Some content of this application is unavailable at the moment.
If this situation persists, please contact us atFeedback&Contact
1. (WO1991018455) A MULTILEVEL COHERENT OPTICAL SYSTEM
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1991/018455 International Application No.: PCT/IT1991/000036
Publication Date: 28.11.1991 International Filing Date: 06.05.1991
Chapter 2 Demand Filed: 03.12.1991
IPC:
H04B 10/532 (2013.01) ,H04B 10/61 (2013.01) ,H04L 27/32 (2006.01)
H ELECTRICITY
04
ELECTRIC COMMUNICATION TECHNIQUE
B
TRANSMISSION
10
Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
50
Transmitters
516
Details of coding or modulation
532
Polarisation modulation
H ELECTRICITY
04
ELECTRIC COMMUNICATION TECHNIQUE
B
TRANSMISSION
10
Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
60
Receivers
61
Coherent receivers
H ELECTRICITY
04
ELECTRIC COMMUNICATION TECHNIQUE
L
TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
27
Modulated-carrier systems
32
Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18, or H04L27/26213
Applicants:
FONDAZIONE UGO BORDONI [IT/IT]; Via Baldassarre Castiglione, 59 I-00142 Roma, IT (AllExceptUS)
BETTI, Silvello [IT/IT]; IT (UsOnly)
CURTI, Franco [IT/IT]; IT (UsOnly)
DE MARCHIS, Giancarlo [IT/IT]; IT (UsOnly)
IANNONE, Eugenio [IT/IT]; IT (UsOnly)
Inventors:
BETTI, Silvello; IT
CURTI, Franco; IT
DE MARCHIS, Giancarlo; IT
IANNONE, Eugenio; IT
Agent:
DOMENIGHETTI FIAMMENGHI, Delfina ; Fiammenghi Fiammenghi Via Quattro Fontane, 31 I-00184 Roma, IT
Priority Data:
47949/A/9011.05.1990IT
Title (EN) A MULTILEVEL COHERENT OPTICAL SYSTEM
(FR) SYSTEME OPTIQUE COHERENT MULTINIVEAU
Abstract:
(EN) A multilevel coherent optical system is disclosed in which a multilevel signal with a coherent optical carrier is provided by means of a modulation of the phase and the polarization of the electromagnetic field propagating through a single-mode optical fibre, a heterodyne transmitter and receiver for said signal being also disclosed. The transmitter comprises a coherent light source (1) providing the optical carrier, a phase modulator (2) modulating the phase of the carrier, a polarization modulator (3-8), and a modulation signal generator (10) providing control signals to the phase modulator (2) and the polarization modulator. The receiver comprises a first stage (12-23) carrying out the heterodyne detection of the phase component and the phase quadrature component of the polarization of the signal received through an optical fibre (11), a second stage demodulating the received signal to provide the multilevel signal, and a processing circuit comparing the received multilevel signal with predetermined reference signals. Such a system exploits the four degrees of freedom of the electromagnetic field propagating through the optical fibre so as to approach closer to the theoretical Shannon limit than conventional systems.
(FR) L'invention se rapporte à un système optique cohérent multiniveau dans lequel un signal multiniveau possédant un support optique cohérent est fourni par modulation de la phase et polarisation du champ électromagnétique se propageant à travers une fibre optique monomode, ainsi qu'à un émetteur et un récepteur hétérodyne pour ledit signal. L'émetteur comprend une source lumineuse cohérente (1) formant le support optique, un modulateur de phase (2) modulant la phase du support, un modulateur de polarisation (3-8) et un générateur de signaux de modulation (10) transmettant des signaux de commande au modulateur de phase (20) et au modulateur de polarisation. Le récepteur comprend un premier étage (12-23) effectuant la détection hétérodyne du composant de phase et du composant de quadrature de phase de la polarisation du signal reçu par l'intermédiaire d'une fibre optique (11), un deuxième étage démodulant le signal reçu pour produire le signal multiniveau et un circuit de traitement comparant le signal multiniveau reçu à des signaux de référence prédéterminés. Ce système exploite les quatre degrés de liberté du champ électromagnétique qui se propage à travers la fibre optique ce qui permet d'approcher de plus près la limite Shannon théorique, si l'on compare avec les systèmes conventionnels.
Designated States: AU, BB, BG, BR, CA, FI, HU, JP, KP, KR, LK, MC, MG, MW, NO, PL, RO, SD, SU, US
European Patent Office (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, NL, SE)
African Intellectual Property Organization (BF, BJ, CF, CG, CI, CM, GA, ML, MR, SN, TD, TG)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
EP0527966US5416628AU1991077598