Archive | 2021
Integration and Control of a MEMS Optical Phased Array Scanner
Abstract
The paper presents an integration and control of a surface micromachined optical phased array (OPA) system based on tightly spaced and narrow piston-motion micromirrors. The individually actuated micromirrors are made of polysilicon and metal thin films to realize an electrostatic actuation and a high optical reflectivity. This configuration enables the realization of an electrostatic parallel plate actuator for each gold-coated micromirror (pixel) where the micromirror beam is suspended by actuating springs at both sides. An electrical interconnect line is made of the first polysilicon layer fixed to the substrate through an insulating nitride layer and is routed underneath the corresponding micromirror to fit a tight pitch of the array. The die carrying the OPA device is then connected to a suitable MEMS package through a standard wire bonding process. A test fixture is designed for the OPA device package. This approach allows to obtain a relatively wide field of view, to operate the device at a low actuation voltage, and to reduce complexity of the system design, fabrication, and integration.