During last decade, the fast-growing communication need has promoted the development of 1.3 £gm~1.6 £gm laser light source. The Cr4+ doped YAG solid-state laser has potential to meet this broadband demand. In addition, diode-laser-pumped solid state laser has the merits of high laser beam quality, long lifetime, compact, and simple structure.
In this thesis, crystal fiber was used as the laser gain medium, and coated with optical thin film at its end facets as the laser cavity. Using this configuration, the volume and cost of the laser can be appreciatively reduced, and the heat dissipation can be improved. The laser-heated-pedestal-growth method was used to grow crystal fiber, which can obtain small diameter at very fast rate. Outside the glass clad Cr4+:YAG crystal fiber, Al-Cu alloy was employed as the heat sink to improve heat dissipation. After grinding, polishing, and coating of this device, the Cr4+:YAG crystal fiber laser was fabricated. Some characteristics of Cr4+:YAG crystal fiber, such as the distribution of Cr2O3 and CaO doping concentration, fluorescence intensity, refraction index, propagation loss, and absorption coefficient were measured and analyzed. A record-low threshold of 0.75 mW was achieved. It is more than 500 times lower than any previously reported Cr4+:YAG lasers, and a slope efficiency of 6.9% was obtained. The ultralow-threshold lasing is made possible by the low propagation loss of 0.08 dB/cm and the high pump intensity of the core. Such a low-threshold operation makes the double-clad crystal fiber laser be compatible to present optical communication systems. In the meanwhile, some simulations of the laser output power have been developed to predict the experimental results.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0703108-173947 |
| Date | 03 July 2008 |
| Creators | Lin, Zhi-wei |
| Contributors | Jausheng Wang, Jui-Yun Yi, Yen-Sheng Lin, Wood-Hi Cheng, Sheng-Lung Huang |
| 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-0703108-173947 |
| Rights | not_available, Copyright information available at source archive |
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