Gas-Filled Hollow Core Fiber Lasers Based on Population Inversion.

摘要

We have created a new class of lasers known as Hollow-core Optical Fiber Gas LASer (HOFGLAS) combining the advantages of fiber lasers with those of gas lasers. Pulsed HOFGLAS has been studied with C2H2 and HCN gas inside the hollow core of a kagome structured photonic crystal fiber, and near-ideal efficiencies were realized. The gases are optically pumped near 1.5 microns using 1 ns-pulses and yield laser emissions near 3 microns. Furthermore, we have improved fiber loss near 3 microns to below the dB/m-levels. In addition, we have demonstrated a CO2 waveguide (silver coated hollow capillary) laser lasing at approximately 4.3 microns when pumped at approximately 2.0 microns with 5-nanosecond pulses, and demonstrated a slope efficiency in terms of absorbed power of approximately 22%. We have explored the feasibility of cw lasing from a hollow fiber filled with molecular iodine (I2) when pumped at approximately 532 nm, and have spectrally resolved the intensity dependence of fluorescence from a 10-cm photonic crystal fiber of approximately 80-microns diameter filled with I2. In an effort to achieve near-IR sources for testing fiber transmission, we have demonstrated a novel thulium/holmium fiber laser near 2 microns.