| Autor: |
Preiswerk, H. P., Lubanski, M., Kneubühl, F. K. |
| Zdroj: |
Applied Physics B: Lasers and Optics; March 1984, Vol. 33 Issue: 3 p115-131, 17p |
| Abstrakt: |
This study puts forward the concept of helical distributed feedback (DFB) lasers. The basic features of this new type of laser are derived by group theoretical considerations on cylindrical, circular linear periodic, and helical waveguide and laser structures. It is demonstrated that not only linear periodic structures but also helical structures show Bragg and DFB effects. Microwave and far-infrared experiments on passive helical metal waveguides reveal Bragg resonances in transmission. These results initiated the first experimental realization of a helical DFB gas laser, i.e. an optically pumped 496µm CH3F laser with a helical metal waveguide of a pitch close to 250µm. This helical DFB laser shows higher-mode selectivity than the corresponding linear DFB laser. Finally, we show that the concept of helical DFB also applies to dye lasers with internal DFB incorporated by a mixture of the dye with a cholesteric liquid crystal. |
| Databáze: |
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| Externí odkaz: |
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