We report for the first time the growth of GaSb/AlSb multilayers and alloys on Si(100) by molecular beam epitaxy. High quality films were achieved in spite of the large lattice constant mismatch of 12%. Room temperature, optically pumped pulsed lasers emitting at 1.8μm have been demonstrated. Lateral photoconductive detectors with responsivities of 0.18 A/W have also been made. The film nucleation on the Si substrate was observed in-situ by reflection high energy electron diffraction. Characterization of the grown epilayers and preliminary optical device results are described.