Distributed feedback laser diodes (DFB LDs)1 or distributed Bragg reflector laser diodes (DBR LDs)2 are the most attractive light sources for long-distance high-capacity optical fiber transmission systems. Although they show single-longitudinal-mode oscillation under high-speed direct modulation, the frequency moves during the optical pulse.3 This frequency chirping will limit transmission length. One effective way to reduce the chirping is to use an external modulator.4 To eliminate the coupling problem associated with an external modulator, a loss modulator was monolithically integrated with a 1.3-μm DFB double-channel planar burled heterostructure laser diode (DFB-DC-PBH LD). A small chirping was demonstrated at 450-Mbit/sec modulation in the DFB LD-modulator integrated device for the first time.
© 1985 Optical Society of AmericaPDF Article