Optical processing device employing a digital micromirror device (dmd) and having reduced wavelength dependent loss

An optical processing device comprising:

• at least two optical input/output ports for receiving an optical beam;
• a dispersion element receiving the optical beam from one of the ports and spatially separating the optical beam into a plurality of wavelength components;
• a collimating lens for collimating the plurality of wavelength components;
• and
• an actuatable optical element for receiving the collimated wavelength components from the collimating element and diffracting the plurality of wavelength components in a wavelength dependent manner;
• and
• a compensating optical element located in an optical path between the dispersion element and the actuatable optical element, said compensating optical element compensating for the wavelength dependent manner in which the wavelength components are diffracted by the actuatable optical element.