Low Polarization Dependent MQW Semiconductor Optical Amplifier with Tensile-Strained-Barrier Design for Optical Datacom and Telecom Networks

We present for the first time an in-depth numerical analyses on a strained-barrier InGaAs/InGaAs multi-quantum well (MQW) structure suitable to realize polarization insensitive semiconductor optical amplifier. The proposed active layer consists of ternary InGaAs/InGaAs MQW structure with lattice-matched well layers surrounded by tensile-strained barriers. Using ternary materials makes the MQW epitaxial growth more straightforward compared to quaternary system. Additionally the advantage of this structure with respect to other types of MQW SOAs, is the use of matched well which makes it easier to adjust the operating wavelength of the SOA. By proper designing the strain level on the barrier one could achieve low PDG SOA for broadband communication wavelengths including C- and S-band. The polarization dependent gain (PDG) of SOA depends on the bias current level and signal wavelength. An MQW SOA with low PDG is designed for optical telecom and Datacom applications in the wavelength range of 1490 nm to 1550 nm. Results show that at biased current of 80 mA and 50 mA, a signal gain of 16 dB and 7 dB is achieved at 1500 nm wavelength, respectively, with a polarization sensitivity below 3-dB. These characteristics make this MQW SOA suitable candidate to be used in photonic integrated circuits.