55 dB CNR over 50 km of fibre in an 80-channel externally-modulated AM-CATV system without optical amplification

Author

Piehler, D. ; Zou, X. ; Kuo, C.Y. ; Nilsson, A. ; Kleefeld, J. ; Garcia, G. ; Ralston, J.D. ; Mathur, A.

Author_Institution

Harmonic Lightwaves, Sunnyvale, CA, USA

Volume

33

Issue

3

fYear

1997

fDate

1/30/1997 12:00:00 AM

Firstpage

226

Lastpage

227

Abstract

The authors demonstrate supertrunking quality performance in an externally modulated 1550 nm AM-CATV system over a 50 km fibre link for the first time without the use of optical amplification. This performance has been enabled by a high-power 1550 nm DFB laser module (17 dBm fibre-coupled output) and differential detection. High power (9.5 dBm), low noise signals from the complementary outputs of an LiNbO ₃ intensity modulator were launched into two parallel fibres. After 50 km, RF subcarriers from two receivers recombined in phase increasing the carrier to noise ratio by 3 dB. The above configuration has allowed 80 NTSC channels to be transmitted with CNR>55 dB, CSO, CTB<-65 dBc

Keywords

amplitude modulation; cable television; community antenna television; demodulation; distributed feedback lasers; optical cables; optical fibre networks; optical modulation; semiconductor lasers; 1550 nm; 50 km; DFB laser module; LiNbO₃; NTSC channels; RF subcarriers; carrier to noise ratio; complementary outputs; differential detection; externally-modulated AM-CATV system; fibre-coupled output; intensity modulator; low noise signals; optical fibre link; parallel fibres; supertrunking quality performance;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:19970153

Filename

575944