Injection-Locked Fabry–PÉrot Laser Diode Transmitters With Semiconductor Optical Amplifier for WDM-PON

This paper describes the investigation of side-mode injection-locked Fabry-Perot laser diode (FP-LD) transmitters for wavelength division multiplex passive optical network (WDM-PON) applications. We teat the case that transmitters are injection locked by intensity-modulated downstream signal light. In this case, an extinction ratio (Ex) of downstream signal light is very important for both sending and receiving properties, and the Ex influences the bit error rate (BER) property. It is desirable to use downstream light with a high Ex for minimizing the receiver power penalty DeltaP of downstream data. However, the downstream light with a high Ex degrades the locking property, and it results in the BER degradation of upstream data. This paper clarifies that there is a tradeoff of power penalties DeltaP for up- and downstream data, theoretically. We propose a method to reduce the penalty DeltaP induced by a high Ex. Fundamental transmission experiments using a semiconductor optical amplifier (SOA) confirmed the effectiveness of the proposed method. We also discuss the proposed method.