title: High-diffractive-efficiency defocus grating for wavefront curvature sensing.
abstract: The optimum phase defocus grating for wavefront curvature sensing is proposed. It features an equidistantly quantized, binary-phase-step defocus grating with a phase-step height of pi. The diffractive efficiency of the phase defocus grating is theoretically computed. The optical transfer function is obtained. The optimum phase defocus grating is fabricated. The high diffractive efficiencies of the +/-1 diffraction orders are verified experimentally, the average values of which are 38.08% and 40.36%, respectively.
authors.affiliation: College of Photon-Electron Science and Engineering, National University of Defense Technology, Changsha, China 410073. xifengjie@163.com
authors.forename: Xi
authors.initials: X
authors.lastname: Fengjie
authors.forename: Jiang
authors.initials: J
authors.lastname: Zongfu
authors.forename: Xu
authors.initials: X
authors.lastname: Xiaojun
authors.forename: Geng
authors.initials: G
authors.lastname: Yifeng