Wen Gang Wu

A Novel Fabrication Technology of Hot Stamping Film

This paper proposes an environmentally friendly energy-saving high-quality laser stamping foil film with particular seam-free feature. The whole idea is to meet the countrys high-end anti-counterfeiting technology, consumer products packaging appearance, high-end gifts demand for the target material. The State Quality Supervision and Testing Center (Guangzhou) detection results shows that it includes many merits such as functionality, security, reliability, ease of use, flexibility, stability and other indicators, the performance meets or exceeds the requirements of enterprise technical conditions.

An Improved Design Method of the MEMS-Based Folded-Beam Micromirror

In this paper, the folded-beam torsion MEMS mirror that meets a set of specified constraints was developed. An optimization algorithm that we newly adopted in the RCS(restricted competition selection) GA(genetic algorithm) could overcome some difficulties in single-search algorithms. Moreover, by the proposed method, the designer’s experience, and view and judgment could be reflected effectively.

Fabrication of the Open-Loop MEMS-Based Tilting Mirror Using the Compound Process

In this paper, a kind of novel open-loop two-stage torsion-mirror optical actuators has been demonstrated. The mirrors are fabricated in SOI wafers, and exhibit good basic electromechanical characteristics. They provide an impetus to being brought into use as optical switches or attenuators, etc. for fiber communication applications.

Design of the MEMS-Based Straight-Beam Micromirror Using a Genetic Algorithm

A system for optimizing the design of a MEMS mirror that meets a set of specified constraints has been developed to optimally serve optical fiber-based networking applications. An optimization algorithm based on genetic algorithms was implemented for the complex nature of the work. FEM verifications reveal that the optimizing results show a good agreement with the simulated result.

Fabrication Comparison of the SCS-Based and SOI-Based Micromachining

The two different fabrications of the Micro-Electro-Mechanical Systems (MEMS) mirrors were compared: a single-crystal-silicon (SCS)-based micromachining and a silicon-on-insulator (SOI)- based micromachining. While the SOI parts had significantly smaller curved device appearance, they were outperformed in most areas by the SCS parts. This was due primarily to the smaller stress factor in the device layer in the SOI parts compared to the polysilicon layer used in the SCS parts.

Comparisons of the Straight Torsion Beam and Folded Torsion Beam Designs for MEMS Micromirrors

The torsion beam design for the micromirrors has an important effect on electrostatic behavior. We investigated three torsion beam designs and determined their effect on electrostatic characteristics as well as resonant frequency. The first design is straight torsion beam, which is the simplest and most commonly used. The second and third designs, add different folded structure to improve the performance. The results suggest that the folded-beam design has a significant effect on actuation performance. The most effective design had a driving voltage approximately one half of that for the simplest design, and the effect on resonant frequency is slightly more modest but still impressive.

Monolithically Integrated MEMS Optical Device with Switching and Attenuating Function

In this paper, a monolithically integrated device composed of optical switch (OS) and variable optical attenuator (VOA) is described. The device shows more functionality and more compactness in the all optical networks. Besides the advantage of wide attenuation range, its fabrication is simple and reliable. In our laboratory, a monolithically integrated optical device has been fabricated and setup for investigation. Experimental results have shown that the proposed approaches improve the compositive performance.

Fast Response MEMS VOA with Grid-Type Shutter

In this paper, a microelectromechanical variable optical attenuator (VOA) with grid-type shutter is described. The device is used to control the power in the all optical nelworks. Besides the advantage of good switching performance and the relatively low driving voltage, its fabrication is simple and reliable. In our laboratory, a MEMS VOA with grid-type shutter has been fabricated and setup for investigation. Experimental results have shown that the proposed approaches improve the VOA performance.

MEMS Scanning Mirror with Vertical Comb Actuator Based on Latching Technique

A MEMS(Micro-Electro-Mechanical Systems) scanning mirror with vertical comb actuator was designed, modeled, fabricated and tested, which can be widely applied in scanning micromirrors, optical switches, and variable capacitors. Purposive latching has been successfully applied to the batch fabrication of vertical comb actuators made of silicon on insulator (SOI). The manufacturing process is introduced, and a novel design of latching structure and mechanical spring is also presented. The latching of microstructures is enabled in a controlled manner and significantly reduces the distance between the combs, reducing the driving voltage. The prototype microactuators operate at the driving voltage of 28 Vdc with 9.6 optical angle. A reliability test on an unpackaged actuator with more than 100 million cycles of operation showed extremely small variation in the scanning angle and the driving voltage, showing no sign of degradation in the induced latching interface or the microstructures.

Development of MEMS VOA with only One Shutter for Dual Signals Simultaneous Operation

A MEMS variable optical attenuator (VOA) with only one shutter for dual signals simultaneous operation is designed for advanced tuning functions. Theoretical electro-mechanism model has also been developed to provide optimization for the VOA design. In experiment, the fabricated VOA device has demonstrated a over 40-dB attenuation range with respect to the driving voltage of one shutter, and it has also realized low polarization-dependent performance. The superior specifications make this device very promising for optical network systems and laboratory equipment.