We report 1.3-mu m mode-locked optically pumped semiconductor disk laser (SDL) made by wafer fusion. The gain medium and the saturable absorber, both based on an InP material system, were integrated with AlGaAs-GaAs distributed Bragg reflectors by localized wafer fusion. An intracavity wedged diamond heat spreader capillary bonded to the gain chip prevents the disruption of 6.4-ps pulse spectrum and supports 100 mW of average power. The results reveal an advantage of wafer fusion process of disparate materials over monolithically grown InP-based gain/absorber structures and demonstrate practical potential of the technique for long-wavelength SDLs.