Phase retrieval and phase hologram synthesis
AssigneeCambridge Enterprise Limited
InventorsJamieson Christmas, William Alden Crossland
Life of this patent
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Abstract
A method of retrieving phase information from input intensity information, representative of a target image, in which a Fourier transform is performed on data and the result used in forming a phase estimate, the phase estimate being inverse Fourier transformed, thereby producing magnitude and phase replay, and wherein not only is the phase reply component but also data derived from the magnitude replay component, iteratively fed back.
Claims38
A method of retrieving phase information from input intensity information, representative of a target image, comprising iterating the following steps:
- establishing a first data set having plural elements, each element having phase information and amplitude information, the amplitude information being derived from the input intensity information;
- performing a Fourier transform on the first data set to produce a second data set having plural elements, each element having amplitude and phase information;
- quantising and storing phase information from the second data set in memory;
- forming a third data set having plural elements, each element having amplitude and phase information, the phase information being derived from the second data set;
- inverse Fourier transforming the third data set to produce a fourth data set having plural elements, each element having amplitude and phase information;
- modifying the fourth data set by input data to produce a fifth data set having plural elements, each element having amplitude and phase information;
- using the fifth data set as the first data set of a subsequent iteration;
- the method further comprising forming the difference between the amplitude information of the second data set and the target image, and setting the amplitude information of the third data set to be scaled to said difference.
A method of retrieving phase information from input intensity information, representative of a target image, comprising iterating the following steps:
- establishing a first data set having plural elements, each element having phase information and amplitude information, the amplitude information being derived from the input intensity information;
- performing a Fourier transform on the first data set to produce a second data set having plural elements, each element having amplitude and phase information;
- quantising and storing phase information from the second data set in memory;
- forming a third data set having plural elements, each element having amplitude and phase information, the phase information being derived from the second data set and inverse Fourier transforming the third data set to produce a fourth data set having plural elements, each element having amplitude and phase information;
- modifying the fourth data set by input data to produce a fifth data set having plural elements, each element having amplitude and phase information;
- using the fifth data set as the first data set of a subsequent iteration;
- and
- storing phase information of the fifth data set in memory for use in a succeeding iteration, wherein a phase information of the first data set for an nth iteration is a scaled form of the difference between the phase information of the fourth data set for the (n−1) and the (n−2) iterations.
Dependencies are inferred from the claim text.