Widely tunable semiconductor lasers/receivers based on grating-assisted codirectional coupler filters

avelength tunable devices based on grating-assisted codirectional coupler filters have been shown to possess enhanced wavelength tunabilities and are promising for use in multiwavelength communication networks. This thesis explores in depth the design, fabrication, testing and analysis in attempts to integrate the grating-assisted codirectional coupler (GACC) filters with quantum wells (QW) for widely tunable lasers and receivers. The optical gain of the InGaAs QW and the index change of the GaAs phase modulator were experimentally studied. Two structures for the tunable laser and one for the tunable receiver have been proposed and investigated experimentally.;The first tunable laser was fabricated based on a constricted-mesa scheme and a 38 nm wavelength switching was demonstrated. The second tunable laser was fabricated based on integration techniques for a two-section active/passive device. A wavelength tunability of...