Fabrication and Measurement of Liquid-Filled and Liquid-Crystal-Filled Photonic Crystal Fiber Devices
| Autor: | Jia-hong Liou, 劉家弘 |
|---|---|
| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 As the photonic crystal fibers (PCFs) are fabricated, it is hard to modulate their optical properties to function as tunable optical devices. To introduce tunable optical properties into the PCFs, one can infiltrate tunable-index materials, such as liquid and liquid crystals (LCs), into the air holes of the PCFs to form tunable optical devices. In this dissertation, we employ liquid-filled PCFs and photoresponsive PLCFs to form novel tunable optical devices. First, we utilize a vacuum pumping machine to infiltrate two liquid sections into the PCFs. A novel Mach-Zehnder interferometer (MZI) with two liquid sections can be successfully fabricated. Unlike other PCF-based MZIs, no damage is made to the PCF structure during the fabrication of our proposed MZI structure. The experiment results show that very clear interference patterns can be obtained, and a extinction ration (ER) of -15 dB can be achieved at λ = 1525 nm. Besides, the temperature and bending sensitivities of our fabricated PCF-based MZI are -176 nm/oC and 15.5 nm/m, respectively. As a result, our fabricated PCF-based MZIs can be utilized in temperature and bending sensing applications. We have also fabricated photoresponsive PLCFs by infiltrating a LC mixture consisting of E7 LCs and the photoresponsive 4MAB into PCFs. By seriesly connecting a photoresponsive PLCF and a PLCF filled with E7 LCs, an optically tunable bandpass filter can be realized. After 5-second blue-laser irradiation, the bandwidth variations of two pass bands are 115 nm and 110 nm, respectively, and the center wavelengths of the transmission bands are shifted about 48 nm and 43 nm. In addition, we dope the Ag NPs into the photoresponsive PLCFs to improve the response time. The measurement results show that the rise time and decay time can be reduced about 38% and 42%, respectively. Finally, a selective blocking technique is used to infiltrate the photoresponsive LC mixture into both-side air holes of the PCFs to from optically tunable PLCF attenuators. By irradiating a blue laser, a maximum attenuation tunability about -26 dB can be obtained at λ = 1100 nm. Our fabricated optically tunable PLCF attenuators possess reversible properties by green-laser irradiation and can be applied in optical tunable devices. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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