50G-PON Downstream Link up to 40 km With a 1342 nm Integrated EML+SOA

A monolithically integrated EML+SOA delivering an output power of +13 dBm is demonstrated as a compact Tx for the 50G-PON downstream link. The device delivers +13 dBm of output power with 6 dB extinction ratio and 55 dB/0.1nm OSNR while also passing the 50G-PON eye mask. By exploiting SOA chirp reduction correlated to the gain saturation effects we demonstrate enhanced fiber transmission performance. Since 50G-PON is going to be the first PON technology to adopt digital signal processing (DSP), we use receiver side equalization (EQ) in a 20 km link to demonstrate a link budget of 35.8 dB. Furthermore, working in conjunction with the 50G-PON equalizer, a link up to 40 km SSMF at 1342 nm is realized.