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Research project
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(2) Organic Photonics: |
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Organic TCO EO Modulator
1.
Motivation of TCO
Modulator Low switching voltage organic EO modulator has become an interest in high frequency photonics area. Low switching voltage improves link gain of RF signal. Very recently after we first demonstrated TCO modulator based on smaller r33 EO material AJL8 [1]., TCO electrode modulator has attracted great attention due to its novel idea and ability to reduce the switching voltage by 5x. Conventional approach to reduce the switching voltage is to utilize high r33 EO material or to utilize push-pull mach-zehnder device design [2,3]. However, all of those efforts were limited due to the nature of the conventional EO modulator structure as shown in figure 1-(a). As seen, the required 2-3μm thick cladding layers to avoid the metal-induced optical loss in the waveguide substantially increase the modulator switching voltage. On the other hand, the TCO modulator structure we proposed as shown in figure 1-(b) will perfectly solve this problem, since the TCO was taken as electrode so the voltage drop on both bottom and top cladding layer was completely eliminated.
(a) (b) Figure 1.
Conventional EO modulator (a) and TCO electrodes Mach-Zehnder modulator (b) structure
comparison 2.
Main Fabrication
Process
3.
References 1. G. Xu,
Zhifu liu, Jing Ma, 2. N. Dagli,
“Wide-Bandwidth Lasers and Modulators for RF Photonics,?IEEE Trans.
Microwave Theory Tech. 47, 1151-1171 (1999). 3. L. R. Dalton, W. H. Steier, B. H. Robinson, C. Zhang, A. Ren, S. Garner, A. Chen, T. Londergan, L. Irwin, B. Carlson, L. Fifield, G. Phelan, C. Kincaid, J. Amend and A. Jen,
“From molecules to opto-chips: organic
electro-optic materials,?J. Mater. Chem. 9, 1905-1920
(1999). 4. J. Luo, S.
Liu, and A. K-Y. Jen, “Recent progress in developing highly efficienct and thermally stable nonlinear optical
polymers for electro-optics,?in Organic Photonic Materials and Devices
VI, J. G. Grote, T. Kaino, eds. Proc. SPIE 5351,
36-43 (2004). |
