AVS 53rd International Symposium
    MEMS and NEMS Tuesday Sessions
       Session MN-TuP

Paper MN-TuP1
Development of Accelerometer Using Multilayered Optical Bandpass Filter

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Aspects of MEMS and NEMS Poster Session
Presenter: H. Toyota, Hirosaki University, Japan
Authors: H. Toyota, Hirosaki University, Japan
M. Yaegashi, Hirosaki University, Japan
T. Ono, Hirosaki University, Japan
M. Shimada, NTT MI Labs, Japan
Y. Jin, NTT MI Labs, Japan
Correspondent: Click to Email
Accelerometer which is micro-electromechanical systems (MEMS) device has begun to be used with the cellular phone and the car, etc. In present, detection range of acceleration is limited by MEMS device structure and its range is very narrow. Therefore, it is necessary to develop the accelerometer which can be measured wide range of acceleration. We propose the accelerometer based on optical bandpass filter. The accelerometer has a membrane structure with Fabry-Perot (FP) resonator. The FP resonator is composed of air gap as cavity layer between multilayered dielectric thin films. Weight is also attached bottom layer. The input light from white light source is introduced into top surface of FP resonator. The output light is extracted from exit aperture of the weight. The output light was measured by monochromator and photo detector. When the displacement of weight is occurred by the acceleration, the thickness of air layer is changed. Then, the wavelength of output light is also changed. It is principle that acceleration can be measured by this wavelength displacement. To obtain the optical characteristics of newly accelerometer, theoretical calculation was carried out by the change of the thickness of air layer using optical simulator. The design wavelength was 780 nm. As the dielectric material, silicon oxide (SiO@sub 2@: n=1.5) and tantalum oxide (Ta@sub 2@O@sub 5@: n=2.1) were used. The peak intensity of 100% appeared at the wavelength of 780 nm. It was found that the change of output light wavelength was varied as the change of air layer thickness. Considering the linearity relation, the effective wavelength displacement was about 120 nm. Then, in order to detect gravity force from 0.1 to 100 G, the wavelength resolution of 0.1nm is required for spectroscopic measurement system, but it is easy to achieve by the use of the general spectroscopic measurement system.