A study of digital optical signal multiplexing technique using short pulse amplitude modulation

• Published in: Electronics & communications in Japan. Part 1, Communications Vol. 86; no. 4; pp. 35 - 41
• Main Authors: Yamamoto, Hiroaki, Numata, Kazunori, Morikura, Susumu
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.04.2003
• Subjects: optical beat interference; optical CDM; optical network; pulse amplitude modulation; subcarrier multiplexing
• ISSN: 8756-6621; 1520-6424
• DOI: 10.1002/ecja.10075

As an optical multiplexing system to be applied to the uplink of a passive optical network, the authors propose short pulse amplitude modulation as a form of optical CDM. Although this method has the attractive feature that no timing control and wavelength control is necessary, the number of multiplexed optical signals is limited by the optical beat interference. In this paper, the signal‐to‐noise ratio and the number of optical signals that can be multiplexed are theoretically discussed when digital signals are transmitted with short pulse amplitude modulation in the case where the DFB‐LDs with identical wavelengths are used as the optical sources and the optical beat interference is generated within the signal bandwidth. It is found that the number of optical signals that can be multiplexed is 8 when the signal speed is 100 Mb/s and the amount of chirp in the LD is 280 MHz/mA. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(4): 35–41, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10075