Apparatus for direct-to-digital spatially-heterodyned holography
US7148969B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2006 |
| Grant date | Dec 12, 2006 |
| Priority date | — |
| Expiry date | Feb 24, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2226/11
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus operable to record a spatially low-frequency heterodyne hologram including spatially heterodyne fringes for Fourier analysis includes: a laser; a beamsplitter optically coupled to the laser; an object optically coupled to the beamsplitter; a focusing lens optically coupled to both the beamsplitter and the object; a digital recorder optically coupled to the focusing lens; and a computer that performs a Fourier transform, applies a digital filter, and performs an inverse Fourier transform. A reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form a spatially low-frequency heterodyne hologram including spatially heterodyne fringes for Fourier analysis which is recorded by the digital recorder, and the computer transforms the recorded spatially low-frequency heterodyne hologram including spatially heterodyne fringes and shifts axes in Fourier space to sit on top of a heterodyne carrier frequency defined by an angle between the reference beam and the object beam and cuts off signals around an original origin before performing the inverse Fourier transform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.