Spatial and spectral wavefront analysis and measurement

• US 7,542,144 B2
• Filed: 11/30/2007
• Issued: 06/02/2009
• Est. Priority Date: 04/12/2000
• Status: Expired due to Fees

• Current Assignee: ICOS Vision Systems Incorporated (Eli Lilly and Company)
• Original Assignee: ICOS Vision Systems Incorporated (Eli Lilly and Company)
• Inventors: Wolfling, Shay, Arieli, Yoel, Shekel, Eval
• Primary Examiner(s): Lee; Hwa (Andrew) S
• Application Number:
  US11/998,564
• Publication Number:
  US 20080088851A1
• Time in Patent Office: 550 Days
• Field of Search: 356/512, 356/515, 356/503
• US Class Current: 356/450
• 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: G01N 21/9506 Optical discs
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 7/14 specially adapted to record on, or to reproduce from, more than one track simultaneously

Abstract

A method and apparatus for wavefront analysis including obtaining a plurality of differently phase changed transformed wavefronts corresponding to a wavefront being analyzed which has an amplitude and a phase, obtaining a plurality of intensity maps of the plurality of phase changed transformed wavefronts and employing the plurality of intensity maps to obtain an output indicating the amplitude and phase of the wavefront being analyzed.

Claims

1. A method of inspecting geometrical variations and thickness of an object comprising:

obtaining a 3-dimensional imaging wavefront, which has an amplitude and a phase, by reflecting radiation from an object to be viewed, wherein said radiation reflected from said object has a plurality of wavelength components, thereby obtaining multiple indications of the phase and amplitude of the 3-dimensional imaging wavefront, wherein each such indication corresponds to a different wavelength component, and each such indication is proportional to either geometrical variations in the object or thickness of the object;

and analyzing the 3-dimensional imaging wavefront by;

transforming the 3-dimensional imaging wavefront including a plurality of different wavelength components, thereby obtaining a transformed wavefront including a plurality of different wavelength components and applying phase changes to the plurality of different wavelength components of the transformed wavefront, thereby obtaining a plurality of differently phase changed transformed wavefronts corresponding to the 3-dimensional imaging wavefront, obtaining a plurality of intensity maps of the plurality of differently phase changed transformed wavefronts, and employing the plurality of intensity maps to obtain an output indicating the amplitude and phase of the 3-dimensional imaging wavefront.

2. An apparatus for inspecting geometrical variations and thickness of an object comprising:

a wavefront obtainer operating to obtain a 3-dimensional imaging wavefront, which has an amplitude and a phase, by reflecting radiation from an object to be viewed, wherein said radiation reflected from said object has a plurality of wavelength components, thereby obtaining multiple indications of the phase and amplitude of the 3-dimensional imaging wavefront, wherein each such indication corresponds to a different wavelength component, and each such indication is proportional to either geometrical variations in the object or thickness of the object;

a wavefront analyzer analyzing the 3-dimensional imaging wavefront and comprising;

a wavefront transformer operative to transform the 3-dimensional imaging wavefront including a plurality of different wavelength components, thereby obtaining a transformed wavefront including a plurality of different wavelength components and applying phase changes to the plurality of different wavelength components of the transformed wavefront, thereby obtaining a plurality of differently phase changed transformed wavefronts corresponding to the 3-dimensional imaging wavefront;

an intensity map generator operative to obtain a plurality of intensity maps of the plurality of differently phase changed transformed wavefronts, and an intensity map utilizer, employing the plurality of intensity maps to obtain an output indicating the amplitude and phase of the 3-dimensional imaging wavefront.