Patent ID: 8433201

Claim:
A method, comprising: communicating an optical signal over a path of an optical communication medium, the optical signal comprising a multiplexed plurality of optical channel components of associated different wavelengths; redirecting the optical signal from the path of the optical communication medium; collimating the redirected optical signal; separating the collimated redirected optical signal into demultiplexed ones of the different wavelength channel components by directing the collimated redirected optical signal onto a grating plane for transmission through slits of an optical interference grating; directing the separated different wavelength channel components to be incident onto respective different portions of an array of modulator elements of a spatial light modulator; equalizing an optical signal strength of the incident different wavelength channel components through optical modulation by settings of the modulator elements of the respective different portions of the array; recombining the equalized different wavelength channel components into a remultiplexed optical signal by directing the equalized components in an opposite direction onto the grating plane for transmission through the slits of the optical interference grating; directing the remultiplexed optical signal back along the path of the optical communication medium; wherein a minor portion of light of the equalized components directed in the opposite direction for transmission through the grating and direction back along the path after remultiplexing is separated from a main portion due to losses; directing at least a part of the minor portion of light of the equalized components separated from the main portion at the grating due to losses onto a detector; generating electrical signals proportional to an optical power of each of the equalized components incident on the detector; and using the generated electrical signals as feedback to set the settings of the modulator elements of the respective corresponding different portions of the array.