing interferometer, Geometric phase lens

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