We present a 3(3 micro-optoelectromechanical systems (MOEMS) phase shifter array that achieves a λ/4 vertical displacement with peak-to-valley deformation within λ/10 (514-nm light source). The mirror reflective surface is made of an aluminum layer with a high optical reflectivity exceeding 90%. Each individual micromirror pixel is controlled and driven by comb drive actuators. The phase shifter array is fabricated using the Taiwan Semiconductor Manufacturing Company 0.35-μm 2P4M complementary metal-oxide semiconductor process. In-house post-processing is utilized to reserve a 40-μm-thick bulk-silicon under the 200 μm×200 μm mirror. This eliminates mirror deformation from residual stress after the device is released. The micromirror demonstrates a vertical displacement of λ/4 at 38 V. The device resonant frequency is 3.71 kHz, and the fill factor is 0.65. This MOEMS phase shifter array can be used as a spatial light modulator in holographic data storage systems.
- Comb drive actuator
- Micro-optoelectromechanical systems
- Phase shifter
- Semiconductor-microelectromechanical systems