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Title: Subcarrier multiplexing with dispersion reduction and direct detection

Abstract

An SCM system for simultaneously reducing the concomitant problems of receiver complexity and dispersion penalty and without requiring the use of an expensive, high-bandwidth optical detector. The system provides both a dispersion reduction and a direct detection to the receiver, with microwave mixers and lithium niobate external modulators that produce sidebands that are only separated by a few gigahertz from a principal laser optical carrier. Digital data streams are independently impressed upon these sidebands for transmission over an ordinary single-mode fiber. Independent high-speed data streams are upconverted to microwave frequencies. These subcarriers are then combined with a microwave power combiner and amplified with a microwave amplifier. A solid-state 1550-nm laser carrier is modulated by the microwave subcarriers. An erbium-doped fiber amplifier (EDFA) is used just prior to long-distance transmission over ordinary single-mode fiber. The transmitted optical signal may then traverse multiple EDFAs to compensate for long-haul optical fiber losses prior to detection. At a receiving end, the optical signal is split into multiple paths. The subcarrier channels are optically pre-selected using a narrowband optical filter, such as a fiber Fabry-Perot (FFP) filter. An optical detector converts the selected optical signal into a baseband electrical data stream.

Inventors:
 [1];  [2];  [3]
+ Show Inventor Affiliations
  1. Modesto, CA
  2. Tracy, CA
  3. Livermore, CA
Issue Date:
Research Org.:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
OSTI Identifier:
870797
Patent Number(s):
5596436
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
H - ELECTRICITY H04 - ELECTRIC COMMUNICATION TECHNIQUE H04J - MULTIPLEX COMMUNICATION
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DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
subcarrier; multiplexing; dispersion; reduction; direct; detection; scm; simultaneously; reducing; concomitant; receiver; complexity; penalty; requiring; expensive; high-bandwidth; optical; detector; provides; microwave; mixers; lithium; niobate; external; modulators; produce; sidebands; separated; gigahertz; principal; laser; carrier; digital; data; streams; independently; impressed; transmission; ordinary; single-mode; fiber; independent; high-speed; upconverted; frequencies; subcarriers; combined; power; combiner; amplified; amplifier; solid-state; 1550-nm; modulated; erbium-doped; edfa; prior; long-distance; transmitted; signal; traverse; multiple; edfas; compensate; long-haul; losses; receiving; split; paths; channels; optically; pre-selected; narrowband; filter; fabry-perot; ffp; converts; selected; baseband; electrical; stream; optical detector; microwave frequencies; direct detection; mode fiber; nm laser; lithium niobate; laser optical; digital data; optical filter; optical fiber; microwave power; optical signal; speed data; data stream; microwave amplifier; single-mode fiber; power combiner; transmitted optical; optical carrier; narrowband optical; wave frequencies; high-speed data; band optical; bandwidth optical; electrical data; /359/

Citation Formats

Sargis, Paul D, Haigh, Ronald E, and McCammon, Kent G. Subcarrier multiplexing with dispersion reduction and direct detection. United States: N. p., 1997. Web.
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Sargis, Paul D, Haigh, Ronald E, & McCammon, Kent G. Subcarrier multiplexing with dispersion reduction and direct detection. United States.
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Sargis, Paul D, Haigh, Ronald E, and McCammon, Kent G. Wed . "Subcarrier multiplexing with dispersion reduction and direct detection". United States. https://www.osti.gov/servlets/purl/870797.
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@article{osti_870797,
title = {Subcarrier multiplexing with dispersion reduction and direct detection},
author = {Sargis, Paul D and Haigh, Ronald E and McCammon, Kent G},
abstractNote = {An SCM system for simultaneously reducing the concomitant problems of receiver complexity and dispersion penalty and without requiring the use of an expensive, high-bandwidth optical detector. The system provides both a dispersion reduction and a direct detection to the receiver, with microwave mixers and lithium niobate external modulators that produce sidebands that are only separated by a few gigahertz from a principal laser optical carrier. Digital data streams are independently impressed upon these sidebands for transmission over an ordinary single-mode fiber. Independent high-speed data streams are upconverted to microwave frequencies. These subcarriers are then combined with a microwave power combiner and amplified with a microwave amplifier. A solid-state 1550-nm laser carrier is modulated by the microwave subcarriers. An erbium-doped fiber amplifier (EDFA) is used just prior to long-distance transmission over ordinary single-mode fiber. The transmitted optical signal may then traverse multiple EDFAs to compensate for long-haul optical fiber losses prior to detection. At a receiving end, the optical signal is split into multiple paths. The subcarrier channels are optically pre-selected using a narrowband optical filter, such as a fiber Fabry-Perot (FFP) filter. An optical detector converts the selected optical signal into a baseband electrical data stream.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1997},
month = {1}
}
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Works referenced in this record:

Optical prefiltering in subcarrier systems
conference, February 1993

Bandwidth efficient transmission of 4 Gb/s on two microwave QPSK subcarriers over a 48 km optical link
journal, July 1990

Fiber Optic Analog--Digital Hybrid Signal Transmission Employing Frequency Modulation
journal, May 1985

8 Gb/s subcarrier multiplexed coherent lightwave system
journal, August 1991

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