SIGNAL DISTORTION AND NOISE IN AM-SCM TRANSMISSION-SYSTEMS EMPLOYING THE FEEDFORWARD LINEARIZED MQW-EA EXTERNAL MODULATOR

被引：32

作者：

IWAI, T

SATO, K

SUTO, K

机构：

[1] NIPPON TELEGRAPH & TEL PUBL CORP, OPTOELECTR LABS, ATSUGI, KANAGAWA 24301, JAPAN

[2] NIPPON TELEGRAPH & TEL PUBL CORP, ELECT COMMUN LABS, YOKOSUKA, KANAGAWA 23803, JAPAN

来源：

JOURNAL OF LIGHTWAVE TECHNOLOGY | 1995年 / 13卷 / 08期

关键词：

D O I：

10.1109/50.405302

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

In subcarrier multiplexing (SCM) optical video distribution systems, the nonlinear signal distortion generated by the combined action of laser chirp and fiber dispersion limits the transmission distance. This paper for the first time shows that low-chirp MQW (multiquantum well)-EA (electroabsorption) external modulators are applicable to AM-SCM transmission systems. The feedforward linearization technique is used to compensate the signal distortion due to the nonlinearity in the modulator's L-V (light power versus voltage) characteristic. The effectiveness of this type of modulator for Suppressing dispersion-induced distortion is clarified experimentally. A feedforward linearized transmitter with composite second order (CSO) intermodulation distortion <-62 dBc, composite triple beat (CTB) intermodulation distortion <-59 dBc and a carrier-to-noise ratio (CNR) >50.5 dB is successfully constructed. It is shown that the transmitter can achieve a CSO <-59 dBc, a CTB <-57 dBc and a CNR >49.5 dB for a 42 channel AM signal and 10 km transmission. Furthermore, estimations of the signal distortion cancellation and the noise characteristic achieved with feedforward circuit modeling are shown. The results obtained here emphasize that MQW-EA external modulators are applicable to AM-SCM transmission systems.

引用

页码：1606 / 1612

页数：7

共 20 条

[1]

Olshansky R., Eichen E., Microwave-multiplexed wideband lightwave systems using optical amplifiers for subscriber distribution, Electron. Lett., 24, pp. 922-923, (1988)

[2]

Yoneda E., Suto K., Kikushima K., Yoshinaga H., Fully engineered multi-channel FM-SCM video distribution systems, J. Lightwave Technol., 12, pp. 362-368, (1994)

[3]

Sabido D.J. M., Tabara M., Fong T.K., Kazovsky L.G., Experimental investigation of the impact of EDFAs on coherent AM analog optical links, OFC'94, (1994)

[4]

Shigematsu M., Nakazato K., Okita T., Tagami Y., Nawata K., Field test of multichannel AM-VSB transmission using an erbium doped optical fiber amplifier at 1.55 μm wavelength range in the CATV network, OSA '90 Top. Meet. on Opt. Amplifiers and Their Applicat., (1990)

[5]

Childs R.B., O'Byrne V.A., Multichannel AM video transmission using a high-power Nd:YAG laser and linearized external modulator, IEEE J. Select. Areas Commun., 8, pp. 1369-1376, (1990)

[6]

Lang T., Bissinger J., CATV distribution in an FITL network, 3rd IEEE Workshop on Local Opt. Networks, (1991)

[7]

Nazarathy M., Berger J., Ley A.J., Levi I.M., Kagan Y., Progress in externally modulated AM CATV transmission systems, J. Lightwave Technol., 11, pp. 82-105, (1993)

[8]

Schmidt R.V., Cross P.S., Glass A.M., Optically induced crosstalk in LiNb03 waveguide switches, J. Appl. Phys., 51, pp. 90-93, (1980)

[9]

Becker R.A., Circuit effect in LiNbOP3 channel-waveguide modulators, Opt. Lett., 10, pp. 417-419, (1985)

[10]

Jumonji H., Nozawa T., Instabilities and their characterization in Mach-Zehnder Ti:LiNbO3 optical modulators, IEICE Trans. C-I, J75-C-I, pp. 17-26, (1992)

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