ABSTRACT
For the generation of broadband tunability over 1300 nm to 1600 nm range in optical communications, Cr4+ ions have been demonstrated in a number of hosts including Cr4+:forsterite, Cr4+:Y2SiO5, and Cr4+:YAG. Since YAG is a cubic crystal with Ia-3d space group, its excellent thermal and optical properties has drawn extensive studies. In recent years, various modes of operation using Cr4+:YAG as laser gain medium have been achieved since the first tunable CW laser of Cr4+:YAG bulk gain medium was demonstrated by Shestakov, et al in 1988.
Experimentally, the Cr4+:YAG crystal fiber was grown by the laser-heated pedestal growth (LHPG) method which provides outstanding crystal quality and can easily change growth conditions, such as growth speed and core diameter. A double cladding technique was developed with pure YAG, silica/YAG mixture, and pure silica as the core, inner cladding, and outer cladding, respectively. The smallest core diameter we achieved is 11 mm. In this thesis, the fabrication process of the Cr4+:YAG crystal fiber laser involving crystal fiber growth, sample preparation, and coating design will be presented in detail.
In order to understand the relation between the microstructure of Cr4+:YAG crystal fibers and the growth conditions, high-resolution transmission electron microscopy (HRTEM) was employed, which reveals the nano-scale information in the core region, the inner-outer cladding interface, and the mechanism of inter-diffusion process during growth. In addition, the thesis also describes the specimen preparation procedures of crystal fibers for the HRTEM analysis. Furthermore, quantitative analysis of Cr4+:YAG crystal fiber was employed by electron-probe micro-analyzer (EPMA) and energy dispersive X-ray spectrometer (EDX), showing accurate characterization of the constitute elements and concentrations. The comparison of Cr4+ fluorescence and dopant concentration of CaO and Cr2O3 will also be presented in this thesis.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0709104-133255 |
| Date | 09 July 2004 |
| Creators | Lai, Chien-Chih |
| Contributors | Chung-Wen Lan, Sheng-Lung Huang, Yen-Sheng Lin, Tao-Yuan Chang, Pou-yan Shen |
| 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-0709104-133255 |
| Rights | not_available, Copyright information available at source archive |
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