WAVEFRONT ABERRATION AND DISTANCE MEASUREMENT PHASE CAMERA

• US 20100091146A1
• Filed: 01/18/2007
• Published: 04/15/2010
• Est. Priority Date: 01/20/2006
• Status: Abandoned Application

• Current Assignee: Universidad de La Laguna
• Original Assignee: Universidad de La Laguna
• Inventors: Rosa González, Fernando, Rodriguez Ramos, José Manuel, Marichal-Hernández, José Gil
• Application Number:
  US12/161,362
• Publication Number:
  US 20100091146A1
• Time in Patent Office: Days
• US Class Current: 348/262
• CPC Class Codes: G01J 2009/0238 the pattern being processed optically, e.g. by Fourier transformation
• CPC Class Codes: G01J 9/00 Measuring optical phase difference devices or arrangements for controlling the phase of light beams G02F1/01; Determining degree of coherence; Measuring optical wavelength spectrometry G01J3/00
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00

Abstract

A system consisting of a phase camera with microlenses placed in the focal point of a converging lens, wherein the camera data, processed using a combined Fourier “Slice” and fast Fourier transform edge detection technique, provide both a three-dimensional wavefront map and a real scene depth map within a broad range of volumes. The invention is suitable for use in any field where wavefronts need to be known such as earth-based astronomical observation, ophthalmology, etc., as well as in fields requiring metrology, e.g. real scenes, CCD polishing, automobile mechanics, etc. The invention is applied to the particular case of atmospheric tomography using ELTs (large-diameter telescopes: 50 or 100 meters).

Claims

1-17. -17. (canceled)

18. A phase camera for obtaining in real time the three-dimensional map of a wavefront and the depth map of a three-dimensional space, comprising

a converging lens,

an array of microlenses placed in the focal point of the converging lens,

a CCD device, and

real time processing means adapted to obtain the focal stack of the three-dimensional space by applying a Fourier Slice algorithm, and

identify the components for each depth of the focal stack of such three-dimensional space by means of a fast Fourier transform edge detection algorithm.

19. The phase camera for obtaining in real time the three-dimensional map of a wavefront and the depth map of a three-dimensional space according to claim 18, characterized in that the processing means comprise a GPU unit.

20. The phase camera for obtaining in real time the three-dimensional map of a wavefront and the depth map of a three-dimensional space according to claim 18, characterized in that the processing means comprise an FPGA device.

21. A process for obtaining in real time the three-dimensional map of a wavefront and the depth map of a three-dimensional space, comprising the following steps:

obtaining an image of the three-dimensional space with a phase camera;

obtaining the focal stack of the three-dimensional space by applying a Fourier Slice algorithm; and

identifying the components for each depth of the focal stack of such three-dimensional space by means of a fast Fourier transform edge detection algorithm.

22. A process for obtaining in real time the three-dimensional map of a wavefront and the depth map of a three-dimensional space according to claim 21, wherein the three-dimensional map of a wavefront and the depth map of a three-dimensional space is applied to an observation selected from the group of an astronomical observation, an ophthalmological observation, a real scene observation, an observation of a surface of a CCD and an observation of a surface of a mechanical part.