Spatial Light Phase Modulator With Bidirectional Tilt-Piston Micromirror Array-Part II: Fabrication and Experiment

In part I of this paper, we have proposed a novel structure of microelectromechanical-systems-based 1-D spatial light phase modulator (SLPM). We have discussed the design of the device and derived the optimum parameters to satisfy the target specifications. In part II, we focus on the fabrication process and experimental results of the device. We show that this device configuration allows us to use a simple fabrication process. We fabricated the device consisted of 24 micromirrors and realized the tilt and piston motions successfully. The measured dc (rotation angle and displacement on driving voltage) and ac (frequency response) characteristics matched well to the simulated data derived in part I. We also examined the distribution of the resonant frequencies over 24 micromirrors and verified that the variance was kept within 2%. As one of the applications of the device, we applied the device to optical beam shaping and succeeded in shaping the optical beam properly depending on the surface patterns of the SLPM. With these achievements, we show that the device can be adopted to a wide variety of applications in optical communication systems and optical signal processing.