Rotational optical alignment for array based free space board-to-board optical interconnect with zero power hold

We present an electrothermally actuated, rotating microlens array for the application of aligning free-space optical interconnects. A bistable mechanical brake holds the rotating stage after alignment so it does not consume any power in steady state. A 4 × 4 double-sided microlens array is fabricated via micro-inkjet printing and is precisely mounted on the lens shuttle with alignment bumps. Our MEMS device has a maximum rotation angle of 2.3° at an average velocity of 5.75°/s, and is capable of correcting angular misalignment of the laser/photodetector array chips. Measured CCD images of a 1 × 4 VCSEL array are presented to demonstrate the function of the device.