Monolithic waveguide coupled cavity lasers and modulators fabricated by impurity induced disordering

Describes results on AlGaAs integrated optoelectronic devices consisting of combinations of buried passive waveguide regions with active multiple quantum well gain regions. The authors have developed a technique for accomplishing this integration in which the waveguide regions have greatly reduced propagation loss at the gain wavelength of the active media. They have incorporated sections of waveguide into laser cavities, and the resulting low (7-11 mA) threshold currents and weak dependence of threshold current on waveguide length confirm the reduced loss and waveguiding nature of the waveguide regions. They have used these structures to monolithically couple laser amplifiers to electroabsorption modulators. Among their results on these devices are electroabsorption modulators with contrast ratios of 23:1 and monolithic Q-switch operation resulting in pulse widths of less than 200 ps. The relative simplicity with which these structures are fabricated via impurity induced disordering techniques promises to result in major impact on practical systems for monolithic integration.<
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