In this thesis, we examine the performance of a new reflective spatial light modulator manufactured by Hamamatsu. This device has 800x600 individually addressable pixels whose size is 18 microns. The patterns to be encoded onto the device are created by a computer program designed by Prof. Don Cottrell of SDSU. We first had to calibrate the phase shift for each pixel as a function of the gray level generated by the computer program. Then we encoded a variety of different diffraction grating functions onto the device. In each case, we changed the way in which the transmission function was encoded over the period of the grating using several techniques including binary phase, a series of stepped level phases, and a linear phase shift. Experimental results agree with theory in each case. Finally, we encoded a lens function onto the device and, using a modified linear phase shift, the output consists of a collimated beam and a diverging phase front that interfere. This has the same effect as a programmable Michelson Interferometer. These results demonstrate the versatility of the device and will allow for a number of new experiments to be performed.