Hsu Dar-Zu, Wei Chia-Chien, Chen Hsing-Yu, Lu Yi-Cheng, Song Cih-Yuan, Yang Chih-Chieh, Chen Jyehong
Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan.
Opt Express. 2013 Jan 14;21(1):533-43. doi: 10.1364/OE.21.000533.
We develop a novel subcarrier-to-subcarrier intermixing interference (SSII) cancellation technique to estimate and eliminate SSII. For the first time, the SSII cancellation technique is experimentally demonstrated in an electro-absorption modulator- (EAM-) based intensity-modulation-direct-detection (IMDD) multi-band OFDM transmission system. Since the characteristics of SSII are seriously affected by the chirp parameter, a simple constant chirp model, we found, cannot effectively remove the SSII. Therefore, assuming that the chirp parameter linearly depends on the optical power, a novel dynamic chirp model is developed to obtain better estimation and cancellation of SSII. Compared with 23.6% SSII cancellation by the constant chirp model, our experimental results show that incorporating the dynamic chirp model into the SSII cancellation technique can achieve up to 74.4% SSII cancellation and 2.8-dB sensitivity improvement in a 32.25-Gbps OFDM system over 100-km uncompensated standard single-mode fiber.
