Abtract
Three different microstrip transmission-line layouts between the pads and an optical modulator waveguide have been designed and compared for their circuit response. In the first design, two 50£[ input and output microstrip transmission lines are connected to the center of the 24.58£[ semiconductor waveguide. In the second design, two 78£[ input and output microstrip transmission lines are connected to the center of waveguide. The third design represents a traveling-wave EA modulator. After optimizing the lengths of the transmission lines through our circuit simulation, we find that the traveling-wave optical modulator (the third layout) have the best circuit response of bandwidth ~22.4GHz and voltage reflection coefficient ~40%. The traveling-wave optical modulator not only overcomes the RC constant limit but also makes use of long waveguide to satisfied the high-speed requirement. At the same time, this circuit increases the extinction ratio and optical saturation power.
In the fabrication process, we use polyimide to planarize both sides of the ridge waveguide and evaporate the top electrode on the polyimide. In addition, we use a special wet etching to form sloped edges for rasing ground pads up to the same level of the signal pad. This will allow us to use coplanar microwave probes to measure the devices.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0705102-202036 |
| Date | 05 July 2002 |
| Creators | Hsu, Yu-Fang |
| Contributors | Jung-Tsung Hsu, Tsong-Sheng Lay, Shoou-Jinn Chang, Wen-Jeng Ho, Tao-Yuan Chang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0705102-202036 |
| Rights | campus_withheld, Copyright information available at source archive |
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