| Recently, based on the porosity characteristics of hollow-core photonic crystal fiber, the research on interaction of light with gas inside hollow-core fiber has become a hot topic. Its application can be found in gas sensing, optically pumped gas laser, and so forth. For the purpose of combination with the advantages of hollow-core fiber and conventional discharge excited gas laser, the discharge excited hollow-core fiber gas laser is proposed and studied theoretically and experimentally in this thesis. The research details are as follows:(1) The gas filling in hollow-core fiber has been studied numerically and experimentally. Using the finite element software, the temporal and spatial distribution of velocity and pressure in gas filling process are computed. The gas filling process is also monitored and recorded with experiment platform. The dependence of filling progress on filling pressure, gas, fiber inner diameter and fiber length is discussed. A quadrupole mass spectrometer is used to conduct the component analysis and process monitoring of multi-component gas. The trend in experiments is agree with that in simulations.(2) The radio-frequency discharge in hollow-core fiber is study theoretically based on fluid model with the finite element software. The temporal and spatial distribution of discharge parameters such as electron density, electron temperature etc., are obtained. And the dependence of these parameters on voltage, pressure, etc., is discussed. The results indicate that sheath width is independent of voltage while it will shrink with the increase in pressure, and the electron density and electron temperature are directly linked to discharge voltage and pressure.(3) The discharge in hollow-core fiber is studied experimentally. A new discharge structure is proposed to obtain glow discharge plasma with long length. The high pressure plasma with a length of about1m is ignited successfully in this structure. Using the optical emission spectroscopy, the plasma parameters in hollow-core fiber, including rotational temperature, excitation temperature and electron density, are diagnosed with different pressures, radio-frequency power, etc. Because of the large ratio between surface area and volume, the hollow-core fiber has the advantage of high heat transfer efficiency. Consequently, the rotational temperature is lower than500K, excitation temperature is low than104K, and the electron density is about1013cm-3. The variation of power and pressure doesn’t cause the remarkable change of parameters above.(4) The propagation of light along the hollow-core bandgap photonic crystal fiber filled with glow plasma has been studied numerically. After the ignition of plasma in hollow-core fiber, the transmission characteristics would be affected by the plasma. The optical field distribution is obtained by simulating with the finite element software. The refractive index of plasmas with different components is computed and brought in the finite element simulation of hollow-core photonic crystal fiber, in order to compute the confinement loss of the fiber. The dependence of attenuation on plasma parameters is discussed.
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