Patent ID: 8154720

Claim:
A method for calibrating a spatial light modulator comprising an array of individually addressable channels, the method comprising: selecting a plurality of first channel sets from the array of channels, each of the first channel sets comprising X channels; operating each of the first channel sets to provide first output radiation; determining a plurality of first intensity values, wherein each first intensity value is determined for the first output radiation provided by a different one of the first channel sets; reducing a difference between one of the first intensity values and a first target intensity value by adjusting control levels of a group of the channels in the array of channels; selecting a plurality of second channel sets from the array of channels, each of the second channel sets comprising Y channels, wherein Y is less than X; operating each of the second channel sets to provide second output radiation, wherein at least one of the operated second channel sets comprises a portion of the group of the channels operated with the adjusted control levels; determining a plurality of second intensity values, wherein each second intensity value is determined for the second output radiation provided by a different one of the second channel sets; determining a correction factor for each of the second channel sets; modifying each second intensity value in accordance with the correction factor determined for the second channel set corresponding to the second intensity value; and reducing a difference between at least one of the modified second intensity values and a second target intensity value by adjusting a control level of at least one channel in each of the second channel sets corresponding to each of the at least one of the modified second intensity values.