Abstract

Coherent detection is the usual solution to achieve high bit rate transmission over long distance. However, it requires a local oscillator and energy consuming digital signal processing that make it not suitable for cost and energy sensitive interconnections and short haul links. In these applications, direct detection is the preferred solution and the main impairment is the chromatic dispersion of optical fibers. In theory, combined amplitude-phase shift (CAPS) codes are able to defeat any amount of chromatic dispersion. However, while they can be detected with a very simple direct detection receiver, their generation is not trivial. Their complexity grows with the order of the code which, in turn, increases with the chromatic dispersion. In this paper, the IQ-duobinary modulation scheme, a novel technique for approximating an order-3 CAPS code, is presented. Such a modulation scheme allows us to bridge up to 18 km at a bit-rate of 50 Gb/s over a standard single mode fiber using a simple direct-detection receiver without the need of any digital signal processing technique.

© 2016 IEEE

50 Gb/s short-reach interconnects with DSP-free direct-detection enabled by CAPS codes

Mohamed Morsy-Osman, Francesco Fresi, Enrico Forestieri, Marco Secondini, Luca Potì, Fabio Cavaliere, Stephane Lessard, and David V. Plant
Opt. Express 26(14) 17916-17926 (2018)

Phase-sensitive amplifier-based optical conversion for direct detection of complex modulation format to bridge long-haul transmissions and short-reach interconnects

Jiabin Cui, Yuefeng Ji, Guo-Wei Lu, Hongxiang Wang, and Min Zhang
Opt. Express 28(2) 2349-2365 (2020)

Stokes vector direct detection for short-reach optical communication

Di Che, An Li, Xi Chen, Qian Hu, Yifei Wang, and William Shieh
Opt. Lett. 39(11) 3110-3113 (2014)

Advanced modulation formats for high-performance short-reach optical interconnects

Qian Hu, Di Che, Yifei Wang, and William Shieh
Opt. Express 23(3) 3245-3259 (2015)

Gradient-descent noise whitening techniques for short-reach IM-DD optical interconnects with severe bandwidth limitation

Qi Wu, Zhaopeng Xu, Yixiao Zhu, Honglin Ji, Yu Yang, Gang Qiao, Lulu Liu, Shangcheng Wang, Junpeng Liang, Jinlong Wei, Zhixue He, Qunbi Zhuge, and Weisheng Hu
Opt. Express 32(2) 1715-1727 (2024)