Title :
High-Speed X-Cut Thin-Sheet LiNbO3 Optical Modulator With Folded Structure
Author :
Aoki, Kenji ; Kondo, Jungo ; Iwata, Yuichi ; Hamajima, Akira ; Ejiri, Tetsuya ; Mitomi, Osamu ; Minakata, Makoto
Author_Institution :
NGK Insulators Ltd., Nagoya
fDate :
7/1/2007 12:00:00 AM
Abstract :
We propose a small-footprint X-cut thin-sheet lithium niobate optical modulator with high-speed and low-driving-voltage characteristics. Since an optical waveguide is folded by a mirror placed at one edge of the modulation chip, the chip can be shortened by about half. In addition, a wide modulation bandwidth can be achieved, because the path-length difference between the optical waveguide and the coplanar-waveguide (CPW) electrode is decreased to as short as possible by placing the CPW electrode as far as possible along the optical waveguide in the folded portion, and the microwave effective index is set to realize effective velocity matching between the lightwave and the microwave. A small footprint of 1.78 times 29 mm, a low half-wave voltage of 2.0 V at dc, and a 3-dBe modulation bandwidth of 20 GHz were obtained.
Keywords :
coplanar waveguides; integrated optics; lithium compounds; optical communication; optical modulation; optical waveguides; LiNbO3; X-cut thin-sheet optical modulator; bandwidth 20 GHz; coplanar-waveguide electrode; electrooptic modulation; folded structure; intensity modulation; microwave effective index; modulation chip; optical communication; optical waveguide; small-footprint optical modulator; voltage 2 V; Bandwidth; Buffer layers; Coplanar waveguides; Electrodes; High speed optical techniques; Intensity modulation; Low voltage; Optical buffering; Optical modulation; Optical waveguides; Coplanar waveguides; electrooptic modulation; intensity modulation; optical communication; optical modulation;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2007.897714
