Arrangement for determining the position of a modulated laser beam in a scattering medium
US4847481A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 28, 1987 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Dec 28, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF41G7/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An arrangement for position finding of a laser beam in a scattering medium with a laser transmitter and a laser receiver followed by an evaluation circuit. In order to be able to differentiate in the incoming laser radiation the unscattered coherent content and the scattered content, the laser transmitter is connected to a modulation circuit for intensity modulation of the transmitted laser beam with a characteristic modulation frequency (f.sub.L >1/T.sub.s) with the pulse duration spread being T.sub.s, which a brief laser pulse experiences upon being scattered in the medium. In addition, the receiver is connected to an electronic frequency filter tuned to the characteristic modulation frequency. Thereby, essentially only the unscattered coherent content of the laser beam is utilized for evaluation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.