Experiments with a polarized electron beam stored in the South Hall Ring (SHR) at MIT‐Bates Linear Accelerator Center will begin in 2003. Currently, the commissioning of BLAST detector is under way. The polarized injector uses for the first time high power diode array laser for photoemission. The laser operates at a wavelength of 808 nm and produces peak power up to 150 W at a duty factor of 1.5&percent;. Higher power is available at lower duty factor. The laser is coupled to a fiber, laser beam emitting from the fiber has an emittance of 200 mm⋅mrad and a set of lenses is used to deliver the beam through polarizing optics to a strained GaAs crystal inside the electron gun. The photocathode has a diameter of 11 mm and the laser illuminates the entire area. The gun optics has been specifically designed for such a large beam spot size. The diode laser provides an excellent stability and convenience of operation. At the same time, large divergence of the laser beam requires special attention to the transport system in general, and to polarizing optics in particular. © 2003 American Institute of Physics