Misalignment Distortion Penalty in Wavelength-Division Multiplexed Systems and Its Reduction Using Fiber Bragg Grating Lasers

        Experimental studies show that DC and dynamic chips in directly-modulated DFB lasers cause distortion penalties even in low-speed (155 Mb/s - 2.5 Gb/s) wavelength-division multiplexed fiber transmission systems when the passband edges of the wavelength-selective components act as frequency discriminators and result in FM-to-AM conversion. Such penalties impose laser-to-filter wavelength alignment accuracy requirements on the order of 0.1 nm for 1 dB penalty. Low-chirp lasers such as directly-modulated fiber Bragg grating lasers are shown to reduce penalties to less then 0.5 dB for 0.2 nm detuning.

By: Karen Liu and Weyl-kuo Wang

Published in: RC20678 in 1997

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