Low-Power Consumption 28-Gb/s 80-km Transmission With 1.3-μm SOA-Assisted Extended-Reach EADFB Laser

Abstract

We extend the transmission distance for 28-Gb/s optical links from 40 to 80 km in a single-mode fiber (SMF) in the 1.3-μm-wavelength window by using an intensity-modulation direct-detection scheme. To extend the link budget, and compensate for the optical loss of SMF, we try to increase the optical output power of an electroabsorption modulator integrated with distributed feedback (EADFB) laser. We apply a semiconductor optical amplifier (SOA)-assisted extended-reach EADFB laser (AXEL) to a 1.3-μm-wavelength light source. To increase the optical output power while using energy efficiently, we design the SOA length in terms of achieving a balance between the laser diode (LD) and the SOA length with a constant injection current of 160 mA. We fabricate an AXEL and an EADFB laser and compare their basic characteristics. By using the high-power AXEL, we achieve the first 28-Gb/s 80-km SMF transmission without the need for digital signal processing or an in-line optical amplifier. The AXEL consumes only 0.26 W and does not require any digital processing or an in-line amplifier and can, therefore, reduce the power needed for an optical network system by tens of watts.