Effect of noise on the performance of optical 3R regeneration

Abstract

The regeneration of optical data signals is an important requirement of WDM and OTDM networking schemes. All-optical regenerators based on cross phase modulation schemes currently require complicated systems of several optical components and modules together with complex control. Here we demonstrate an optical 3R regeneration in a single DFB laser. The key to this regeneration process is to gain switch the DFB laser with a clock signal extracted from the data signal in order to retime the converted signal. A data signal at 10Gbits/s sent to 80Km in a SMF with poor Q is reamplified, retimed and reshaped by this laser. However the uncorrelated jitter (amplitude and phase noise) primarily present due to the spontaneous emission in the directly modulated transmitting laser as well as in the gain switched DFB laser (Regenerator) can very easily distort the whole regeneration process. In this paper we propose a systematic approach to tackle this problem to effectively enhance the performance of optical regenerator. An improvement of orders of magnitude in BER measurement can be achieved. The proposed approach results in a regenerated signal whose optical power, Q factor and extinction ratio are considerably improved by the regeneration process.