Polatis Photonics, Inc.

Continuum Photonics, Inc.

Timothy Scott Glenn

Kamyar Ghandi

Nesbitt Ward Hagood, Iv

A controller in an optical switch providing optical coupling of an optical signal between a source port and a target port employs, in at least one axis, gradient control using a feedback loop that compensates for alignment error between a source port and a target port in an optical switch. In at least one other axis, the controller generates a control input according to a control law that results in variable attenuation of optical coupling between the source port and the target port in the optical switch. A dither signal may be applied to the control input in the at least one other axis. Amplitude of the applied dither signal may be varied.

Method and apparatus for variable optical attenuation for an optical switch

A free space optical switch that uses both an open loop control mode and a closed loop control mode. The open loop control mode is used to transition to a state where at least some light is sensed at a destination port. A closed loop control mode is then used, whereby a series of controlled dither signals are adjusted for system dynamics. Modifying the dither signals in this matter allows moving actuators at a rate that is much closer to the natural frequency of the underlying system, and hence speeds up the system convergence process. Variable modulation amplitudes may be employed on the dither signals to maximize convergence speed. In particular, changes in the dither signal can be made in accordance with the change in amplitude as a function of a gradient along a parabola that models the optical system response. According to still further aspects, the dither signals may be compensated for a desired and selectable attenuation level of output optical power.

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Somerville, MA, United States of America

Timothy Scott Glenn