System and method for providing an eye safe laser communication system
US6594043B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1999 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Dec 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/40
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A system and method for producing an eye safe laser communication system. The system and method detects an interfering object in the optical path and cuts off or reduces the power in the communication beam to safe levels. In one embodiment, a second laser diode transmitter and receiver is installed in each network node. The laser transmitter is pointed at a corresponding network node and the pulses travel in parallel with the communication beam. The pulses are reflected back to the transmitting node where they are detected. Their flight time is measured. When an interfering object is present, in one scenario, the pulses bounce of the interfering object and return to the receiver in the transmitting node, resulting in a reduced flight time. This reduced flight time is interpreted as an interfering object and the beam is shut down or reduced to a safe level. In a second scenario, the interfering object absorbs the detection beam. In another embodiment, a CCD camera is used to capture a reflection from an object in the path of the communication link. In this embodiment the CCD has an overlapping field of view with the communication transceiver's transmit laser. The laser's transmissio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.