The Experts below are selected from a list of 18720 Experts worldwide ranked by ideXlab platform

S. A. Pereselkov - One of the best experts on this subject based on the ideXlab platform.

Pablo Artal - One of the best experts on this subject based on the ideXlab platform.

  • Interferometric Method for phase calibration in liquid crystal spatial light modulators using a self-generated diffraction-grating
    Optics Express, 2016
    Co-Authors: José Luis Martínez Fuentes, Enrique J. Fernández, Pedro M. Prieto, Pablo Artal
    Abstract:

    An auto-referenced Interferometric Method for calibrating phase modulation of parallel-aligned liquid crystal (PAL) spatial light modulators (SLM) is described. The Method is experimentally straightforward, robust, and requires solely of a collimated beam, with no need of additional optics. This Method uses the SLM itself to create a tilted plane wave and a reference wave which mutually interfere. These waves are codified by means of a binary diffraction grating and a uniformly distributed gray level area (piston) into the SLM surface. Phase shift for each gray level addressed to the piston section can then be evaluated. Phase modulation on the SLM can also be retrieved with the proposed Method over spatially resolved portions of the surface. Phase information obtained with this novel Method is compared to other well established calibration procedures, requiring extra elements and more elaborated optical set-ups. The results show a good agreement with previous Methods. The advantages of the new Method include high mechanical stability, faster performance, and a significantly easier practical implementation.

G. N. Kuznetsov - One of the best experts on this subject based on the ideXlab platform.

Qiang Chen - One of the best experts on this subject based on the ideXlab platform.

  • Testing large aspheric surfaces with complementary annular subaperture Interferometric Method
    Advanced Optical and Mechanical Technologies in Telescopes and Instrumentation, 2008
    Co-Authors: Xi Hou, Baiping Lei, Bin Fan, Qiang Chen
    Abstract:

    Annular subaperture Interferometric Method has provided an alternative solution to testing rotationally symmetric aspheric surfaces with low cost and flexibility. However, some new challenges, particularly in the motion and algorithm components, appear when applied to large aspheric surfaces with large departure in the practical engineering. Based on our previously reported annular subaperture reconstruction algorithm with Zernike annular polynomials and matrix Method, and the experimental results for an approximate 130-mm diameter and f/2 parabolic mirror, an experimental investigation by testing an approximate 302-mm diameter and f/1.7 parabolic mirror with the complementary annular subaperture Interferometric Method is presented. We have focused on full-aperture reconstruction accuracy, and discuss some error effects and limitations of testing larger aspheric surfaces with the annular subaperture Method. Some considerations about testing sector segment with complementary sector subapertures are provided.

  • experimental study on measurement of aspheric surface shape with complementary annular subaperture Interferometric Method
    Optics Express, 2007
    Co-Authors: Xi Hou, Li Yang, Qiang Chen
    Abstract:

    Based on our previously reported annular subaperture reconstruction algorithm with Zernike annular polynomials and matrix Method, we provide an experimental demonstration by testing a parabolic mirror with the complementary annular subaperture Interferometric Method. By comparing the results of annular subaperture Method with that of the classical auto-collimation Method, it is shown that the reconstruction results are in good agreement with the auto-collimation measurement. In addition, we discuss some limitations of characterizing annular subaperture measurement data with finite Zernike coefficients in our algorithm, and also show the possibility of characterizing higher spatial frequency information with adequate Zernike coefficients. It is believable that the reported Method can be extended to test the surface shape of some large concave aspheric mirrors with acceptable accuracy.

Sidney R Nagel - One of the best experts on this subject based on the ideXlab platform.