OPTIMIZATION OF A NOVEL LATERAL DEFORMABLE NEMS ZEROTH-ORDER GRATINGS: ANOMALOUS DIFFRACTION STUDIED BY 3-D FDTD METHOD |
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| Chen Wang, Jian Bai, Qian-Bo Lu, Guo-Guang Yang |
- Abstract:
- This paper discusses the analysis and optimization of a novel optomechanical zeroth-order grating transducer based on an anomalous diffraction phenomenon, namely Wood’s type anomaly, in which tiny changes in the displacement of the nanostructured grating elements lead to a dramatic increase or decrease of the optical reflection amplitude. With this special feature, this structure is an ideal sensor component to observe very small displacement. This device is very sensitive to wavelength, the period and the width of the grating. Here, we analyze the performance of the structure with different parameters and optimize the original structure corresponding to 850 nm through 3-D Finite Difference Time Domain method (FDTD). Simulation demonstrates the new structure is of higher sensitivity and signal strength, namely extinction ratio. Moreover, in order to enlarge the tiniest size of the original structure which is closely related to the incident wavelength, we change the wavelength to longer ones, e.g. 1053 nm, 1310 nm, 1530 nm. The calculation predicts the optimized structure designs of those wavelengths are of performance similar to the original one’s but much less strict demand for processing precision, which makes it possible to be fabricated with current surface micromachining processing similar to that used for the fabrication of polysilicon MEMS. Besides, structures of several visible incident wavelengths, such as 532 nm, 632.8 nm, 670 nm, 753 nm, are also analyzed and optimized, which gives great convenience to the installation and calibration of such device as well as observation of its performance. All the calculated data enable us to apply the structure into fields required for different sensitivities with different grating designs and thus broaden the further usage of such novel structure, as structures of different parameters are of different sensitivities and signal strengths.
- Keywords:
- Nanoelectromechanical systems (NEMS), grating transducer, 3-D Finite Difference Time Domain method(FDTD), microelectromechanical systems (MEMS), optical resonant detections
- Download:
- IMEKO-TC14-2014-53.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC14
- Event name:
- TC14 LMPMI Symposium 2014
- Title:
11th Symposium on Laser Metrology for Precision Measurement and Inspection in Industry
- Place:
- Tsukuba, JAPAN
- Time:
- 03 September 2014 - 05 September 2014