Micromechanical Optical Switch Using an S-Shaped Deformable Thin-Film Mirror

In this study, a novel micromechanical optical switch that comprises simple, easy-to-manufacture components is proposed. The proposed optical switch incorporates a few flat substrates, including a flat electrode array and S-shaped deformable thin-film mirrors, the number of which is determined based on the number of incident light rays. In the proposed switch, a light ray between the substrates is reflected by the thin-film mirror and passes through one of the substrates. These components can be easily fabricated without using a deep reactive ion etching process. The optical switch can be used not only for communication networks but also for display systems and scanners.

As a common core unit of an optical switch for these applications, prototype core switches were fabricated using the microelectromechanical system fabrication technique, and their characteristics were evaluated. One of the prototype core switches was driven at an applied voltage of 130 V. The switching time was shorter than 2 ms. Then, for the driving voltage reduction, dielectric layers and suitable driving procedures were used and their usefulness was experimentally evaluated. For overcoming a charging problem caused by the dielectric layers, two driving procedures were applied to the prototype core switches and evaluated. The experimental results show that the improved driving procedure with a DC voltage of 30 V was proven to drive the switch without residual spot vibration.

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Fig.1. Driving principle of a micromechanical optical switch using an S-shaped deformable thin-film mirror

Fig.2. Motion of a prototype micromechanical optical switch [Video: Click the figure]

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Fig.3. Prototype of micromechanical optical switch

Key papers

[1]
Kaiji Sato: Driving Voltage Reduction of a Micromechanical Optical Switch Driven by Electrostatic Force Using an S-Shaped Deformable Thin-Film Mirror, Journal of Advanced Mechanical Design, Systems, and Manufacturing, Vol.7, No.3, (2013) pp.410-421.
[2]
Kaiji Sato and Kazutoshi Okutsu: Basic Characteristics of a Micromechanical Optical Switch Using an S-Shaped Deformable Thin-Film Mirror, Journal of Lightwave Technology, Vol.29, No.18, (2011) pp.2805-2811.