100-Gbit/s/λ EML Transmitter and PIN-PD+TIA Receiver-Based Inter-Data Center Link

Beyond 100-Gbit/s/λ high-speed inter-data-center link composed by hybridly integrated electro-absorption modulator (EAM) and distributed feedback laser diodes (DFBLD)-based transmitter at 1306 nm, and received by a PIN-PD + TIA optical receiver is demonstrated to carry 104-Gbit/s pre-emphasized PAM-4 data for 2–10 km single mode fiber (SMF) propagation. The EAM + DFBLD transmitter offers an average power of −1.5 dBm, an excellent side mode suppression ratio of 53 dB, an on/off extinction ratio up to 10 dB, an analog bandwidth of 25 GHz, and a relative intensity noise of -137 dBc/Hz. The PIN-PD + TIA module exhibits 30-GHz receiving bandwidth. For on-off keying (OOK) format, the allowable data rates at 62 and 60/54 Gbit/s for BtB and 2-km/10-km SMF cases obtain receiving BER of 1.48 × 10 ⁻¹³ and 3.4 × 10 ⁻¹⁴ /1.77 × 10 ⁻¹⁴ qualified for error-free telecommunication. Even at simulated inter-data center link, the receiving power sensitivity and power penalty at 54 Gbit/s can achieve −6.43/−6.26 dBm and 0.07/0.24 dB after 2-/10-km SMF propagation. To efficiently utilize the limited transmitter bandwidth, the directly encoded PAM-4 data transmission reveals qualified BER slightly enlarged from 1.4 × 10 ⁻⁴ to 2.3 × 10 ⁻⁴ when transferred from back-to-back to 2-km SMF transmission. Lengthening the distance to 10-km SMF degrades the maximal PAM-4 data rate to 50 GBaud with a received BER of 2.3 × 10 ⁻⁴ (less than KP4-FEC criterion). The 50 GBaud PAM-4 link provides receiving power penalty of 0.11/0.24 dB after 2-/10-km SMF propagation, which is attributed to the narrow-linewidth DFBLD responsible for extremely low RF fading effect under nearly zero dispersion condition. The transmitting frontend with amplitude/phase pre-emphasis function makes the receiving end compact and cost-effective, which exhibits the higher spectral usage efficiency of 4 bit/s/Hz and the better receiving sensitivity of −5.5 dBm at the lower power budget of 2.8 fJoule/bit than previous works.