Experimental study of an off-axis three mirror anastigmatic system with wavefront coding technology.

Wavefront coding (WFC) is a kind of computational imaging technique that controls defocus and defocus related aberrations of optical systems by introducing a specially designed phase distribution to the pupil function. This technology has been applied in many imaging systems to improve performance and/or reduce cost. The application of WFC technology in an off-axis three mirror anastigmatic (TMA) system has been proposed, and the design and optimization of optics, the restoration of degraded images, and the manufacturing of wavefront coded elements have been researched in our previous work. In this paper, we describe the alignment, the imaging experiment, and the image restoration of the off-axis TMA system with WFC technology. The ideal wavefront map is set to be the system error of the interferometer to simplify the assembly, and the coefficients of certain Zernike polynomials are monitored to verify the result in the alignment process. A pinhole of 20 μm diameter and the third plate of WT1005-62 resolution patterns are selected as the targets in the imaging experiment. The comparison of the tail lengths of point spread functions is represented to show the invariance of the image quality in the extended depth of focus. The structure similarity is applied to estimate the relationship among the captured images with varying defocus. We conclude that the experiment results agree with the earlier theoretical analysis.

[1]  E R Dowski,et al.  Realizations of focus invariance in optical-digital systems with wave-front coding. , 1997, Applied optics.

[2]  Dorian Kermisch.  A deterministic analysis of the maximum entropy image restoration method and of some related methods , 1977 .

[3]  Robert H. Cormack,et al.  Wavefront coding: jointly optimized optical and digital imaging systems , 2000, SPIE Defense + Commercial Sensing.

[4]  B. Roy Frieden.  Maximum-information data processing: application to optical signals , 1981 .

[5]  Sergio Vazquez-Montiel,et al.  Wavefront coding technology in the optical design of astronomical instruments , 2004, Iberoamerican Meeting of Optics and the Latin American Meeting of Optics, Lasers and Their Applications.

[6]  Pantazis Mouroulis.  Depth of field extension with spherical optics. , 2008, Optics express.

[7]  Feng Yan,et al.  The effect on tolerance distributing of an off-axis three mirror anastigmatic optical system with wavefront coding technology , 2008, Optical Engineering + Applications.

[8]  No-Cheol Park,et al.  Breaking diffraction limit of a small f-number compact camera using wavefront coding. , 2008, Optics express.

[9]  Mark A Neifeld,et al.  Relaxing the alignment and fabrication tolerances of thin annular folded imaging systems using wavefront coding. , 2007, Applied optics.

[10]  Ramkumar Narayanswamy,et al.  Applications of wavefront coded imaging , 2004, IS&T/SPIE Electronic Imaging.

[11]  V. P. Pauca,et al.  Extended depth-of-field iris recognition system for a workstation environment , 2005, SPIE Defense + Commercial Sensing.

[12]  Andrew R. Harvey,et al.  Wavefront coding for aberration compensation in thermal imaging systems , 2001, Optics + Photonics.

[13]  Feng Yan,et al.  Image restoration of an off-axis three-mirror anastigmatic optical system with wavefront coding technology , 2008 .

[14]  Eero P. Simoncelli,et al.  Image quality assessment: from error visibility to structural similarity , 2004, IEEE Transactions on Image Processing.

[15]  Nicholas George,et al.  Smart camera with extended depth of field , 2005, International Commission for Optics.

[16]  Robert Brown,et al.  Design and optimization of aberration and error invariant space telescope systems , 2004, SPIE Optics + Photonics.

[17]  Xuejun Zhang,et al.  Manufacturing and testing of a cubic SiC surface , 2009 .

[18]  Giuseppe A. Cirino,et al.  Design of cubic-phase distribution lenses for passive infrared motion sensors , 2003, SPIE Defense + Commercial Sensing.

[19]  Feng Yan,et al.  Optimization of an off-axis three-mirror anastigmatic system with wavefront coding technology based on MTF invariance. , 2009, Optics express.

[20]  W. Cathey,et al.  Extended depth of field through wave-front coding. , 1995, Applied optics.