Impact of laser linewidth on optical channel spacing requirements for multichannel FSK and ASK systems

Author

Elrefaie, A. ; Maeda, M.W. ; Guru, R.

Author_Institution

Bellcore, Red Bank, NJ, USA

Volume

1

Issue

4

fYear

1989

fDate

4/1/1989 12:00:00 AM

Firstpage

88

Lastpage

90

Abstract

The sensitivity penalty is evaluated for amplitude-shift-keyed and frequency-shift-keyed multichannel coherent systems that use lasers with linewidths which are a significant fraction of the bit rate. The study was conducted for both ASK and FSK systems using a single-filter receiver with nonsynchronous detection. For FSK systems, both NRZ (nonreturn-to-zero) and alternate mark inversion (AMI) signal formats were studied. The optical channel spacing is strongly determined by the laser linewidth. For example, with the FSK-NRZ data rate of 150 Mb/s, the optical channel spacing which gives 1-dB crosstalk penalty is 4 GHz when the intermediate frequency linewidth is 50 MHz (laser linewidth is 25 MHz), as opposed to 1.8 GHz when the linewidth is negligible.<>

Keywords

amplitude modulation; frequency shift keying; optical communication; optical modulation; receivers; 1 dB; 105 Mbit/s; ASK; FSK; alternate mark inversion; amplitude-shift-keyed multichannel coherent systems; bit rate; crosstalk penalty; data rate; frequency-shift-keyed multichannel coherent systems; intermediate frequency linewidth; laser linewidth; nonreturn-to-zero; nonsynchronous detection; optical channel spacing requirements; sensitivity penalty; single-filter receiver; Amplitude shift keying; Bit rate; Channel spacing; Frequency shift keying; Local oscillators; Optical crosstalk; Optical filters; Optical receivers; Optical sensors; Optical transmitters;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.87912

Filename

87912