Optical demultiplexer for optical/RF signals
US5450223A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 1993 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Sep 7, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2011/0035
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An optical demultiplexer includes an electrooptic modulator (410) which modulates a beam of light (418) in response to frequency-multiplexed radio-frequency (RF) information signals, to produce diverging beamlets of light (420). The diverging beamlets are separated by a spatial separator arrangement (426), and each beamlet (420), including the information of its RF carrier, is coupled to a separate optical detector (428). The detector (428) can extract amplitude modulation from the signal. In order to reconstruct the RF signal as well as the amplitude modulator, an optical "local oscillator" signal (OLO) is coupled to each detector together with its information signal. Signal loss due to vibration or misalignment is avoided, and heterodyne mixing efficiency is maximized in an embodiment of the invention, by propagating the OLO and information signals through a single-mode optical fiber to the detector. In a particular embodiment of the invention, the OLO signal is applied to a first fiber (622), the information signal is applied to a second fiber (610), and the first and second fibers are coupled together by a fiber-optic coupler (612). In another embodiment of the invention, the O…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.