Method and system to align holographic images
US5982513A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1998 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Feb 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H1/26
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and a system to re-align onto a detector array a holographic image of a Fourier region hologram stored in a medium, with the medium spinning around a first axis, and the hologram being generated by a reference beam and a signal beam. In generating the hologram, the reference beam is incident on the medium with respect to a second axis at a second-axis-incident angle, and a third axis at a third-axis-incident angle, such that the holographic image of the hologram when reproduced by the reference beam is aligned onto the detector array. Also, the three axes are substantially orthogonal to each other. As the medium spins, the medium's orientation can change through tilting with respect to the second and the third axes so that the holographic image when reproduced by the reference beam is not aligned onto the detector array. In one embodiment, the holographic image is re-aligned onto the detector array by tilting the reference beam such that when re-aligned, the incident angle of the reference beam on the medium with respect to the second axis is intentionally tilted to be different from the second-axis-incident angle, and with respect to the third axis to be different from th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.