Device for optical heterodyne detection and mirror system suitable for use in such a device
US5237442A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1992 |
| Grant date | Aug 17, 1993 |
| Priority date | — |
| Expiry date | May 11, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/64
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In an optical heterodyne or homodyne receiver an optical system (140) is used in which the local oscillator beam (L) is combined with the signal beam (S). Simultaneously, these beams are split into orthogonally polarized sub-beams. For this purpose the optical system (140) comprises polarization-sensitive beam-splitting layers (141a and 141b) and neutral beam-splitting layers (142a and 142b) which function as beam-combining elements. In order to align the directions of the exit sub-beams of the signal beam (.sub.11, S.sub.12, S.sub.2, S.sub.22) and the local oscillator beam (L.sub.11, L.sub.12, L.sub.21, L.sub.22), the angles (.alpha., .beta., .gamma., .delta.) enclosed by the beam-splitting faces are chosen to be such that two angles located opposite each other have a combined magnitude of 180.degree.. This is realised by providing the layers (141a, 142b and 141b, 142a) on side faces of one prism (140a, 140b).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.