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Title: Subcarrier multiplexing with dispersion reduction and direct detection

Abstract

An SCM system is disclosed 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. 2 figs.

Inventors:
; ;
Issue Date:
Research Org.:
University of California
OSTI Identifier:
426634
Patent Number(s):
5,596,436
Application Number:
PAN: 8-502,732
Assignee:
Univ. of California, Oakland, CA (United States)
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 21 Jan 1997
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; MULTIPLEXERS; OPTICAL FIBERS; DATA TRANSMISSION; DESIGN; MICROWAVE EQUIPMENT

Citation Formats

Sargis, P D, Haigh, R E, and McCammon, K G. Subcarrier multiplexing with dispersion reduction and direct detection. United States: N. p., 1997. Web.
Sargis, P D, Haigh, R E, & McCammon, K G. Subcarrier multiplexing with dispersion reduction and direct detection. United States.
Sargis, P D, Haigh, R E, and McCammon, K G. Tue . "Subcarrier multiplexing with dispersion reduction and direct detection". United States.
@article{osti_426634,
title = {Subcarrier multiplexing with dispersion reduction and direct detection},
author = {Sargis, P D and Haigh, R E and McCammon, K G},
abstractNote = {An SCM system is disclosed 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. 2 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1997},
month = {1}
}