Micromechanical Optical Crossconnect with 4-F Relay Imaging Optics

We describe a novel optical configuration for a microelectromechanical system (MEMS)-based beam-steering optical crossconnect. It incorporates 4-F imaging optics to relay light to the MEMS chip. This makes the system more tolerant to fiber-microlens misalignment. The use of a relay plus Fourier lens and patterned mirror removes the skew angle on the MEMS array and reduces the maximum angle for the MEMS mirror. A prototype 110 × 110 crossconnect employing imaging optics was constructed to validate the approach. This achieved a mean fiber-to-fiber insertion loss of 2.9 dB.