Lensless imaging with reduced aperture

• US 8,379,214 B2
• Filed: 03/02/2009
• Issued: 02/19/2013
• Est. Priority Date: 01/12/2005
• Status: Expired due to Fees

• Current Assignee: John Farah
• Original Assignee: John Farah
• Inventors: Farah, John
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): Cook, Jonathon
• Application Number:
  US12/380,586
• Publication Number:
  US 20090219541A1
• Time in Patent Office: 1,450 Days
• Field of Search: 356/450, 356/521
• US Class Current: 356/450
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01B 2290/10 Astronomic interferometers
• CPC Class Codes: G01B 9/02032 generating a spatial carrier frequency, e.g. by creating lateral or angular offset between reference and object beam shearing interferometers G01B9/02098
• CPC Class Codes: G01B 9/02041 characterised by particular imaging or detection techniques
• CPC Class Codes: G01B 9/02098 Shearing interferometers

Abstract

An image of an object can be synthesized either from the Fourier components of the electric field or from the Fourier components of the intensity distribution. Imaging with a lens is equivalent to assembling the Fourier components of the electric field in the image plane. This invention provides a method and a means for lensless imaging by assembling the Fourier components of the intensity distribution and combining them to form the image with the use of amplitude splitting interferometer. The angular spectrum of the electromagnetic radiation consists of wavefronts propagating at different angles. The amplitude of each wavefront is split and interfered with itself to create sinusoidal fringe patterns having different spatial frequencies. The sinusoidal fringe patterns are combined to form an image of the object. This method applies to coherent and incoherent light.

Claims

1. A method of imaging an object comprising:

Receiving electromagnetic radiation comprising wavefronts propagating at different angles,

Splitting the amplitudes of the wavefronts,

Interfering each wavefront with itself to create non-Fizeau fringes having different spatial frequencies,

Combining said non-Fizeau fringes to form an image of the object.

2. An interferometer for imaging an object comprising:

A means for splitting the amplitudes of incoming wavefronts propagating at different angles,

A means for interfering each wavefront with itself to create non-Fizeau fringes having different spatial frequencies,

A means for combining said non-Fizeau fringes to form an image of the object.