Wideband tunable REC-DFB laser array using thin-film heaters on the submount

A wideband wavelength-tunable 4×5 distributed feedback[DFB]semiconductor laser array based on the reconstruction-equivalent-chirp[REC]technique using a simple tuning scheme is demonstrated.It consists of 20 DFB lasers with 4×5 matrix interleaving distributions,two-level cascaded Y-branch optical combiners,and one active semiconductor optical amplifier[SOA],all in-series integrated on one chip.Unlike the traditional thermal-electric cooler[TEC]-based wave-length-tuning scheme,the tunable 4×5 REC-DFB laser array achieves a faster and broader continuous wavelength-tuning range using TaN thin-film heaters integrated on the AIN submount.By changing the injection current of the TaN resistor from 0 to 190 mA,the proposed tunable laser achieves a wavelength-tuning range of～2.5 nm per channel and a total tuning of over 50 nm.This study opens up new avenues for realizing cost-effective and wide-tuning-range semiconductor lasers.