ABSTRACT
In this paper, the newly developed 3D-constructed AlScN piezoelectric MEMS mirror is presented. This paper describes the structure and driving mechanism of the proposed mirror device, covering its driving characteristics in both quasi-static and resonant scan modes. Particularly, this paper deals with various achievable scan patterns including 1D line scan and 2D area scan capabilities and driving methods to realize each scanning strategy. Bidirectional quasi-static actuation along horizontal, vertical, and diagonal scanning directions was experimentally characterized and even under a low voltage level of ±20 V, a total optical scan angle of 10.4° was achieved. In addition, 1D line scanning methods using both resonant and non-resonant frequencies were included and a total optical scan angle of 14° was obtained with 100 mVpp under out-of-phase actuation condition. Furthermore, 2D scan patterns including Lissajous, circular and spiral, and raster scans were realized. Diverse scan patterns were realized with the presented AlScN-based MEMS mirror device even under a low level of applied voltage. Further experiments using high voltage up to ±120 V to achieve an enhanced quasi-static scan angle of more than 20° are ongoing to ensure repeatability. This multi-functional MEMS mirror possesses the potential to implement multiple scanning strategies suitable for various application purposes.
ABSTRACT
The rapid detection of trace gases is of great relevance for various spectroscopy applications. In this regard, the technology of external cavity diode lasers (ECDLs) has firmly established itself due to its excellent properties. Outside of the laboratory environment, however, these still have some restrictions, especially with regard to high acquisition rates for sensitive spectroscopy applications and mode-hop-free tuning. In this article, we present our innovative GaSb-based ECDL concept, in which a resonantly driven microelectromechanical system actuator is used. With this, a defined frequency range can be tuned extremely fast and without mode hops. Results of the characterization and its use for the rapid detection of trace gases are presented.
ABSTRACT
This article presents design, fabrication and characterization of lead zirconate titanate (PZT)-actuated micromirrors, which enable extremely large scan angle of up to 106° and high frequency of 45 kHz simultaneously. Besides the high driving torque delivered by PZT actuators, mechanical leverage amplification has been applied for the micromirrors in this work to reach large displacements consuming low power. Additionally, fracture strength and failure behavior of poly-Si, which is the basic material of the micromirrors, have been studied to optimize the designs and prevent the device from breaking due to high mechanical stress. Since comparing to using biaxial micromirror, realization of biaxial scanning using two independent single-axial micromirrors shows considerable advantages, a setup combining two single-axial micromirrors for biaxial scanning and the results will also be presented in this work. Moreover, integrated piezoelectric position sensors are implemented within the micromirrors, based on which closed-loop control has been developed and studied.
