Title :
Laser linewidth requirement for eliminating modal noise in pulse frequency modulation video transmission
Author :
Nakamura, Masaru ; Suzuki, Nobuo ; Uematsu, Wtaka ; Ozeki, Takeshi ; Takahashi, Sadao
Author_Institution :
Toshiba Corporation, Kawasaki, Japan
fDate :
10/1/1984 12:00:00 AM
Abstract :
The relation between laser linewidth and modal noise was studied in a pulse frequency modulation transmission system through employing a distributed feedback laser which shows linewidth broadening of more than 2 Å. A 6-dB signal-to-noise ratio fluctuation for a 7-km transmission system, using a conventional Fabry-Perot laser, was reduced to 0.3 dB for 1.8-Å linewidth. It is pointed out that more than 1-Å linewidth is required to reduce the modal noise and to obtain a high-quality PFM transmission system.
Keywords :
Feedback lasers; Image communication; Optical fiber communication; Pulse-frequency modulation; Distributed feedback devices; Fabry-Perot; Fluctuations; Frequency modulation; Laser feedback; Laser noise; Noise reduction; Optical pulses; Pulse modulation; Signal to noise ratio;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.1984.1073674
