Novel InGaAlAs/InGaAlAs quantum well multimode-interferometer-Fabry-Perot laser diode

In this paper, we demonstrate a novel InGaAlAs/InGaAlAs quantum well multimode-interferometer-Fabry-Perot laser diode (MMI-FP LD) in which a 1x3 multimode interferometer is inserted into the conventional FP laser waveguide to generate single wavelength emission. The designed and fabricated laser diode shows a single longitudinal mode lasing with side mode suppression ratio (SMSR) of 25dBm at a wavelength of 1567nm with driving current of 170mA and can be tuned over a certain range by adjusting the driving current. A laser diode incorporating a 1x3 MMI and three single mode waveguide outputs is also proposed which could be potentially used to generate a 3-channel single longitudinal mode coherent source using injection locking. The simple structure of this single longitudinal mode laser significantly eases the fabrication processing enabling an increase in the yield and a reduction in the cost compared with the traditional single mode lasers.