本篇論文主要工作為可調式雙光柵元件之設計、製作及量測。在
設計方面吾人以傅式光學和商業軟體G-solver 來分析設計分析可調
式雙光柵元件。吾人設計了兩種可調式雙光柵元件，一為以相同週期
相同相位厚度的矽光柵所組成Type A 雙光柵，可做為可調式光衰減
器，可調制零階範圍由48.52%調制到0.08%；二為以一週期和相位
厚度皆另一光柵之半所組成Type B 雙光柵，為設計的1 x 2 光開關可
將光強由正一階切換到負一階或反之，及效率由31.43%降低到
3.66%。並提出了一種利用雙光柵改變共振模態來做為1310nm 和
1550nm 的波長切換器的構想。
在製作方面, 吾人以半導體製程和微機電製程技術製作平面式
矽光柵和雙光柵光調制器，分別進行量測雙光柵光調制器之光學效果
和梳狀致動器致動特性。在量測上，吾人將兩組平面式矽光柵組合雙
光柵元件，可得Type A 雙光柵零階繞射光調制範圍為20.4%衰減到
1.4%；Type B 雙光柵正負一階繞射切換強度為19.1%衰減到1.4%，
量測結果顯示Type A、Type B 之光調制效果之趨勢與模擬結果相同。
此外，在梳狀致動器驅動效果的量測方面，吾人以電壓驅動梳狀致動
器測試，當外加直流偏壓130V 可驅動雙光柵光調制器約16μm，驗
證了雙光柵光調制器結構設計的可行性。

Design, fabrication and measurement of variable dual grating will be
showed in this paper. In design, we analyze dual grating element by
Fourier Optics and G-solver 4.20. We suppose two types of dual grating;
Type A is forming by a 0.5 grating with a period Λ and π phase depth, the
other is same. Type A can be used for variable optical attenuator, which
dynamic range is from 48.52% to 0.08%. Type B is forming by a 0.5
grating with period Λ and π phase depth, the other is another 0.5 grating
with half the period Λ/2 and π/2 phase depth. Type B can be used for
optical switch by +1 order and -1 order, which the intensity can be
modulated from 31.43% to 3.66%. And we suppose a resonant-type dual
grating and it can be used for switch of 1550nm and 1310nm.
In fabrication, we use semiconductor technology and MEMS
technology to fabricate silicon grating and dual grating modulator. In
measurement, we use silicon grating to simulate dual grating. Dynamic
range of Type A modulate from 19.4% to 1.4%. Type B can be switched
from 19.1% to 1.4%. The result of measurement show the change same
simulation. In moving of dual grating modulator, comb drive is moving
16μm with 130V. The design of dual grating is proved that it can work.

參考論文
[1] A. Kar-Roy et al. “8 x 8 Symmetric Nonblocking Integrated Acoustooptic Space Switch Module on LiNbO3” IEEE Photo. Tech. Lett.4 (1992)
[2] J.E. Fouquet et al. “A Compact, Scalable Cross-Connect Switch Using Total Internal Reflection Due to Thermally-Generated Bubbles” IEEE, pp.169-170 (1998)
[3] I.G. Manolis et al. “Reconfigurable Multilevel Phase Holograms for Optical Switches” IEEE Photo. Tech. Lett. 14 (2002)
[4] S. Sumriddetchkajorn et al. “Self-Aligning 2 x 2 Fiber-Optic Switch Using Liquid Crystals” IEEE, pp.135-136 (1999)
[5] D. I. Halliday et al. “The Theoretical and Experimental Behavior of a Thermooptic Bulk Deflector Fiber-optic Circuit Switch” J. Lightwave Tech. LT-5, (1987)
[6] P. D. Dobbelaere et al. “Digital MEMS for Optical Switching” IEEE Communications Magazine, p.88-95 (2002)
[7] W. S. Rockward et al. “Crossed phase gratings with diffractive optical elements” Appl. Opt. pp. 5075-5085 37 (1998)
[8] W. S. Rockwrd et al. “Light modulation from crossed phase gratings” Opt. Lett. 23 pp. 491-493 (1998)
[9]D. Bloom et al. “grating light valveTM for high resolution display”Solid State Sensors and Actuators Workshop, Hilton Head SC, June 1994.
[10] C. Gudeman et al. “Using the Grating Light Valve Device as a multichannel variable optical attenuator (VOA) for the 1.55 μm spectral region”Proc. SPIE 4653 pp. 56-61 (2002)
[11] W. Suh et al. ”Displacement-sensitive photonic crystal structures based on guided resonance in photonic crystal slabs” Appl. Phys. Lett. 82 pp. 1999-2001 (2003)
[12] W. Suh et al. “Mechanically switchable photonic crystal filter with either all-pass transmission or flat-top reflection characteristics” Opt. Lett. 19 pp. 1763-1765(2003)
[13] C. Marxery et al. ”Applications of SOI-Based Optical MEMS” IEEE JOURNAL ON SELECTED TOPICS IN QUANTUM ELECTRONICS, 8 pp.148-154 (2002)
[14] Kaspar F.G. ”Diffraction by thick, periodically stratified grating with complex dielectric constant,” J. Opt. Soc. Am. 63, 37（1973）
[15] Knop K. “Rigorous diffraction theory for transmission phase grating with deep rectangular grooves,”J. Opt. Soc. Am. 68 1206（1978）
[16] M. G.. Moharam et al. ”Rigorous coupled-wave analysis of planer-grating diffraction” J. Opt. Soc. Am. 71, 811 (1981)