Patent ID: 7567756

Claim:
A method for adjusting a dither amplitude of one or more MEMS mirrors in an optical switch having an input port, and an array of one or more MEMS mirrors that can be selectively optically coupled between the input port and one or more of N optical output ports, where N is an integer greater than or equal to 2, the method comprising: aligning the one or more MEMS mirrors to achieve nominal peak coupling between the input port and each of the N output ports; storing to a non-volatile memory digital-to-analog converter (DAC) settings for positioning each mirror in an open control loop as a function of the selected output port, wherein the DAC settings include N signal values S c , wherein each signal value S c corresponds to a signal applied to the given mirror to position the mirror to couple an optical signal between the input port and a different one of the N output ports; and determining a dither amplitude DITHER(x) for one of the MEMS mirrors positioned to couple optical signals to an output port at a position x using the stored DAC settings, wherein determining the dither amplitude DITHER(x) includes: fitting the N signal values to a polynomial of a parameter corresponding to a position of an output port; determining a slope of the polynomial at a value of the parameter corresponding to a given output port; and determining the dither amplitude DITHER(x) based on the value of the slope.