A method and apparatus is provided for processing an optical beam. The method includes spatially dispersing an optical beam received from an optical port into a plurality of wavelength components. The wavelength components are focused and at least one of the components is selectively directed to one of the optical ports by reflecting the focused wavelength component at least twice from a DMD before being directed to a selected one of the optical ports. A resolution of the focused wavelength component is optimized when it is reflected from the DMD a first or second time at the expense of the other time when it is reflected.