Asymmetric Twin-Waveguide 1.55-μm DFB Lasers for an Optical Beam Forming Network

An asymmetric twin-waveguide 1.55-μm DFB laser integrated with a passive waveguide crossing was fabricated for the optical beam forming network. A DFB laser with a side-mode suppression ratio of >45 dB and a waveguide crossing with a 16 dB crosstalk suppression ratio were obtained.