Accession Number:

ADP006990

Title:

System Limitations for Fiber Amplifier Cascades,

Descriptive Note:

Corporate Author:

NIPPON TELEGRAPH AND TELEPHONE CORP TAKE TRANSMISSION SYSTEMS LABS

Personal Author(s):

Report Date:

1992-05-22

Pagination or Media Count:

4.0

Abstract:

The performance, of an amplifier cascade system is taken to be the product of transmission bit rate, B, and transmission distance, L. In amplifier cascade systems using the IMDD scheme, signal spontaneous beat noise, spontaneous-spontaneous beat noise and shot noise are present in addition to receiver thermal noise, while local oscillator shot noise and local oscillator-spontaneous beat noise are additional factors in coherent systems. Signal-spontaneous and spontaneous-spontaneous beat noises generally predominate in IMDD systems if many cascaded amplifiers are used. Conversely, in coherent systems, local oscillator-spontaneous beat noise predominates. In such cases, system performance is approximated by B X L fmodSNR, X PSNF, where fmodSNR, is a function of required SNR and amplifier spacing, , depending on the moddemod scheme, Ps is the amplifier output power, and NF is the amplifier noise figure. Therefore, the system performance depends on amplifier spacing and amplifier performance given as PSNF. As the spacing decreases andor amplifier performance increases, system performance increases. However, it is limited by four conditions 1 Fiber dispersion, 2 Amplifier performance, 3 Noise accumulation, and 4 No cascaded amplifier.

Subject Categories:

  • Electrical and Electronic Equipment
  • Fiber Optics and Integrated Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE