By using a linearly wavelength-scanning 1.55 μm laser source and a rotating plane mirror to control the direction of the illuminating laser beam, a laboratory-scale spotlight mode synthetic aperture ladar (SAL) is established. The SAL operates stably and the generating high resolution images are in accordance with the prospective results of imaging theory. Typical spotlight mode SAL images are illustrated, including images of a cooperative target, images of a diffusive target, constant tracking images, coherent superposition images and incoherent superposition images of the same target.