Mid-infrared gas filled photonic crystal fiber laser based on population inversion

We demonstrate for the first time an optically pumped gas laser based on population inversion using a hollow core photonic crystal fiber (HC-PCF). The HC-PCF filled with (12)C(2)H(2) gas is pumped with similar to 5 ns pulses at 1.52 mu m and lases at 3.12 mu m and 3.16 mu m in the mid-infrared spectral region. The maximum measured laser pulse energy of similar to 6 nJ was obtained at a gas pressure of 7 torr with a fiber with 20 dB/m loss near the lasing wavelengths. While the measured slope efficiencies of this prototype did not exceed a few percent due mainly to linear losses of the fiber at the laser wavelengths, 25% slope efficiency and pulse energies of a few mJ are the predicted limits of this laser. Simulations of the laser's behavior agree qualitatively with experimental observations. (C)2011 Optical Society of America